iain atkins

Hi just wondering if any techies can give me some pointers.

As per title i have a UK MY97 with John Banks' original design fuel cut lifter.

My boost appears to be spiking a little in 4th & 5th. I would like to run 17psi with hardly any spike.

As standard the car would spike to about 15.5psi and hold around 14psi. When i installed the FCL that turned to a 17.5 psi spike and 16psi held. I actually had a 18.5/19psi spike at one point in 5th (for a split second) and it then settled quite quickly to 16.5psi.

If i were to slacken off the actuator would this help reduce the spike or not?

I have a 1.2mm restrictor as standard and a 1.15mm and 1.1mm as well, but i don't want to use the smaller one till i can cure the spiking.

If i adjust the defend zone will this help?

Any comments


Iain

john banks

When you installed the fuel cut lifter and saw a substantial increase in boost that suggests that the restrictor or pipework was too small or restrictive for the breathing mods/turbo spool up speed/wastegate duty cycle map combination, and this is confirmed by it reaching 19 PSI. Slackening the actuator might help if it was tightened already. If not a larger restrictor would be better. In saying this I am assuming the setup on the MY97 is as the MY99/00 - I have not played at all or even looked at any earlier than a MY99, and I heard some of the earlier cars (MY96 and before?) need a restrictor size reduced in one of the return pipes off the 3 port (?) Not sure if this applies to your car or not. Whatever, the behaviour suggests the effective bleed off is too high for the boost you desire.

Making the start of the defend zone earlier may stop the ECU pulling back the boost so much - ie same peak/held.

iain atkins

Thanks for the reply John.

I can confirm that the restrictor trick is the same as the 99/00.

I have just remembered that i bought a flow control valve from pipemore when you reported on your experiences of it. The only reason i stopped using that was because the valve was heavy enough to cause the boost control hose to kink causing wild overboost.

I might try and get some stiffer hosing and then try with the flow control valve. Problem is the samco stuff is too bendy, any suggestions??


Iain

john banks

Stiffer stuff works very well. No suppliers that I can suggest. I beg for it and am running out fast.

Scott.T

iTrader: (2)

Glad to see you got it in and working then Iain.
I'd go with slackening the Actuator a turn 1st, as I know that I had large peaks when I tightened the Actuator B4 I fitted the FCD.

For your info my MY94 doesn't peak at all, but then the Actuators only set to give me 15psi at the moment.
Also I don't beleive the restrictor on Pre'96 (which is on the Bleed side of the 3-port solenoid) makes much difference, as in the past I've run without that hose connected an no difference was noticed.