it sounds to me like you went into 4 gear to me.

I use lockup when I raced my camaro. its applied all 2nd and 3rd gear. went .15 quicker and 2-3 mph faster with the lockup engaged compared to unlocked. mine is a manual lockup switch though since I use a 700r4 not a 4L60E. also, I had 3:73 gears until last spring, then the gears broke and I had to switch back to my 3:42's. HUGE diff. just between those gears. but I too would recomend 4.10's if your drag times are more important then rpm's down the freeway. but Im sure you'll be happy eitherway.

oh, my car was a 383, but I got a 1.56 with the 3:73's in cool air, and could only muster a best of 1.59, but mostly low 1.6x 60's with the 3:42 AND 20RWHP more compared to when I had the 3:73's.

Id bet 11.0's too with some better gears and the right launch technigue.

how did you launch off the line? dead idle to WOT on the last yellow or 1500rpm against the footbrake then let off the brake and WOT? launching off dead idle will get you the best 60' times if your car will hold traction. those are the same tires I had and theyre plenty of tire to hold low 1.5x 60's long as your susp. is halfway decent.

chris

 

EDIT: just noticed your last reply about the n20. ok, depending on how much nitrous your goin to run, might just leave the 3:42's in there. if only a 100 shot, 3:73. if more, Id stick to the 3:42's. course, i you went up to 3:73's and alot of juice, you could take some gear out by using taller tires. 27" or 28" depending on where the rpms are at when you cross the finish line with the new gears and nitrous.

 

Yeah I like 3.42's for spray also and thats why I ran them for so long, not to mention 10.17@132mph on the stock 10bolt and a 200shot.

 

I launched it by the 1500 rpm technique you listed...Not sure on the RPM but seemed to be just over idle.

 

You guys think I should ditch the 4l60e and go with a th350 or th400?

 

Do you want less first gear and no lockup or OD?

The 4L60E can take all a naturally aspirated LT1 can throw at it and as much as most power adder ones can as well IF done by the right shop.

 

Not having OD and lockup doesn't really bother me. And I'm not sure if having less 1st gear would be that bad?

 

No, have Frank @ CPT build you a 4L60E.

 

yeah they can be strong enough, but even the ones built by the right shops still break sometimes. I dont blame people for wanting to have a bulletproof tranny and just forget about it. you could be one of the lucky ones who make lots of 10 sec. pass's, or you could be one of the ones that pay shipping costs several times cause things break. Im not goin to say who, but my buddy bought a $1400 4L60E, had it break once, had to have a local trans shop fix it, the company paid for the repairs. then it broke again (totally diff. problem) and they only gave him a portion of the bill the 2nd time through, and told him to not call back cause they werent goin to help anymore. then he had to have the local tranny shop redo the trans out of his own pocket. so now he has about $2000 into his 4L60E and ALOT of downtime. I will say its NOT cahall or probuilt. those are the two that I personally do like. Ive talked with both guys a few times each over the years. its a diff., known company.

anyways back on track...

you havent said how much juice and how much will this be raced? Ive seen tons of TH350's in 9 sec. cars, so thats what Id do. but it is a costly crossover since lots of things need to be swapped out to make it work. would it be faster then a properly working 4L60E, no. will it survive repeated drag strip pass's, it should. again still has to be built right. th400's are a little bulkier,alot heavier, and they consume more HP. thats why I like the th350's better on paper. if you did go A3, you will be giving up the awesome first gear ratio. that change alone would be like droping down to 3:08's in the back. but its only for first gear. fine if you got soo much power you cant get traction, but if you got traction, then your just giving up 60foot by switching. I was building my car for low10's on alot of spray, and decided to keep the 700r4. but only cause I got a guy at my work that does my trannies for me for a fraction of what the big shops are building them for. plus I didnt want to give up my OD or the first gear. you just gotta weigh the differences and how you plan on using the car.

chris

 

You can see by my sig that I had to make the choice you are pondering. I did this years ago when the 4l60 was always the weak link.

If I were to do it again, I would probably just get a built 4l60e. It seems places like CPT and a few others have found a way to make them live. I am not convinced on thier long term durability, but they seem to hold up fine for the average weekend racers.

 

I'm looking to spray 200-250 shot eventually. I would like to try for N/A times right now so I may go with a 4.10 and when I want to hit it with the juice I'll just swap some 28" tires on it.

The car is made to race and thats it. I drive it on the street some but its sole purpose it to drag race.

So you think a properly setup 4l60e will be faster than a th350.

 

yeah but only cause of the first gear ratio advantage getting off the line. and the lockup if you use it while dragracing. some wont do it, I never had a problem with it though? and back to back testing clearly showed me that it does help.