1991 (USDM) Prelude SI

B21A1 - 2.1L DOHC

Friend of mine races on a figure 8 track every friday, full contact. He comes in 2nd consistently and says he needs a better transmission in order to catch up with the first place dude.

Any transmissions or mods you would recommend instead of the stock SI transmission for better acceleration? He's getting creamed on takeoffs or when they have to wind down and speed back up.

 

What's the budget? And what does his class allow? You could look into a different final drive, but I don't know if one from a newer B trans would fit, or be within budget or rules. What engine and transmission does he have now?

 

Well, I'm not sure on the money situation. There are no rules against the transmission that I know of, just forced induction and nitrous.

His engine and tranny are the stock ones from the SI that year.

 

That statement doesn't clear anything up since you never specified the year/model. (There's more than one Si variety)

 

Sorry I just spoke with him about it:

1991 (USDM) Prelude SI

B21A1 - 2.1L DOHC

I can't seem to find any codes on the transmission online, it's the stock one supplied for that year. 5-Speed manual.

 

D2A4 = your transmission code

Gearing is as follows:

1 - 3.307
2 - 1.809
3 - 1.289
4 - 0.964
5 - 0.812
R - 3.000
FD - 4.266

 

Sorry but your not going to get any other transmission to bolt up to that motor. Its either the 88-89 or the 90-91's.