765 from bowtie overdrive

[RICH]

i recently bought a project car that had a 700r4 L3 in it. i was thinking that this will be the weak link of the project so i had bowtie overdrive upgrade the trans to what they called the 765r4. i was told this can handle up to 850 hp, what do you think???

[MonzaRacer]

Its a 4l65e or a 4l60/700r4 upgraded with 4l65e internals and a perf build, if they have good rep (builder) then give it a try if your game.
4=4 forward gear, L=longitudinal design, ie rwd, 65=torque capabilities, 4l65e has 5 older ones have 4, and better bearings and such to up torque capabilities

[RICH]

thanks, sounds like you know what your talking about. i sent the trans in for the upgrade.

[PhillipM]

A buddie of mine has one of those from BTO... He is putting 625 to the wheels and has broken 3 of them. He is now on his 4th and must take it easy until he can get something stronger. Sorry, I would have replied before but I just found this. For 600whp level and above I would definitely look at something else or go 4L80. You never mention what kinda power you were hoping to put down.

Also, don't do burn outs into overdrive... apparently that burns them up :( lol

http://www.youtube.com/watch?v=yTdfR_UqsDk

[RICH]

ok, i"m starting with a 434 small block 10.5.1 comp.(595 hp) i am going to change the cam from a 109 (Lsa) to a 112-114 (Lsa) to be able to run a pro charger with minamal boost(5pounds of boost) for the already high comp. motor, the goal was 750 hp.

[d.c.]

I think you may want to review your choice here. I put BTO's 765r4 in a client's car with a 502 ram jet under the hood. The first one started slipping clutches within 75 miles. The second one seems to be ok, but time will tell. BTO makes decent stuff but in a heavy car which we have with big traction, and big power there is only so much these trannies can take. It really depends on how and where in your rpm band you are making power. If your engine is producing big torque at low rpms, say less than 3000, then trouble will come your way sooner or later. The fluid pumps have trouble generating enough line pressure at lower engine speeds so big torque overcomes clamping force and internal slippage starts. This produces huge amounts of heat, dumps clutch material in the overheating fluid and you now have a $2500.00 boat anchor. It's not that BTO makes a bad tranny, they don't. Its just that as always real world applications and application of forces can be very different then even the best planning, parts, and engineering. This said have you considered a TH400? Having an overdrive in these cars ie pleasure vehicles that get driven maybe 2 days a week realistically is overrated. If fuel consumption is an issue none of us would be putting the engines that we do in the cars that we do. Highway rpms can be made totally livable with proper gearing and tire size selection. So if you can get around this a th400 is stronger, simpler, and cheaper tranny that has every imaginable gear, linkage, convertor, pump, etc. etc. readily avaliable.

[RICH]

d.c. just noticed your repley, thanks for the in put the car came with 700 r4 with zero mile, so i thought i would upgrade to 765r4 to save what was already there, butt it sounds like i will have a" boat anchor" before i can change over to th400 or six speed. thanks.