What Caused My Car To Do This?

[TUF250]

Hi all.

I have an R33 S2 GTS-T Manual

- Fully services with new plugs (0.9 gap heat range 6 NGK)

- 3 inch Turbo Back exhaust (bellmouth type dump pipe)

- K&N Pod (clean AFM regually)

- R34 GT-T SMIC

The car runs great, real smooth, good on fuel (98only), NEVER backfires, misses or splutters!

Note the car runs std boost (confirmed with an aftermarket boost gauge) but I have done the free boost mod (gives 7psi through the whole rev band, not the factory 5/7 method)

Now my car seems to suffer from mild R&R on really cold nights (sub 10degrees, which is common in melbourne at the moment). The car will take off hard, flatten in the midrange, not misfire just seem flat, then pick back up in the top of the rpm band.

Tonight I took off from the lights, got into second (had three people in the car, more load than usual?) and at about 3000rpm I stepped on the pedal (to show off a bit ) and the car took of then, bang, hit some sort of hard cut. It was like I rapidly took my foot of the accelerator andthe whole drive line banged. After this the car drove fine but I didnt boot it again as I was worried.

What has caused this and what is it? R&R? Boost cut? (because of the 7psi in the midrange when it expects 5?)

Any thoughts?

Also someone said that all ECUs respond differently to this mode, mine seems sensitive as all it takes is a cool night to carry on yet some people can run 12psi in winter with no problems and more mods than me??? Is it worth swapping my ecu for another one?

thanks!

[KiwiRS4T]

Bite the bullet and get an aftermarket ecu now - Link, Vipec, PFC whatever. Then you can put boost up to 10psi and the car will run heaps better. Later when you want the bigger turbo etc etc you will be able to tune for it.

[TUF250]

yeah wont be modding the car anymore from here, just the 10psi solenoid and a toshi remap which I assume will get rip of my flatsport problems.

was really curious to know what it was that my car did and why?

[TUF250]

well the end result was a vac leak, heard a hissing noise and followed it (must have gotten worse no was now audiable) and found it! replaced the hose and she is back to her normal self again!

[Ultimategtr]

Haha the same thing happened to me. I thought crap, need to take out a loan for a new engine.

[TUF250]

yes its very nice to having it running at its best again