Twin Screw Search

[Sykohtic]

So if I can find one for non-bank shattering money, Ive thought about upping the idea from using a Eaton M90 with a shrunk pulley to using a twin screw setup.

What cars can you think of that came with a factory twin screw? I know there were a couple Merc AMG cars that had them. Eaton M90s are a dime a dozen with all the T-Birds and Gran Prix GTPs in the world, but I want the boost capability a twin screw unit allows if I can get my hands on it.

I think it was digger that last told me that someone was working on a M20 twin screw setup with a Merc blower, but I can't seem to find that project. The car will be a M20B29 for the extra torque, so I feel like it should be able to turn the pulley just fine.

Not looking to buy right this moment, just want something to look for on the junkyard hunt.

[R1dd1ck913]

What kind of boost are you looking for. On my Tbird SC I'm running about 18 psi with the eaton m90.

[Sykohtic]

What kind of boost are you looking for. On my Tbird SC I'm running about 18 psi with the eaton m90.

Probably in the 20s. The idea is to get it very solidly between 340-400 BHP if possible, so I'll have to be pushing as much if not a little more boost than most heavy hitting M20 turbo setups, even with a 304 cam, long tubes, and stroker setup (and possibly some additional porting).

The highest boost M90 setup ive seen was like 21 lbs I think? I could very well have just overlooked something, in which case point me in the right direction.

[varg]

You won't get anywhere near 340hp with an M90, and in all likelihood making that much power supercharged will cost a lot more than doing it with a turbo.

[Sykohtic]

You won't get anywhere near 340hp with an M90, and in all likelihood making that much power supercharged will cost a lot more than doing it with a turbo.

To put it in perspective, and no offense, I dont care that a turbo is cheaper. If I wanted to be cheap I'd just go buy an S50 and swap it in and not waste my time with an M20 lol

This is why I'm looking for a twin screw, like the title says. Makes plenty of boost and super unique. Also, the goal of the car isn't to see how much power I can make for no money. I know its more expensive to supercharge, but that doesn't stop me from finding options to get what I want for the best deal possible; that's just comon-sense smart buying.

I appreciate the post, but turbo is among the last things I want my car to be.

[Sykohtic]

Went on NCE30 Group and asked the same question, results are very good.

After talking it over with some of the people in the group and doing some research, there are a couple sources for good and reasonably priced twin screws. Any Mercedes Kompressor engine either uses a twin screw Eaton M45 (4 cyl) or Eaton M112 (6 cyl).

From the factory, Merc already had the M112 shoving a bar into that V6, and Id bet thats nowhere near the full capability of that blower. Additionally, the 3.2L C-class Kompessor cars with this blower are about a dime a dozen, so sourcing the blower should be easy.

Im surprised no one piped up about the M45 blower though. That unit has been used on the Mini Cooper S, and has been used on M42 motors, at least according to a couple other posts on other forums I found. Not sure how much boost an M45 can make though considering its a relatively small unit.

[whodwho]

FYI Eatons are not a twin screw compressor, they are a roots style. There is a big difference in efficiency between the two types.

For using an Eaton on a 2.9 you would want to use at least an M62, an M45 is just to small for any kind of boost and Eatons just get hot trying to spin them up for more.

[Sykohtic]

FYI Eatons are not a twin screw compressor, they are a roots style. There is a big difference in efficiency between the two types.

For using an Eaton on a 2.9 you would want to use at least an M62, an M45 is just to small for any kind of boost and Eatons just get hot trying to spin them up for more.

Alright, fair enough. I wish I could find a true twin screw, but in that case I guess I would need to go with an M112 to make the required boost?

So do you think If I could get a ported M112 with a custom intake to fit in the bay, cool it with water meth injection, intercool, and vent the blower out of say the hood for extra heat expulsion I could get it to hold enough efficiency to spin fast enough to make heavy boost?

[stopsign01]

blower input

I'm new to the forced induction M20 game, but prior to this owned a few late model ford lightnings. The Eaton M112 is indeed a roots style blower, but I swapped a TVS blower from a 2013 on up GT500 on with an adapter plate and little else. The Eaton gets super hot and very ineffecient above about 15 lbs of boost on a lightning. The rotors are just not designed to be spun much harder and you make more heat than boost. The twin screw is definitely the way to go. The TVS's can be found fairly cheap, and a very good blend of low end torque from a roots, with the high rpm power of a twin screw. Also check Whipple and Kenny Belle if money isn't as important.

[Nutzy]

Yeah, covered already but those Eaton's are just a high-helix roots. You can go larger, ie, to the 112, but you are still faced with a rotor style that does not like high PR's without getting all leaky and hot.

Sprintex, Whipple, Lysholm are three brands that come to mind.

I like the project concept - good luck.

[Sykohtic]

Yeah, covered already but those Eaton's are just a high-helix roots. You can go larger, ie, to the 112, but you are still faced with a rotor style that does not like high PR's without getting all leaky and hot.

Sprintex, Whipple, Lysholm are three brands that come to mind.

I like the project concept - good luck.

So whats the opinions on Sprintex? I mean I know I might be on a stretch here considering this isn't exactly commonplace equipment for an E30, but jsut curious. Im on their website looking, and they have blowers that definitely top what apparently the max potential I'm gonna get out of a M112 is.

Link:
http://www.sprintex.com.au/superchargers/

First one I looked at was the S5-100. Maxes out at 36lbs boost, and claims potential max gains at 134 horsepower, which places me at around 300 bhp with a stock, top notch M20. Mine will be rebuilt with the 2.9 stroker and supporting mods, so that would go up a little bit. That ones priced at just over $1800 (Price link below).

Then I looked at the S5-150. They claim gains of up to 200 bhp, which puts me hard into the 300s (again, perfect world with a perfect M20). While Im sure there are some sizing things to look at, what surprises me is that the S5-150 is around in the exact same price range as the S5-100. In fact, in the basic case, its $100 cheaper.

I assume that the gains promised are potential with supporting mods like cams, headers, and intercoolers since I can't find anything to tell me to think otherwise. Anyone care to take a look and see what they think?

Price link (you'll find the blowers on their own down around page 3):
http://www.sprintex.com.au/wp-conten...tober-2013.pdf

[Nutzy]

I'd be looking at a blower with about 1.5 L displacement - S5-335. That one has an engine power output up to 500hp.

[Sykohtic]

I'd be looking at a blower with about 1.5 L displacement - S5-335. That one has an engine power output up to 500hp.

You really suppose I need one that big? I mean, after assessing what I said myself, I can see your angle of going with a bigger blower so it doesn't have to work as hard, but the 210 below that is claiming gains of 300 bhp and says it's designed for 1.8-3.0L engine capacities. I mean 300 bucks difference is rather reasonable probably when you consider the fact you get an extra half liter and that 500hp potential which does mean a much easier trip if I wanna go dead to 400.

Also, I've seen a claim or two saying that these blowers dont HAVE to be intercooled. How valid do you think that is? I mean, intercooling it would probably make much easier power, but if I dont have to, then that frees up weight and money. I figure ill take a card from the Hellcat deck and feed the system through a modded headlight housing anyway.

[Ether-D]

The 1.5 L is about right, if not just a bit big for the m20. But you'd rather have too much and pulley it down than have too little and try to pulley it up to compensate and then deal with belts slipping and too much heat.

The twin screws will give you about 15%(+/-) more boost than roots at similar intake temps. My Eaton m90 m20b25 is at about 220HP (non-intercooled) with a first try home tune by a complete amateur (me). I make 9-10 psi peak, depending on how cold it is outside.

340hp will be rather difficult (but probably not impossible) unless you have a pro tune and some serious charge cooling.

[Sykohtic]

The 1.5 L is about right, if not just a bit big for the m20. But you'd rather have too much and pulley it down than have too little and try to pulley it up to compensate and then deal with belts slipping and too much heat.

The twin screws will give you about 15%(+/-) more boost than roots at similar intake temps. My Eaton m90 m20b25 is at about 220HP (non-intercooled) with a first try home tune by a complete amateur (me). I make 9-10 psi peak, depending on how cold it is outside.

340hp will be rather difficult (but probably not impossible) unless you have a pro tune and some serious charge cooling.

I suppose a S5-355 it is then. There's a shop in Concord, NC, that I plan on taking the car to, especially for the tuning. I'm looking at several stages for the build.

1. Auto to manual conversion, coilover conversion with refreshes to some suspension components, professional electrical system work, get the motor (stock) really solid with a light refresh like new belts and ignition components.

2. Conversion to aftermarket ECU. Basic tuning (possibly dyno) to optimize the stock M20 and set a baseline for more extensive tuning later on.

3. Bigger/wider wheels and tires and body work to make them fit if necessary. Brake upgrade, swap to braided lines.

4. Stroke M20 to 2.9L, long tube headers and exhaust system, convert to electric cooling, upgrade cooling, head work and porting, possibly up-sized valves. Tuning to optimize new setup. May do some painting or refinishing of the engine bay while the engine is out.

5. Install S5-355 Twin Screw Supercharger, charge piping and intercooler install, custom intake for blower and custom mounting. Tuning. Consider the addition of flex fuel capabilities if needed.

6. Finish all body work and aesthetics. Because who needs their car to be one color when you could have more performance first?