8cd03gro

Ok so i was talking to droptop at the meet tonight about possible ways of getting more low end power out of the centrifugal blowers. I talked to him and a few of the other guys about some boost control type setups i have seen from guys with camaros with centri's, and while driving home i really started to think about a way of doing this without spending an insane amount of money. Of course NOBODY absolutely NOBODY should attempt this without talking to a professional, because obviously i am not one, but it is a rough idea, and i really think some of these would work.

OK, so let's say you want to run 12 psi because you don't feel safe going much further on the stock engine, but you want more power down low. A smaller pulley will make boost faster, this is a fact, but a smaller pulley will also make more peak boost. The idea is to bleed off some of that boost in the top end, so you can use the smaller pulley and make boost faster, but make the same amount of boost at peak, so it is not significantly more wear on your engine. There are a few ways you could do this that i think would work.

1. Setup a wastegate, diverter valve or something similar between the blower and your TB. Set the spring tension so it bleeds when you reach 12ish psi on the blower ( this would take some time to get working properly). Some things would have to be taken into account when you are doing this, like compressor surge problems, the maf-s going crazy, etc. But it definately could be done.

2. Another way of doing this, which would probably be better, especially with maf cars like ours , but would be more complicated would be to have a butterfly valve BEFORE the blower and BEFORE the maf-s. This way, tuning would be considerably easier. You would have to set it up somehow to open up and flow more freely in certain situations and it would take alot of work/design time/money to do but is definately doable.

Now i don't know exactly where the safe limits of the certain ati and vortech head units are, but i know some people are running quite a bit more than 12 psi, so there are smaller pulleys that will not over-spin the blower. If you were to use, say a 14 psi pulley, with this kinda setup bleeding boost or limiting it at 10 psi, you would probably be able to run with or faster than a car without this kinda setup running 12 psi because all the way until the very high rpm's you are making more power. let's discuss boys and girls!

rmays06

Once again Clay over my head....lol nice idea thou!

8cd03gro

well since there is no input from anyone except ron so far, i will just keep talking hahha. I found that rebecca of vmp tuning's car is running the vortech at 15psi, and making just under 400rwhp and justin thinks there is considerably more in it. If you were to do one of the previous setups i talked about with the 2.62" pulley (15-16 psi) and bleed off after 12, you would have relatively the same torque curve as the car just running the 2.62 normally until probably 5k-5200 rpm's then you would kinda go flat. rebecca's car puts down 300 ft lbs to the wheels at just about 3k rpm's and it climbs very steadily. you would have to talk to justin about his opinion on running the 2.62 on the v-2 head unit, and this is ALL just speculation, but if anyone is interested, i will help them do the research for this.

rygenstormlocke

Rebecca's car is 400rwhp on race gas. Just an FYI.

As for your idea, I know on my setup, the addition of the boost controller changed my power band, and actually allowed me to build boost sooner. I heard of SC's with simular setups, but not sure how streetable it is. One thing we have yet to see is a Centri with 4.30's. Centris love tall gears, and that would definitely get them out of the hole. If I had a centri, I would be running centri cams and 4.30s on a beefed up 8.8. Jmo.

beaustang

This sounds like a much cheaper and efficient (and safe) way to accomplish this goal.

8cd03gro

i dono about that...the gears yes, but the heads/cams are not at al cheap.

rygenstormlocke

LOL, I didn't say it would be cheap. But 4.30's on a centri, I'd do it. Just run a tall tire on the street.

8cd03gro

haha i know, beaustang did. What im talking about would cost you under 500 bucks completely done if you know what you are doing.