turboxs HPBC spikes

[95tsiawd_86]

i got my TXS high-performance mbc on my car and i cannot get it to stop spiking. and its a big enough spike to where its annoying. I have adjusted it lots of different ways and i am pretty sure i have it installed correctly. Anybody have this problem, if not how do you have yours adjusted? thanks

 

[phatTSi]

I used to have the dual stage and in my opinion it was a piece as well as most of turbo xs stuff. I would sell the boost controller on the trader and buy an xbc or a joe p.

 

[turbolarry]

I have the same one and it has never spiked, not with the t-25 or big t-28.

http://www.turboxs.com/HPBCinstallation.htm

 

[95tsiawd_86]

its interesting you should say that. i put a XBC from a friends car on my car and....go figure.....NO SPIKES. Might take that idea of selling it into consideration.

 

[phatTSi]

If i were you i would do what i did sell it on the trader and get a joe p. I believe that Import Evolution (site sponsor) is still having a special on the Joe P. its like 35 i think but if not its still only 50.

 

[VRMAN]

If it isn't spiking on your friend's car, maybe you should try to diagnose the cause of the spike instead of just selling it.

 

[95tsiawd_86]

VRMAN read post #4 more carefully

 

[LiquidGS-T]

^ , everybody says to eliminate vacuum lines as much as possible, i'm about to give this a try.

BUT, i had a joe p mbc on my 16g, worked great, never had a problem with it

I just recently threw on a T04B V-Trim, and the joe p can't control it at all. Same setup as the 16g, nothing changed, and now it spikes 26psi to run 15, thats horrible... I had to take it off. Still trying to come up with a solution.

 

[steel_3d]

Are you guys t-ing off the bov line or another manifold pressure source?
Try a bit lighter springs

 

[doug]

I prefer to go from the turbo's compressor nipple (if your turbo has one) to the MBC, then from there to the wastegate actuator nipple. If your turbo doesn't have a nipple on it, your IC piping might, so use that. Keep hoses as short as you can.

 

[steel_3d]

Going off the turbo nipple is what causes the spike. I know because I had it that way originally and it was spiking, but going to the bov line gave almost zero spike. What you want is a manifold signal instad of one close to the turbo.

The other thing this does is it avoids boost taper. As the rpm's increase the restriction in the intake tract increases. 15psi at the turbo nipple won't equal 15psi in the manifold anymore. So you set your mbc for 15psi, which you get at 3k, but by 7k you'll be getting let's say 13. The whole time the turbo nipple will be seeing let's say 16psi and opening the wastegate accordingly. But if you reference off the manifold pressure, it will always hold 15psi in the manifold, which is (hopefully) what your boost gauge is measuring.

I don't consider the length of hose to be relevant. I have like 8ft of hose coiled up for my boost gauge, and it still responds instantly to any throttle movement. I also never paid attention to the length of hose to the mbc, and I've never had boost spike issues on different turbos since I switched to the bov line.

You won't know till you try.