stevieturbo

Yea, but if you put a softer spring in, and have access to both ports independently, it will give you a wider range.

71 chevy

iTrader: (18)

Stevieturbo's suggestion is a good one. Use a softer spring, mbc on top port, and another mbc on bottom port.

If you apply full pressure to the top port and none to the bottom like you are thinking of doing,I bet you overboost the engine. You'll have spring pressure plus boost pressure pushing the wg closed but only exh pressure pushing open.

Forcefed86

iTrader: (4)

Righto I got it. Hadn't planned on putting full pressure to the top. I’ll leave it as I have it hooked up now. Top port will have the manual valve in the car controlling the amount of pressure it sees. I’ll start with no pressure to see what the spring alone nets me. Then I’ll add as necessary.

Thanks all. I’ll give it a go as soon as I can. Unfortunately it looks like 5 days of thunderstorms here.

Forcefed86

iTrader: (4)

Took the lightest of the 2 springs I had in it out. 9lbs of fury... Still pretty quick with 12* of timing and high 10 AFR's, but no more tire spin. Need to dig through my junk box to find a vacuum relay and wire up a block off for the lower port.

Somewhere in mexico...

rotary1307cc

iTrader: (5)

You would be surprised what a controller with ramping abilities with do for traction

100 dollars says it would hold 25psi on the street if you brought it in over a couple seconds

silver_82

^^^ yeah you would be surprised. Were up to 21 psi on a friends 275 radial street car and its totally manageable. Boost by speed/gear/rpm are all things that make it possible. I know you don't want an elec boost controller but man they are nice

stevieturbo

Another simple on/off or open/closed manual valve will do fine

Forcefed86

iTrader: (4)

I'm sure I could, not making near the power some folks are and I'm on larger tires than most too. (295/55) I have no desire at the moment to run more boost on the street though. This things enough of a death trap as it is. I use the boost compensation tuning deal. Just wanted to make a clean pass so I could adjust my fueling without traction issues. If I dial in the low boost, it's usually spot on when I turn it up.

Until I start spinning at the track, i'll hold off on the big boy BC. May break down and buy one later on...

thanks all...