MK5 Golf GTI
General => Random Chat => Topic started by: Hurdy on November 26, 2011, 11:35:29 am
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I've wrecked my brain thinking about this and am still conflicted. The pro's and cons for each are mind boggling. So a problem shared is a problem halved as they say :laugh:
So, what do you all reckon, for FWD - which is best, big power?, big bhp/ton?, a balance of the two? Which is best for track?, which is best for road? which is best overall?
My mind settles on lightweight and a balance of power that suits the car, but what is the best power to weight for a FWD?
Mad power and lightweight can ruin a car, but then too much weight and not enough power is probably dire too!
Some MKV's on here have over 250bhp/ton, is it worth going beyond this or not?
Discuss and help sooth the mind of a raddled and rattled old modifier :driver:
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you ever seen a clio 172 phase 1 stripped out and plexi glass fitted? a few went to oulton with the mk5 boys a few months ago and every one was how fast the little bugger was and not much could keep up with it as they all thought it had a turbo fitted but the guy opened the bonnet and it was bog o stock :driver: to say it upset em all :signLOL: was funny as it proved light weight and balance works perfectly.
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But would it have been even better with a turbo and more power?
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faster on the straights yeah but it might upset the balance a little i think its like the xbow i drove everything about it was so well balanced as a whole package and with the map and a milltek it was better but the balance was a little off but don't get me wrong bloody fast :smiley: .Its all about the balance as you could have 600bhp but still get your arse handed to you by a 200bhp light weight car as it will be able to abuse its hp but the high power just can't put it all down hence why the little clio trophy was able to pretty much kick a lot of bigger cars arses in evo trials.
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you having the diff done?
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Least weight as possible BUT the chassis has to be able to cope with the power also the delivery of the power would be important aswell. Best doent have to mean quickest.
Also power to weight and outright power are kinda the same thing if you have huge power you going to have a good hp per tonne.
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My choice is a high revving N/a in a lightweight shell. One of my old cars weighed 720kg, had a race spec 1670cc making 214hp and 155 ft/lb making peak power at 9500rpm. Not much could keep with it. No wheelspin issues etc... Not an ideal road car due to noise and poly windows etc...
I have been in a fair few lightweight turbo cars with 300+hp and they just struggle to get traction, even with a diff. but they behave OK on the road and the extra power means you dont need to compromise so much on losing the comfort and daily driver aspect to get the power to weight correct.
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lightweight with 214hp 0-70mph
&list=UL
the noise was addictive
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you having the diff done?
Need you ask :signLOL:
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lightweight with 214hp 0-70mph
&list=UL
the noise was addictive
AHHH the sweet sound of throttle bodies!! I had some on a 106 rallye and it was addictive to say the least at 170bhp and 750kgs!
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I remember when you initially got the car, and you said that 250hp would be the sweet spot........It took you all of 1-2 months before you started hunting the big power :grin: and your pulling me in with you :scared:
I personally agree with your initial thoughts tbh, and believe that any more than 250hp on these platforms will just become a nightmare or waste of time.
When i mentioned to VWRacing that i was surprised to have torque steer with such small power, they agreed saying they couldn't believe how much blades had with only a stage 1 map. So i cant imagine what it would act like with another 60-70Hp. You would spend most of your time fighting the torque steer instead of trying to corner or accelerate smoothly. To much more power and i thik we will end up surpassing or ruining the capabilities of this chassis.
If your chasing 1/4 mile times then yeah big power, low weight. But these chassis/engine combos are great for twisty track work, and dont need huge power to pull it off, unlike alot of heavier machinery
you having the diff done?
Need you ask :signLOL:
Ive been doing a lot of inquiries about this. Quaife, Peloquin and wavetrac have said that unless they can get hold of a cheap DSG7 gearbox they are not that bothered about developing it. APR Australia have been developing one alongside a german company, however that is a plate differential and not a ATB diff.
Main issues with that are that plate differentials need servicing as the plates wear down. They are not a fit and forget item, so whilst plate diffs are regarded as being superior to ATB diffs, is that a good option if its not going to last very long??
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If I were in a position to set my car up for track I would strip in out to reduce its weight first, before considering more power.
~1000kg and ~300 bhp should be enough power for anyone.
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Meg trophy? Did I just say that :signLOL: I have to say for track stuff, 200 bhp per tonne is plenty in a fwd, particularly on a short circuit, as much as I love the stage 2 ed 30 I'm not convinced that the power is necessary, I think your car John would have done similar times on track without the engine work tbh.
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Hmm, you maybe right. I think that maybe a switchable map for me on a hybrid turbo and water/meth would make the bigger bhp, but could be switched DOWN for trackwork and UP for 1/4 miles to give me the best of both worlds.
I reckon the Polo can get to a sub 1100kg without stripping the interior at all. Maybe power can get up to 280-290bhp with w/m = 255-260bhp/ton or leave as it is for trackwork at 210bhp/ton and with a diff should be interesting.
You see my quandry! as the car stands now it is very fast around the twisty stuff, but not so fast on the straights, however if I up the power then the balance swaps and the straights become faster and then it is more about timing turns between power off/brake/turn/power on, rather than piling into a corner with good balance and letting rip on the way through. :evilgrin:
N/A is great for reducing wheelspin as the torque is lower, but then the same questions can be aimed at torque - big lbft or smaller lbft and lighter car?
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I ran various maps on the SPS for different things, track version was low torque and 280BHP in the MK5, I found this to be the best balance - for every few tenths gained by being faster into a bend, you're losing them not being able to get back out. Finding speed through a corner is key, and that's nothing to do with power.
The Chapman theory. Always. Adding lightness is generally free and massively effective. Chucking more power at a car to make it faster around a track is the wrong way to go.
The single best thing Team Bora did with their track car was get the MKI TT wishbones/uprights with Defcon inserts/solid bushes. I believe you have the same basic chassis as a MKIV?? Going on from there, raid the VW Motorsport catalogue for the triangulated rear beam, or have Statlers fab one.
Thinking on, there may be a watered down Group N version of the Polo R rally car? Given you can buy all the race car bits from Renault for the Clio, you may be able to snaffle stuff off the Ibiza/Fabia/Polo race cars??
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fwww.rallysportlive.com%2Fwp-content%2Fgallery%2Fvolkswagen-polo-wrc%2Fvolkswagen-polo-wrc-8.jpg&hash=d38ddf537b8a79bebaad6780c85e131658a1b3f6)
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Something like this:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fu48%2FRSR_photos%2FDSC08941.jpg&hash=d5895719f09f816e6f9f51209be50aaa054b1606)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fqq341%2FAli_M24%2FDSCN4261.jpg&hash=bb4d98321cc4e01359bc665aa6f5791e2fa3b1a4)
This seems to explain pretty well how it would help
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fac193%2Fdaved96%2Ftoe003.jpg&hash=6e829e2ca421ca280fc0c25cf985effad658f87c)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fac193%2Fdaved96%2Ftoe004.jpg&hash=9aeb61479f468a443133f8e83d4c66f18bf7d12d)
Wander how much of a difference that would make? So VWRacing do things like this. If i was to take the plunge on something like this, i would have to get it done by guys like that, who understand chassis dynamics a fair amount more than most. Anyone can weld on some ties, but that sort of thing could make or break the handling id imagine.
Who else run teams in the VW cup that could undertake this kind of work, i know of VWRacing, Grant Motorsport and KPM racing. Our rear beams are neigh on identical to the mk4 platform as well, so there might already be plenty of options available. I presume theres plenty of the 1.8T Polo GTIs running in the VW Cup
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^ Yep.
You can buy one straight off the shelf from VWR, Christ knows what it'd cost though? I'd imagine most MKIV chassis stuff in the race series will have a modded rear beam. I'm almost certain you can buy a kit from somewhere in Germany to do it yourself though, let me ask Tabs and get the name of it.
Joe Fullbrook pretty much built his Bora himself, and that dicked everything in the VWCup with a 3rd of the budget. He really knows his onions. Him or KPM may be an alternative to VWR.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fwww.vwmotorsport.com%2Fvwpics%2Fimages%2FGolf%25204%2520Kitcar.jpg&hash=a69c55ef6c1ceb4c6c89f430f8e11144ac856057)
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That's excellent info :happy2: Cheers guys.
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That's excellent info :happy2: Cheers guys.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Ftomalexander.files.wordpress.com%2F2011%2F01%2Fdo-it.png%3Fw%3D595%26amp%3Bh%3D435&hash=b6c7955c3dcf912edfc9b58f56447bb4a590d361)
Come on John, your the nominated guinea pig for this
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'Reet.
Some people think you need IRS to be quick, the French have proven you don't. Most motorsport applications will run a modded rear beam.
Same theory as the MKV wishbone swap. You're getting cast wishbones which have more caster and camber, you can also sleeve the rear bush to make it near solid, as per the early TTs.
Added benefits of moving ARB location, flipping balljoints and giving better allowances for avoiding bump-steer when lowering.
LCR/TT/R32 donor
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fuk-mkivs-net%2Fuk-mkivs_track_car%2Fwishbones-2.jpg&hash=68354300c385c5c7a92891e802ce2c005b444056)
Defcon insert, note how small the new bush is going to be compared to a normal MKIV.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Faudittrs.files.wordpress.com%2F2011%2F01%2Faudi-tt-mk1-8n-suspension-performance-defcon-bushings-3.jpg&hash=8361dc0fc91d95d22f9f163e2c056495177e0828)
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Just came across this here http://www.ultraracing.com.my/Bars.asp?ID=4064 (http://www.ultraracing.com.my/Bars.asp?ID=4064) it says Polo mk5 1.2TSI. Not sure what the deal s with this, the current Polois the mk8 iirc, but the 1.2TSI is a new engine!!!!! Might be because the USA haven't had the fill range of pools in the past.
This is basically triangulation
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fwww.ultraracing.com.my%2Fvgreenwap%2Fimage%2FModel%2520New%2FVW%2FPolo%2520Mark5%25201.8T%2FVW%2520Polo%2520MK5%2520rear%2520lab.jpg&hash=134caf5d0b4d0431a1e9255002c955e3ed7c769e)
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That appears to be bolted to the body, rather than the beam. I'm not convinced.