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Rb25 Slow From 5000rpm Onwards

islade

By islade,
in Engines & Forced Induction

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islade Rising Star

islade

Posted
Posted

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 :laugh:

Isaac

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https://www.sau.com.au/forums/topic/246451-rb25-slow-from-5000rpm-onwards/
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RB JET Apprentice

RB JET

Posted
Posted (edited)

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 by RB JET
nuclear_skyline Mentor

nuclear_skyline

Posted
Posted

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 Veteran

Pal

Posted
Posted

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.

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