GT-ER

These pulleys work perfectly and go down to 1.9" ( stock is 2.8" ). I just installed a 2.5" on my friends car with zero issues.

http://www.pulleyboys.com/store/prod...2&cat=9&page=1

Can't beat the price either.

EDIT: let me clarify something. Apparently kleemann changed the pulley system on the eatons at some point and there are two types of pulleys. If you have a pulley with 4 small bolts then it won't work. This will only work with pulleys that have a single large nut in front.

Viper98912

I used pulleyboys before on a different car and all went ok as well. Be careful not to overspin the S/C

GT-ER

I've overspun superchargers ( have seen others do it ) for as long as I can remember. As long as you can keep the heat in check, all is well.

2MCHCAR

Thank you for finding this!!

Did your friend get a retune?
Did he check his A/F ratio on the dyno? Power numbers?
Was the install easy? What does it involve?

Viper98912

No, you didn't quite get it. When I meant overspin, I meant over the max of the supercharger, not the stock setup. The eaton I had before had a max of about 17,000 rpms, and after that you got way out of it's efficiency range. But more importantly was that you need to be careful at those rpms with bearings going loose, rotors crashing into your housing, and shavings of metal going into your intake duct and cylinders. Not to mention your broken supercharger.

GT-ER

Oh...yeah, I didn't read it that way. Sorry.

GT-ER

I'm working on the retune part. At full throttle the car is fine but part throttle is still kinda quirky and after the smaller pulley the car doesn't shift smoothly at WOT, it jerks violently at each shift. A/F ratio is at low 11's ( sometimes dips into the high 10's ). No dyno yet though, hopefully soon. We only have crappy 91 here though ( only one gas station gets 93 which is where I get it but my friend works and lives pretty far away from the gas station so he only uses 91 ). Not really sure I'll see 400whp but then again, it's hard to gauge whp since my car is much more powerful.

Install was super easy. The pulley is not pressed on so it was as easy and removing the belt, removing the nut and swapping the pulley. 20 minutes tops. The kleeman idler pulley was always slightly off alignment and the smaller pulley I installed doesn't have the EXACT offset as the oem one but it's close enough and I added a washer behind the kleeman idler to align it better. I romped on it more than 20 times today and had zero issues.

betrezra

I would data-log the following on a full throttle romp:
fuel pressure
boost
AFR
Mass Air Meter Voltage

You might have to reset adaptations with the new pulley. GL.

I'm curious to see what boost you are seeing now.

GT-ER

Unfortunately I just realized the oem map sensor doesn't go above 5psi or so, so I'll find how much boost it's making at the dyno.

I've already logged AFR, MAF Voltage and fuel pressure. All is well.

91RS

Hmm, that doesn't look the same as mine. Mine is held on with 4 bolts.

GT-ER

Okay, let me clarify something. Apparently kleemann changed the pulley system on the eatons at some point and there are two types of pulleys. If you have a pulley like the one pictured above then it won't work.

91RS

That's unfortunate.

GT-ER

Yeah. Kleemann has a 2.6" pulley for you but it's like $150 or so.

Viper98912

Not a problem at all, contact pulley boys and tell them you want a custom pulley, they should be willing to make it. In fact, you should probably send them your pulley so they can take measurements to make your new one, then market it here on the forum as a new product. I'm surprised Kleemann doesn't make smaller pulleys themselves? That looks like an easy bolt on mod.

91RS

Kleemann told me I have the 2.6" pulley already, but I haven't measured to confirm. I was running 7PSI of boost before the headers and I haven't had it dynoed yet again to see if it went down any. I talked to Cory at Kleemann and he said I don't want to run any more boost than that because of the high compression (11.0:1) of the NA 5.5L. An E55 is only 9.0:1. I don't really know enough about boosting engines and compression ratios and all yet to know what will happen.

GT-ER

On an eaton I wouldn't overdo it because it's a very inefficient compressor. With the 2.5 I installed timing is already way low and raising boost even further would make the timing even lower and will only make the exhaust temps hotter and make you slower. If you had the autorotor then you can definitely go higher even with the oem compression, but the tune has to be spot on. Maybe 10-11psi or so on pump gas.

I'm running 14psi ( and running 20* of timing on 93 oct ) on my E55 and I can ( and will ) go higher.

91RS

I'm confused as to how the type of sc would make a difference in the amount of boost that can safely be run if it has to do with the compression of the engine. That might be my research project for the day.

GT-ER

Simple, heat. An efficient screw type compressor will make a lot less heat at higher boost levels than a roots type can.

91RS

I wish I had known that. I think Kleemann still had one Autorotor left when I bought my kit...

GT-ER

Yeah. My friend found out his was an eaton as well only after he bought it. Regardless, they can make good power. I've seen them make over 500whp on non mercedes applications.

tw2

If you had a totally awsome intercooler it wouldn't be an issue for the engine at all.... except if the supercharger fails due to too high rpm. Of course there is a very low limit to how much intercooling you can package into these engines. Of course higher efficiency is a much better way to go. Centrifugal best > twin screw > roots worst.

Viper98912

The difference for non-centrifugal s/c's is the rotors themselves. In an eaton/roots style, there are curved triangular-like lobes that interweave each other to "push" the air into the engine. In the screw type, there are male and female screws that interweave each other and compress the air between them before exiting into the engine. One is compressing by restriction in the engine, the other is compressing in itself.

91RS

So how would one know if there's too much heat? Overheating, detonation, etc.?

Oh, I did measure my pulley today and it does look like the 2.6" pulley.

GT-ER

You would generally see a lot of diminished return. A temperature sensor post intercooler would allow you to see if the intercooler can handle the heat as well.

tw2

As GT-ER said. When you raise the boost 1psi you get a certain increase in power to the wheels. As you get out of the efficiency of the supercharger the gains diminish. You might start off with 25whp gain per 1 psi increase up to 7psi. When you go from 9psi to 10psi for example it might go down as low as a 5whp gain. You want to stop well before this point or get another supercharger. This works for all types of supercharger and turbo's.

Are there centrifugal kits for these cars? You already have heaps of low down torque anyway and it would be so much easier to package a proper intercooler and they are often up to 99% efficient.