For some reason my car was shifting at the stock shift points at the track. The shift points were bumped up months ago with LS1edit. I run a Yank Y3200 which has a shift extension of 4200 rpms.I confirmed this with Atap. My trap speeds were way off by 7 mph. I then manually shifted both shifts at 6300 rpms. The car gained lost mph, but my shift extensions were no where near 4200 rpms, they dropped well below that.

What's odd is I gained the lost 7 mph after manually shifting, but my ET only improved by .10 with a identical 60-ft.

Any comments or suggestions (besides fixing the shift points)?

 

why are you manually shifting it? just put it in D or OD and go.

 

1) It's too hard to evaluate your setup without a list of your mods.

2) Post the numbers from both time slips.

3) If you have a stock engine you are probably floating the valves at 6300.

4) I would only manually shift my FLP IV over the prior two years when I was trying to see if I needed to change shift points (before the advent of LS1 Edit). It's useful if your car is shortshifting otherwise I would not do it.

 

7 mph loss is generally not caused by shift points unless you are shifting at 5000 rpm. More typical is 1 or 2 mph on a stock cam car and 2 - 4 mph on a cammed car.
Are you down on power (e.g. bad weather?) that will also reduce shift extension a bit.

 

Sorry I should have posted more information. I run the 02 LS6 cam and springs, hence the higher shift points. I manually shifted because after atapping the first run it showed shifting at the stock shift points. As an experiment I manually shifted the car which resulted in higher trap speeds. What I thought was odd was I could run up to 6300 rpms by manually shifting. I can only assume the PCM must take in consideration other parameters for shift points (Rpm vs load?).

I never manually shift the car and felt it was worth a try. I'm going tonight to have the car looked at by the shop who tuned it.

Corrected DA was 2,066 feet. But between the runs the weather was the same and the air intake was 112 degrees for both runs.

 

Your rev limiter must be higher now from when you got the car tuned.

 

If you shift manually timing is pulled out by your computer. You will slow down.

 

Does a stock trans let you shift manually up to any rpm, or only with a shift kit? With the trans-go you can hold the gears as long as you want til the rev limiter right?

 

Just came back from the shop and the shift points were still stock. Don't know why, but I watched him program the correct ones.

I manually shifted one time and hit the limiter, so you definitely can rev past them.
I didn't see any timing pulled while shifting, but I will check the log.

Now it's back to the track.

FYI- I heard the large variance in trap speeds can be caused by how the car goes the lights and especially the f-bodies are sucseptible to this. So if you pull off the gas it can lift the nose causing inaccurate readings. Also it depends on the how flat the track or if it has a crown to to the surface.

 

dont you mean if you pull of the gas the cars noce goes down? I know when I let off after the traps the car nose dives

but maybe they didnt save the changes to the edit program before he programed. Ive done that a few times... Ive changed it on edit, but forgot to save the file and then program lmao

 

Manually shifting ur stock 4l60 will kill it.

 

Why is it so bad for it to be manually shifted? I know mine never shifts where I want it to, and it is built with a trans-go in it.

 

It's a computer controlled trans, when you hold it in gear, then upshift it may actually slow you down. Just put it in D and hang on.

 

I manually down shift, to hear exhaust cackle. I love the sound of a healthy v8. Anyway, will this downshifting harm the tranny also? If so any solutions?

 

I only manually downshift to 3rd (D for Camaro) from OD before going WOT (my trans builder recommended using 3rd instead of OD). I never go lower than 3rd (D) manually. Switching between 3rd and OD should have no adverse effects, but if you're putting it back into say first at a speed which you should be in 3rd or 4th at, then I would consider that to be abusive behavior towards the trans.