Jacko

See its funny you say that because now that I think about it I no doubt have boost spike. But on the other hand i may have creep also, problem is its been so long since I drove the car I can't remember

dsddcd

This is not assoicated with the wastgates temperature it is actually Air Density. The duty cycle for the boost controller needs to be adjusted relative to air density which is effected mostly by air tempreature and altitude.

So what you are seeing is change in temperature under the hood which changes the density.

The only way to correct this is to setup the boost feedback using either the PI loop or duty cycle feedback in the AEM EMS.

JoeyBalls

[QUOTE=dsddcd,Nov 4 2010, 01:03 PM] This is not assoicated with the wastgates temperature it is actually Air Density.

Jacko

E Tune FTW

godmachine

I have same issues with creep on my full-race mani. Like someone else mentioned Tony has done a custom 60mm full-race manifold that held low boost like a champ.

Also talked to full-race themselves which gave the option of adding a 2nd flange/wg. They stated I would have to route it out the fender or some jazz like that so I passed.

My solution is race gas all the time

dsddcd

I comend you for looking for a solution, not everyone trys.

TRBOKEV

Jacko

I don't know if this is a stupid question but.... How does race gas fix the problem ?

Mijae007

I'm just going to add to this ancient thread. Kind of a long explanation so bear with me. I have a 3 port mac solenoid that has been working great for boost by gear on my flashpro. I had my frequency set at 50hz and had my boost duty cycle range anywhere from 20-40% ranging from a low of wastegate spring pressure of ~11psi to a high of 20psi respectively. It ran solid like this for quite some time until my tinkering-ass decided to mess around with the oil catch can setup.

Long story short, for my catch can setup I used to have both ports on the valve cover vented to atmosphere, then decided to run closed loop, ran into boost issues (with the catch can not sealing exhibiting symptoms of a boost leak etc etc), so then reverted back to the original vented setup but still having boost issues. Now, when i go wot it will hit target boost, but steadily drop down ~5psi by redline. I rechecked all my lines, thought I had a kink in one of the vacuum lines so fixed that, but still have the same symptoms.

I tried raising the boost duty cycle in flashpro, and it will initially hit a slightly higher psi but again drop 5psi or so then hold there up to redline...so changes in the tune result in very minimal change. It seems to hold the boost steady at or just 2psi or so above my wastegate spring pressure regardless of duty cycle % changes.

Are these symptoms of a bad solenoid?? It's just weird because of the timing of it. There was nothing wrong before i messed with the catch can, and now that everything is back how it used to be, the car is acting up. I really just need to stop messing with it... -__-

Mijae007

Okay, tinkered some more. First off, let me start by saying it is not easy to test for this on the street. Especially when boost kicks in hard and kicks the rear out while you're trying to monitor your boost levels. First advice, datalog and keep your eyes on the road!

Okay, so I had a feeling my solenoid was acting up because of voltage issues. Maybe the valve is getting sticky and requires more juice now to get it to open/close. I was sharing the 12v line with my turbo timer so I removed my turbo timer in case that was stealing power away from the solenoid. Now I can hear my solenoid working as I hit my target boost level: i can hear the turbo oscillating "wahwahwahwah" holding the target psi whereas before it would not oscillate and make just a "wahhhhhhhhhhh" sound gradually losing boost towards redline.

So...im going to conclude my problem is the solenoid going bad and a secondary issue of the 12v power source. I may need to relocate the solenoid someplace else in the engine bay as it sees a lot of heat where its currently located...maybe that contributed to it prematurely failing.