Brainf*rt......(m)

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Oct 23, 2001 | 05:39 AM

S4gasbord

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Brainf*rt......(m)

Has anyone thought of sticking an Eaton supercharger where the Y-pipe currently is? Then we could have a sequential super/turbocharged engine and the pressure ratio across the turbos' compressors would be much lower to achieve the same level of boost. Alternatively, we could achieve higher boost without working the turbos too hard.

The intake port of the Eaton supercharger is ideally positioned for the stock intake system to feed it. We'd have to work out a manifold to get the air out to the turbos though. It would probably result in a pretty ugly bump in the hood too. I think there is enough room between the engine and the radiator to puta drive belt in.

Is what I'm talking about sound reasonable or is it utter rubbish?

DISCLAIMER: This is a purely academic exercise from someone who obviously has too much time on his hands.

Oct 23, 2001 | 06:09 AM

Bat137

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Lancia used that setup back when Cheever was driving for them

But I haven't seen or heard of somebody using both on a modern car. Now we have electronic control and variable valves to take up the slack.

Oct 23, 2001 | 06:46 AM

S4gasbord

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Re: Lancia used that setup back when Cheever was driving for them

Yeah, that was my impression too after thinking about it a little more after posting. Lag reduction was not my primary motivation, especially not with K03s. It just seems like our little turbos are prone to failing as soon as we crank the boost up. On the other hand, a monster 2.7TT with huge turbos (T06s?) might benefit in terms of lag reduction. I'm rambling now.

Oct 23, 2001 | 08:15 AM

Pat-SoCal

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Sure.... if you want a microwave on your motor :P

If you're going to spend some time seriously researching this... don't use the eaton as a template. In my opinion the Eaton supercharger is the worst (besides kenny belle) supercharger on the market today. It takes the inefficient design of a [cheap] roots style blower, and puts it right over the engine.

I could go on ranting, but I'll stop with an example of why Eatons suck: Look at the S281.

p.s. whipples (the bigger cases) work good on towing applications, so I won't knock them for that. My dad's suburban runs pretty hard: 14:46.

Oct 23, 2001 | 09:04 AM

S4gasbord

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Errr... so are you saying we should use centrifugal compressors?

I'm not quite sure if I understood what you said.

I agree the Eaton supercharger is just a roots blower with a twist in the rotors to minimize the pulses. The only reason I started with that is because I might be able to get them cheap ;-)

I thought the whipple is better because it compresses the air within its own housing though.

Oct 23, 2001 | 10:10 AM

Pat-SoCal

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centrifugal blowers are the most eficient

...for their size. I think we can all agree that street blowers are the best for brute, full range horsepower.

Eaton superchargers are just not efficient. Consequently they produce mass amounts of heat. Not the best thing you want to be sitting on top of your motor.

In the S4's don't have a problem spooling up the two small turbos. Therefore, it doesn't make much sense, to put any kind of spool-up enhancing mechanism in the non-charged inlet air stream.

Suppose you DID put a blower on the car to help the turbos spool up. While the turbos MAY spool slightly quicker, the added heat from ANY blower would be enough cancel out any gain that a blower could offer.

Oct 23, 2001 | 10:25 AM

S4gasbord

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Ahhh... grasshoppa has seen the light...

My original thought was to reduce the pressure ratio across the compressors on our turbos so they don't die so quickly when running higher than stock boost.

Then I carried on thinking how we would put bigger turbos and the lag associated with that, but I forgot about the temperature rise. Hmm... air/water intercooler between the blower and the turbos? (OK, now that is just plain silly).

That got me thinking about the Whipplecharger and how it compresses within the housing so maybe it is a little more efficient than your average blower. I know centrifugals are the most efficient, but even belt driven ones have lag (a la Vortech).

My final thought evolved into replacing all that hardware with a nice simple N2O system, instant response AND charge air cooling.... which is what I was after in the first place..... shucks.