I have an EM1 used solely for circuit driving (caged and 2400 lb with driver). The unknown in the following is how I will add power when I do so; undecided whether to do a small turbo (<300 whp) or go for >200 whp NA. Either way, that won’t happen until next year.

The trans is out right now for a LSD to go in (MFactory 1.0 way plate) and a few carbon synchros. I’m tempted to change the FD while I have the trans apart. I was thinking 4.9 but I’m a bit concerned that if I did go turbo I would wish I used a 4.7 FD (or even the stock 4.4). I could always switch back so I figure going for 4.9 may convince me to stay NA. I have looked at speeds at my usual tracks and I think the higher FD will be a benefit. I’d love to simulate it. Thoughts?

Also, I thought I would change the clutch while I have a good opportunity. The current one feels okay; I don’t know what it is but the pressure plate is white. I’m inclined to use the Exedy Stage 2 3-puck (08950B). That would work if I end up with boost, but is there a disadvantage to it if I end up staying NA (other than the increased cost over a stage-1 clutch)?

Is the Exedy HF01 a good flywheel choice?

Thank you.

 

MFactory 3/4/5 close gear set (1.028 5th is straight cut, 1.054 5th if semi-helical), MFactory 4.0 FD. Best setup for road courses, even on boosted setups. I had a customer that was going through stock ITR transmissions like crazy with his 250whp boosted EG. A new ITR trans was only lasting him 1-2 events before shearing teeth off of 3rd or 4th. He hasn't had an issue since I built the trans for him with the setup I listed (7+ years now).

 

Interesting, thanks. Is that the set shown here? Seems similar but yours is straight cut on 3rd and 4th. Do you remember the ratios of each gear, as they seem to offer a range. This may be something for down the road, as my plan was to put in an LSD and now scope creep has taken a firm grip...

 

The set pictured is 1.636/1.313/1.028. This is the most popular setup that I build for my track car customers.