Hi all,

I was wondering what MPH you guys are at when shifting into OD at WOT. Mine shifts at 110mph with my 26" tires and 114mph with the 28" tires. It is shifting at 5800 RPMs. It seems kind of low, and I don't want to run my 150 shot because of this (I am trapping 113 on the 100 shot). So if you can please let me know when yours is shifting into OD . Thanks!


PS - I understand that LS1s have different shift points. Like I said, my LT1 shifts at 5800, so if you could tell me where it's at at 5800 instead, that would help me better.

 

this should help http://www.f-body.org/gears/

 

I haven't had the chance to find out, but doing the math it is somewhere around 130. But I am shifting at 6350 (If I remember right)

 

hmmm i think mine finally shifts into OD at about 115 or around that, and my shift points have been raised 200 rpms every shift ext. Hardly ever do it so not 100% sure

 

Guys,

the converter slippage does not allow me to use a standard calculator

 

It should be close shouldn't it? Especially with a smaller stall.

 

Yeah, there's not very much "slippage" with a 3200 stall.

 

not to safe to shift into OD at WOT is it?
i blew up a built 700 that way, and ive seen other people do it as well.

 

110?? my car with 4.10s will hold out 3rd til that. im going to 3.73s soon bc im hitting OD in the quarter. It should be higher than that.
im on 255/5/16 bfg drag radials, and stock stall.

 

humm lets see i trap close to 115 on a 26x10.5x16 tire and i still have plenty of room to go. easily near or past 120. i put my car in drive or 3, so it locks out 4th and wont go into OD at WOT. my shift points are 6200 rev limiter at 6500. its all on how its tuned i suppose. worse comes to worse just run the taller tire

 

Guys,

Keep in mind, a 3200 stall in an LT1 is pretty decent sized, especially considering I just have bolt-ons.

Also, I'm shifting at 5800 (another thing to keep in mind).

 

I'm running 28" tires. What RPM are you at @ 115mph?

 

I am trying to figure out how much slip is normal for a hi-stall converter. I compute yours slip at 114MPH w/ a 28" tire @ 5800 RPM's as 13.67% slip. But what doesn't make sense to me is that with a 26" tire, same situation but at 110 mph your converter slip is 9.38%.

Maybe it would be more beneficial to you to find out how much your converter should be slipping to know if yours is shifting at the right MPH. Or you could contact Frank, at CPT and see if your tranny/converter will hold up to locking your converter on the big end to make sure you don't run out of gear, if so that may be your only option besides a larger tire, or higher shift points.

 

i wish i could remember exactly but i think that its around 5700 rpm... i know on the street on 275/40/17 street tires ive taken 3 up to 130 and still had some room

 

the taller tire is putting more of a strain on the converter, as it sees less actual gearing.
the 26" tire is "easy" on it. thats why it doesnt have as much slip. it affectivly has more gear with the smaller tire.