700r4 capabilities?

[Reaper]

Do you guys know what a 30 spline 700r4 with upgraded servos and clutches would hold up against? Will be around 600 HP hard ran..... Should I just eat the gas mileage and build my TH400? Thanks, Tom

I have a big block by the way.... and street/strip with street slicks....

[Reaper]

The more and more I look at comparisons between a th400 and 700r4's Im thinkin Ill just build up my th400 and possibly save some headaches.... What kind of gas mileage you guys think a 700 might give vs the th400 as well as track times.... Thanks again Tom

[502ci]

Awhile back I was looking for a transmission that would hold up to abuse and the overdrives sounded good till you looked at how much hp they can only take.

 

For the average person those units are great but I myself wanted something to handle 1,000 + hp.

 

What power level are your plans?

 

I went with a built TH400 and put a gearvendors under/overdrive unit on it.

 

This unit is not cheap costing like $2,400 but can handle 1,200 hp all day. Can even be modded to handle more.

 

I love mine, it drops my 4.11 down to a 3.22, saves gas and wear on the engine also.

 

Maybe you are already familiar with this product, although I`m still amazed at how many people never heard of it.

 

It mounts in place of your tail shaft and looks like this...

 

 

 

Here`s a link to the site... www.gearvendors.com

 

[Reaper]

Yeah I know about the gear vendor but very expensive. I want the tranny to handle what ever I can throw at it. I will prolly end up building my th400 and saving for a gear vendor.... Sounds like a reasonable idea Thanks

[Guest]

The Gear vendors would help out the 1st to 2nd RPM drop on a 700R4....lol

 

The TH400 would be better for mostly drag racing uness you have to drive more than 50 miles one-way.

[Reaper]

Giving up two or three miles per gallon isnt that big of a deal for not breaking my trans every year.... Maybe in a year or two Ill get a gear vendor and be good

[MeanMonte]

for me one of the best advantages of the 700r4 is that i can run my 3500 stall and lock it up so it doesnt burn up the trans and keeps the rpms down a bit due to the 4.11's the company i got parts from claimed good for 600hp and they had even better stuff than what i got!

[680HPStroker]

I agree with MeanMonte here. The parts for todays 700r4 are 100% stronger than the factory weak pieces that GM put in them. I have a 600hp big block with a specially prepared 700r4 and have thrashed it pretty hard both on the street and on the dyno. The track will be next. When built right you can tighten up that 1st to 2nd shift rpm drop, but if you are racing who cares about that as you are going to shift it manually anyway. Let's not forget the monster 3.06 1st gear ratio a 700r4 has. With all the parts and tech info out there, people are still knocking these transmissions. I feel that for a serious street car with a big stall and a tall rear gear that these transmissions deserve a hard look. There is nothing like screaming down the highway with your rpm's tacking up there and when you settle out in OD with the converter locked up your rpm's drop 1,000-1,500 depending on gear ratio. With a turbo 350 and a 4.10:1 rear gear I used to tack 3,600rpm's at 65mph. Now with 700r4 I'm at 2,200rpm's with the same 4.10:1 gear. For the life of me I fail to understand the logic of worrying about gas milage when building a high power engine. I didn't even worry about it when choosing the 700r4 for my application. I was more concerned about engine longevity and cruising comfort. I will say this that even though I can't give you an exact number I use the same amount of gas with a 600hp big block and the 700r4 as I did with a 400hp small block and a turbo 350. So I feel there is definitely something to be said about the 700r4's potential fuel savings. Once again as always just my two cents.