okay, so this is my final post about boost. Is there anyone that have had this or has this problem....

(please dont tell me my boost controller is set to high because it is not)

I have a log if anyone wants to look at it

First Senario:
Soo... I launch the car hard off of 2 step, first gear its peaking 20 ish holding like 19 to 18 shift hard into 2nd gear and pow hits about 21 holds about 18/19 to redline... same for next couple gears... Boost is hitting target, and holding fairly close.

second:
driving at or around 4500/5000 in any gear 2,3,4,5 and throttle it hard... Boost hits just about where it was in the first senario, and holds about the same also..

final:
Driving at or around 2500rpm in 2nd,3rd,4th,5th gear... If i throttle it to the ground its boosting around 26/27 and dropping off to about 18/19 fairly fast blowing my UICP right off of my throttle body..


No matter where my MBC is set, it still is spiking EXTREMELY HIGH and FALLING off fast.. I switched between 3 MBC's in the past 2 weeks (turbosmart, slowboy racing, and turbo XS "w/bleeder) and so far the Turbo XS did the best, but the turbo smart did okay for the money...

Questions...
1) Do i have possibly a boost leak?
2) Is my wastegate bad?
3) if there is a hole on my soft pipe, would this be the result of it?

 

It's never a bad idea to do a boost leak test, but it sounds like your problem is compressor surge, especially since you are running a MBC. There's really no way to fix that, aside from buying a ported turbo or a FP Green/20GLT.

 

Question though, why would it all of a suddon start if thats the case... It was fine after my tune, and i had no issues until i put a different FMIC on there, and took it back off. Thats why i think its a boost leak maybe, because i did play with every hose and connection.

thanks for the info

 

if you put a fmic on and the spiking started to happen why not do a boost leak test before even making this thread if you yourself stated you thought it could be the problem?

 

check your ebay 02 housing...

 

Your scenarios are what you should expect. You only see peak boost when rolling into boost from low rpm. Launching and rapping through the gears or punching it from 4500-5000rpm (way after peak boost hits) will never show your peak boost. You only see it when rolling into boost from below the peak boost rpm.

That being said, it makes no sense that you can't get the spike to go lower by turning the boost down. It also makes no sense to use those 3 MBCs. Why would you use those 3 instead of MBCs known to work well like the Hallman or Forge? Both the TXS and Turbosmart are very poor MBCs. I don't know about the Slowboy one, since no one uses it, but it's likely just a generic one that isn't as good as Forge or Hallman.

Regardless of all that, it could be a damaged wastegate, I suppose, but the boost should definitely go down if you turn down the MBC...

 

its your fuel map its got a nasty hole in it . tune the nos timing you'll run 9's









good luck with it eric if you need a hand to wrench on it bring it down my house man i will help ya as much as i can

 

Not as easy as it sounds lol, my dumb *** buddy was comparing inlet sides of our turbos when i did my manifold and 02 housing.. he then put the hose back on flipping the clamp so that it is virtually UNREACHABLE to get the clamp off of the turbo inlet side. (its facing down like directly on the bell housing or whatever) i want to send him anthrax through the mail, but decided against it.

 

Okay so i dont sound stupid, i originally had the SBR MBC on the car, it was tuned like that and had absolutely no issues. After clutch install i put a fmic that didnt fit and had issues with it feeling wacky ever since. (even after the reinstall of the stock fmic) In the mean time i switched out my buddies TXS mbc with mine and it felt better.. (so i thought) thinking it was then my MBC i purchased a turbo smart one (which i was told has very good quality) and it seems to be just about the same....

I am hoping i dont have a damaged wastegate, and i was hoping there would be an easier answer to this, but in reality it looks like i am going to have to yank that whole section out and see what i can do (didnt want to unless i purchased the evo green, and dont wanna blow the cheddar on it right now)


Time to either make a boost tester, or schedule an appt.

 

ebay 02 housing? Its a DNP

Could a crack in manifold or 02 housing or anything of that sort resuly in whats happening?

 

simple advise...boost leak test and get a hallman or forge mbc either one of those are the most common and best in my opinion

boost leak test should help you out though...it can't hurt

 

No!


check for boost leaks and all connections!

 

here is my log from a recent run in 3rd gear at 2500 rpms
My peak load is something like 350 or some crap like that.

Anyone want to put some input behind this...

 

you must set your boost in 5ht gear you roll on the boost start at 2500rpms in 5th gears then you floor it to whatever it spikes thats the boost you are runing if its a higher boost turn down the boost controler and try again the same way

 

Ok so I see a couple of issues, most of which were addressed with Warr's post....

(1) If you are hitting 21 psi during your 2 step (so first gear), then your real peak boost will be more like 25 - 27 psi which is what you saw in your 5th gear 2500 rpm WOT pull...

(2) The fact that your MBC is not able to dial down your boost helps narrow the problem...

IMHO you either have:

(1) A problem with your MBC -- either the spring is too stiff or the MBC is not working...I doubt this is the issue, but it could be...

(2) My guess is that your WG is not opening or is only opening partially. Have you connected the WG boost line (the one from your MBC that goes to the WGA) to an air compressor and determined what psi is required to open the wg (activate the arm)? If you cannot move the WG rod with 20 psi then you have a problem with your WG. If it does move, but does not fully extend, then you need to lengthen the rod by turning the turnbuckle...(Have you or someone else, shortened the wg rod, if so lengthen it such that it almost slips onto the wg.)

I hope this helps...