R32 Gtr Down On Power

[Moodles2]

My R32 GTR is pretty much stock except for: Nismo front pipe, catco ceramic highflow cat, apexi n1 catback, K&N panel filter, adj. cam gears (set for more midrange torque), Gizzmo MS-IBC

Compression results (psi, starting from cyl #1 to #6): 175,175,165,175,175,175

I would have expected about 220-250kw at the rears with these mods, but only getting 199kw at the rears with 14.7psi.

Boostworx said they found a leak at the inlet manifold gasket and it explains the low power, but I've been unable to find the leak myself and a mechanic who works on Skylines couldn't find the leak either.

If the timing belt has skipped a tooth, can this also explain why I'm down on power?

Another thing I thought of is K&N panel filter oiled nature, I brought it new and have never oiled it since it comes out of the packaging already oiled, could there be oil on my AFM causing the loss of power?

Any ideas I haven't thought of?

Forgot I'm running Nistune, with a fairly safe tune.

Edited May 12, 2009 by Moodles2

[fantov]

Hey Mate,

Sounds a bit strange, with those mods and running 1 BAR you should be able to break 200KW!

With the leak coming from the inlet manifold did they notice it under load or at idle?

It would definitely account for some loss of power but the question is why didn't they fix the leak upon discovery?

It's probably something you want to attend to sooner rather than later!

Doubt the K&N filter oil has clogged up your AFM's although you can always take em off and spray them with a bit off electraclean!

Goodluck.

[Moodles2]

Car was booked in for tune at the time, plus I insisted on going metal gaskets instead of genuine nissan paper types, I've been putting off doing it (since it's a 4.5-5hr job for a trained mechanic) because the mechanic who did the 2nd opinion for me couldn't find the leak. So I'm alittle confused

[R.3.2.G.T.R]

is your cat new-ish, maybe collapsed, you can alway drop the catback and see if there's an improvement.. mine was 230kw at 13psi

is the car running / idling normally otherwise?

[Moodles2]

cat is new from justjap, it was installed with the front pipe at the same time, before that dyno sheet was taken

car runs good at the moment, idles pretty smoothly at around 1100rpm

Edited May 12, 2009 by Moodles2

[STATUS]

Car is pretty much spot on for a untuned r32 GTR. The boost leak may explain it. Spray aerostart around the plenum and tb's if the idle picks up you have a leak (may not show up, as it may be a pressure only leak).

Nistune on your mods should see 215-230rwkw, we do them all the time. Must be a car issue.

[R31Nismoid]

Is it a new motor?

175 IMO is too high for a 20yr old RB26 in the vast majority of cases.

You can make 230-250rwkw on the stock ECU, so with a tidied Nistune - same deal, should be 230-250rwkw.

So yes its down on power especially considering you've got a bit of correction applied to that graph - so it would be even lower if the IT: was same as ambient.

Why didnt Boostworx fix the leak or tell you where it was if they found it?

Also - i wouldnt be running 1bar on R32 turbos mate - back it off to 12psi, if a turbo fails its highly likely it will destroy your motor - not a cheap excercise

[R31Nismoid]

could be the cat has collapsed also - check that, ceramic cats are not exactly friendly in many cases

[Moodles2]

Old motor, from 01/1994 with 62,xxx on the odo. If the cat has collapsed, if I hit the underneath with a pipe, will I hear loose bits and pieces shaking about, or will I need to take the cat out and inspect it?

I've tried Spraying WD40 liberally around the tb and plenum when idling but nothing, going to get some aerostart/brake cleaner and try again. Boostworx found the leak and were sure it was the intake manifold gasket advising me to run on low boost until the plenum it out and the gasket changed (since it's my daily I needed it, and decided to book it in later once ive sourced some metal gaskets)

Edited May 12, 2009 by Moodles2

[R31Nismoid]

unless you have a log book saying 62 - even then thats still high for a reasonably well km'd 32 IMO.

Not saying it would be a farked motor, just more so the comp test might not have been done right - try getting a leakdown test @ some point

ideally you want to drop it from before the cat - best way to diagnose some kind of restriction

[Moodles2]

Have the service logbooks leading up to 58,xxx where I took ownership of it

[Mike__]

maybe there dyno just reads a little lower than others / maybe they've inputted a wrong parameter

does it 'feel' slow? maybe drive another car with identical mods, Or even better hit the 1/4 mile and your terminal speed should be ~178km/hr+

just saying there might be more to it than a dyno readout

don't oil the filter - > not good for AFM's

mike

[Moodles2]

Shaun at Boostworx says he uses the same dyno settings he uses for all 6 cylinder cars, cat is still intact (front and back). Boostworx made a mistake with the inlet leak diagnosis, had a 2nd mechanic try and find the leak and couldn't. Took it back to Boostworx and they couldn't find it again. Then again the day I had it dyno'd and tune tidied up it was a 45degree C day (and the dyno sheet says AT is 25, which if ambient temp is very wrong).

[Moodles2]

I've cleaned my AFMs, replaced my cam cover with a clear trust item so had a poke around in there. Boostworx installed the adjustable cam gears for me (4 degrees advanced on the intake gear, 0 on the exhaust gear). I remember before dropping it off, my CAS was dead center in the slots, it wasn't until yesterday I noticed it's current position (before replacing the cover) is to the left, between the extreme left and middle.

Correct me if I'm wrong, but doesn't that mean the current CAS position is retarding the timing versus where the CAS would be if it were in the dead center position?