Having 2 problems here. The car is equipped with a GT35r on a stock block/head with the stock metal MR BOV. When driving on the highway in 5th gear during light/part throttle movements I'm bucking a little.

I 'think' it's due to the BOV being too stiff to open up enough at part throttle and let the larger amounts of air the 35r produces back into the MAF pipe. Does anyone else have this problem?

My other problem, which I don't think there is an easy solution for, is compressor surge in 5th gear. It seems the stock head doesn't like to flow the amount of CFM a 35r puts out at only 3500 RPM, lol. My compressor cover is the 'type S' with the ported shroud but it still surges. I was thinking of upgrading to an electronic BC so it will only let me boost x psi by x rpm. That way in 5th gear I could smash the gas and not have to worry about pedeling to get around the surge like I do now. Anyone have have any more input?

 

You could upgrade your compressor housing to the anti-suge .70 AR. I have it on mine and there's no surge in 5th at all.

 

that is the one I have....

 

fwiw,



could you be running a little lean at part throttle, cruise? a lean car will buck in light throttle.

 

Lol, sorry...reading skills for the lose. For some reason I thought I saw pics of your setup and you had the drilled housing. Maybe upgrading your cams will be all the flow increase your setup needs to keep from generating surge.

 

that is the housing I have. I thought thats the one you were talking about.

 

No, thats not the housing that I have. I have a 35RLSP, the compressor housing has actual surge ports.

 

Both housings help to fight surging. The one with the slots is supposed to work much better than the bullet style porting. So your givin it another shot huh? Glad to hear it .

 

I have the same problem. Bad bucking in 5th @ part throttle. I think my BOV is a B!#*%.

 

There are only 3 ways to really stop the compressor surge in high gear:
1) Dont try to floor the car at low RPM in that high of gear
2) Put a larger turbine housing on the turbo.
3) Try to "clean up" the route for the air from the compressor outlet to the intake manifold. Any restriction in this region will make your car operate closer to the surge region.

 

You forgot one very important cause . . .

Many reported surging issues are caused by tuning issues, not hardware issues. Many of us running similar setups have no issues at all, despite having virtually identical hardware.

FYI

 

Always in boost,

Aren't you running with no MAF screen?
.

 

I have been running w/o a screen for about 2 weeks now. I'm trying to find a MAF in decent condition but not having much luck.

when I made this post though back in mid Oct my MAF was fine.