C5 Tranny Experts????

[YO-EL]

Why would my car be "alive" , quick , etc, when doing the wheel clean & burnout prior to racing, but then at the line while power braking say 1500-1700 rpms, it sounds weak, and is always SLOW to respond at launching?

The car actually runs supreme, but is always sluggish off the line. Like I said, at idle to WOT, car ROARS & spins tires during quick clean off & ROASTS them doing burnout. But once I'm at the line, its a dog to move. Any thoughts??????

Some guy said maybe I have a worn clutch band in the tranny, good for a good burn out and then gets warmed up and stretches a little.

Anyone ever heard of this??????

[Rich Dunbar]

Hi Ellis,

It is possible for bands to overheat and lose some of their grip, especially under the rigors of drag racing. They don't really stretch per se, but rather the friction material on the band gets hot and loses its ability to grip. At the extreme of band wear the band actually gets burnt. Overheating/burning a band would result in a slipping condition in the trans, which you would see as RPM's increasing with no resulting increase in MPH.

That being said, I doubt your problem is a band problem. The 1-2 band in your 4L60E trans comes on (grabs the clutch drum) in second gear and fourth gear, not first and 3rd. The only components engaged in first gear are the low/reverse clutch pack and the 1-2 sprag (one-way clutch). Here again, if these components had a problem, there'd be more of a slip condition, not the "bog down"/loss of power that you're describing.

To me the problem you're experiencing sounds more like an engine performance/fuel delivery issue.

Feel free to call me at the shop if you'd like to discuss further. 610-642-4344.

[YO-EL]

I agree wholeheartedly with you Rich, & thanks for responding.

RPM's are not spooling up, and I feel like you , something is not right with engine or fuel, timing etc.. somewhere along the line...

Its almost like when I brake stall it, timing is being pulled.

The clean off & burnout are fast & hard, but after the burnout, up at the line, when I brake stall it, it really lugs.

I believe abuse mode is completely disabled, so it may be more of an air/fuel/timing advance issue.

I heard that after the wheels spin, there is knock.
I had the knock sensors desensitized to pull 0 degrees of timing from 0-3000 rpms if knock was present, so I am totally at my wits end!

I may have to find a tuner who can accompany me to the track & autotap my car to see exactly just what is happening.

I've been battling this inconsistent launching for 2 yrs now.

Sometimes my car jumps out of the gate, other (most) times its a dog... Really lugs.... uggggggg

[REDGAR]

El could it be traction? You are sitting in sticky stuff so you will not be able to get the tires off the line the same as you do after running through the water box. You do put quite a bit of heat in your tires, more so than others, and I bet that has something to do with it. I have kept going with bigger stall to try to resolve this in my car.

Does it feel the same if you don't brake stall?
Does it feel the same if you brake stall without a burnout?

[YO-EL]

That is also a thought, & I tried to to tach it up slightly higher to 2000 rpms, but at that level, I spin.

Edgar, I know you're not the auto technical guru, but on April 3, how about doing one of the time shots in the GM High Tech race for me, and tell me what you think...

I am planning on having 2 other guys do this as well for their thoughts, Mikie C, and maybe Mackey.

[REDGAR]

If time allows, sure I will. Hope you don't use my run as a dial cause I might be a "little" slower than you in it.

[YO-EL]

I'll do the 3 time shots in the Challenge.
You guys take the other ones...
I am more concerned at your impressions on launching & the R/T's than the ET..