tuajer

"However, one thing that it doesn't do is alter your part throttle shift points. For this, you need to send your computer to Hypertech (or one of many other ECM companies) so they can reprogram all the part throttle shift points to match your new gears. Because after a gear swap, your part throttle shifts will be out of synch. Since shorter gears rev higher, the stock ECM will still be shifting at its preset points. So the engine may hit 3000 or 4000 RPM before shifting (whereas before it should shift at 2000 RPM under partial throttle)"

I'm trying to get my ecm reprogrammed for 3:73's and the shop I went to is now suggesting I use the Hypertech since their program can only do stock gears. But now I found this on a f-body site about the part throttle stuff.

Doesn't the hypertech allow you to change shift points for WOT and part throttle? should I just get it reprogrammed for 3:54's at the shop?
thanks in advance

NUckINg FuTS

On my '86 the hypertwch chip DID infact change the part throttle shift points (most noticable on the 1st to 2nd gear shift)

95AquaC4

I would think that it takes care of both.I would imagine that if you set the WOT shift points, the pcm will automatically reset the part throttle points. I am not 100% sure of this, and hopefully someone who knows will chime in soon, but I can say this. I switched to 3:54's from 2:59's. My shift points are fine at part throttle, and WOT, without sending out my pcm. However, there is no choice for the 3:54 gear ratio. Choose the 3:45 ratio, and come down on your tire size. I dialed mine in with 25.5 on the tire height. Hope this helps! :seeya

tuajer

thanks guys.
I should probably mention that I got a 2200-2300 TC also and a transgo. will the HPPIII be able to reprogram for those too?

Just want to make sure cause the guy who rebuilt my tranny doesn't want to warranty it without the proper recalibration.

CORVETTE MIKE

What size tires are you running?I have the hypertech to, and iam running 3.54 gears,need to no what to set mine at.

95AquaC4

I have the stock GSC's, and BFG Drag Radials. They are pretty close in size. I used 25.5. You'll have to go by trial and error. If your running stock tires, the 25.5 tire height should get you close.

CORVETTE MIKE

Are you talking front or back tires?I think the fronts are the ones you go by.

CORVETTE MIKE

I have 275-40 on front and 315-35 on back,what should i go with?

silver & red CE

I use the HyperTech on my Impala with 3.73 gears, TransGo shift kit and a 2500 stall speed TC. It changes the part throttle shift points as well as the WOT, works just fine.

You want to use the rear wheel size, that's where the speedo reading is taking from (the trans output speed with the gear ratio figured in).

When you have the option to frim up the shift points (in the HyperTech menu) choose NO, your shift kit will firm things up just fine.

Eric


[Modified by silver & red CE, 8:34 AM 11/15/2002]

Phil-tha-Rush

here is one of MANY tire calculators availabls.

go a search on any search engine for "tire diameter calculators" to see more.
http://www.geocities.com/monterospor...alcs.html#mpg6

your fronts are 25.6614"
your rears are 25.6811


[Modified by Phil-tha-Rush, 10:05 AM 11/15/2002]