Im very impressed with the numbers your car is producing at the track. Im curious about what kindof dyno numbers your making with your th400 and what convertor you use. Ive just recently went to a th400 from a t56 and a solid roller setup. My old setup produced 676rwhp and 842rwtq with a hydro cam. Id like to know how much hp you lost with your th400 and what your race weight is also when you ran your best NA and n20 runs. and how much n20 did you spray to get the 9.5

appreciate any help you can offer me.

 

On a Mustang dyno my car puts down about 410 RWHP on a 28" drag slick. Before we managed to turn it up it was sub 400. A lot of that was due to a significant exhaust change at about the same time I did the tranny. Before that I had the car tuned on the M6 and it was 475 RWHP on a Dynojet. My guess would be a loss of 50 HP to the tranny, but we picked up about 20 HP with the exhaust change thrown in there.

To make this more interesting, a 200 shot on my direct port brings the car up to 550 RWHP and it ran 9.7x's. A 300 shot put 650 RWHP down with 9.5x's 145 to 147 MPH and terrible 60's. If you go back and do the math that HP and ET simply doesn't add up for a car that weighs 3450 pounds. It really puts motor horsepower around 500+ RW because it actually would take upwards of 850 to 875 RWHP to run those ET's at that weight. I realize it's sort of fuzzy math, but if you go to any ET/ MPH / Weight calculator you'll see that it doesn't add up.

Like I mentioned in the previous posts, don't be alarmed by the numbers too much. It's just a tuning tool, that's it. First of all a Mustang dyno is absolutely hell on an automatic. The same car with an automatic versus a manual will get slaughtered in a king of the dyno contest, especially on a Mustang. But at the strip you will notice some significant differences. I can't tell you what my peak torque is on the dyno, my converter flashes above 5200 on spray so we only sample from 5200 RPM to 7500 RPM.

The converter I use is a 9-1/2" Neal Chance two piece racing converter. It's a slick unit that allows me to basically unbolt it and replace the stator with another one to achieve a different stall speed. Instead of shipping the converters back and forth it works out really nice. It's quite a bit more expensive then a one piece, but you can get a one piece NCRC at a comparable rate to other one piece units. Overall it's a great converter, I'd highly recommend it personally. They don't really advertise here because it's not their core market but there are a few people that use them.

In my case I noticed a gain of a .5 second and 2 MPH straight up on it's first pass NA. I never sprayed the six speed, it didn't last too long on motor before it blew up with the rear end. I'd like to work out my 60' issues and hopefully the car will put down some more impressive numbers. I only sprayed 300 at the Thunder Shootout and it was radically different compared to a 200 shot. Played hell on the tires too.

Overall you can't really beat the reliability of it. If you get a really well built one it will last for a long time. I had Carl Rossler build up one for me. That included an aluminum drum that was hubbed, so you can drive it on the street. It has some upgraded billet components as well, an ultrabell, etc.

Anyway, let me know if you want any more information. Feel free to tear apart my numbers. The number 5 spot is up for grabs!

 

Derty,

I just had a custom 9" put in the car and am real close to getting my TH400 next. Did the billet components of your tranny save some rotational weight? Also, I was curious what the ballpark costs of Rossler's tranny with the upgrades is.

Thanks.

 

I'm not sure about the gains or losses on the billet components. I'd expect them to be fairly close in weight. I was more interested in strength. A Rossler tranny can start out below $2k. The ultrabell is $200, the hubbed drum is another couple hundred, deep tranny pan, etc. etc. When it's all done you can get upwards of 3200 bucks. It's roughly rated around 1500 HP compared to a stock unit which is rated to about 800 HP. He also makes a billy bad *** version that's about 4500 bucks which he runs in his 6 second Bel Air.

 

I talked to Carl and he suggested just getting the billet aluminum high gear drum for weight savings and strength in one of his competition 400s. They definitely have a lot of options and he mentioned there's a super stock 400 that starts just under $3k that sounds bad ***. It's not the full blown version that you listed, but would probably be pushing that price with a sleeved drum, deep pan etc, speedo etc. Will probably make a decision within the next two months on which version to go with.

I'm looking forward to this mod as I think I'm blowing through my Midwest converter (42-4400 stall w/no lockup) on a small shot of gas.