Turbo Boost Cutout

Hi all, hope everyone had a fantastic New Years. Looking forward to meeting up again during 2012.

Quick question regarding the turbo boost cutout on a GTA turbo. Am I correct that this is a feature of the ECU on the GTA? and that it's set at 1.1bar? More importantly: is it A) adjustable or B) can it be bypassed in some way?

Many thanks!

It is adjustable on the 21turbo ecu, but I know i have a modded ecu for a gta so.it is.certainly modifiable. On the 21 its an adjustable potentiometer which needs to be adjusted using pressure to get it set accurately. Whether or not the GTA is the same i could.not tell you tbh

Si21

It is adjustable on the 21turbo ecu, but I know i have a modded ecu for a gta so.it is.certainly modifiable. On the 21 its an adjustable potentiometer which needs to be adjusted using pressure to get it set accurately. Whether or not the GTA is the same i could.not tell you tbh

Si21

http://www.renaultalpinetuningservices. ... +Upgrade+/


There is no bypass possible with the GTA .It is ECU controlled .
DG used to supply a ' fudgepot' for the MAP sensor output but that just fools the ECU and I would not recommend you go down that road .

I believe it is all mechanical on the GTA, with the actuator operating at a set pressure.

It is definitely adjustable though with some aftermarket bits. A manual adjuster screw or an more elaborate electronic device that I forget the name of. Seen them both in action on Mr Miles's car.

Edit: clee posted while I was typing

Yes ,you can up the booooost by those means but it does not alter the fueling or timing ....
Wind the actuator arm in or put a bleed/dawson's device on but ....

Lee, totally agree, I think you just type a lot faster than me.

I type a lot

Dave is/was running Adaptronic so his setup is programmable and perfectly safe to play around with .
I'm not scaremongering but with these engines now being over 20 years old and from what I've seen starting to look it ,careful thought should be given before upping anyting innit

Okay, so more explanation needed for clarity.

After 12 months of ownership, I'm getting that need-more-power-scotty feeling Been looking at all the options (reading a LOT of past threads on here): intercooling, bigger turbo, aftermarket ECU, methanol injection, etc, etc... will definitely be doing something this year, but in the meantime a quick/small fix was needed.

Boost-o-matic was only showing 3/4, so I fitted a boost gauge, and a Dawes device (R-Spec) so I could wind on a little more. She's boosting 9.5psi with slight spiking to 10.5, but if I wind on anymore then she hits the brick-wall of the over boost cutting in which is odd because the overboost is supposed to be 1.1bar right?

Thought I'd heard/read that the cutout could be adjusted/modified/soldered/butchered in the ECU or summet?

That is the pot wired into the map sensor input .It fudges the input voltage to the ECU so it thinks it's getting less than it is and you can run more boost .

Overboost is set in ECU so if that is what it is then that is it .I don't know where the 1.1 bar figure comes from , probably folk law ....

So I need one of Lee's super chips then...?

Yes. Or the stand alone management route.

I've been through most of these options. PM me your number and i'll give you my take on it if that helps.

Max boost on a GTA, according to the factory workshop manual, is 0.8 BAR +/- 0.5bar.
So 0.85 BAR max. (12.3 psi)

This is what i had mine set to, and Clee suggested not to go beyond that, so i didnt.
Dont think the PRV responds well to throwing on more boost anyway, you just generate more heat.

Ok the standard GTA Turbo has a boost limit built into the ECU. It's supposed to be set at 0.85 bar but in my experience it does vary slightly from car to car. The ECU can be modded with a piggyback that removes this limit. With this out of the way you can raise the boost as much as you want. Standard injectors will run around 1 bar before going lean. The standard turbo is very small too and therefore gets very hot if you increase the boost too much. On a standard engine my recommend mods would be the piggyback mod and raise the boost pressure 1 psi at a time (using either a simple mechanical bleed valve or an electrical one if your feeling flush) on a rolling road until they say its running out of fuel. You'll get to about a bar without any problem normally. This should see a 15-25 bhp increase depending on engine wear and what your turbos like. You can nick another 1 psi boost increase if you increase the fuel pressure using an adjustable regulator. A 5 GT Turbo K&N air filter drops in the standard air box for a few BHP. An decent exhaust will net a few more. Then you start talking big money - turbo, injectors, intercooling and ECU all need changing to go beyond this level - Approx 230 bhp on a good condition engine.

[BIG_MVS]

Didn't the Brodie Britain (BBR) ECU "Chip" do this from memory? I.E Increase the boost and overide the cut out?

The Superchips one didn't do a lot so I have heard apart from relieve you of your hard earned back in the day

Mr or as I now call him DR Faulks will be able to tell more as he has had most of them apart.