Well I just got the car on the dyno yesterday after the addition of a TCI TH400 with a 8" 4400 stall, trans brake, my bogarts and 28inch tall Hoosiers. My pull with my 6speed and stock ZR1 rims was 504rwhp and 487rwtq. WIth slicks on and everything through the automatic she made 421rwhp and 511rwtq, so I lost about 83rwhp but gained 24rwtq with the new setup, Ill list my setup below:

FMS 396 stroker
Strange 12 bolt
TCI TH400 4400 8" stall and Transbrake
All BMR suspension products
8 point Cage
car weights 3580 with Ron Mowen in it (CamminBeaSSt)

I have only had a chance to take it to the track once since I got the TH400 in it, and it was a CRAPPY 1/8th mile track, but my best time was a 7.14 at 97mph with a 1.39 60ft....definatly with weight reduction I can get allot more out of it.

 

That is a HUGE LOSS.. Wow!! I did not know those trannies hurt that much..

 

that is a bit extreme, but look at the power and consistency it makes up for.

 

Well his old dyno was with street tires compared to 28" slicks. That alone would be worth 20 rwhp or so.....

so that brings the difference to 63 rwhp (geez thats still a bunch)


I wonder how much mph loss in the 1/4 youd see from stick to auto..

 

i think one of the reasons for the major loss is the converter.....

wouldnt a 10 inch converter with a lower stall be a little more efficient...ie make more power? not saying that converter would be the fastest at the track, but just wondering

 

I'll say if you over layed the two graphs directly on top of each other, that the Auto Graph will have a higher average HP and torque across the whole band, just the peak HP suffers.

Ryan K.

 

I lost more than that with my Th400 PI converter swap. Around 100rwhp. And dynoing on slicks will not make a 20rwhp difference, plus his drag wheels are lighter than street wheels.

 

Also what heads and cam do you have? What is your compression?

 

I think the converter ate up a lot of power.

Might want to look at something a little more efficient. We typically see 30-50RWHP loss through a TH400 vs 6 speed.

 

Ive dynoed several cars (as i own a dynojet) with street tires with full air pressure (i.e. 17 wheels low pro tires) vs wrinkle wall ET Streets/Drags @ 12-15psi

And typically yes i do see 20 rwhp losses on the higher horsepower cars.

 

I have seen 15RWHP between radials and slicks as well

 

yup same here, i have personally lost 16 rwhp between my radials and my 28" et drags at 15 psi on the same day.

 

Can we see the graphs?

 

My heads are TEA 5.3 stage 2 heads with a competition hand finish, my cam I BELIEVE if i remember corectly is a 238/240 with like 600ish lift, small cam. I can have the dyno up, but it will be week because Im in Auburn for school and the graph is in Atlanta. It was my understanding by TCI that I would get better times with the 8" Converter over the 10"...........any comments on that?