Gtr Turbo Spool-up

[liber8_d]

OK. First up, I've searched but didn't find what I'm after.

Now, my car is an R32 GTR. It has cat-back 3.5 or 4inch exhaust I think, HKS pods, HKS cooler pipes, EBC, plus a HKS turbo timer and Apexi multi checker(PFC yet to go in). I think thats all the performance mods. (I know TT & checker aren't perf.) I only have a Greddy boost guage that reads in kg/cm2.

Turbos are believed to be standard, but I really have bugger all idea if they are or not; I can see Garrett on one of them though, thats it.

At what revs should I be getting boost? And when should I have full boost?

Currently I start getting positive pressure around 3500ish, then about 0.5kg/cm2(7psi/0.49bar) at 4000rpm. I think its at full boost or almost by about 5000rpm. Full boost I think is about 1.1kg/cm2 (15.5psi/1.079bar). I

Is this normal? I think its a bit laggy, but this is my first GTR and first turbo so I dont know....

As I said above I have PFC sitting at home to go in, and I'll probably get new front pipes+dumps+hiflo cat put on when I get PFC in, so that should spool it up a bit earlier I hope.

[liber8_d]

If you have trouble converting pressure measures (psi-bar-kg/cm2) I use convertme.com

http://www.convert-me.com/en/convert/pressure

I have to get a guage that reads psi, because thats what I think in with pressures.

[Beer Baron]

on my GTR with stock IC, stock dumps, stock front pipes and just 3 inch cat back system. my car hits 14psi at around 3700 or 3800. it was higher than that but a little fiddling with the boost controller and with the cam gear timing it spools up much earlier.

full boost at 5000rpm is way to high for a stock GTR. they do feel a bit laggy compared to other standard turbo cars though.

[liber8_d]

Thanks Richard.

Thats what I thought. It might not be 5000rpm, but its almost that high.

Anyone have any ideas what'd make it boost up late?

I don't really. It hasn't had a tune yet, so I'm hoping it'll get sorted out when I get the PFC in and tuned, and new front pipes and dumps.

Anyone else have any input?

[2510s]

When I got my GTR it was very slow to climb onto boost. It has 2510s, HKS dumps, MINES ECU, standard modified airbox, and had a 3.5' exh. I added front pipes and gutted the cat, and it made a major difference, makes full boost about 1000rpm earlier now...... GUT THAT CAT!!!!!!

[T04GTR]

mad i diddnt think they came out with t04rs stock. just kidding that is way to late.

but normal if its in FIRST gear.

[hungry6]

liber8d , check to see if you got a decent dint in your exhaust, or out of setting cams wheels, or incorrectly set EBC.

[liber8_d]

Thanks guys.

There doesnt seem to be any big dents in the exhaust, but I'll get under her tomorrow and have a better look. I know sweet bugger all about how the EBC works, and little about cam wheel settings, but I'll try to look into them.

I'll try to take her out for a drive tomorrow (I'm at work now, without GTR), and plot revs vs boost level properly. For reference, I was in second or third when I was testing, not first, it revs out too quickly.

I'm thinking its just the timing is out, but I don't know. It could have aftermarket turbos for all I know; I have no reference point as to what it SHOULD be doing.(except you guys)

[Cool Hand Luke]

As to4gtr said, dont do them in first, at least 2nd....

[liber8_d]

OK, I didnt have much time to test her out, but it is actually WORSE than I thought.

I really need someone else in the car to help me tell what boost at what revs(that should happen tomorrow), but I did a few runs using the shift alarm on my multi checker. In second gear mostly, and third a couple of times.

At 4000 its making about 0.4kg/cm2. At 5000 its making about 0.8kg/cm2. At 6000 its making nearly full boost, just under 1.1kg/cm2.

I know there is something wrong now. Any sugestions as to what would make it do this? Bad turbo/s? Timing way out? Cracked hoses?(had one earlier)

One of the truckies at work said it sounds like it is missing on one cylinder, but he is the only one who has said this, and the car has been around many people in the know(mechanic friends, compliance guys etc). I suppose it could be; I'm an ex Subaru guy, so I'm used to a bit of a burble.

We'll check that out tomorrow too, just to make sure it isnt that.

[oRiCLe]

whoa, .4 at 4000rpm...should be spoolin faster than that i think...meybe a vaccuum leak? wastegates jammed open? turbo missing bits to make compression (like wheels)? check the hoses would be a first, stock should spool from 2000ish, well mine did when they worked, have gt2530s now and even they hit full boost about 3700-4000rpm?

gl finding the problem!

[oRiCLe]

what have you got the EBC set to or what is the max it has been set to?

[liber8_d]

Its an old school HKS 'Electronic Valve Controller'. It has three buttons that you can press for 'low', 'high', or 'manu', and a dial on the right hand side, for the manual setting, that goes from min-max. I have no idea what this is actually set at.

When I was testing I had it on 'manu', and the dial turned to 'max'. Max boost is estimated at 15psi

Tomorrow I'll try to test it on 'low', 'high' and a few different levels of the 'manu' setting, just to see if that makes any difference.

[oRiCLe]

careful with the max boost setting, standard GTR turbo's dont like the plus side of 14psi very much...been there, done that

[hungry6]

I'm putting $50 on the EBC being out of setting