I'm having a problem getting my tranny to shift during a hard nitrous launch. I can launch at 3500 or so and cut high 1.4s or low 1.5 and it's fine, shifts good. But when I try to launch around 5500 it takes off like a rocket but won't shift 2nd. It gets harder to pull back (like it's bound up). So I lift and drive down the track, when I get to the return lane it's stiff but then I wiggle the shifter side to side in neutral and it loosens right up and shift fine

I don't really know the hp level of the motor, but it's a forged 346 with ported ls6 heads and a little bit of nitrous (200 shot) I have to change the gears cause it hit's the rev limiter at the 1000ft mark, but it drifted through with a 10.26 @ 120

I think that maybe the case is flexing and binding the shift rods. Does that sound crazy?

Thanks
Frank

 

Why are you trying to leave that high on a nitrous pass anyway? Lower is usually better on the jug. Sounds to me like you're doing great for what you have- H/C stock cubed LS1 on crack running low 10's cutting 1.4 60's...

I'm no tranny expert but I've had friends with various stick cars have the same problem, when they try and leave at a high RPM on gas the tranny won't shift.


IMO, keep leaving at 3,5k and keep on gettin'. I wouldn't worry about it until something breaks. And no, you're not at the limit of the tranny. i would imagine you're probably around 600ish on the jug. There are people with a lot more HP running T-56's.



Beautiful car BTW...







Jon

 

Thanks, Cumnbyu. It's nice to know that I'm not the only one with that problem. I really wanted to squeeze a 9 second pass out of it so I figured why not just leave harder . I think I better get my gearing straight first so I can make an entire pass.

Frank

 

boosted one- badass ride

 

I also don't think the t56 is the problem, are you using a hydraulic clutch like we do in the fbods? I think that is a major factor as to the manaual shifting problems. There seems to be no "good" aftermarket clutch that really works.

 

Cooooooooool Car.......

 

I have had a similar problem. I just yank the hell out of it to get it outta gear and into the next one. It feels like i'm shifting pretty fast but on video it don't look that fast. And this is with fresh rebuilt tranny that has all the bells and whistles

 

Thanks for the compliments guys!

Here's a video of the run if your interested.

Video

Frank