speed limit?

[heavychevy98]

Anybody know what or if the speed is computer limited in 4-hi?

 

[ShadowRejects]

Id like to know as well.

 

[Horns]

What year truck?

 

[heavychevy98]

mine is 98. 350 5 speed 241c if it matters. And if i remeber reading correctly ShadowRejects is a 94 Z71.

 

[ShadowRejects]

mine is 98. 350 5 speed 241c if it matters. And if i remeber reading correctly ShadowRejects is a 94 Z71.

correct mine's a 94!! shouldve included that in my name or something..

 

[Aloicious]

the 98 has a programmed speed governor in it regardless of 2hi/4hi selection...I think stock is 98 or 99 MPH....not 100% sure about the 94 but I would guess it would be similar...

on the 98 you can get a tune to raise the governor (you can't eliminate it altogether, but you can raise it ridiculously high)...mine is set to 255mph....on the 94, I believe you can get a chip burnt to change it as well...but you'd want to talk to someone more familiar with OBDI chip burning.

 

[heavychevy98]

Alright then. i knew bout 2wd but my buddy said his nbs will only run 55 in 4hi. he was tryin to hook at the strip and it just stopped pullin at 55 and he hit 2hi button and it toook off again. just curious if mine is the same.

 

[Aloicious]

Alright then. i knew bout 2wd but my buddy said his nbs will only run 55 in 4hi. he was tryin to hook at the strip and it just stopped pullin at 55 and he hit 2hi button and it toook off again. just curious if mine is the same.

as far as I'm aware, his shouldn't have any 4hi speed limiter on it either...but I've not examined a GMT800 tune in detail for a while.

 

[Darrin De May]

the 98 has a programmed speed governor in it regardless of 2hi/4hi selection...I think stock is 98 or 99 MPH....not 100% sure about the 94 but I would guess it would be similar...

on the 98 you can get a tune to raise the governor (you can't eliminate it altogether, but you can raise it ridiculously high)...mine is set to 255mph....on the 94, I believe you can get a chip burnt to change it as well...but you'd want to talk to someone more familiar with OBDI chip burning.

Didn't know that there WAS a speed governor until very late the other night when I was heading East on Interstate 10 over the hill at Whitewater and punched the accelerator as I crested the top and was coming down the other side. It felt like the truck was having catastrophic engine failure until it dawned on me that it must be the ECU making it cut out. Wow! My wife's 2015 Subaru Forester XT Touring makes a gentle little "beep!" when you hit 100 mph, what I experienced in the C3500 was completely unexpected!

 

[MIHELA]

A 94 will have a speed governor at 98. The PCM doesn't have any way to distinguish 4HI from 2WD, and doesn't have any sort of separate scalar for it. Even in 4LO which the PCM has an input for, it would only be limited by the rev limiter.