Custom intercooled S/C kit. Ideas? Thoughts?

ThingyNess · 11-12-2008, 01:55 PM

Well, I've finally got the little CRX up and running happily with its 3-stage VTEC engine, and it's lots of fun. 130-140hp and a curb weight < 2000lbs even with half a tank of fuel is pretty entertaining. (yes, I took it over the scales.)

I do wish it had more power though, and I'm not willing to pay the exhaust restriction and scavenging penalty and go turbo. I'm trying to find a way to shoehorn an M62-M90-sized blower into my little D15, preferably where the A/C compressor would normally go. Since I have neither power steering nor A/C, there'll be tons of room once I make my own header.

However, counterclockwise-rotation superchargers aren't exactly easy to come by. I've considered biting the bullet and buying a B-series JRSC kit to cannibalize a CCW M62 from, but there has to be an easier/better way.

Anyone heard of any good experiences converting standard eaton blowers to CCW rotation? Or any good ways to reverse the drive direction externally, or really any good way to make the damned thing work.

I'd love to be able to pick up a used M90 from a domestic V6 since they're super cheap and readily available and fab up a kit from that. I do have a CNC milling machine in my garage, among other things, so I'm not afraid of a little fab.

Any links to people who have already done this on a Honda, suggestions, ideas, or comments would be welcomed.

I had a chance to go for a short ride recently in an ubercharger-equipped Miata. The stock engine is a 1.8L that makes only slightly more HP than my 1.5 vtec does from the factory. With the intercooled m90 at ~14psi, it makes something like 240hp to the wheels and 215lb/ft to the wheels, and throttle response and low-end torque are nothing short of spectacular. It is a deceptively fast car.

(dyno chart below)

http://www.flyinmiata.com/tech/dyno_..._200kpa_99.pdf

Now THAT is a torque curve.

Jesse (Fizz) · 11-12-2008, 02:00 PM

I heard mention of just running the belt on the wrong side, of course you'd need to do it properly with a flat surface pulley and plenty of belt to pulley coverage.

ThingyNess · 11-12-2008, 02:04 PM

That's not a bad idea. I had thought of that. and it would make my life a LOT easier, since making flat-faced pulleys is nice and easy compared to the grooved ones. I'd be pretty worried about belt slippage, especially at my boost levels. Even the 6-rib belts often have slippage problems, and they have a lot more surface area than a flat belt.

...

That brings up an excellent idea though. I wonder if one can find a source for dual-sided ribbed belts? That would be an easy solution to the problem. I'm going to poke around some industrial supply vendors at work today and see if I can't dig some up.

Jesse (Fizz) · 11-12-2008, 02:34 PM

You mean like this?
http://www.wipo.int/pctdb/images/PCT...b_pfx.g4-b.jpg

ThingyNess · 11-12-2008, 04:35 PM

Yes, in fact. I found that picture from the patent in my google search as well. Apparently gates does make them. Some of the chrysler V6es in the vans use a double-sided serpentine belt that I might be able to make work, although it'd likely be too long.

BoneSpec · 11-12-2008, 08:37 PM

Why not just spin the blower backwards?????

Then add a clutch to control engagement........

Wait, that was eight years ago

M90 on a GSR

Looks puny next to a REAL blower

SOHCinWA · 11-12-2008, 09:07 PM

So much smaller but what a great punch...

f00ker · 11-13-2008, 04:07 PM

Originally Posted by BoneSpec

Why not just spin the blower backwards?????

Then add a clutch to control engagement........

Wait, that was eight years ago

M90 on a GSR

Looks puny next to a REAL blower

any more pics of the piping involved in that? Looks nice

BoneSpec · 11-13-2008, 09:37 PM

I never finished my version of the design since a custom header was needed.

It's just like piping a turbo setup.

ThingyNess · 11-14-2008, 03:29 PM

A roots blower is a positive displacement air pump, and as such, yes, it will work backwards. However, from an aerodynamic perspective, I might as well punch myself in the face.

The adiabatic and volumetric efficiency is pretty much cut in half by using the inlet as an outlet and vice versa. I can't remember where I read that, it was a long time ago, but I think it might have actually been Magnusen that tried that on their blower dyno. It worked, and it certainly will make boost, but it will suck. Hard.

I'll see if I can dig up the information from my archives.