3.8L supercharger?

[Anonymous]

so a larger pulley is necessary then.

 

[MLINE]

I forgot about the jackshaft pulley.

Either a larger pulley on the blower or a smaller pulley on the crank will slow it down. Also like Rancherlee mentioned the stock SC used about a 2.5:1 blower pulley drive ratio. So you would need to come up with a pulley size combination that works.

 

[Anonymous]

i use a roots blower(eaton M90)in a blow through setup on my hemi inline six .use pulleys to spin the blower to 14000 rpm at max engine revs and you will make good boost.yu'll never look back.stays alot cooler than a turbo too.

 

[Anonymous]

i use a roots blower(eaton M90)in a blow through setup on my hemi inline six .use pulleys to spin the blower to 14000 rpm at max engine revs and you will make good boost.yu'll never look back.stays alot cooler than a turbo too.

I HOPE you are using an intercooler of some sorts with that M90 at those RPM/boost levels, the M90 is REALLY bad at blowing hot air. @ that supercharger RPM and 10psi it is adding close to 200*f to the air temp from the compression AND low effecency of the blower. Under full throttle acceleration on my supercoupe I was seeing air temps in the 250-300*f range before the intercooler in the summer. Turbo being the MOST effecent of the bunch ACTUALLY make alot less heat even though they are spun up by the exhaust. A turbo only adds around 70* temperature @ 10psi. Vortech style blowers add about 100*f @ 10psi.

 

[Anonymous]

Why would one system create different temperatures than another? If you are compressing a given volume of gas to the same PSI, temp rise should be the same.

 

[Asa]

the end goal is the same, but you're not doing it the same way
the turbo is more efficient at creating boost than the M90

 

[Anonymous]

But physics doesn't change between induction types. Compressing a given volume of air to 10psi should result in the same temperature rise no matter how it's compressed.
I am assuming that the volume compressed is the same with each system, that each system is creating 10psi, and that no blowoff valves are releasing boost.

 

[Asa]

Roots type pumps were actually not originally intended for use as air compressors (our understanding is they were designed, of all things, as blowers for ventilation!) so some of this increased manifold pressure is recycled back into the blower case, reducing efficiency and creating additional heat.

http://www.thrashercharged.com/l67_htm/intercooler.shtm

from all i know of it, it's just got some peculiar design flaws that make it inherently less efficient than most other roots blowers, and pretty much all turbos
much like the log head has a peculiar design flaw (from the aftermarket perspective)

however, i think the important part of that is the bit after the parenthesis

there are different ways to do pretty much everything, to keep someone quiet you can knock him out, or you can shoot him in the head
either way he'll be quiet but which is the most efficient method?

 

[Lazy JW]

Roots blowers were designed by the Roots brothers for blowing air through their blacksmith forges.
Joe

 

[Anonymous]

no intercooler, but the motor runs on propane fuel.no detonation at 8.7:1 and 30" of advance and definately no heat problems!

 

[Anonymous]

Blowers like the M90 create ALOT of turbulance, the eatons are only about 55-60% effecent at converting boost into HP. Say an engine makes 150hp Naturally asperated and using 14.7lbs of boost you could make 300hp with 100% effecency of the power adder (which is NEVER going to happen). Now take our good old eaton M90 at its 60% rating and lets figure out how much power it will add to our 150hp @ 14.7psi. Take 150 X .06(for 60%) then add it to the original hp rating of 150 to come up with a close estimate of the amount of power you should make. This gives us 240hp (with a gain of 90hp) and its costing us 60hp worth of HEAT (heat lost in the belt drive, blower case, BOOSTED AIR).

Now lets figure out a turbo on the same engine at 90% effecency
150 X .9 (for 90%) + orginal HP and we figure out we are now making 285hp while loosing 15hp worth of HEAT due to excess back pressure in the exhaust.

As you can see a turbo on a 150hp engine could make 45more hp while running the same amount of boost as an engine blown by an Eaton supercharger.

 

[Anonymous]

Actually, modern roots blowers are MUCH more efficient than the old Roots blowers of hot rod past. You'd have to check Eaton's site, but the latest blowers are doing much better in terms of efficiency.

Eaton just released the Gen V M90 for the 2004 model year... this was featured only on Pontiac Grand Prix GTP's as far as I know, and the same goes for 2005.

Then Gen III M90 is featured on 97+ Regal GS, Bonneville SSEi, Olds LSS, Monte Carlo SS S/C (2004+), Impala SS S/C (2004+), and (until 03) the Grand Prix GTP.

The Gen III is a much improved design over the older Supercoupe blowers. Much like the Gen V is a step ahead of the Gen III.

Older GM applications (pre 97) used the M62, which IS too small.

You can find pulleys for the GM applications I listed here: www.southfloridapulleyhq.com www.zzperformance.com and www.grandpirxstore.com

www.intense-racing.com also sells them, but they have come under scrutiny recently for some shady dealing.

On the GM applications I listed, stock boost is around 6-7psi, with a 3.8L motor.

How do I know so much? I run a "modified" Grand Prix GTP as a daily driver

I won't begin to argue whether a turbo or S/C is better, because there is no real "better." They each have advantages and drawbacks.

 

[Anonymous]

89-93 Supercoupes = Gen II M90
94-95 Supercoupes = Gen IV M90 (coated rotors, square rear port, tighter clearances)
The Generation V M90 shouldn't even be considered a new generation, its pretty much a whole new design and actually compresses the air(like an Autorotor/Whipple) instead of just moving the air. Definatly a HUGE step forward. The 5.4L in the Ford GT (40) uses a M112 gen V

 

[Anonymous]

Oops... my bad, I didn't know they ever got the Gen IV.

Thanks for correcting me there!

 

[Anonymous]

ya, you don't see many Gen IV though, the 89-93 supercoupe guys snap them up quick for there cars. Gen IV's got for over 500$ on Ebay, Gen II are a dime a dozen (I bought 2 of them off ebay for 150$ each for porting)

 

[Anonymous]

Yep, Gen II and II are all over ebay. I just got a great deal on one... paid $112 for an entire Gen III w/ TB and all electronics. I needed some spare parts and a snout to finish off my ported blower.

A guy on another forum I'm, on got LUCKY just a couple of days ago and caught a Gen V on ebay with a buy it now of $150.

 

[FrankBoss]

I looked at using the 3.8's eaton blower on a 2.3L for a while and there are companies offering sealed barings for this model...Just if you want to have a draw system...

But a blow threw allow the oppertunity(SP) to use a inter cooler!

Frank