[matrix]

Im assuming the blower will mount on the right side of the motor where the AC compressor generally goes? That would be the deal breaker for me. I have smoothed my firewall, added a Vintage air setup, and have a sanden compressor close to the stock location. I would love a blower but cant give up the AC and therefore believe I am probably stuck adding a single turbo on the right rear side of the engine where the AC suitcase usually resides.

[matrix]

Ummm..... I just read the previous post that I had ignored because it had the word Ford in it. If I can keep my AC Im in. Would really like to see at least one picture.

[Tom Vaught]

The a/c kits is supposed to come first. The supercharger will be on the drivers side. Most of your stuff should be able to be used as is or modified slightly to work with the Supercharger kit as it was designed to work with Pontiac a/c.

You will be able to see pics probably in the next couple of months.

Tom V.

[Tom Vaught]

ttt

[opnwide]

I'm def interested. It'll be another 6-12 mo before the rest of my car is ready. I am also considering a rear turbo system by STS. I've got to have my AC in Texas.

[Tom Vaught]

The Centrifugal Blower system will work a lot better than that Rear Turbo deal. (I do Turbo System design for a living for Ford, lol!)

The A/C bracket system comes out first so you will be able to keep your cool in Texas!

Tom V.

[Pete D]

This centrifugal compressor topic has me curious. If you have a minute or three I was wondering if you could elucidate myself on some of the engineering trad-offs.

As I understand it the amount of air it supplies is a function of many variables such as blade pitch, RPM, inlet and outlet diameters, pressure differential, air density, differential temperature, parasitic power and so on. Given that are there tables or plots that show airflow as a function of the variables I mentioned?

I had read somewhere that centrifical compressors don't do much until you are in the upper ranges of RPM. Is this true? Or is it linear with RPM?

Is it possible to provide so much boost that the mixture ignites from compression regardless of the presents of spark?

Is the one you are talking about a "blow through" type? If so how do you keep the air pressure from pushing gas back out of the carb jets? How do you maintain carb calibration?


Hey, I'm just a curious guy. Thanks for a great topic!

[gregsgtos2]

check out this auction on ebay.i think you will all find it very interesting.230185575300

[Tom Vaught]

Gregsgto2,
why are you posting a ebay listing for some pontiac heads
in this topic?

Quote:

"This centrifugal compressor topic has me curious. If you have a minute or three I was wondering if you could elucidate myself on some of the engineering trad-offs.

As I understand it the amount of air it supplies is a function of many variables such as blade pitch, RPM, inlet and outlet diameters, pressure differential, air density, differential temperature, parasitic power and so on. Given that are there tables or plots that show airflow as a function of the variables I mentioned?"

Specification guide is shown here:

http://www.vortechsuperchargers.com/...ation%20Guides

Compressor maps are shown here:

http://www.vortechsuperchargers.com/...pressor%20Maps

Quote:

"I had read somewhere that centrifical compressors don't do much until you are in the upper ranges of RPM. Is this true? Or is it linear with RPM?"

Not linear. If you had 16 psi of boost pressure on your pontiac at 6000 rpm you will have 1/4 the boost or 4 psi at 3000 rpm. 4 psi at 3000 rpm is a lot more power vs a NA engine at the same rpm where an engine might have 75% volumetric efficiency.

Quote:

"Is it possible to provide so much boost that the mixture ignites from compression regardless of the presents of spark?"

If you had an engine with a lot of boost 30 psi, high compression, and low octane fuel you would suffer from very high cylinder pressures and hurt the engine parts. With a compression ratio in the 8.0 to 9.0 range and 12 to
15 psi of boost you will have plenty of power and should be able to run on good fuel without issues if you have the right camshaft event timing.

Quote:

"Is the one you are talking about a "blow through" type?"
Yes.

"If so how do you keep the air pressure from pushing gas back out of the carb jets? How do you maintain carb calibration?"

The fuel bowl is vented to the airhorn, same as the carb venturi. Pressures are balanced under boost same as a na carb. Pressure in the bowl is higher with boost therefore you need to have a fuel pressure regulator that has a boost reference line to raise the fuel pressure to the carb under boost. Stock engine you have say 6 psi in the line to the bowl. With 5 psi of boost the bowl will still see 6 psi after the needle and seat you now the boost fuel pressure regulator will raise the fuel line pressure to 11 psi. The fuel pump must be a high quality fuel pump designed for boost. For 6-8 psi boost a boost referenced mechanical fuel pump MIGHT work but much better to use a good electrical fuel pump.

Hey, I'm just a curious guy. Thanks for a great topic!

No problem.

Tom V.

[opnwide]

I was considering the STS system because it seems like a stealthy way to add some power. Run a factory style y pipe rearward to the turbo mounted in the old muffler location. Run the out pipe from turbo up the other side of car to carb. Two three inch pipes would look somewhat stock from underneath, unless the turbo was spied.

What are the downsides that you talking about, besides 8 psi at 3000rpm and 8 psi at 6000 rpm?

thanks

[PONTIAC DUDE]

Originally Posted by opnwide

I was considering the STS system because it seems like a stealthy way to add some power. Run a factory style y pipe rearward to the turbo mounted in the old muffler location. Run the out pipe from turbo up the other side of car to carb. Two three inch pipes would look somewhat stock from underneath, unless the turbo was spied.

What are the downsides that you talking about, besides 8 psi at 3000rpm and 8 psi at 6000 rpm?

thanks

How are you gonna drain the oil back to the pan from the turbo that low?

[6D6GOAT]

Originally Posted by PONTIAC DUDE

How are you gonna drain the oil back to the pan from the turbo that low?

i think they use some sort of sump and pump setup to get the oil back to the motor.

[Tom Vaught]

Quote:

"i think they use some sort of sump and pump setup to get the oil back to the motor."

The normal plumbing is a tube from the turbo drain to a small "box" sump that has two fittings. One fitting goes to the valve cover to provide make up air to the scavenge pump and also pulls a nice vacuum in the engine. The other fitting goes from the "Box" to the scavenge pump.

Any foamy oil from the turbo "takes a ride" on the air coming from the valve cover to the scavenge pump and is drawn out of the turbo.

Tom v.

[Pzary3233]

Tom,

Where would the Alt and PS pump go, or would I have to go to a manual steering set up?

[Tom Vaught]

If you will be patient for a month or so a magazine article with pics with address a lot of your questions.

Tom V.