boost problems

[DCVING 6]

running on the stock chip, stock turbo, etc.

With the stock, uncut factory wastegate, I am running a rock solid 13psi.
I installed the BstC commander and took it out for some tuning. I would get the car into second and roll into the throttle and test the boost in 3rd. Got it to a steady 17psi in third. I mashed the gas from a 5mph roll and the boost gauge jumped to 20, so i lifted a bit. (only running 93 octane)
after the spike, it settled down to 17psi for 1st and 2nd, but once i hit 3rd, it went down to 13 and stayed.

 

[scottyb]

I've noticed some inconsistencies also, so I'm interested to see replies.

Regarding the spike, I have the same problem and no solution yet. I have been able to minimize if by turning the trigger up higher and rolling into the boost so that it's already building boost before the boost commander comes on.

 

[DCVING 6]

Hey Scott,
Are you saying you turned up the TPS trigger so the boost commander doesn't kick on until your spooled up?

As far as the boost dropping in third, I don't really understand. I always thought it was the opposite.

Maybe something to do with the converter locking up?

 

[scottyb]

Yes, I have the TPS trigger turned almost all the way up. I think I have it up so high that it's greater than the 75% required for PE mode and scanmaster record.

I have alcohol, so I've got it turned up higher and this is my setup:

WG adjusted for a base of ~14.
BSTC turned all the way up so I get ~20 on one solenoid.
When I make a run, I don't go WOT, but try for greater than 75%. The boost runs up to ~14, when it gets there, I mat it and it rises to ~20 when the BSTC kick in and I have minimal spike (maybe 21 or a hair more).

If I mat it without doing this procedure, then the boost will spike to as high as 24-25 lbs and settle back to 20 or so.

I have always had spike problems, and I have attempted several methods to control. This spike seems to get real bad whenever I'm attempting boost greater than 20. I have found no way to control. I know I can run 22 lbs with no knock, but I can't control the spike at that level. I have tried all kinds of crap, including grainger/bleeder/BSTC...etc. I've tried a larger oriface in the "y" connector, and it works well, but my adjustability is limited to the point that it is no longer useful. I'm not even going to start about the issues I have when I try a 2nd solenoid.

I honesty believe that boost ramps up too fast for the design of these control items. The only thing I have not done is port the wastegate hole, but that is typically done for boost creep and that's not my problem. I don't think it will help.

Perhaps a bigger, slower spooling turbo is the answer.

 

[jastrckl]

porting the hole also helps out with spike issues. Make sure all the vacuum hoses are good, no leaks or cracks. make sure the 3rd gear scaling dip switch is off or set appropriately. it normally DROPS boost in 3rd when this switch is on, by an ammount set by the trimpot on the back of the controller.