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Author Topic: compression results?  (Read 223 times)

Offline ald1717

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compression results?
« on: May 04, 2022, 08:52:37 pm »
in 2 minds as to sell up or do a hybrid or stage 2+,     was going to do a compression test to give me an idea of the health of the engine but never tested a turbo only high compression na which was around 170 psi  can someone chime in with a healthy reading for me to work off

Offline OllieVRS

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Re: compression results?
« Reply #1 on: May 05, 2022, 12:21:15 am »
Quote
After getting it towed home, I changed the oil and filter and did a simple compression test. All cylinders were in the 140-145 psi range. VW says it should be 170psi+ for new engine and it's time for a rebuild under 109 psi so I think I'm ok that front.

This is from back in September after my car suffered low oil pressure twice. As well as evidence on the oil pump of low oil pressure in the past, and way too long service intervals, it's safe to assume my car was abused. And even after all that abuse it's not even halfway to the rebuild threshold.

I can't say what compression is needed to 'safely' modify your car to stage 2+, but as long as your compression is higher than mine and closer to VW specs you should be 'safe'.

Offline Pudding

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Re: compression results?
« Reply #2 on: May 05, 2022, 08:29:21 am »
For the ED30 at least, VW quote 14 bar on a new engine.  I tested mine (hot) a few years ago and that is what it measured across all 4. That was with a cheap Gunson tester from Halfords though, so not sure how accurate it is, but the important thing is consistency across all cylinders, not necessarily the numbers.....so long as they're above VW's minimum.

K03 engines have a higher compression ratio, so might show a little more on the gauge.

Someone on here a few years ago was in the same boat.  Old engine....sell up and move on, or invest in stage 3.  He ended up buying a brand new CDL engine from TPS and a TTE420 turbo. That's a £6.5K chunk right there before even getting into the mapping and other supporting mods, so it gets real expensive, real fast!



2007 ED30 | 2009 TDI 140

Offline ald1717

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Re: compression results?
« Reply #3 on: May 05, 2022, 04:32:26 pm »
thanks for the info, have seen a fair few engine failures at stage 2+,    so if my engine isnt at the best health then that will make my mind up for me...

Offline Pudding

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Re: compression results?
« Reply #4 on: May 06, 2022, 08:38:21 am »
Yes indeed. One or more pistons usually crack from all the extra cylinder pressure/heat.

It happens to EA888 engines as well when pushed too hard, but the internet will have you believe Golf 7R stock engines can handle 500hp  :grin:


2007 ED30 | 2009 TDI 140

Offline ald1717

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Re: compression results?
« Reply #5 on: May 06, 2022, 10:54:00 am »
im well aware that they can and do fail when running over 500bhp,  but most tuners find them quite reliable when kept around the 450-460 mark, i think a daily driver thats only run hard in short bursts is completely different to tracking, 

Offline Pudding

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Re: compression results?
« Reply #6 on: May 06, 2022, 11:13:33 am »
There's no such thing as reliable when adding 150+ hp to an engine spec'd for 300hp.  Tuners don't do extended testing in Dubai or Siberia.  They just bolt bits on, map it, and give the keys back.  When and where it blows up is entirely unpredictable.



2007 ED30 | 2009 TDI 140