Converter multiplication ?

[L79racer]

Originally Posted by 1320racer

If you have questions as to whether your current converter is optimum for your combo speak to Charlie Plott at ATI.

As to my car's specs...

522 BBC, turbo400, 4.57 gear.



Slowed to run low 9.0's all season long at near 150



More importantly what are the specs of your car/combo?

Pump gas 383, glide with a 1.80 gear set, 5500 stall and 4.56 rear with a 29" slick and or a 295 drag radial. I shift at 7200 and run through at about 7000. That T400 gets you going with the bigger 1st gear.

[1320racer]

If you think a turbo 400 "gets you going with the bigger 1st gear" why aren't you running one?

what is the best and average ET, MPH and 60 foot and at what weight? Also how many passes on this combo as it now?

Need all the details of the car/combo to determine if it's running near optimum and if the converter is right.

The devil is in the details and if the combo is mismatched, you'll never get the 60 foots you're looking for regardless of whose converter is behind that engine.

Did you read this...

Originally Posted by 1320racer

Be prepared to provide him with factual data, including but not limited to what does the converter flash to on launch, what RPM does it fall back to on the gear change(s) and what RPM is it crossing the stripe at and the only way you'll know this is with a playback tach or data logger.

[L79racer]

Originally Posted by 1320racer

If you think a turbo 400 "gets you going with the bigger 1st gear" why aren't you running one?

what is the best and average ET, MPH and 60 foot and at what weight? Also how many passes on this combo as it now?

Need all the details of the car/combo to determine if it's running near optimum and if the converter is right.

The devil is in the details and if the combo is mismatched, you'll never get the 60 foots you're looking for regardless of whose converter is behind that engine.

Did you read this...

Well as the T- 400 goes. It weighs more than the glide and uses more HP to turn. So they say you will be faster with a glide but will not 60' as good as a 350 or 400. This is my first automatic so I'm still learning. I did speak to Ati when getting my converter and did tell them all the details and specs and I have what they speced for me. Dont get me wrong, I am not saying that I dont have the right converter. I was just stating that a few other racers said I should have told ATI it was for a super stock car and they would have done something different to the multiplication in the converter. I was wondering if there was any truth to this. I'm at 2900 lbs race ready. For what I have and run its pretty damn near close. Just felt it leaves soft. I'm sure a little more gear or 28"slick would pick it up a bit. I ran it all last season and made about 50 passes with it.

[1320racer]

how big are the heads, what is the cam @ .050, what intake manifold and what carb?

[L79racer]

Originally Posted by 1320racer

how big are the heads, what is the cam @ .050, what intake manifold and what carb?

195 comp. ported AFR heads solid roller 2.58 / 2.65@ 50 Victor Jr. 2" spacer with a hp 950 Just under 11.1 compression. 1 3/4 headers

[Alan Roehrich]

You don't have enough gear, nor do you have enough low gear in the transmission. You don't need to try to "fudge" anything by telling them you're putting it behind a Super Stock engine, besides, when you give them the specs, they'll know. You need a 4.88 or a 5.13, and about a 1.90 low gear.

[L79racer]

Originally Posted by Alan Roehrich

You don't have enough gear, nor do you have enough low gear in the transmission. You don't need to try to "fudge" anything by telling them you're putting it behind a Super Stock engine, besides, when you give them the specs, they'll know. You need a 4.88 or a 5.13, and about a 1.90 low gear.

Thanks for your input. I will be trying a 28" tire to see how it likes it and what rpm it will be at crossing the big end. If it likes it, I will go to the 4.88 and 29" tire.

[1320racer]

Originally Posted by L79racer

195 comp. ported AFR heads solid roller 2.58 / 2.65@ 50 Victor Jr. 2" spacer with a hp 950 Just under 11.1 compression. 1 3/4 headers

2" spacer equals too much plenum volume which helps to kill the launch though and the cam is too big at .050.

That said, the quick fix is more gear or a 3 speed trans and a shorter tire.

Here's an example of a 3160 lb. footbrake launched ride slowed every week to run low 10.0s with a sbc under the hood backed by a 1.80 1st gear glide that leaves with a best 60 foot to date of 1.27 and has run 9.77 @ 138+ with a manifold having less plenum volume than yours and no 2" spacer

[L79racer]

Originally Posted by 1320racer

2" spacer equals too much plenum volume which helps to kill the launch though and the cam is too big at .050.

That said, the quick fix is more gear or a 3 speed trans and a shorter tire

Thanks for your input also. I will try the shorter tire to see if it likes it. Then add more gear if it does.

[L79racer]

One more question. If I change the gears to 4.88 and it leaves harder will I not see a big increase in the top end rpm because I would get there quicker? I dont want to be spining it higher than 7400 up top.