need help selecting transmisson

[barra72cuda]

putting a 572 w/770hp and 700 tq in my 69 satellite, cant find an automatic overdrive transmission that will hold that amount of tq w/out modifying my trans tunnel. Is there anyone with a similar build that could point me in the right direction?

 

[Kern Dog]

If you have the $$$ to build that engine, maybe you have enough left over to consider the Silver Sport Transmissions GM based 4 speed automatic. They are spendy, but the car will remain UNcut.

 

[5.7 hemi]

Gear Vendors....done!

 

[Grabinov911]

Gear Vendors....done!

LOL. For a "good" write up on installing a Gear Vendor, see my "80 Grit" thread. I literally JUST (I mean 30 seconds ago) posted the first entry in my Gear Vendor install string... Stick with me and I'll provide al the detail I can. I'm hoping the 727 / Gear Vendor combo is as bulletproof as I'm told it will be.

 

[barra72cuda]

I talked to the tech at silver sport already their stage 3 a41 only holds 650tq.

 

[Kern Dog]

Fine. How sticky are your rear tires going to be? If you cannot hook up all the power, the trans will never "see" all the power.
My 295-45-18s go up in smoke with my relatively moderate 440/493. I'm making 500 gross HP at the most. My trans probably thinks it is behind a 440!

 

[barra72cuda]

gear vendors was a last resort for me, they still require some modifications

 

[Kern Dog]

LOL. For a "good" write up on installing a Gear Vendor, see my "80 Grit" thread. I literally JUST (I mean 30 seconds ago) posted the first entry in my Gear Vendor install string... Stick with me and I'll provide al the detail I can. I'm hoping the 727 / Gear Vendor combo is as bulletproof as I'm told it will be.

The GV is a decent idea, but the .78 OD seems inadequate. They have been coasting with that design and ratio for many, many years. You'd think by now they would have adapted and offered a taller ratio. The Mopar 518 has a .69 ratio, the Silver Sport GM based trans has a .70. The 2004R that GM had has a .67. Manual transmissions today are even into double overdrive.

- - - Updated - - -

gear vendors was a last resort for me, they still require some modifications

Very minor though. I had one and liked it in theory. I had some vibration issues that later turned out to be UNrelated to the GV unit.

 

[barra72cuda]

Iam going with 335/30/zr18, my car has been mini tubed with 4 link coil over suspension, I shouldn't spin much lol

 

[Grabinov911]

Iam going with 335/30/zr18, my car has been mini tubed with 4 link coil over suspension, I shouldn't spin much lol

Hey Barracuda,

I don't mean to be argumentative, but my experience with my "pro touring" tire setup is that it actually spins easily despite the width of the tire. I am running a sticky Continental tire in 295/45/18 and with "the same" 440/493 that Kern dog has, putting about 500 gross HP, and the tires go up in smoke so easily that when I first ran it I thought something was wrong for a second. Granted your suspension is better than mine. But:

I floored it coming off a stop sign. No motion, no tire screeching. Looked in the mirror - Tires spinning like crazy with no sound but the motor. They don't even smoke that much. It was so much fun that I'm on my second set of rear tires (expensive fun). Take a look at the videos of the "Hammer" car. Same thing.



My guess is that drag radials, with their tall, soft sidewalls and low pressures absorb the driveline force more evenly. The short sports-car sidewalls are SO stiff that the tread sees all of the force from the driveline instantly. After that it's nothing but silent smoke!

I also questioned Gear vendors about a deeper overdrive - I'd like to be able to run 130 for an hour - but they just don't do it, so I went with the .78. We should know by this evening how much modification is required. Either way, once the car is running a mini-tubbed four link with a 770HP motor and all the modifications associated with that, I'd say your past worrying about modifications!

 

[Budnicks]

I haven't used one of these "yet", I was truly considering it thou...
I don't know much about them either, just what they said & their claims,
"allegedly" from mild to 1200hp
I talked with them a while ago now, for like an hour with an engineer/tech dude IIRC
like 3 years ago [I know that's pretty bad, procrastination at it's best]
but you may want to check them out
SMR Transmissions shorty Overdrive, gear-venders combo's
different levels Powerhorse 727, Street pro 727, Pro Sportsman727,
Competition Eliminator 727 or MegaTorque 727 or trans-brake 727
GV shortie-option can be added to any of them for like $3050+

or have a qualified tranny guy,
that knows Mopars/727tf's really well, build it for you

http://smrtrans.tripod.com/smrtransmissionsintro/id32.html

It's not an endorsement just something to look at/consider,
not sure if it's proprietary or not, too long ago, but it's some cha-ching $$$$

good luck & happy Moparing

 

[barra72cuda]

Thanks for the great input, I will try that link, I have a bb 727 laying around I can use, seems like it would be worth it in the long run

 

[69 GTX]

I went with the reg GV as I was told the shorty needed more trans tunnel mods. Mine is in the garage but not in the car yet. I got the tranny & GV through Cope he said it was good to 650 (the 727) he might be able to beef up the 727 to take more maybe.

 

[jakepup]

I am going to be putting about 800hp to the treads with a 727 I got from keith at 727 specialists, I got the added hp option for a total $1200, I believe he is now a gv dealer as well. I asked if it was going to handle the power and he stated as long as your not running full slicks at the track its not going to smoke the tranny cuz it will never hook up like stated above, im goin got be running 305/45/18 nitto drag radials. sorry the car is about 2 weeks form being finished so I cant give you any input as to if its REALLY going to hold up