Boost Spikes Overboosting

[BMWHATR]

I just installed my blow off valve (forge) and i started to get a wierd boost spikes. I am running stok 11psi and when i floor it it goes all the way up to 19psi. WTF? at first i thout it was my gauge but after puting a new one still dos the same. Don't know what too look for plz help

 

[JBeclipse1]

do you have an exhaust?? or any other mods?

 

[BMWHATR]

Yes i have a 3" exhaust with no cat. i also had a boost controler withch i disconected after the boost started spiking up.

Ok today i was driving down and i went throu my 1st and 2nd gear and the boost first jumps up to 15-16psi and then like a sec later goes to 12psi. I have been told that it could be my Stock blow off was bad.

But i just want to know if any one els has a problem like this.

One thing dos anyones turbo wines in the morning when u just start the car for about 5min till it gets worm?

 

[Parsalian05]

wait, i thought you said you installed a new bov? if you still got the stock 2g bov, lose that thing . you also said you took off the MBC? im guessing you tried messing with it before you took it off? i just need a little more info and i can help ya out.

 

[phatTSi]

What hes saying is that he replaced his stock bov with a forged motorsports bov and he started spiking. When he had his stock one on it dind't do this and hes being told its doing this now because he has a good bov on and isn't leaking as much, or atleast thats how i understand it.

 

[BMWHATR]

What hes saying is that he replaced his stock bov with a forged motorsports bov and he started spiking. When he had his stock one on it dind't do this and hes being told its doing this now because he has a good bov on and isn't leaking as much, or atleast thats how i understand it.

YEAH thats Corect but i still don't understand why i have the boost spike? and is that normal or not?

 

[kyleporambo]

Yes I also have a bad problem with spikeing.
When I installed (correctly, I triple checked) the mbc and set it good (the lowest setting, again triple checked) it boosted up to close to 20 psi on a
2g gen tsi fwd automatic
2.5 inch turbo back exaust w/o kitty(catilitic converter)
ebay open air filter
on a t-25
rewired fuel pump
[edit]
oh I have a 1st gen bov too
[edit]
(thats it)
and the booost would not come down it just kept rising and rising.
But when I hooked up the stock boost control solenoid it regulated it to 15.5 (where I want it).
Could it be the mbc it was a ebay special?

 

[BMWHATR]

The problem is i took off my boost controler and its still pushing the boost. i am runing it of the vacuam line rgith now and still boosting about 12psi staddy and about 16 psi when just starede to wind up then it droops

 

[unior]

your running straight to the wastegate from a boost source and it still spikes that high?

WG actuator stuck or something?

 

[BMWHATR]

your running straight to the wastegate from a boost source and it still spikes that high?

WG actuator stuck or something?

Yeah it weard check the wastegate and its fine kind of hard to open it with my hands but it opens. some people told me that cuz my old blow off valve was leaking and u see BIG difference. but still will check evrything as soon as the car gets cold

 

[unior]

one thing you can do is rig up a bicycle pump or air compressor to the WG actuator line

once you hit 10-15 psi that thing should open up and you should see it move - then go back to its restful state when you let the pressure out

double check those vacuum lines to from boost source to wg also - make sure there are no leaks in those lines - or it would be like running your own custome boost controller

 

[4Restore]

Boost spikes are often caused by using plastic connectors to join vacuum hoses together being to restrictive (metal ones have thinner walls). Check any couplers or tees to make sure you are getting the needed quanity of air quickly enough. Pressure isn't everything, you need a certain volume at that pressure to fill the actuator. If it fills too slowly a spike will occur. Keeping your hose as short as possible will also help.