Lithiums - E30 / M50TU Eaton-M90 Supercharged Thread

[Lithium]

I think you're reading the chart wrong. The 26 & 2.607 at the top of the column are the tooth count and pitch diameter of the small pulley.

It looks like you're thinking 2.607 is the drive ratio, but it's not, if you're using a 56 tooth crank pulley and a 26 tooth blower pulley. The actual drive ratio with that combo is 2.154.

Of course the belt drive won't be consuming 52 horsepower... it'll be able to transmit 52 HP.

However, if "RPM of the faster shaft" means what it looks like it means, you'll be well off the high end of that table, because that would be 5500 blower RPM, which will be 2550 engine RPM with that pulley combo.

The table is set up with the tension limits of the belt in mind. That basically means the torque you can transmit is the allowable belt tension times the radius of the smaller pulley. Since the smaller pulley is on the faster shaft, they call it the faster shaft.

Since you're spinning your engine to 6500, the blower will turn 14000 with a 56/26 pulley pair. Since the power transmitted is a slightly non-linear function of RPM, I guesstimate that extending the table that far would show that with the faster shaft turning that speed, the belt drive can transmit ~120 HP. That's a *SERIOUS* blower.

Dark Will - You are totally correct - I apologize if my wording was not clear.
Thanks for the thoughtfull feedback.

I think it has a chance because @ 14000RPM the Eaton-M90 only requires 55HP to drive it. (see bottom of chart below)

I have ordered the pulleys & will get them fit on the car in the next couple weeks. I will update as I go along.

[Lithium]

Update - Crank pulley adapter designed (below) I will get it cutting on a CNC machine this evening. Excited - Must have car running for June 4th - Big event!!
Also did some research on belt tensioners - The hydraulic ones on timing belts sound like the best bet for this application - Ordered one from a Volkswagen - I sure hope it does the job.

[The Dark Side of Will]

I remember the days when draftsmen had dictionaries as well as parallel motion arms. ;)

[Lithium]

Got the Crank Pulley mounted & started on the blower pulley last night.

[Ether-D]

That pulley adapter is killer. I may want one someday if you'd do another one.

[Lithium]

My toothed belt just arrived - Can you feel the boost???



Tonight I will see if it fits...

[Lithium]

It's all together & runs nicely - Just needs more fuel - Time to start tuning all over again.
Saw 7.5 PSI when blipping the throttle - I'm hoping to see around 10 under load.

[Ether-D]

So fricking cool. Can you hear the belt now? I feel like I've read that the toothed belts can make some noise. I've never heard my timing belt though. This is great. I hate it when my tension isn't just right and it slips.

[Lithium]

So fricking cool. Can you hear the belt now? I feel like I've read that the toothed belts can make some noise. I've never heard my timing belt though. This is great. I hate it when my tension isn't just right and it slips.

It runs really quiet - Its an 8mm HTD belt - teeth are round and run really smoothly / The blower whine is louder because I am spinning it faster now 14200 @ redline!!!

[Ether-D]

It runs really quiet - Its an 8mm HTD belt - teeth are round and run really smoothly / The blower whine is louder because I am spinning it faster now 14200 @ redline!!!

I'm glad you blazed this trail.

[LJ851]

The videos aren't loading?

[Lithium]

The videos aren't loading?

They are YouTube video's - The links seem to be working for moi.
Sorry...

[Ether-D]

LJ is probably just being hilarious. I bet he wants to see vids of the toothed belt in action.

[Lithium]

LJ is probably just being hilarious. I bet he wants to see vids of the toothed belt in action.

That one flew right over my head - Let me see what I can do about a video tonight.

Back to business - Ordered some 30lb injectors to go with the new pulleys.

Hopefully get to some tuning next week.

[Lithium]

No luck with Tunerpro scaling for the new injectors - The XDF files I downloaded are not complete enough to actually tune the car - What a major disappointment.

- Recently I have been in touch with http://www.renovelo.com/real-time-tuning/
I am going to go this way - I think it suits my needs & equipment & skill set the most.
$1200 for PNP-MS3 is way above my pay grade and frankly the Blower tuning should not be that difficult because it's so linear.
- I will still need to scale the constant and load tables for the larger injectors though.
Jeff Reno has been in touch and seems to quite supportive and interested in the project.
I will keep you posted on how it all works out - ChrZ!!!