help supercharger with wastegate n boost controler

[srt-4 8u]

I see on a centrifacal supercharger lets say u have a 10psi set-up on a 98 cobra, boost will start 1-2psi and slowly climb to 10psi at redline. so if u change to a smaller pulley lets say 20psi, add a wastegate w/4psi spring and a boost controler ( or electronic boost controler) so u could run any boost you want, 4psi for gas saver. 10psi for all out, and 12psi if your filling lucky.

So by putting a 20psi pulley on, wouldn't you create much more psi at a lower rpm. As the rpm cilmb the wastegate n boost control keeps u at 10psi.
Giving u a much better hp n tq #'s across the board.

I see lots of centrifacal supercharged svt's on here, and don't read anything about using a wastegate and boost controler to bennifit from more boost down low and the control over boost (for example on the street launch on 4psi for 1st gear then go to 10psi for 2nd gear)

Why is this not allways used, are the bennifits not worth the cost. is their something im missing. if intake air temp is a issue then you just add a intercooler, any help would be appricated

 

[69gt4speed]

Been talked about before, u would need a blow thru maf setup. That way u can dump extra boost before the maf and the engine won't know anything but final boost/flow. Otherwise u feed hot air back in before the maf if a drawthrough setup. Might need a 360 deg sample maf or that new maf out though. Imo blowthru maf is better on higher hp w turbo or big centri. Unless u use a fast/aem etc. ecu w a map system. Eliminates a maf sensor. I'd go blowthru unless u have $$. Now some might say mo hp drain but I say mo overall pwr under the curve imo.
Based upon my experience racing them (mostly 2v) 10~12psi the traction isn't that much a issue w a centri compared to a pd on the streets w crap tires. They just rev it higher off a dig. Be nice to adj. though imo. a extra feature to cheat with bottom line. How many times has a turbo 4 guy said 19~20 psi, u smell race gas and figure 24 psi at least?

 

[THAITED]

I'll be doing mine soon, I like the idea that you can adjust the boost.

 

[97samssnake]

I thought that centri. blowers didn't make any boost down low though? So you couldn't exactly force it to make boost, could you?

 

[LS1PUSSOUT]

it still needs the centrifugal force behind it to make boost theres no way of getting around that. Adding a small pulley will only ramp up the boost faster once it comes on. The wastegate keeps it from pushing more than the set amount. You have to be sure that you dont push the impeller speeds faster than whats recommended though. The idea is to max out boost pressure at the lowest rpm possible.

 

[98 Saleen Cobra]

Suscribed I have never heard of this, and I would be interested on how it works and how much money...

 

[CntrySVT11]

there was an article on this in mm&ff a while ago, very interesting read. They did manage to increase the boost response, pretty sweet if you ask me.

 

[IUP99snake]

I thought that centri. blowers didn't make any boost down low though? So you couldn't exactly force it to make boost, could you?

Force it to make boost? what do you mean?

You're right, the centri blowers DON'T make that much boost down low. Say you want 10lbs of boost, but the centrifugal blower only makes that at redline. At 3000RPM, you've only got 4 or 5 lbs of boost. Say, you want to keep the 10LBS of peak boost, but want more midrange power, you could theoretically install a 20LB pulley, (which would make 10LBS of boost at a lower RPM), and bleed off the excess boost to make a continuous 10LBS of boost throughout the majority of the RPM range (much like the boost curve of a postive displacement blower). With a boost controller, much like a turbo wastegate which bleeds off an adjustable amount of pressure, you could even control your boost on the fly.

The only problem I can see running into would be with the parasitic losses at high RPM. The blower would be consuming the same amount (or close to the same amount) of power, as if it were making the peak boost the pulley were designed for, although you'd be be bleeding some of it off.

Homer

 

[IUP99snake]

there was an article on this in mm&ff a while ago, very interesting read. They did manage to increase the boost response, pretty sweet if you ask me.

http://www.musclemustangfastfords.com/tech/mmfp_0708_vortech_centrifugal_supercharger_wastegate_install/index.html

 

[LS1PUSSOUT]

heat becomes an issue with high boost on those smaller blowers too...

 

[01greycobra]

i never heard of a boost controller for supercharged cars.....i always though it was just for turbocharged cars.

 

[IUP99snake]

I'm planning on reducing the pulley size on my procharger from 4.0" to 3.1, but I don't want to exceed 10LBS of boost.

I don't think I need a fancy boost controller, and wastegate, just an extra bleed valve that begins to open when 10PSI is reached. Does anyone know where I could find a basic bleeder valve that would have the capacity of venting off excess boost?

Or, is there anything I could add to the vacuum line to control my existing BOV?

Homer

 

[THAITED]

It's actually works. I read about it on MM&FF. The idea is to use the smaller pulley to get the max boost out of the centri-blower then control it by Boost controller and wastegate. So your max boost is 27 psi on Paxton Novi 2000. You adjust boost to 16 lbs via the controller for street driving/pump gas. The boost will bleed off as soon as it hit 16 lbs or what ever your boost set up to. This way the boost will come on sooner so your car feels like twin screws. BTW you can adjust the boost to max psi with the boost controller and run race gas at the track so more power to the people. I just don't have any money right now otherwise I would get it done already.

 

[albino96]

Sounds awesome. The only problems that I see are the excess parasitic loss as mentioned earlier, and the blower won't last as long if it's running 20 psi vs. 10. For a street driven setup, I wouldn't go too crazy with it, but it is an awesome idea.

 

[thomas91169]

i never heard of a boost controller for supercharged cars.....i always though it was just for turbocharged cars.

they are basically using a wastegate and boost controller to bleed off excess boost. kinda like how a wastegate on a turbo reroutes exhaust gases around the turbine instead of through once a desired boost level is achieved, and continues to reroute gases to maintain a certain level.

you run a smaller pulley to multiply the boost levels to bring on boost sooner but you have the gate to bleed off boost once you reach a certain level. however like someone stated above, the parasitic loss of a centri spinning at xx psi when the motor is only seeing xx psi may be slightly counter-productive. however its a good little doo-dad if you can make it work, you can get the midrange power of a Roots/TS blower but get the pull up top of a Centri.

 

[Helomech74]

There is a guy over on modfords that just did this and his car makes pretty damn good power. He has a video with it on the dyno and plenty of pics as well. I think it's a great idea, and if you did this with say an F1 blower or something it would boost up pretty damn quick because of step up ratio and running only 20psi on it isn't even stressing it at all. I had thought about giving this a shot since I have a couple of wastegates in the shop from a couple of old turbo setups. I just need to get the blower. I don't want to try this with a P1.

 

[98 Saleen Cobra]

Bad ass I want to do this now... We will have low end torque finally!!

 

[Cobra Was Here]

It sounds like an awesome idea, but how much extra load would it put on your belt system? Also, won't your blower overspin or just wear out quicker?

 

[97samssnake]

Ok, even with this set up, would the centri blower make any boost below 3k rpms? And for those of you with centri blowers pushing 20+psi, what kind of boost are you seeing at or below 3k rpms?

 

[albino96]

It sounds like an awesome idea, but how much extra load would it put on your belt system? Also, won't your blower overspin or just wear out quicker?

Biggest problem IMO. I guess you coudl run an F1A or something that can take the high boost like that, but they are expensive. On a DD car I wouldn't want this.:read: