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If the gauge was reading 100lb then the thing wouldn't pull a drunk sailor off your sister. So I would say there is something not quite right with the gauge or the setup for the test. Is the battery fully charged & in good nick?

Did he do a wet test?

Edited by djr81
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No he didn't do a wet test and I agree with you, a few other threads have said that if the compression is THAT low the car would be making sfa power and this car was an CRAP load faster than my car and felt tighter through the revs with smooth power all the way. I can only assume the guage/tested was stuffed/stupid but I think it's a reasonable sign that the figures are all pretty close. If the engine is anything ike the rest of the car, it shold be immaculate more or less. Now I have to decide if I want to take the risk =\

Hah, we're talking some serious bucks for the car and I'd hate to buy it only to have it fail on me in some serious way in the near future, I know all engines will eventually wear out etc etc but it's hard when the main thing I wanted from today was some good compression figures and it doesn't seem like I got them, either because the engine is failing or because the tester/guage was stuffed. In my mind the figures do not match the performance given ~128psi is the lowest limit for RB26DETT compression, and that's for a worn/tired engine, this felt to be neither.

4x90 psi and 2x100 psi, not what I would expect from a good engine!

Does your mechanic know what he is doing? Its a bit funny that the numbers are so round, 90 and 100. I must say thats its hard to believe that compression is so low on all of them and the car running so well .

Your mechanic should know that 90psi is very low for any engine, even a 2 stroke engine would have more than that. Even if he never seen a GTR before he should know.

If I was you I would do leakdown test as well, if the compession numbers are correct she will have some leaks either from the top-end or bottom-end but a leakdown test will confirm where its loosing compression from .

It was just at an Ultra Tune in Richmond - I'm in Wodonga bout 3hrs away. I had my GTS25T inspected at a different Ultra Tune (Coburg) and it didn't get more than 120 across any cylinder and has been an excellent car in the time I've owned it, no oil usage no blow by no smoke etc. Maybe Ultra Tune just suck or have crap gear =\ What's a leakdown test worth and where's a good place to get one done in or around Mt Waverly?

I've spoken to a few mechanics now regarding this and everyone says that if it was making those figures it would not even run properly let alone make the power I felt when I drove it. I think we can safely say the tester/equipment is not 100%.

What's a leakdown test cost and where's a good place to get one near Mt Waverly?

Edited by ActionDan

Spoke with the tester and explained what figures the car should have got and so forth, he's convinced his tester is busted and he noted 'If that's what a worn RB26DETT feels like then a new one must be like a boeing 747, it's simply too smooth and too strong to be a worn out engine. I'll calibrate my tester" etc etc.

That sounds like what I was thinking myself.

Mate if you wanta professional to check your car out go to see Geoff Nicholls @ Prestige in Glenferrie. He has looked at all of the cars i have purchased and a send all my friends to him also. He charges you a decent price and knows everything back to front.

His number is 9818 4555

I've spoken to a few mechanics now regarding this and everyone says that if it was making those figures it would not even run properly let alone make the power I felt when I drove it. I think we can safely say the tester/equipment is not 100%.
What's a leakdown test cost and where's a good place to get one near Mt Waverly?

No idea , sorry mate I'm in Sydney, I wouln't use this mob again though.

O.K the numbers are low but also the variance is a little on the big side , they should be a lot closer , again I don't think you can trust those numbers .

A leakdown test involves pumping compressed air in the cylinders via the tester itself and it will give you a% of lost pressure, anything under 5% is good .

Smart guy aren't ya. So why don't you tell me how pod filters are better than an enclosed factory airbox on a street car? You'd know right because you've tested back to back right.... right.

Well, I've tested back to back. Was not a high-powered GTR by any means (250awkw at the time).

Made a difference. No dyno graphs, sorry.

This of course is probably because the stock box has an inlet area of about 60cm2 compared with about 120cm2

for the pod; and a filter area of about 375cm2 vs maybe 1000cm2 for the pod. I had a stock panel, then a (better)

K&N panel in the stock airbox, then a (best so far) K&N pod.

The pod is in the front LHS guard so intake temps should be down if anything compared to the stock snorkel.

Of course, most pod 'kits' that replace the stock airbox and leave the pods right where the box was don't have such

an increase in intake or filtration areas; and sucking hotter air in is always going to be a disadvantage. Some of the

foam ones going around look downright dangerous to me (the foam seems to degrade real fast, leaving holes

and leaving me wondering where those bits of foam actually went).

I just don't think that 'pods are no better than a factory airbox on a street car' is accurate. Maybe 'typical pod

kits that replace the stock airbox won't be much better than the factory airbox'?

Regards,

Saliya

Edited by saliya

2nd comp test was done this morning at another mechanic, car rated between 145 and 148 across all six standard dry test. Mechanic rates the car as being in excellent condition all round.

I'm gonna buy it =D

Any more info on those rebuilt turbo's from Slide?

Run an oil analysis, it will tell you what wear is occuring.

Dan, that sounds a bit better, but do none of these "mechanics" know how to do a "wet" compression test or are they all just slack?

Don't have the Sliders yet, and they won't go on until all the bits arrive, but word is they will get you all teh chicks :teehee:

I thought wet was only done if there was reason for concern? If not then I'd say they;'re slack. I'm buying the car so we'll know soon enough how healthy it is =D

What does he rebuild them to? steel wheel, ball bearing? what power are they good for etc. for $1400 I couldn't see them being ballbearing?

Why bother with a dry test if it only takes a moment extra to do them wet?

Steel wheels and bush bearing, just a centre cartridge and the housings are machined. Stock 32/33 are bush and since mine isn't intended to be a full race car and I always take the time to come in steady, I don't really see the need, I have a race car for the expensive work.

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