R34 GTT Running Too Much Boost?

[Dyzzii]

Hi guys

 

I have an R34 GTT and am concerned with the boost levels it's running. It has some basic bolt-ons including a front mount intercooler, full 3inch de-cat turboback exhaust, apexi pod filter and custom cold air intake. The stock 2-stage boost controller has also been grounded out.

 

However I've been having issues with how much boost it's running. It's occasionally hitting the 1bar mark on the factory boost gauge, and it does not have a boost tap. I believe that was causing issues as the car had severe flat spots through the rpm range and was missfiring and spluttering occasionally on boost. I read up and unplugged the factory 2-stage controller and it now sits on 7psi constantly, which i'm much happier with.

 

My 2 questions were, why/how is it boosting this much without a tap or controller, and could the missfire/break up I was getting on boost be because of the boost levels it was running? Feels fantastic on 7, and pulls properly the whole way to redline. Have checked and gapped my spark plugs to .85 too. Was planning on getting it tuned on a link ecu but just wanted to check for ideas here first about those two things.

 

Thanks guys

[GTSBoy]

Probably not misfiring.  Could be, but probably not.  The standard ECU gets really upset if you go over about 12 psi.  First you get rich & retard.  Then it starts boost cutting, which feels like a miss.....because it is....just a deliberate miss.

As to why it's overboosting.....who knows?  The factory boost "leak" through the solenoid might have been made a lot larger, which will raise the boost above the ~7 that it is supposed to run.

[KiwiRS4T]

I wouldn't bother investing in a Link unless you have radical mods in mind...and even then a Nistune chip can probably handle it for a lot less money.

[Dyzzii]

I'm sure a Nistune would handle it perfectly fine too, but i'm kind of by the concept of "do it once do it right" and feel like a link would give me better results long-term. I'd likely upgrade the turbo and injectors down the line too 

[niZmO_Man]

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