if you're starting to fall off ~6000-6100R RPM's, wouldnt you want to shift closer to 6000, 6100 at most?

 

Dmoor88, actually no! This can get real difficult to explain but let me try a simple way to explain this to you? Say your car made the following HP numbers at RPM and had say, a 1,500 RPM "step" between shifts:

Before shifting the car makes
350 HP @ 6,000 RPM (This is the peak).
348 HP @ 6,100 RPM (Down 2 HP from peak)
345 HP @ 6,200 RPM (Down 5 HP from peak)

After shifting from:

6,000 RPM (making 350 HP) new RPM is 4,500 RPM and car makes 260 HP @ 4,500 RPM

6,100 RPM (making 348 HP) new RPM is 4,600 RPM and car makes 264 HP @ 4,600 RPM

6,200 RPM (making (only???) 345 HP (i.e. down 5 from "peak") new RPM is 4,700 RPM and car makes 270 HP @ 4,700 RPM

Under these conditions it would actually be better to shift at 6,200 RPM and "ride down" the power curve after "peak" power, because you will gain more power after the shift, since the car will start from 4,700 RPM where it will be making 270 HP vs starting from say 4,500 RPM where the car is (only) making 260 HP! Do you "get" what I'm trying to explain???

 

I thought i've read on here that you want to shift 500rpm's past peak. I dunno if thats a good rule of thumb or not.

 

well i tried Dave at combination motorsports and got no reply so I guess ill look elsewhere. Anyone know of any online places that carry the 847 for a good price?

 

I take that back he just sent me an email and even apoligized for the hold up. very good man

 

Heres what Dave recommended
TN230XL(230/236, .544/.555 on a 112 LSA) what do you guys think? That vs. the 847?