iain atkins

Hello,

Just wondered if i can grasp some help.

UK 97 (the one with the straight intercooler - facelift) with FCD (defending from 3.54v to 4.20v) 1.15mm restrictor, decat, induction etc, afr meter (always rich on WOT).

Basically i'm trying to eliminate boost spikes etc. Car holds 17.5psi in 5th and tails off to 15psi at 6,250rpm. The downside is that occasionally it will spike to 19.5psi and then immeadiately drop back to 17psi then build in the last 0.5psi. I'm gonna try a 1.5mm restrictor in the bleed off side of the control solenoid (2-port) to try and control the spike.

Is there any other way i can get a held 17.5 without spikes (apart from different ecu's etc). When i sort my funds i'm gonna go Link ECU, but for the moment i want control with the present ECU.

Would raising the defend point from 3.54v to say 3.6v help the spiking?

I will e-mail you my phone number, as i'm trying to get an answer soon.



Iain

iain atkins

Anyone else help???

The restictor in the bleed from the control soloneoid (back to the main inducion) helped a little, but its still spiking like a spiky thing grrrrrrrrrrrrrr.

I have tried the 1.2mm (standard restictor) and without the second restrictor in the bleed off side it was spiking up to 20psi at 3750 WOT in 5th - not good. I have now got the spkie down to 17.5psi and its holding 16psi, and it feels flat.

This spiking stuff has only just started to happen, up until yesterday it was going up and holding a perfect 17 / 17.5 psi, with very little overshoot.

I have cleaned out the control solenoid and pipework with carb cleaner, and it was only very slightly oily. This still hasn't rectified the problem.

It's no colder than it has been of late either.

Getting frustrated,

Tired etc. . . . . .

Cheers



Iain

PS, I do have a dawes, but i'm reluctant to take boost control away from the ECU, incase of det etc.

iain atkins

Oh and i have done an ECU reset as well, and adjusted the defend zone up (which has helped a little)

john banks

Go for the Dawes and use a knocklink. Or use an adjustable restrictor valve, but with a 2 port solenoid you will never get the boost control quality you are expecting.

iain atkins

thanks john,

i do have my dawes, which i've never fitted.

I know the fueling is ok @ 17.5 psi held in 5th, and there is no knock (borrowed det cans), so shall i set it to say 17psi?

Cheers



Iain