Overboosting Stock Computer?

[Drift Freak]

Hi guys, the other day i put a HKS 2540 on my RB20 R32 and got it going I haven't got the wastegate connected so it boosts of its head When she gets to about 13-14 psi it coughs and splutters bad like its got a boost cut??? my question is does the standard computer have a boost cut or something of the like? God i can't wait till my Power FC turns up And also the new HKS turbo doesn't have a wastegate line fitting on the compressor housing like the standard turbo where should i connect my new wastegate pressure line?? Any help is greatly appreciated

[RB SANDY]

dont drive the car if it is free boosting. eg. no wastegate

[Drift Freak]

Yeah i know i shouldn't RB SANDY but i need the wheels for work will just have to take it easy (no gassin it). can yougive me any advice on how to hook it up???

[RB SANDY]

you can try to tap in where the std bov is, if you have got a long hose try and put it where the std boost gauge is.

Edited September 9, 2006 by RB SANDY

[RB SANDY]

Also yes the standard computer does have a boost cut and it saved your motor, if all else fails disconnect the line that goes the std bov so the boost just leeks out.

[Drift Freak]

Cheers mate i've got some hose so i'll try both of these today. fingers crossed it all works. cheers mate

[BHDave]

The standard computer does not have a boost cut and you dont want to get your wastegate signal from the same point as the bov or boost gauge signal.

You need to take the wastegate signal from before the throttle body, not after, the closer to the compressor outlet the better. Get a nipple brazed into the compressor outlet pipe.

I'd suggest that the missfire is due to slightly rich mixtures, 15 year old coils, and plugs (and gaps) not suited to the level of boost you are running.

[WazR32GTSt]

the rb20 ECU doesn't go all gay like the rb25 ECU when boosted..

it does ruin things, but not as much

[ellie]

As said above = no boost cut, just your afm reading outside of the maximum standard mapping causing rich and retard!

[Drift Freak]

Cheers guys, I tried what RB SANDY said and disconnected the blow-off valve, works well by allowing the extra pressure to escape.

BHDAVE thanks mate you confirmed what i was thinking, i need to remove the compressor housing and either tap a thread for the nipple or get one braised on. Cheers guys your input is much appreciated

[Rolls]

Id advise highly against driving it until you can get a proper tune sorted and hook the waste gate up. Infinite boost on an untuned engine = BANG