MK5 Golf GTI
All Things Mk5 => Modifications & Technical Area => Performance Modifications => Topic started by: Carrera2RS on May 01, 2011, 04:20:27 pm
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Chaps, I have done some measuring and I have found the wheel position is notably different with longer bottom arms
Roughly adding 1 degree of negative camber will have the following effects :
Tyre outer edge at the top of the arch will move out by approx 3mm an 14mm at the bottom. The track will increase by 18mm (9mm a side) , the front ride height will drop by 5mm.
Adding 1.5 degress of neg (circa 2 degrees total) :
Tyre outer edge at the top of the arch will move out by approx 5mm an 21mm at the bottom. The track will increase by 26mm (13mm a side) , the front ride height will drop by 7.5mm.
The thread on the control arms is sufficient to cope as the track rod ends will neat to be wound out by a similar amount to the track.
I will see if I can purchase ET50 8 x 18's as the wheel does touch the inner arch occasionally under hard cornering and encountering a bump mid corner. I have ET45 8x18's currently
With circa 2 degrees of neg with ET50's I will be running a front track increase of circa 24mm, 12mm a side :wink:
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and i'm running -2,3 degree of negative camber front, maybe that's why my ET48 8,5x19" with 235/35-19" hits occationally :laugh:
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at -2.3 degrees, if I read correctly your wheel upper edge will be some 3(offset)+say8(5mm tyre per side and 1" strech)+5 (if lowered and adding 1.5 degrees neg)
So probably some 16mm out at the upper edge !
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at -2.3 degrees, if I read correctly your wheel upper edge will be some 3(offset)+say8(5mm tyre per side and 1" strech)+5 (if lowered and adding 1.5 degrees neg)
So probably some 16mm out at the upper edge !
I deffo have to do something to my inner fenders, with this and my 10mm wider front fenders the inner fenders aren't sitting right. :sad1:
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Sounds like you should have plenty of clearance with 10mm extra width. I had no problems running stock bottom arms, 225/40 18's on 8x18 et 45. the will place the outer wheel edge 11mm further out and tyre probably 8-9mm.
My ride heights are now 338F, 323R. They were 335F, 323R before. I was targeting 340F, 325R, they seem to have settled
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the clearance is there, the trouble is the stock inner fenders doesn'r "rest" in the wider fenders and as such are getting "adjusted" by the tyres :wink:
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I dont seem to get any arch clearance issue after fitting the TT arms. Maybe the vRS has a slightly wider front. The issue I do have is the WALK combined with the TT arms has given me too much caster and the wheels are much closer to the front of the arch than the rear. I have modded the WALK and managed to pull the subframe back slightly, but I may go back to the standard consoles with some superpro bushes.
What caster are you two running? Mine is around 9degs 15 mins. I would like it to be around 8degs 15mins.
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I was thinking of doing this to my octy but I think I will just stick to normal superpro/powerflex console bushes and not fit the TT control arms.
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I dont seem to get any arch clearance issue after fitting the TT arms. Maybe the vRS has a slightly wider front. The issue I do have is the WALK combined with the TT arms has given me too much caster and the wheels are much closer to the front of the arch than the rear. I have modded the WALK and managed to pull the subframe back slightly, but I may go back to the standard consoles with some superpro bushes.
What caster are you two running? Mine is around 9degs 15 mins. I would like it to be around 8degs 15mins.
Mine with WALK and TT mk2 lower control arms is set at 8,3(4-8)'
http://www.mk5golfgti.co.uk/forum/index.php/topic,7823.msg246912.html#msg246912
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I will mod the WALK some more then to get the wheels back where I want them.
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I dont seem to get any arch clearance issue after fitting the TT arms. Maybe the vRS has a slightly wider front. The issue I do have is the WALK combined with the TT arms has given me too much caster and the wheels are much closer to the front of the arch than the rear. I have modded the WALK and managed to pull the subframe back slightly, but I may go back to the standard consoles with some superpro bushes.
What caster are you two running? Mine is around 9degs 15 mins. I would like it to be around 8degs 15mins.
Alex, what's wrong with more caster? I'd like to have even more !!
:wink:
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Can someone tell me, if the S3 hubs and wishbones make the track wider??? I seem to be getting some banging from the front when I turn the wheels but it doesn't happen every time? I think the driveshafts outer joints are not seating properly? so when they are turned they are coming apart then going back in when straightened up.
I have checked every thing for loose bolts and cannot find anything :sad1: I usually look at the drop link has they are the most common to make noises.
Darren
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I'd wonder if the track is wider with the S3 hubs.
I've fitted them for a week and couldn't see anything different.
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Can someone tell me, if the S3 hubs and wishbones make the track wider??? I seem to be getting some banging from the front when I turn the wheels but it doesn't happen every time? I think the driveshafts outer joints are not seating properly? so when they are turned they are coming apart then going back in when straightened up.
I have checked every thing for loose bolts and cannot find anything :sad1: I usually look at the drop link has they are the most common to make noises.
Darren
I doubt it. if you had trouble with the driveshafts i wouldn't be able to drive with the TT arms :scared:
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I guess with the TT arms it would be better not to adjust the camber to max.
About - 2° should not be any problem as so many guys have it this way without any issues.
:wink:
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By my reckoning the track with TT arms will be some 9mm per degree of additional negative camber per side. This is because the hub centre will move out by circa this much using this method for adjusting camber. (top mounts different story)
I doubt if the splines would be insufficient to deal with this movement ?
If the MkV has 1 degree of neg via the bottom arms then this will alway be the case irrelivant to the hub and arm used. Since the shaft will need to be extended by 9mm to reach if the centre bolting is the same on an S3 and not sat further out than the VW. I see no reson why this might be the case.
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Hi guys, have fitted TT wishbones and eibach arb's today, already have WALK.
Car feels awful - will book laser alignment tomorrow.
What settings do I need to advise them I want? Was going to run -2 degrees negative camber on front as per BDM Alex's thoughts on the matter but do I need to advise them of other settings or will they just sort it out as they see fit?
Thanks
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Did you mean TT wishbones??
If you mounted TT arms and did not do any Toe adjustment no wounder the car is awful. If this is the case I truly know what you are experiencing. Fix the wheel alignment and things will get much better. Toe out should be around 6 degrees now which is way off scale... Fix the toe to be 5 minutes Toe in and the car will fell much much better.
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Right, under regular circumstances go for 5' toe in per wheel on both front and rear.
:driver:
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sorry yes, did not proof read any posts - my spelling is atrocious today!
Sorry, but how come you measure "toe" in minutes? It seems odd to measure cars geometry with a unit of time (am sure has different meaning here though!)
Thanks will advise wheels in motion of your comments and hope they can sort it out
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1° = 60' (european)
Don't think about it - your mechanic will know about.
:wink:
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Berg i assume you are not naval educated :wink: Neither am i :laugh:
It's a term developed by the English navy waaayyy back when they used a Sekstant? to determine their position compared to the sun or other objects on the sky. so it a general used term which you will also see on a globe.
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Berg i assume you are not naval educated :wink: Neither am i :laugh:
It's a trem developed by the English navy waaayyy back when they used a Sekstant? to determine their position compared to the sun or other objects on the sky. so it a general used term which you will also see on a globe.
I see Captain, a salty sea dog I am not :smiley:
ok wont think about it just get them to sort booked in tomo
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I will update following a visit to Wheels in motion.
I expect to settle on around 2 degrees of negative and parallel or small toe in at the front (5 minutes). My ride heights are currently 338F, 323R and I may rais a little.
With 1.7 of negative and 8 minutes of toe in the front does not feel as good as I had hoped. It feels a little clumsy and less precise as you turn in. The in corner grip and balance is better, but somehow straight ahead is a little blunt. I am also well aware that too much track can greatly affect things, I have no idea where the KPI angle is on the Golf and how this has been affected.
I'll keep you posted of how things measure up and what settings I settle on. Oh I also think I might have PSS10's and not PSS9's as I am told the 10's have 10 settings and the 9 have 9. My units have 10 settings
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Well, the only difference between PSS10 and PSS9 is the number of available settings. If you have 10 settings it is definitely PSS10.
Also PSS9 is not manufactured for Golf since the end of 2008 (I think, have to double check to be 100% sure).
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They must be PSS10's then as they are only 3m old
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Car is with wheels in motion at mo.
they seem to be saying that if i run -2 degrees negative camber that i will just scrub the tyres and wont help traction? He has advised to get rid of the Conti's and get R1R/RS2 etc on.
am sure they will set up well though, father in law has just called me to advise has driven it back down the m58 and says is running well :happy2:
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2.15 is the maximum RECOMMENDED negative camber for the rear tires. If 2.15 is ok for the rear wheels why is it not ok for the front tires?? So I really doubt there is a problem there...
Not to mention that during cornering the negative camber is reduced...
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i know am sure if Alex is running at -2.15 must be ok, might get BDM to have a look at it in future when maybe get RS4 valve done
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Berg,
I'm at wheels in motion tomorrow, any guidance would be appreciated. :happy2:
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There is nothing wrong with running the extra camper. You don't get extra wear issues as long as the toe is set correct. I run 2.5 degs negative front and 2 degs negative rear with no wear problems. I do 50 miles per day too. There are a few m3s we look after that run 4 degs negative at the front!
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Extra camper. :laugh:
I have been runnng well over 2 degrees of camber and have no sign of extra tyre wear whatsoever. :happy2: What i tend to do though is not slow down for roundabouts and the occasional right hand sharp bend. :innocent:
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Berg,
I'm at wheels in motion tomorrow, any guidance would be appreciated. :happy2:
unfortunately, i had to get my father in law to take car in as cant have any time off work at mo so i did not get much out of the visit
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A useful hour or two
The car has now moved to matched front camber at just less than 2 degrees, it was close but slight differences between left and right. Toe now straight ahead and a small correction to rear toe.
Rear camber adjusted down to 1.5 degrees neg (to reduce understeer). The ride heights measured at 335F and 322R. I will probably lift to 340F and 325R this was my target but adjisting cambe then affects ride heights. The geometry will not be affected by a few mm of ride heigh adjustment.
I will also continue to experiment with damper settings and also try different roll bar settings.
The settings of Front ;
2 degrees neg (1 deg 55 mins)
zero toe (parallel)
8 degrees 23mins caster
PSS10 3/10
Roll bar soft
Rear
1.5 degrees neg (1 deg 29 mins)
13 mins toe in (L 6 mins, R 7 mins)
PSS10 4/10
Roll bar hard
All other checks showed the car close to spot on (set back, lateral offset etc)
So far the car feels a little less fidgety, better balanced and less 'front fighting back'. Les understeer and better directionality and confidence.
Not perfect yet, but getting there :happy2:
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The settings of Front ;
2 degrees neg (1 deg 55 mins)
zero toe (parallel)
8 degrees 23mins caster
PSS10 3/10
Roll bar soft
Rear
1.5 degrees neg (1 deg 29 mins)
13 mins toe in (L 6 mins, R 7 mins)
PSS10 4/10
Roll bar hard
So compared to your settings mine are
1.47 and 1.33 negative front camber
0.05 toe both sides
8 degrees 36 min caster (LF) and 8 degrees 23 minutes caster (RF)
Rear
1.44 degrees neg and 1.42
10 mins toe in (L 5 mins, R 6 mins)
Fairly similiar in some respects but you are running the more negative camber whic I will need to do to get the benefits from the TT wishbones I presume?
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the clearance is there, the trouble is the stock inner fenders doesn'r "rest" in the wider fenders and as such are getting "adjusted" by the tyres :wink:
....When you say "stock inner fenders" don't you mean the stock wheel arch linings?
I know this is something I have asked you about and you haven't done anything yet to mod them to fit/join the carbon fenders. Surely not a difficult mod?
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the clearance is there, the trouble is the stock inner fenders doesn'r "rest" in the wider fenders and as such are getting "adjusted" by the tyres :wink:
....When you say "stock inner fenders" don't you mean the stock wheel arch linings?
I know this is something I have asked you about and you haven't done anything yet to mod them to fit/join the carbon fenders. Surely not a difficult mod?
You're right RR, it's the stock wheel arch linings, actually i have a plan :party:
I'll buy 2 new wheel arch linings, split them longitudinal, use the outer parts, the old ones will get the outer 10-15% removed and then cut across to app. the middle, then the new ones will be put in and marked against the old and then both parts will be put together. :pomppomp:
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I have experimented a little with tyre pressures, currently running 36F, 34R
The combination is very good, balance is now very close to neutral. I am currently having no arch problems cornering hard. I might put the order of a set of 8x18 ET 50's on hold (5 mm further in per side than my current ET45's)
I will experiment over the weekend a little, I may try adjusting ride platforms a little up 1/2-1 turn F, up 1/4- 1/2 turn at the rear this will add 2-3mm front and back. This should put the heights to 340F, 325R.
Then given my rear toe was 2mins total, I am wondering how reducing toe a small amount from 13 mins on the current set up might feel (should increase oversteer a touch) I'll talk to Tony and see what he thinks.
I'd be interested to those who have settled on a set up have the car set to. The other option might be to add 15mins of camber at the front and back to 2 deg 15 mins F, 1 deg 45mins back.
I like the balance of feel, weight and stability at the front with parallel tracking. I have more confidence at higher speeds than a touch of toe out on the previous setup.
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IIRC a straighter rear setup should loosen the rear up.
My rear toe is a little straighter than yours being the same as bergs... 10mins total.
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Carrera, what brakes do you have ? 8x18 is good but is ET50 enough if one wants to go with some Ap racing 356mmx32 6 pots ? Wouldn't ET45 be better in this respect (maybe succed to avoid spacers) ?
I'm running like -2.3 camber in front and close to 0 toe and -1.5 camber on the rear and 10mins toe in. Also don't have any uneven tire wear problems !
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You make a good point regarding brake clearance.
I am currently running ET45 8 x 18 TD's al round. As I have not had any arch problem over the last week, I have put my order on hold for two ET50's
I am awaiting VWR to restock their 352/32 six pot kit. I would prefer AP Racing or Bembo but the VWR size equivalent is cheaper. I will continue to experiment with tyre pressures and ride heights. At the moment the balance when settled mid corner is extremely good and close to Neutral.
The feel straight ahead is better, the initial turn in still needs more weight and precision for me. I am wondering if another 15-20 mins at the front might help ? I am also wondering if I reduce the rear toe in to say 10 mins. Plus I may try putting the front roll bar on full hard to improve feel then perhaps I can achieve better turn in and feel and keep the mid corner balance ?
Fuscobal what ride heights do you run and suspension set up ?
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Setting the front ARB to hard will help initial turn in and may increase traction issues at corner exit. :wink:
Don't go too low on rear because you need travel. With only 325 mm I'd strongly recommend a
stiff rear to prevent hitting the bump stops. This would cause oversteer.
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Don't know the current height (especially ince I lost some weight) but I'm using the PSS10 at 7F/7R on the track and 2F/2R on the street. Sways are on stiff both but at the last Hungaroring session they were on soft both + 5F/5R for the suspension. Height is however close to equal F/R (about 64cm from the ground to the wheel arch) !
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I have jus measured my floor to arch looks like 640ish front and 630ish rear. I suspect the 'lost' 5mm between wheel centre measurements and floor measurements is down to the position of the wheel centre and arch.
I have settled on 33 psi front 32.5 rear cold (well warm weather, but no direct sun on tyre) after a drive they come in 34.5-35 F and 34-34.5 R
I am very happy with this set up. I tried experimenting with damper settings and I have settled again on 3F, 4R. I was going to drop the rear pressures a little, but the balance is now very good indeed, it's extremely balanced around roundabout, so I thought leave it alone !
The car is currently the best I have had it. :happy2:
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Well, Carrera, it seems we are both running on the same height and pressures. I measured the height to be 635-645mm (not the same everytime because I need a straight plane wich I don't have here...maybe when I go to my mechanic). The pressures I'm using on the track are also between 32 and 34PSI. Tried softer but my car is too heavy and they got overheated. As for the suspension, have you tried harder on the track ? I used 5/10 both F and R but I would try like 7/10 F and 8/10 R next time !
My car had the following weight evolution :
- 1715Kg in Aug 2010 when I was on street tires + OEM arms and I had my lady with me ! > pulled a terrible 2'29''
- 1636.5Kg in Oct 2010 when I was on R compound tires + TT arms and did not have the lady and the rear seats anymore ! > pulled a good 2'18''
On the future events this year I should have something like this > 1636.5 - 80 = 1556.5 Kg. For next year, I'm planning to get to about 1450Kg with me inside !
What's your weight Carrera ?
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That weighs more than my vRS estate with my weight in it! Are you sure that's right?
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Wow your car is heavy !
my car on the scales with a 3/4 full tank weighed in at 1444kg without me in (But my gym kit in the boot). The shocking thing was the difference between rears and fronts. The GTI is one nose heavy baby, no wonder dialling out understeer is hard work. I weigh 80kg so with me in clothed it is circa 1535 kg
My car is manual, is yours DSG ?
I will experiment with tyre pressures, the car seems pretty sensitive to a 1lb adjustment, I dropped 0.5psi more off the back and I didnt like it. I have bought an accurate guage (1%) so will measure and let you know what I settle on. I have tried 6,7 7,8 and 8,9 F,R on the road and it was very fidgety and crashy, plus I notice the back at over 4 dropping as you go over a bump, you aware the back is still coming back from bump when the car lands. Im sure no problem on a smooth track but not great on the road.
Try 3F, 4R for the road, I don't think you'll lose much comfort but it will tighten things up a bit.
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the clearance is there, the trouble is the stock inner fenders doesn'r "rest" in the wider fenders and as such are getting "adjusted" by the tyres :wink:
....When you say "stock inner fenders" don't you mean the stock wheel arch linings?
I know this is something I have asked you about and you haven't done anything yet to mod them to fit/join the carbon fenders. Surely not a difficult mod?
You're right RR, it's the stock wheel arch linings, actually i have a plan :party:
I'll buy 2 new wheel arch linings, split them longitudinal, use the outer parts, the old ones will get the outer 10-15% removed and then cut across to app. the middle, then the new ones will be put in and marked against the old and then both parts will be put together. :pomppomp:
....I've sourced some Seibon carbon wings in the UK and so plan this to be my next mod. Splitting the arch liners is exactly what I had thought as a good way of sorting it. :happy2:
Sorry for short off-topic :smiley:
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Nice, looking forward to seeing them, will you spray red ?
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Nice, looking forward to seeing them, will you spray red ?
....Definitely. Otherwise it'll look like one of those awful Smart cars :sick:. I'll be stealing Danish Jake's idea though and exposing GTI lettering in the carbon by masking during painting - His displays the .:R logo on each carbon wing. :happy2:
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Red, please try and weigh both OEm and Seibon if you can ! Carrera, my weight is so big because of my audio system wich has about 150Kg !
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Hmmh, are RHD Golfs heavier than LHDs? :ashamed:
Without me inside and with empty fuel tank my GTI is about 1280 kg.
Equipped as below. :wink:
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Hmmh, are RHD Golfs heavier than LHDs? :ashamed:
Without me inside and with empty fuel tank my GTI is about 1280 kg.
Equipted as below. :wink:
maybe the difference is between 3 and 5 doors??
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Red, please try and weigh both OEm and Seibon if you can ! Carrera, my weight is so big because of my audio system wich has about 150Kg !
....Good idea. I have access to some DEFRA-approved digital scales which are regularly recalibrated, so that should be accurate enough!
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I am back to wheels in motion this week. I will be trying the front roll bar on full hard, then deciding if I work to other settings with this on hard or soft.
Tony will then advise which tweaks to apply. At the moment my wish list is a little more consistent feel and weight as I turn in and the tyres build up slip angle and any more I can reduce the feeling that the front is working harder than the rear (albeit the balance is very neutral and tracktion very good indeed)
The options would seem to be add a little more front camber, reduce the rear toe
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Interesting I have just looked at the figures for the front and rear track, I can't work out with offset how they match up to stock figures (I suspect they have assumed I am running 7.5 width rims) BUT I can see that with the same wheels my front track is 45mm wider at the front and the stock is 18mm, This suggests that at 2 degrees of negative via TT arms widens the track by 13mm per side. This ties in to my earlier fag packet calculations :happy2:
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Just playes a little with the car yesterday with ESP off and with the suspension on 2/F and 2/R + both sways on hard, the rear goes around like crazy. While this might be good for tight courses, I think it is quite dangerous on high speed tracks. I should try to either put the BSH 27mm RSB on soft, either increase front suspension stiffness. What do you guys say ?
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Interesting, I would try softening the rear ARB, surprised yours is so lively at the rear and my car just sticks at back, feeling like most of the work is being dne at the front.
You could try upping the dampers on the front by a click or two as this would be quick to try
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I would put the back ARB on soft.
27 on soft is harder than 24 on hard (as I have) so you should be fine. If this is not having the results you expected then start adjusting the suspension stiffness.
Cheers :happy2:.
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What exactly does the car do? When does it this? And what do you do when it does that?
I tend to agree with Carrera and Rex, but at first tell us more.
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Okay out of interest I found somewhere quiet to explore understeer/ oversteer. With my current settings the chassis is performing very well indeed ( making me wonder if I should fiddle much more ! )
Turning in aggressively loads up the front tyres quickly, it is actually quite hard to force the car to push wide, but it will. If you apply too much lock too quickly and unsettle at speed the poise is upset and it will push wide, but the bite is still quite respectable and it will regain and track again quite quickly. Turn in smoothly and quickly and the feel is actually a lot better than expected, weight is good and feel very informative.
Load up and turn in sharper and the balance moves to the front, you can feel the limitation of grip is now more front heavy. lift off and it stops tucking in and 'pulling' round in a tight arc, but no oversteer, just a shift of weight to the rear. I am sure I could provoke lift off oversteer, but I would have to try harder. Drive smoothly and the car is remarkably well behaved, change direction when loaded up and it response in a very settled balanced competent way with competence and accuracy.
I would like a nat's less front loading but this is probably driving RWD for the last 20 years where I suspect the balance with no throttle would be very similar (or possibly a tad more understeer), but the ability to balance understeer and oversteer with entry position and throttle is a familiar RWD thing that I am going to have to re educate myself to FWD characteristics
All in all, quite impressive tbh, but no scary oversteer.
My bars are currently Neuspeed 25mm full hard rear, 25mm soft front
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what tyre pressures have you settled on as best?
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Being I'm on my 19" rims now, I'm using 2.6bar (38PSI) F and R. These 19" have very little grip as expected. Strange is that with both bars on soft the car was quite neutral and I thought...hey, if I'm putting them both on Hard the ration should be about the same but it seems that somehow the BSH 27mm RSB got much harder than the H&R 26mm FSB. The back gets loose when I'm accelerating hard during the corner (pretty unbelieveable for a FWD) and of course while turning in aggressively ! Drove an OEM ED30 the same day with 18" and while it was far from having my grip it was much more predictable and understeering !
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Interesting, I am wondering if your rear bushes are worth checking, I agree I can see no obvious reason why the balance would not stay consistent on full hard all round ( unless the diff in spacing or bar mount/construction means there is a greater difference on full hard.
In any event the sort of overseer
Sounds like rear toe out. Perhaps worn bushes under load flex or your rest toe in is marginal moving to toe out undr load.
I'd get her up in the air and do the good old scaffold bar test....
Load up the suspension with the lever from underneath choosing lever points carefully and see how much wheel movement you have under load ( you might be surprised ) this will show geometry flex under load.
Interesting all the same !
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As Fuscobal has H&R front and BSH rear arb, and BSH being the stiffest rear ARB there is, you cannot compare hard front and hard rear. the front on hard may increase torsion strength by for example 40% and the rear on hard 120%. i don't think that there will be any advantages by setting the rear on max. unless the front ARB is upgraded to a similar stiff item as the rear.
Just my 2 pence :wink:
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Carrera2RS what speeds did you do the tests at?
What are your ARB?
With my H&R 26/24 bars I had oversteer quite a few times. Some of the times the road surface had a kink in and that unsettled the car. But on some occasions there was nothing wrong with the road surface... My car just oversteered... I was either mid corner with no throttle or on exit with a little throttle. Once I hit the gas and counter steer on exist the car would settle.
Fuscobal I bet that the weather in Bucharest is not sunny and warm. I also think that you did not have the chance to heat up the rear tires. If you remember our first trip to Hungaroring, in the first corner I had a monumental oversteer (not intended...) because of the cold tires. I think this also played a part in your experiments.
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My roll bars are Neuspeed 25mm f and 25mm rear
The speeds were not very high speed corners as there are very few places you can load up to that point. I doubt you would find any opportunity to load up higher on the road.
I also doubt anyone would get the car beyond the limit at higher speeds without notably exceeding the limit, so realistic for what you might expect on the road.
It may behave differently on the track at higher corner speeds. I think your tyre temp point is a good one !
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Yes, of course I keep in mind my tires were not heated. Can't do it around town. Another thing I don't like is my steering rack is starting to make cluncking noises over the bumps and responds with a delay wich increases with the speed ! Might have to replace it soon and this is not cheap. Unless I find one on a totalled car, It will delay my plans of getting the polepositions !
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what tyre pressures have you settled on as best?
With my set up, I have settled on 33.5 R 35F warm. This is after a non sporting drive in traffic this morning 12 miles, the outside tem 10 degrees. The cold temps were 31.5R, 32.5F
I hope this helps :happy2:
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You shouldn't drive hard a car with coilover set on soft and sway bars set on hard.
Keep in mind that sway bares act like strings. If dampers are set too soft they can't absorb the sway bars energy and then you can get very brutal oversteer.
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I'll keep that in mind and will play with the hardness soon !
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I actually think the PSS10 for the Golf is quite heavily damped. settling at 3F, 4R sounds soft, but the rear at 5 is heavily enough damped on rebound that the back of the car will 'land' on the ground before the suspension has the chance to recover from compression.
It's also interesting that BSH advise fitting the 27mm bar alone as a method to reduce stock GTi understeer.
I may well be very wrong but my guess is that soft/worn rear bushing with perhaps low rear toe figures are possibly the cause. I keep thinking about increasing the roll bars to full hard with 26/27 and I simply see no reason why the balance would be that bad in comparison to my car. 25 hard rear, 25 front soft, 3f, 4R, stock toe rear, parallel front 1.5 deg camber rear and 2 front.....
I take other points of view but would check alignment and rear toe ?
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Here you go......
I tried full hard all round, better feel and weigt and turn in, but chassis balance to forward. It feels very safe and grippy but it's just how much and when it will push wide.
Added a tad more front camber (10-15 mins) and now 5 min toe out and back to soft front ARB. :happy2: :happy2: :happy2:
Now very happy indeed. Better feel than before with soft ARB, feels very balanced and just as neutral mid corner better turn in and accuracy. Not fidgety in my book with 2 deg 10 mins of front camber and 5 mins toe out, feels nice and less blunt and dull. Nice steering weight and feel.
Not sure if the ultimate grip is any better (certainly no worse) than the settings last time round, but the feel is better and precision improved.
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Carrera, best way would be to have a track nearby and test the stiffness settings on PSS10. I'm afraid that we as drivers can be fooled into thinking certain settings are faster while they may not be in reality. We are not professional racing drivers and don't have the experience to say a car is or is not faster just by the feel. For this we'd need a track and access to a ramp nearby where we can play with Suspension, ARBs and geometry !
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Yes, it's very easy to get fooled by your self. :wink:
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Well, greasy roads and the chance to explore limits at sensible speeds, well yep I can provoke oversteer, but easily balanced and the poise balance and behaviour is text book stuff, anyone watching would be fooled into thinking I was talented. It's coming close to reminding me of a FWD equivalent of an E30M3 (I had one for many years and was complimented on my driving around spa by a pro, I didn't tell him the reason he couldn't shake me off with slicks in a very low class BTC of some equivalent was the sublime chassis and near tyres as good as his slicks - Dunlop DJ01's)
This car has moved into the great category, I'm gobsmacked. If I'm slower on the track I'm happy too. It's a point and shoot roadie to enjoy day to day, I am actually excited about the drive to work tomorrow...... which I never expected from a GTi :wink:
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I have had two glasses of wine since getting home, so my view might be more balanced in the morning !
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Gents
I thought it might be helpful to set out the actual figs (recognising my last setup showed very small differences when back on the same rig, so accuracy to 2-3 mins is clearly a pointless challenge)
Front
Ride height 338 mm
Camber L -2 deg 10 mins, R -2 Deg 0 mins
Toe L - 6mins, R - 6mins (toe out)
Caster L 8 deg 13 mins, R 8 deg 14 mins
SAI L 16 deg 36 mins, R 16 deg 21 mins
Bilstein PSS10 setting 3/10
Neuspeed 25mm bar full soft
WALK
Tyre pressure 35 psi after a 20 minute normal journey (32.5 cold)
Tyre Pirelli P Zero 225/18 92Y XL MO
Rear
Ride height 324mm
Camber L -1 deg 37 mins, R -1 deg 30 mins
Toe L 6 mins, R 7 mins (toe in)
Bilstein PSS10 setting 4/10
Neuspeed 25mm full hard
Tyre pressure 33.5 psi after a 20 minute normal journey (31.5 cold)
Tyre Pirelli P Zero 225/18 92Y XL MO
I will still look to raise by some 5mm or so, mark very carefully the collars and experiment a little. I was looking to move from 335 F, 320R to 340F, 325R it didn't quite hit those heights after settling over a few hundred miles
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Better go for 330 to 335 mm rear. :wink:
I suspect I had the problem of too less suspension travel by myself when
I was as low on the rear like you.
This may have caused the sudden massive oversteer I had on 180° corner.
If you're going to do a new alignment try toe in on front.
:driver:
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Bruce, tks
I will try raising the rear to 330mm.
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I have to add from the view of aesthetics I prefer the side skirts being horizontal.
Sadly if you adjust the suspension due to this the travel will be critical at rear
:sad1:.
This depends on the stiffness of your suspension (springs, ARBs, dampers) of course.
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I couldn't agree more, very happy with the look at 338/324
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi799.photobucket.com%2Falbums%2Fyy277%2FIWCDoppel%2FIMG_1547.jpg&hash=8d095f6f795cea9587513bb59b6bc4005e2503b4)
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I currently have 337 front and 330 rear. I had 337 front and 320 rear before.
Even with 320 rear my ''side skirt line'' wasn't level.
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Got to change my steering rack and things got much better no. I've also measured the ride heights to be 343F and 345R. Dropped the rear to 337 and set the suspension to 8F and 7R in order to dial out some of the oversteering I was talking about ! Will also try 2.1bar on front and 2.0bar on rear as opposed to 2.3F and 2.3R wich wore my Kumhos more on the center !
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I am now running 4-5mm front and rear. Measuring 342-343, 329-330
I did this and changed tyres for new Pirelli Zeros (The same as before) again set at 35F, 33.5R when warm (33, 32 cold) The suspension was reset...... due to changing the bottom mount, only the tracking front and rear changed, now measures :
Front
Camber : -2 deg 4 mins, R -2 deg 10 mins
Castor L 8 deg 20 mins, R 8 deg 8 mins
L -0.2mm, R- 0.2mm (out)
Rear
Camber L -1 deg 36 mins, R -1 deg 29 mins
toe L 1.0mm, R 1.0mm (in)
At present it is good, but not quite as good in terms of balance and grip. I am putting a few miles on new tyres before concluding
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From what the bruce told me, toe out is not the way to go...
I had toe out (0.05' on each side) and now I have toe in (0.10' on each side). The car is much more responsive. I did not have the chance to see if this new toe setup is better for the track, but I suspect it is... I will test it on the 21st..
Here is my setup:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi1237.photobucket.com%2Falbums%2Fff469%2Fvladpanut%2FP6066534.jpg&hash=98a4e1efb2e1d73f94438c144be8a72d7a8f0e78)
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Carrera, I also find strange your rear negative camber wich is the smallest I've seen. Most guys run -1deg50mins with rex having even more at -2deg10min. I will also increase rear a little to -2deg to reduce oversteer. Tour -1deg36min could lead to a happy tail !
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I run 1°10' all four wheels at the moment.
I still have the S3 arms and wanted to give it a try.
Found a very interesting article. Although about comparing
simulations sw vs. seven-post machine there are some
nice data shown. The stock front suspension bushes flex
causes enormous shift in toe especially on the outside wheel:
http://tesis-dynaware.com/fileadmin/Downloads/Referenzen/VW_ATZ_Messdatenbasierte_Fahrdynamiksimulation.pdf
see 'Bild 1' right below (toe) and 'Bild 8' (steering angle)
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Found this:
http://forums.vwvortex.com/showthread.php?5634381-Technical-Data-and-Modifications-for-Hardcore-Enthusiasts&p=77083134&viewfull=1#post77083134
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Interesting, I am now playing with suspension settings on an F10 M5, checked to remember my journey with the Old Golf, I wonder how She's getting on now :happy2:
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Interesting, I am now playing with suspension settings on an F10 M5, checked to remember my journey with the Old Golf, I wonder how She's getting on now :happy2:
Blast from the past... hows things? Hows the M5 then?
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It's quite quick as a stock car with competition pack :wink:
It's only covered 7k miles, so probably not fully run in. It's a big car with a large footprint, so not a checkable golf. But it's about to be lowered on Dinan adjustable springs, have a little more camber and larger adjustable roll bars. Hopefully that will make it 'shrink' a bit.
It's lovely loaded up in a big corner with amazing grip from 295 / 265 Michelin PSS tyres. If you short shift with the close 7 ratios and give it large amounts of throttle it's ballistic without being too scary :pomp pomp:
The more I get to know t the more I like it, its surprisingly revvy too. At last they put proper brakes on it the 6 pots feel more than adequate. The steering is also very good (supposedly much better on the CP specced cars). The cabin is a nice place to be and it's got that unique combination of Power and finesse with just enough about the car (lower, 20" wheels, deeper spoilers and subtly flared arches etc) to make people pull over on the motorway :evilgrin:
I'd love the amazing Ti Akprakovic exhaust but £5k!….
Hows everyone else doing ?
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PS If anyone is interested in a one owner 50k mile Alpina D3 Biturbo, please give me a shout it's for sale currently