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Hey guys

So I've pretty much done the whole 'stage 1' mods according to this site

http://nissanskyline.6te.net/tuning_GTS25T.htm

Turbo back 3" X-force exhaust

Cooling Pro Type 2 Intercooler

Grounded solenoid

Aftermarket actuator set for ~12 psi

ECU tuned for 12 PSI on stock turbo, r & r removed etc, bought from SECURITY, not custom tuned

Customised enlarged snorkel to fit IC piping + Apexi panel filter

Front strut brace

...and results are dissapointing imo

I haven't dyno'd it yet, but it feels really slack until it hits mega rpm, take off is just sad, any old commonwhore would chomp me.

I'm thinking turbo lag is a major factor.

I think it could do with a new fuel pump and maybe gapped plugs (?), clutch seems fine, not really convinced to get an ebc

My aim was about 200rw, and I was thinking with the 33's lower weight it should be as quick as a stock 300ZX TT or Soarer, which are both specified at about 300HP, but I've driven both of those cars, and I'm sure they would rip this a new one :rofl: . Hell even a stockish 180sx I drove seemed quicker than this.

So yeah very dissapointed to be honest, and I don't want to spend 3-4K on a turbo and everything that goes with it, I'll just lose it all when I sell the car for less than I bought it probably :domokun:

Anyone else in the same boat?

Edited by vault13

If the tune on the ecu is reasonable, i would suggest that your boost curve is not ideal, you need some form of boost control other than the "grounded solenoid" and wastegate spring. even a gated bleed or ball valve will give you a much better spool and fatten up your midrange.

if you are on the stock turbo, its not lag. or at least its not the turbo causing the lag.

the tune you are using is also not for your car, so you cannot expect it to suit. if you want to make the best of the ecu tune you have you need to make sure your car has everything exactly the same as security's was, and hope that the timing and fuel it spits out are close. what type of ecu is it? if power fc then you need to get it retuned. if some modified version of the stock ecu, if the tune is close enough you can get a decent result because the computer reacts to feedback whereas the fc just does set maps and doesnt adjust constantly.

Yeah I thought long and hard about the ECU tune, the reason I bought it from SECURITY was he said its tuned to get the most out of these mods at ~12 psi stock turbo.

Not really convinced about the boost control jeff, I had a turbotech set up and it didn't really make much difference, I don't see an ebc doing any better, ok maybe a little better but I cant justify another $500 on something that does a marginally better job than a $20 turbotech.

Basically I'm thinking of ditching the FMIC and going back to an R34 SMIC, or maybe ditching the 33 for a soarer :rofl:

Edited by vault13

Yeah that definitely doesn't seem normal, when mine was near stock (just exhaust and filter) I had a meet where I ended up lined up with a manual TT 300ZX with the same mods and I beat him MARGAINLY each run. However, if I had a front mount, ecu and tune I'd like to think I would have completely trounced him :rofl:

A stock turbo isn't normally laggy, something else is going on there... when are you reaching boost? Could be a leak in intercooler/piping.

Not sure but I think SECURITY had his ecu tuned to suit a Slide max oversize hiflow.. which would be way off the mark for your car.

tt 300zx's are quick cars and would take any gts-t with the same mods, soarer's are the same deal.

a tune makes all the difference, you should get a real ecu

or have it tuned in real time on your car, or even better post a dyno plot of how the ecu performs

a well setup and tuned gtst with the usual mods (fmic, exhaust, clutch, tune, intake, 12psi) will crank 200rwkw or just under and should be loads of fun on the street

ign timing makes all the difference here, my maps are aggresssive as fark and it absoluttely tears it up

stock solenoid is slow at building boost, it opens the gate very early in the piece. If the cooler install is new, i guarantee you have done something wrong. where is your wastegate getting the boost signal from? the kit will luikely have removed the stockpiping that had a nipple for the controller. if this is hooked up wrong, you are running straight off the wastegate.

to get good results from a turbotech, you are better off without such a high wastegate spring. if you want 12psi from a 12psi spring, you need a proper gate or ebc.

honestly, go over your intercooler install with a 7 or 8 mm ratchet, its free and is a likely problem at this point

Toowoomba hey :rofl:

Brett you know anyone in town who could retune this ECU?

Its got one of those square sockets with a H8 chip in it.

A stock turbo isn't normally laggy, something else is going on there... when are you reaching boost? Could be a leak in intercooler/piping.

Not sure but I think SECURITY had his ecu tuned to suit a Slide max oversize hiflow.. which would be way off the mark for your car.

tt 300zx's are quick cars and would take any gts-t with the same mods, soarer's are the same deal.

I had a nipple tapped into the piping in place of the old one.

Sure there aint no leaks here either :rofl: I'm obsessive compulsive when it comes to tightening.

Yeah maybe the stock solenoid is carp.

stock solenoid is slow at building boost, it opens the gate very early in the piece. If the cooler install is new, i guarantee you have done something wrong. where is your wastegate getting the boost signal from? the kit will luikely have removed the stockpiping that had a nipple for the controller. if this is hooked up wrong, you are running straight off the wastegate.

to get good results from a turbotech, you are better off without such a high wastegate spring. if you want 12psi from a 12psi spring, you need a proper gate or ebc.

honestly, go over your intercooler install with a 7 or 8 mm ratchet, its free and is a likely problem at this point

Its been complied < 1000km ago, so I would assume they checked basic stuff like that.

start with the basics, check its mechanically ok first.

compression test, leak down, check timing belt is not out a tooth somewhere, check CAS ignition timing is set correctly etc

If you have an aftermarket actuator (which i assume is adjustable) get rid of the factory solenoid completely and just run the actuator. It removes complexity and a potential problem.

Then stick the car on a dyno and see what the boost and afr's are doing. If it's a slug, the dyno will show it's a slug.

im ocd about it too, but i have done a lot of intercooler installs, and in testing find that they werent clamped enough despite my best efforts. my own car had a massive boost leak. the problem with boost leaks, is they only happen on boost, so short of removing the bonnet and smashing a window, you just have to check and recheck.

i would say half of the cars i had boost leaks in cooler piping, it was actually the turbo outlet hose connector, which you dont even touch in the install. check throttle body too, as some people remove the clamps there every service.

sounds like your line to the solenoid is in the right spot. i would consider skipping the solenoid and running off the wastegate to see if its any different, its only one hose connection.

also check your silicone hose to the solenoid is not cracked, some of the thinner diameters peel away like a banana when you force them over a connection even if its the right size.

unfortunately if it isnt any of this, you may need to get it on a dyno and have a looksee with a pro

Should have gone with the PFC in the first place :rofl:

You reckon autotech or paramount could tune this H8 chip?

Haha, toowoomba sucks for tuning options. Only people who do chips are autotech and paramount.

You're better off selling the chipped ECU and getting a PFC, then getting it tuned by rob at autozone or Terry at paramount performance

Yah yah I know I should dyno before I start complaining.

I still think GTST needs to rev too hard before you see any power, all the dyno charts I see are really peaky, which means almost anything down to granny's vdub can do you on take off.

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