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R34 With Aftermarket Turbo But Stock Ecu...?

thommo

By thommo,
in Engines & Forced Induction

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thommo Mentor

thommo

Posted
Posted

Did a search and couldnt find much to answer my question.

So Im looking at an R34 and the owner has fitted a gtr-s (quoted as running 11psi) but has retained the standard ecu? car has been driving like this for 15,000km (18 months).

Does this sound right?

Surely the stock ecu is struggling to work out what is going on and the car would drive pretty ordinarily... i'm kinda assuming he's had something in there ie pfc, which he wants to keep post sale. Mods include - ebc, full exhaust, 040 pump, front mount and zorst.

Cheers

**RB2530** Proficient

**RB2530**

Posted
Posted

A point about your question...

The ECU has no idea what size turbo you are running...The good thing about engine management platforms that use MAFs is you can do a lot of mods and the stock ECU will handle it. Safely!!.. Platforms that use MAPs are a completely different ball game...

All the stock ECU is worried about is airflow. It matches fuel to airflow. If your airflow exceeds a threshold (which increases with rpm) it progressively cuts spark. This 'is Not' R&R. R&R is triggered by pre-ignition. This is one of the most misunderstood things on these forums.

I run a stock RB25DET ECU on an RB30DET with a GT3076R and have done so for 2 1/2 years now. It makes around 280rwkw and afrs are safe. EGTs are good as well. I get around airflow cut by changing exhaust cam timing and introducing a little bit of lag. The ECU doesn't like too much airflow at too low an rpm and if you avoid this, the setup works well.

This is not crap and dyno runs were done by a well respected tuner on these forums...

So IMO I think your engine will be fine. Airflow cut is the saviour and will occur well before any overly lean conditions occur...

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