Has anyone tried running a smaller/low boost procharger on a bracket car, something equivalent to a 250 blower?

quote:

Originally posted by top189h:
Has anyone tried running a smaller/low boost procharger on a bracket car, something equivalent to a 250 blower?

Sure, belt driven. A friend bought a sbc kit, everything minus Blow thru carb, for around $3,500 I think.

He still hasn't out run my sbc n/a, his goal. I think he's been 6.08 @ 3200 lbs, 406 sbc on gasoline. Gasoline, really isn't the hot ticket ProCharger.

I don’t think it would work very well, at least not trying to do the same thing everybody else is doing where they take a 1000 hp engine and bolt on a couple hundred hp.

I looked into putting a small turbo on a Bbc to make a few psi of boost. It’s not really possible and the exhaust side wasn’t the problem.

A small compressor wheel on a big engine at low boost ends up way off the map.

A roots blower doesn’t really care what’s underneath. The less restriction a centrifugal compressor has, the more power it takes to turn.

For a procharger or a turbo to end up in that same ~1200-1300 hp range economically, I think you have to start off with a much smaller cubic inch long block.

Centrifugals are a little more efficient than roots all things considered.

I think we can all agree that a roots (or a variant of it) makes boost as soon as you open the throttle.

Centrifugals need RPM to make boost, and that fact alone can work for or against you. It has everything to do with the pulley ratio, gear ratio (in the blower itself) and the compressor wheel design. I've driven some street procharged cars that make boost off of idle but at are max blower speed by 5500 RPM, and I've driven others that were a little on the sluggish side down lower, but the more RPM you wring out of them the more power it makes-THOSE, are fun.

Turbo's, just real hard to get anything with a budget in mind, that will work correctly. Either too small or too big. There is a VGT (or VNT depending on the manufacturer, same principle for both), and that can certainly make up for a lot, however it hasn't gained a lot of steam with gas burners. Diesels yes but not too much with gas burners. Could be due to the higher EGT. Dunno. We tried one on a 2.3 Ford once, 28 psi at 1600 RPM and held it to the 6250 fuel cut, but it took a LOT of tuning, ingenuity, rigging, and frankly wasn't worth the aggravation. On that deal it would bend the stock rods.

speaking of turbo's I'd like to someday do a footbrake car with a turbo (or two), just don't know how to go about it-and still maintain consistency.