R33 No power between 4000rpm and 5100rpm!

[SoarertoR33]

Hey.

I really hope someone can help, i have a Series 1 R33 Gtst it's mostly factory but i have recently had a Garrett GT30 with the nissan exhaust housing fitted with a hybrid frount mount intercooler, K&N Air filter, blow off valve..... it's allmounted on the factory exhaust manifold, factory dump and front in to a 3inch exhaust and all runs off the factor ECU and AFM at around 14psi.

The problem is, apparty from my range of factory gear, the car hauls ass all the way to 4000rpm and between that an 5000rpm its a real dog but after about 5100rpm it goes like a champion all the way to redline. This happens from 10psi up.

I read that this could be caused by small hair line cracks in the coil pack so i pulled them out and taped em up like it said but this seemed to make absolutly no diffrence.

Just looking for some ideas.

Cheers.

[Dale FZ1]

My R33 missed like a pig in the same rev band - something like wet ignition - until I taped the coils. Went fine afterwards (no missing), but the same range feels like a big flat spot. Sensation is like you are hard on the throttle and applying the brakes simultaneously. The insulation tape might stop the misses, but the coils may be failing internally. Just a thought.

[rs73]

Could it be the factory ECU not be able to cope with the new turbo?

If so you might wanna consider a piggy back like SAFC or E-Manage, or even go full computer like PFC or Wolf3D, Motec etc...

[Al]

I can't believe ppl upgrade turbos b4 ecu, injectors, etc.

Replace the factory ecu with a Pfc or Wolf3D and your problems will magically disappear, not to mention the amount extra kw's to be gained.

[SoarertoR33]

I've read that the AFM might be doggy, so i'm going to give that a go....just gotta find someone round here with one. Next thing on the menu was going to be the Apexi Power FC but $1200+ is on the back burner.

Oh also it feels like a big flat spot like it's being choked.

[rs73]

Well, spending $1200+ on PowerFC on a car with stock turbo is a more logical upgrade path than spending a fortune on aftermarket turbo first, since stock ECU will start behaving weird past 9psi & stock R33 AFM will maxed out above 12psi.

Replacing your AFM with Z32 item will be useless if you still have the factory ECU as the ECU won't recognise the Z32 afm reading. You'll need to replace the ECU with PowerFC at the same time, since PFC has an option to recognize Z32 AFM on RB25.

[morlock]

What you are hitting is the factory ECU "flat spot". Quite common and will be resolved once some kind of engine management is introduced.

[SoarertoR33]

Cool cool, sorry for my illogical way of thinking, I came over to the Jap Import sceen form the old V8's and as you all know when youv'e been playing with carbies and porting cylinders - ECU's and Air flow Meters are an all new game!. Does anybody know where i can get my hands on an Apexi PFC for the cheapest possible price???

Thanks fellers.

[GDZ1LA]

its the vvt kicking in and out, u will notic it more in a higher gear, i gota pfc and the problem vanashed

[nizmokid]

I have a larger garett BB turbo from GCG Rated at 450hp and I am only running a standard computer with safc2 and it runs like a train...dynoed it and got 230rwkw......but next mods are new ECU & larger 555cc injectors! want to go the PFC but might go a MAP style ECU and ditch the airflow meters!

but not bad from a stock computer with a piggyback!....my injector are at 85%....not upping it anymore!