0331gunner

I ran a 10.87 at 127 mph with the t56. I put a th400 with a 3500 stall. went to the track and was only hitting 11.8x at 115 mph. What gives? its a double balloon tq converter and the trans is made to hold up to 1200 hp/tq. any ideas??

Duffster

iTrader: (103)

60's? Shift points?

Cam72aro

iTrader: (28)

Converter too loose? Converter too tight? 60' before and after? 1/8 before and after? Trans brake? Yes or no? Are you n/a boosted or spraying?

djfury05

iTrader: (30)

He was 60'ing in the mid 1.5s low 1.6s consistently with the T56.. I don't know what it is now I haven't seen the slips but it is not even close to 1.5s

0331gunner

60 ft before was around a 1.5 after it was a 1.8. foot brake. but it didnt matter how high i took the rpms up. and the air pressure didnt make a diff. Im n/a but going to spray it soon thats what I wanted a trans that would handle up to 1200 tq.

0331gunner

around 6000 rpms but the it feels like the motor wants to go highter but the rev limiter is at 7200. we went from 16 psi all the way down to 10 psi in the tires nothing really made a diff.

djfury05

iTrader: (30)

I don't see how a TH400 swap with 3500 stall could be responsible for a drop of 12mph.. something isn't right

95_transam_lt1

iTrader: (6)

if you get the 60' down to 1.5 it will only be at 11.20. the prob with the 60' is im assuming its a nitrous converter which without spray is a dog out of the hole. the other .3-.4 im not too sure, but the 400 is geared so lets say you swap 4l60 to an 80 or a 400 it will slow you down due to worse gear ratios. you need to research the transmissions side by side

95_transam_lt1

iTrader: (6)

what was your mph at the 1/8?

Cam72aro

iTrader: (28)

Bet the converter is too tight. What is the converter?

djfury05

iTrader: (30)

Maddog transmissions built the TH400 and supplied the converter.. he told them he was going to spray a large shot like 400shot +.. this is what he ended up with. I think all he knows about it is its a 3500 stall with double anti balloon plates.

Jake's Performance

iTrader: (2)

A 12 mph loss represents a huge HP loss. While a T56 and clutch is more efficient than an auto and torque converter, there isn't going to be that kind of mph loss.
2-4 mph would be realistic loss.
The TH400 gear ratios are not all that different than the T56. 2:48 vs 2.66 typically. The torque multiplication effect of any torque converter will more than make up for the ratio difference as it relates to 60'.

You need to check your tune up. I suspect something is amiss in the engine/tune.

What is the actual flash of the converter when launching?

Jake's Performance

iTrader: (2)

Also,
Every .1 of 60' is generally .3-.4 tenths in the 1/4 on a NA combo.
So your issues could be related mostly to 60', but the mph loss indicates another issue as well.

Let us know what you find.

Cam72aro

iTrader: (28)

If he told them that big of a shot its going to be a pig on motor. Its way to tight to be ideal for a n/a setup. I had an s10 a few years back that had a real tight nitrous converter in it. It would only go 3800 on the brake. On motor it went 6.90's in the eighth and 10.90's in the 1/4. If it had a 5500 or 6000 converter it probably would have gone low 10's on motor. I sprayed 250 off the brake and it went 5.70's and 8.90 in the 1/4. I think the converter is way too tight or something is wrong with it. It could be slipping severely also.

Vince B

iTrader: (1)

I think cam72aro kind of hit the nail on the head here. Not that I'm a big fan of MD. However if the converter was built to be hit a 400 shot it is probably not stalling correctly running NA. What is the converter flashing to currently? 26-2800?

95_transam_lt1

iTrader: (6)

i thought every .1 in the 60' was .2 in the 1/4?

and if its a nitrous stall you cant compare to the old setup. either spray it or get a loose converter. my buddys got a nitrous stall and it 60' like **** because he doesnt spray out of the hole

djfury05

iTrader: (30)

Thanks for posting man I actually told him on Facebook to call you tomorrow and provided him ur website and phone number lol..

I know nothing of how a stall works can u explain what flash means? The car doesn't move unless rpm's are 3500 or more. He can footbrake to 4000 and not move. That is all I know.

djfury05

iTrader: (30)

Ok I looked up what flashing means and I think he would have to go out and try it and let us know

0331gunner

0331gunner

I will post the other time slip when i get it out of the car.