Rb25 Slow From 5000rpm Onwards

[islade]

Hey guys, I have a 1993 R33 Skyline.

I recently had it converted to manual, at the same time, i had a full service (inc spark plugs), new timing belt and water pump (by NisPro).

The car has 3" catback exhaust, turbotech manual boost controller set at 10psi, VeePort BOV and a HKS mushroom air filter, stock ecu and smic.

When flooring it, the car seems to pick up nicely around 3-4000rpm, but once it gets around 5, the boost guage still reads 10psi, but the car seems to take noticeably longer to get to 7rpm than from 3 to 5rpm. I had a friend with a 32 drive it, and he confirmed, from 5000rpm i've got nothing!

The car isn't hesitating/stuttering/making funny noises, it just seems like it's n/a from 5000rpm onwards.

I'm wanting to work out what's wrong. Jez suggested it could be my coil packs. After reading a few threads on SAU about them, I think i'm going to try and find a working pair to test that theory, what else can i look at?

Thanks guys

Isaac

[PHA71L]

are the plugs gapped to .8?

[RB JET]

I had the same problem in my 33. My ecu was richening a/f mixtures and retarding timing. Power FC and a good tune fixed me up, but if i were you id get it on the dyno and get the problem diagnosed that way. Itll save you a lot of money in the long run.

Edited November 27, 2008 by RB JET

[islade]

Had the car in for a check.

Car was running messed up timing because it's an auto ECU with manual transmission.

Got a manual ECU and SAFCII i'm gonna chuck in tonight and booked in for a tune next thursday at gavin woods w00t!

[nuclear_skyline]

very well could be the bad rich and retard thing... too much air coming in so the stock ecu craps itself - dumps heaps of fuel in and pulls all the timing...

[Pal]

i done a manual conversion 3 years ago and have only just changed my ecu to a manual one(had SAFC2 fitted). it done nothing to the power when flooring it, only cleaned up idling and cruising. you need to get yourself at minimum a SAFC2 and get it tuned.

[and3_3]

If changing the ignition timing and injection doesn't work then maybe a restriction in the exhaust?

[mico]

my money is on the ecu.