Supercharger engine setup

[whodwho]

Here was a dyno sheet from a dyno day that I went to just days after swapping out an auto trans and swapping out #19 injectors for some #28 because I was maxing out the 19s(using a RRFPR) so this was only a require fuel change and not retuned so it was getting into untuned territory and the AFRs were climbing quick. There is a dip where I had pretty much stopped tuning because I didn't think it would be making power above 5500 where the SETA redlines at.

It was running about 8 psi here I believe and I was really surprised to see it pulling past 6k and looks like it could have pulled a bit more than the 6300 tuned in that area.

[Ether-D]

So I was intrigued by the eta cam thing. Digger, are you saying it won't really do anything? That makes me sad. Because if it would, that would be neat. Also, I have one sitting on the shelf. I get the feeling meta doesn't have/want a cam grinder. Budget style. Anyway, what would the difference in power band likely be between the two?

[digger]

you can nicely improve the exhaust port with the correct port shape, this is where i would focus before worrying about a bigger valve

those cam details are useless, it only matters what the valve motion is. only the cam grinder needs to worry about the profile of the cam lobe

http://www.r3vlimited.com/board/showthread.php?t=368069

i wouldnt go down the less duration path it doesnt make sense, a split cam with more exhaust duration is often used but you dont really want a narrow LSA

[Meta]

Thank you.. I've been having a hell of a time trying to work out what kind of powerband I'm going to get. Mostly want to avoid it feeling like a diesel and falling on its face by 4k.

[Lithium]

Here are a few links that helped me make decisions.
I doubt an M90 will pump much more than about 11or12 PSI unless it's ported etc...
My guess is 280/290HP - but amazing torque & throttle response.
I haven't had my car on a dyno yet / but when the pedal hits the floor the boost is instant & so much fun.

The Jegs article is really well done.

http://www.mscperformance.com/specpg2.html

http://zzperformance.com/3800/pulleys-belts/modular-pulley-system-1.html

http://www.culvermotor.com/Engineering-Formulas/Pulley-and-RPM-Calculator.html

http://rivperformance.editboard.com/t7823-faq-m90-supercharger-info

http://www.jegs.com/s/tech-articles/...+-+Centrifugal

[Meta]

I think about 12-15 psi should do the trick...

[Meta]

I have read the majority of your thread ether-d.. You're my low budget superhero lol. I still need to read yours though lithium. A built in bypass seemed like it might have been a little overmatched so it's good to know multiples can be used. I've heard a roots blower doesn't make actual boost because it doesn't compress the air. Is it possible to get higher boost out of the m90 with a pulley change? I would love to push output into the 350whp range if it's practical

[Lithium]

BlowA

I'm running the GM one. Nice to know I don't need to run a bypass. So I should put the throttle before the blower then? Hmm seems so weird.

I have an Eaton-M90 on my E30-M50 car - Throttle body needs to be before the blower with any type of roots blower & you absolutly need a bypass - I have two of them 1.0" ID and coupl use probably one more when I up the boost.
Build thread in my signature.
ChrZ!

[Ether-D]

I have the throttle before the blower and it's lovely. Have you read my (extremely long) original build thread? It's a lot of crap, but a lot of good trial and error too.

[Meta]

I'm running the GM one. Nice to know I don't need to run a bypass. So I should put the throttle before the blower then? Hmm seems so weird.

[whodwho]

No air in no air out - this is a common setup and I believe how they ran stock, it also helps cut down the blower noise.

Are you running the tbird one or one from a GM? The GM ones have built in bypass built into them, the tbird one doesn't. You will want to run some kind of bypass to help transition from idle/off idle

[Meta]

Somebody was just telling me they ran a m90 and had to pull through the throttle body to avoid boost spikes when it opens. This would put my throttle between the air filter and the blower then sending it pretty much unregulated into the cylinders... This seems like total bologna from where I'm sitting... Can anyone confirm this?

[whodwho]

Looking forward to what you come up with. 8^)

[Meta]

Outstanding.

[whodwho]

That's why I was running it, an ETA cam in a 885 head is what is in a SETA engine. There is a 4 journal and a 7 journal version of the cam so you should be able to find a 7 journal cam.