t400 with stock 3.42 gearing

[Six_Silver]

I would like to know how well a t400 works with a stock 3.42 gear. For those of you using this setup, did you have to change the gearsets in the trans? This will be for a mid 10 car at 3700lbs.

 

[CopGn]

Just curious but what is the stock gearing in the 400?

 

[Six_Silver]

I was referring to the 3.42 gear in the 8.5" rear end.

 

[chris718]

2.482/1.482.works great in the 10 second zonewith 3.73 final drive .if you want a custom ratio give me a call.

 

[Chuck Leeper]

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Mine works just fine at 3680#. 9.98@141.. Best short time has been 1.44 w/ a tight street converter.

 

[ttypewhite]

Chuck Leeper- Wow, that mph is killer, what happen to the et, outta curiosity? You should be in the 9.60 to 9.50 area with awesome top end charge.

 

[Six_Silver]

Originally posted by chris718
2.482/1.482.works great in the 10 second zonewith 3.73 final drive .if you want a custom ratio give me a call.

I dont want to change the rear gear from 3.42 to 3.73 though. I am looking for responses about the stock 3.42.

Are all of you mid 10 guys with t400's running a different rear end gear? I thought at least a few of you would have the stock gear......

 

[Chuck Leeper]

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Originally posted by ttypewhite
Chuck Leeper- Wow, that mph is killer, what happen to the et, outta curiosity? You should be in the 9.60 to 9.50 area with awesome top end charge.

The data log shows approximately 2 sec's w/ the TPS at/near idle on 2 occasions.[ 4% one time and 22% the second time. 95% is WFO.]. The driver had a problem on launch w/ WFO control, and again at 8 sec's into the run, he pedalled it to keep it under control....
Problem seem to be centered around the ft tires being radials, and the rears being bias ply. We are also concerned there's not enough caster in the alignment.

Going to try again w/ an alignment and some ft runner tires...
You are right, it should go some mid 9's and perhaps 2-4 more MPH.
The data log also shows the boost at 27psi, while the Innovative controller was set for 30... Don't know what's up there yet.. Never had a problem w/ it before.

The short time was 1.58, so a converter change should put it back to it's previous best of 1.44, or better.

 

[Scott231]

Originally posted by Six_Silver
I dont want to change the rear gear from 3.42 to 3.73 though. I am looking for responses about the stock 3.42.

No No, James. He is talking aobut changing the gear set inside the transmission.

 

[Six_Silver]

Right but he said with 3.73 final drive. That doesnt apply to me since I am asking about a 3.42 final drive.

I would like to know if anyone in the mid 10 second range is using a stock (3.42 rear end gear or "final drive" gear whatever you want to call it) with the "stock" t400 gearset. If the gearset in the trans is not stock, what are you using?

 

[J Banning]

Originally posted by Six_Silver
Right but he said with 3.73 final drive. That doesnt apply to me since I am asking about a 3.42 final drive.

I would like to know if anyone in the mid 10 second range is using a stock (3.42 rear end gear or "final drive" gear whatever you want to call it) with the "stock" t400 gearset. If the gearset in the trans is not stock, what are you using?

I'm interested in this subject also.

Anyone???

 

[Nick Micale]

Originally posted by Six_Silver
Right but he said with 3.73 final drive. That doesnt apply to me since I am asking about a 3.42 final drive.

I would like to know if anyone in the mid 10 second range is using a stock (3.42 rear end gear or "final drive" gear whatever you want to call it) with the "stock" t400 gearset. If the gearset in the trans is not stock, what are you using?

Have dealt with a couple mid-10's GN using TH400. Mine, I went back to 3.42's from 3.73 as it reved too quick right past the power band.

Just finished a stage II motored car and it has 3.73's which also requires too soon a 1-2 shift. We will probably keep the 3.73 gears and compensate by going to 29" tires.

Dic Kereny's TSM car has 3.42 gears with TH400/28"tires and works great down into the 9's!

All these are stock TH400's and have stock internals except for a trans brake.

 

[chris718]

if you are looking to net a similar 1/2 and 2/3 shift recovery rpm with a th400 than the 3.73 final drive with the the 2.482/1.482 /1 will net similar results if ratio changes are made at the same mile per hour .this is because the ratio of stator freewheeling inside the convertor changes in relation to engine load and rpm drop induced during ratio changes.however the rpms will be higher in hi gear up top and also mphour if you have he right convertoreven though you are not using a lock up convertor.this is in effect for hi powered mills with entended rpm potential,most certainly real world considerations in the equation of why we would use a th400 in the first place.any time the ratio is numerically lower we can gain traction and reach a longer distance before a ratio change,and when we move the ratios closer together we go faster.