Hey everyone! I have a boost issue! FD is pretty much stock besides intake and exhaust. Here's my problem: When I WOT in individual gears eg 2nd gear, I will spike to 14psi for a split second, then it will go to 12psi, then by the secondary turbo its drops to 5psi.. this happens in WOT under any gear (without changing gears), but when I WOT (changing gears) such as 1st to 2nd I see no more then 10psi holding strong, even secondary turbo, although it does take a slieght moment to hit full boost, but i'm not worried about that! Anyone have any ideas? I do have a manual boost controller but for some reason don't think its working... so if anyone could let me know how its done correctly to insure its correct would also be great!!! Thanks in advance!

Edit: As for my boost controller. Its a turbosmart boost controller with the two nipples and nozzle to adjust the boost. At the moment, i've got it connected between the wastegate actuator and the nipple it orginally comes from. So from the nipple to the boost controller (in) and from the (out) of the boost controller to the wastegate actuator... hope thats correct... but nothing... and i've tried swapping position incase the (in) and (out) were the wrong way around and nothing... i've also blocked off the other end of the wasgegate actuator... is this correct? or totally wrong!? Thanks guys!

 

I forgot to mention that If I were to WOT in first only (without changing) I see 10psi but then drops to 5psi as the secondary kicks in... so no spike in first... but every other gear if only WOT in that gear...

 

It sounds like you have the controller working ok. Keep one end capped. Direction doesn't matter - it works as a restrictor, not a check valve.

For the boost problem, I assume you're sequential? What is controlling the precontrol?

What you're saying about different boost patterns depending on the situation, would it then be true that you only get the 12-14-5psi when you start your pull below 4000 RPM? If you go to 8k then shift you'll start pulling the next gear around 5krpm, and get 10psi all the way. Is that the same as when you shift at 6k and do the next gear pull from 3.5k up?

First address the 14psi boost spike. This is dangerous.

Next address the 10-8-5. I suspect if you change your turbo control solenoids it will solve it.

 

yes I am sequential. I haven't touched the precontrol. It is true that it only occurs when I start my pull below 4000 RPM. If I shift at 8k, I will get 10psi, and if I change at 6k I will also get 10psi but if I change gears at 3.5RPM I will spike to 14. I did notice while checking my boost controller that my hose was actually pressed up against something therefore blocking the hose, so i'll fix this and test it again and hope this will help.

I know that 14psi is very dangerous, I was obviously spiking before I got a boost gauge which was a year after I purchased my FD and nothing has happened as of yet (fingers crossed) thats why i'm trying to deal with the problem!

Edit: Even though I spike, I do not hit fuel cut, hope that helps also.

Thanks dgeesaman!

 

Ok... took my FD for a drive... at 4000RPM in second, I started pulling, hit 10psi and straight away started to decrease to 5psi (turbo control solenoids) but didn;t spike... but if I start the pull earlier then 4000RPM it will spike to 14psi! (even after the change in hose for boost controller) Any ideas!?

 

Bump!

 

Bump!

 

I would take out the solenoids and test them - turbo control, charge control, and charge relief specifically.

You can also tee into the turbo control lines and observe during driving to see which of the solenoids is not opening up at the right times.

Dave

 

Hey guys, I thought I would bring back my old thread instead of starting a new one! I've replaced my check valves with VITON check valves, boost is fine, I get perfect pattern but I still get a ot of lag when changing gears. It takes a while to build boost. Now, what I did notice when I was replacing my check valves is that the check valve leading to the double throttle I beleive was blocked off? COuld this be the problem? THanks guys!

 

Bump!