transmission decision and help!!!

ChevyKiller

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At that power level go with a 4R70W good to about 1100 HP.
The TH 400 is beefy & heavy.
I have the Lentech 4R70W with manual valve body & transbrake,i have had it for 2 + years & have made 450 passes with no problems.Call Len & talk to him he holds patents on the 4R70W valve body & has a lifetime deductible warranty on the trans.Tell him you were talking to Randy from Ontario. www.mounceracing.com www.lentechautomotive.com

You are kidding, right? My TH400 is almost 100 lbs lighter than my 4r70 was. (89 lbs)

Both are about the same in regards to you need a disptick, a shifter, Drive shaft, and have to fab a crossmember/brace if you buy a unit already set-up for an S197 (meaning comes with the right bell housing, converter, etc.)

The TH400 is wayyyy stronger than the 4r70 and if you are going to go to the track every now and then and mostly drive on the street - I would go with the 4r70 with an OD. If you are going to beat the shit out of it at the track - go with the TH400 and save yourself headaches to come. I broke the 4r70 3 times and have not yet had a hint of damage to this TH400 and I'm running in the 8's at 160 mph. I was breaking the 4r70 with far less power than I'm pushing now. I also had tremendous overheating issues standing on the trans brake on the 4r70. If you stand on the brake with the 4r70 - those things get smokin' real quick. The TH400 is a far better 'drag' trans but I prefer the 4r70 for the street easy over. You'll want to have that OD on the highway - believe me.

As always, it comes down to want you want - a street car or a race car. I have learned the hard lesson over the years that you just can't have both - no matter what anyone tells you or tries to sell you - you can't have both, believe me.
 
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Born To Run

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You are kidding, right? My TH400 is almost 100 lbs lighter than my 4r70 was. (89 lbs)

Both are about the same in regards to you need a disptick, a shifter, Drive shaft, and have to fab a crossmember/brace if you buy a unit already set-up for an S197 (meaning comes with the right bell housing, converter, etc.)

The TH400 is wayyyy stronger than the 4r70 and if you are going to go to the track every now and then and mostly drive on the street - I would go with the 4r70 with an OD. If you are going to beat the shit out of it at the track - go with the TH400 and save yourself headaches to come. I broke the 4r70 3 times and have not yet had a hint of damage to this TH400 and I'm running in the 8's at 160 mph. I was breaking the 4r70 with far less power than I'm pushing now. I also had tremendous overheating issues standing on the trans brake on the 4r70. If you stand on the brake with the 4r70 - those things get smokin' real quick. The TH400 is a far better 'drag' trans but I prefer the 4r70 for the street easy over. You'll want to have that OD on the highway - believe me.

As always, it comes down to want you want - a street car or a race car. I have learned the hard lesson over the years that you just can't have both - no matter what anyone tells you or tries to sell you - you can't have both, believe me.

How much does your TH 400 weight ? How much is your TC ?
Yoy mean to tell me that Chevy truck tranny is lighter than mine?
Mine weighs about 125 lbs without the TC,yours is 100lbs lighter,com'on!
With all respect,enlighten me please.

I have beat the shit out of my 4R70W,my car is track only for 2 years.I have stood on the TB alot 5-6 sec sometimes,it has been great,the OD did not help when i streeted it,fuel was about 8 mpg as the converter is an non lockup.
 

ChevyKiller

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How much does your TH 400 weight ? How much is your TC ?
Yoy mean to tell me that Chevy truck tranny is lighter than mine?
Mine weighs about 125 lbs without the TC,yours is 100lbs lighter,com'on!
With all respect,enlighten me please.

I have beat the shit out of my 4R70W,my car is track only for 2 years.I have stood on the TB alot 5-6 sec sometimes,it has been great,the OD did not help when i streeted it,fuel was about 8 mpg as the converter is an non lockup.

Shit - my art carr 4r70 was almost 200 lbs!!! - my th400 is is in the 120-130'ish

I had a non-lock-up as well as the OD helped quite a bit when I streeted it. I would get 10-12 mpg versus 6-8 without it. I would cruise at 65 mph @ about 3600 rpm in OD and 65 mph would be around 4500 in 3rd

I suppose the converter should have lot's to do with the various life on the trans brake so perhaps I had some shitty converters on my 4r70 - well, not perhaps - I KNOW I did...lol

However, I have seen other 4r70's also run into heating issues. Do you have a trans temp gauge and do you monitor your trans temps at the track? My trans temps on the 4r70 where light years worse than what I see now on the TH400.
 

Born To Run

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Shit - my art carr 4r70 was almost 200 lbs!!! - my th400 is is in the 120-130'ish

I had a non-lock-up as well as the OD helped quite a bit when I streeted it. I would get 10-12 mpg versus 6-8 without it. I would cruise at 65 mph @ about 3600 rpm in OD and 65 mph would be around 4500 in 3rd

I suppose the converter should have lot's to do with the various life on the trans brake so perhaps I had some shitty converters on my 4r70 - well, not perhaps - I KNOW I did...lol

However, I have seen other 4r70's also run into heating issues. Do you have a trans temp gauge and do you monitor your trans temps at the track? My trans temps on the 4r70 where light years worse than what I see now on the TH400.

Holy shit 200lbs,that is heavy.My converter is about 96% eff when we last measured,its the original one with at least 700+ passes on it using the TB.When i cruised i went on a 3 hour trip & i burned 3/4 of a tank of 94 octane using OD & not getting on it as i did not have high octane in it.
My converter is a 9.5" from some place in British Columbia!Len gets them there,it is about 25 lbs pretty heavy.

I have no tranny guage or means to tell how hot she gets,its made to go or made to blow,hell i don't even have a shift light.Last spring on a tear down everything was mint,so we added a extra clutch to 1st & final & turned up the line pressure to 240 psi.Lens tranny's will only support upto around 1,100 HP, Johnny Lightning did a bunch of progressive testing with his turbo truck & once he laid down 1200 + HP it failed a few times.At my power levels & ET's of 10.68-10.90s with 60' times in the 1.42ish range & the fact i don't abuse it(i beat on it) it works fine.I launch @ 3000 rpm,which is 1000 rpm below the stall.What was your launch & stall??Most passes in an 8 hour period of racing was 14 @ Commerce Georgia last year i doubled classed & then they decided to make it a one day event instead of two.
 
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