Alright, I need some advise on if I should swap out my T56 for a TH400.

Here is my setup:
engine makes 402rwhp with my MS3 cam. I will be adding nitrous this winter.
Currie 9" with detroit locker
Sphon torque arm
made my own lower control arms, in the lowest hole on the brackets
BMR Panhard and SFC
Wolfe 6 pt cage
QA1 12 way all around set at:
- setting 2 front driver, setting 3 front passenger, rears are 5
300lb springs in the front
...forget what springs I bought for the rear lol

Viperized T56
Spec 5 clutch with Quicktime scatter shield
1200hp steel driveshaft with cryo dipped u-joints

ET Streets 28x11.5 in the rear

I had the interior out with these videos, weighed at 3350 without me in it.

Leaving off the 2-step at 5500rpms

The week before I took these videos, it was in the 80's and I would get 2-3 rotation of tire spin off the line, worked really great, but I didn't have my shift light and I was doing shake downs.


The night of these videos the temp was in the 40's, track was VERY sticky, as you can see the front wheels pull because of the dead hook, and then I loose all momentum.

1st pass - best time - hit the rev limiter in 1st and wasn't on the 2-step long at the tree
http://www.youtube.com/watch?v=O-cidM67ujY

pass #4 - last of the night and the year - it's running rich, as you can tell from the backfires at the line lol
http://www.youtube.com/watch?v=RNBOh7WJBPc



I can't decide whether to switch to a TH400...I like throwing gears, but
1) If I blow the trans/clutch next season, it'll probably be down for a year
2) I don't want to risk hurting the engine from a missed shift
3) I could run faster --how fast could I go?


If you want the time slips I can post up that information


Now I KNOW i need more practice, these were basically just shake downs, but I feel if I switched to an auto my gains would be huge

Looking for opinions based on what you've seen from what I've provided.

 

Sticks are hard to run at that power level. You need that tire spin to keep it from bogging, or slip the clutch.
For me I was lucky to have 2 good runs in 10 passes. The best passes were running though the clutch, didn't live long.
Looking to go A3 myself, either TH350 or 400 with a 4k stall.

 

yeah i'm at 402, but plan on adding another 150 shot of juice ontop of that next season.

An auto would be so much easier to wire up for nitrous than a stick.

Cant decide, anybody else?

 

Just out of curiosity what is your race weight?

Most folks can't shift a T56 and run as good as a well-setup TH400 setup. If the car is mostly about drag racing I'd do a TH400 and save the T56 for when you decide to street drive again in a few years.

I have street driven TH400's and they are no big deal, the new project car will get one, probably a 4800 maybe 5000 stall. It's a little big for street driving but I don't mind.

 

All I can say is this, That cam is not doing you any favors and that ET Street should be swapped for a ET Drag.

My car....


m6 - 12 bolt - 4.10's BMR LCA and TQ arm - Stock Shocks - 4k+ race weight - VRx4 cam 228/230, making 380-385 - full exhaust w/ cats - tune -Tex oz700 clutch

ran 12.30's @ 112-113 w/ a 1.78 or so 60 foot.

The car was rolling on convo pros, and the smallest ET drag they make. I had thechef w/ me lining me up, got a good burn out 5.5k dump with no 2 step and managed pretty good. The car needs QA1's which I have bought and I have R series fronts on the way. I also just got a UMI Drag bar and TQ arm relocation bracket.

We hop to be leaving level and popping the wheels decently.

When I see the first vid, that cam has such shitty under curve power, its almost a 2 step is not needed. To be honest I have no clue where the top end is either as apparent with the mph.

With the nitrous, it may become a differnet beast but for now I think that car def leaving too soft.

 

150 shot should bring enough torque to pull you to the 60' if the car is set up for it. Problem is that same chassis set up wont work off the bottle.

With an auto, the converter is very forgiving to this situation.

BTW, what ratio is in the rear, and in what gear and rpm do you cross the line?

 

Yea, I was meaning to get to the same point. I was just pouring over the M6 setup. I am too curious on the gear ratio.

 

without me, and only the factory (leather) driver's seat, it was 3350lbs

I'm thinking about switching to a th400, just for the fact that I'm less likely to break something...plus I should be able to run a lot faster.

 

The cam seems to make pretty decent power, but a lot of it is uptop. On the dyno, it was still making power above 6500rpms, but at the point the stock lifters would start to float. The gas was bad and it was running very rich that night. In the spring I plan to have it retuned, and then tuned for the nitrous hit.

I would think the ET streets are doing just fine, from my understanding the ET Drag is the same tire, just isn’t DOT approved? Cars are going 7 seconds with the ET Streets.

The car just lost all power on those runs because it was practically dead hooking, and bogging the motor I believe.

 

Gear ratio is 3:90, it's just what was in the 9" when I bought it used.

I cross the line in 4th.



What do you guys think? I'm sure I need a different gear ratio, but I'm not going to change it right now.

Just wondering what kind of improvements I would see with an auto over my T56....

So with the spray I should be at around 550rwhp

 

You are 250, so 3600 raceweight?

 

ET streets are much stiffer and the compound is not as good as Drags. N?A the car prob need a 4.10 min if not a 4.30 but when you put the jug on, your going to want a 4.10 max.

As for the auto, its going to drop ET like crazy. The biggest issue is the lost of the O/D but you get that consistant slip on launch.

 

280
so 3630 raceweight

I need the fat driver! mod

 

Any guess on how MUCH of a drop in ET?


The track, which is one of the best in the country is literally 10 minutes from my house, and thats just a straight shot down a country road, so I'm not worried about O/D...this car is becoming just race only...slowly...

After picking up my vette this year, I have no reason to keep the F-Body streetable. I just need to be street legal until I get a trailer

 

If I tossed a stalled RMVB Th400 and lets say the stall was 4,400 or so. I would go from 12.30's probably down to 11.90's or even 11.80's.

 

I'm happy with my A3 swap. And my 5200 stall isn't too bad on the street.

 

I was just curious about the 4k plus race weight? Did you scale it or just adding up parts? It seems like a ton of weight.

 

Are you in the mountains or something? Do you know the DA where you run?

Because in my opinion either your racing on top of a mountain or your car isn't running right. I'm not tryin to brag but my car ran 111mph with a lid, ported TB, and homemade ram air on 18in street tires... I would make sure it running right (seafoam, oil change, plugs, wires, fuel filter) and check the tune..


FWIW my guess is you will pick up atleasat 3-4 tenths switching to an auto with big stall...

 

spending ~$3,000 for a TH400 swap just for 3 tenths doesn't quite seem worth it?

So, I'm thinking that once I stop granny shifting, and get my tune back in order, since the gas was about a year old, even with Sta Bil in it, I should be around 12.50'ish...

I was hoping going auto would throw me into solid 11's, then a 150 shot would put me.....?

 

3-4 assuming your shifting and launching decent currently.. if your not maximizing your setup as a 6sp you could see more.. I would look into the car some more as I said above though..