m30b35 supercharged

[csermonet47]

Interested to see how this goes. I hope you follow through with it!

[Click]

Yeah interested to see how this goes. I've been weighing SC vs turbo for my b35 but I've pretty much decided on the turbo since SCs usually rob about 10% of your power, but the low end power is nice.

[george graves]

So - when adding something like an eaton m90 to an m30b35, how is the gas mileage when you're just cruising around town? Are you really only using more gas when you're on the gas/rev's a lot? How does that work?

[LowR3V'in]

It must be real bad.
How much boost you get at 2,500rpm?

I get about 13-14mpg with a turbo.

[george graves]

^no offense - but sounds like you're just taking a wild guess. I don't know the answer either - that's why I'm asking.

Doing some reading -there are people that claim to get better gas mileage with the SC (on the freeway)

Many people assume a blower is making boost 100% of the time. In actuality, the blower normally only goes into boost when the throttle is opened substantially or when the vehicle is under load, such as going up a steep hill or pulling a trailer. In order to make boost, the blower must get air, and during most driving you will only have the throttle open a slight amount. Interestingly enough, even when not making boost, the spinning rotors improve the volumetric efficiency of the engine to the point where you can maintain high cruising speeds at lesser throttle openings, and in normal driving around town, you will notice that the vehicle is much livelier even when not making boost. This phenomenon can improve gas mileage under certain circumstances, although typically on an overall basis fuel economy will decrease about 3%. This isn't much of a factor. If your car was getting 20 mpg before the blower that means you will be getting 19.4 mpg after the blower installation but with a 40 to 50% increase in horsepower.

Twin-Screw and Roots type superchargers are very common on Truck applications where people desire most torque and horsepower for towing and off the line power. It is also very commonly used for road course racing where more instant power is needed. The characteristic of a Twin-Screw and Roots type supercharger normally provides boost instantly. Unlike the Centrifugal type superchargers you do not need to wait until redline to see the higher boost levels for it normally will be present throughout the whole RPM band. Because of the boost curves this type of supercharger is idea for anyone seeking a lot of HP and Torque instantly, which makes it perfect for towing heavy loads or someone that needs the extra power in the lower, mid, and higher RPM range.

^ That makes me excited

Also, for a street car....

Also, the additional low end torque allows for a taller rear end ratio

[yert315]

I am still curious on how you plan to run the belt(s). I see you mentioned custom crank pulley. Will you be running a serpentine belt setup?

[Woofer]

Sweet build! Let's see some pics!

[CHIF8008]

man i always wanted a M30 supercharged


so down for slightly less MPG but much more power

[cheapshot]

Interested to see how this goes. I hope you follow through with it!

You and me both! I have every intention to and hope that I don't hit any snags that would cause me to abandon it. The good news is that this is not my dd so I can take my time and make sure that it is done right.

Yeah interested to see how this goes. I've been weighing SC vs turbo for my b35 but I've pretty much decided on the turbo since SCs usually rob about 10% of your power, but the low end power is nice.

This is true, but I will take the 10% thievery for the 50% bump in power and low end torque!

It must be real bad.
How much boost you get at 2,500rpm?

Mpg is really not a big concern for this project but I doubt it would be any worse than a turbo setup, should be better. Also, the amount of boost at a given rpm is completely dependent on the pulley ratio.

I am still curious on how you plan to run the belt(s). I see you mentioned custom crank pulley. Will you be running a serpentine belt setup?

This is a very interesting question. I am not 100% sure on this yet. My original plan was to run a dedicated serpentine belt off of the crank to the sc, however, I have a buddy of mine who thinks I should do one single serpentine belt to drive it and the accessories. That seems to be a much more difficult route to go as I would have to make sure that all other components are being driven at the proper ratio.

And George, thanks for posting the info on the SC's! Where did you come across that?

[RagtopE30]

Greg, Just spend some quality time measuring your OE accessory pulleys, shaft diameters, and (well I hate to use wheel terminology but) offset. Once you know these your local decent auto parts store should be able to help you find the pulleys for your application without the cost of custom pieces.

[cheapshot]

Greg, Just spend some quality time measuring your OE accessory pulleys, shaft diameters, and (well I hate to use wheel terminology but) offset. Once you know these your local decent auto parts store should be able to help you find the pulleys for your application without the cost of custom pieces.

Are you referring to if I go with a complete serpentine setup?

[cheapshot]

So these are the parts that I picked up today.
Eaton m90 SC with charge pipe and intake
FMIC
RRFPR, not sure if this is the one I am going with. It was a freebee and that scares me.
Misc. Charge pipes and bends
Innovative wide band (still need the innovative gauge)

Parts still needed
Maybe BEGi RRFPR (I have a line on this from another forum member but have yet to pick it up)
Coupler kit (I have a line on this from another forum member but have yet to pick them up)
Innovative wideband gauge
Boost gauge
Oil pressure gauge

Anything I am forgetting?

[RagtopE30]

Yes full serpentine

[slammin.e28]

In for this.

I'd love to FI my e28, but just put headers on it and don't wanna fuck with them again.

[ForcedFirebird]

Yes full serpentine

Don't need to go full serpentine. Just use a ribbed belt, tensioner and add a second pulley for the front of the v-belt crank pulley.