M6 or auto for 700 rwhp drag car

I have been doing some research about what I should use, but am still not convinced of either one. I currently have a m6 in my 96Z and love to go through gears, but when my motor and everything else is put on the car that will be a different story. I do plan on geting a tranny to hold well over the power aloted, but still dont know which way to go. It seems to me that not many people are very successfull with a m6 (besides Tanner) when they have high hp out put and go to the strip very often.

So what tranny is suggested, and why?

An auto will give better consistency.

What about duribility, performance, strenght, and dont autos loss hp also

700 Hp isn't woth much if you cant put it down on the track. An A4 w/ a 3000 or so stall will do the trick. Along w/ SFCs, you'll make some nice 1/4 mi times.

I'd have to lean towards either a TH400 or a 4L80E if you want the option of overdrive for street use? :shrug: If you really will have power that high, I think the TH400 is the only tranny that's "tried, tested, and true" to hold up to that severe amount of abuse? :confused: Unless you went with an AFTERMARKET type standard (Richmond or something?? :confused: ).

But with a good, heavy duty stall converter, WELL built TH400, I think that would be the best 1/4 mile setup for ~700 RWHP :cool:.

Sounds good. Whats the benefit of over drive? Will it give me the option of very little street driving just to show the car off.Smilie

Overdrive means a gear ratio in which the transmission output shaft rotates more than once for each rotation of the input shaft. For instance, 6th gear on an M6 F-body is a 0.50:1 ratio, meaning that the output shaft rotates twice for each rotation of the input shaft.

The end effect is that the engine can be turning a reasonable RPM at highway speeds. To get an idea of what it would be like to not have overdrive, spend a few days driving your car without ever using 5th or 6th gear (both of which are overdrive ratios).

You'll use more fuel, the engine will be louder when you're cruising, you'll impart more wear on your engine due to higher RPMs, etc etc etc.

A TH400 is a three-speed transmission, and the highest ratio is 1:1, which is the same as 4th gear on an M6 F-body.

If I wanted to do an automatic drag car in the 700rwhp range, I'd be talking to Frank Cahall. :)

TH400+Gear Vendors

TH400 is a proven way to go. We are giving the 4L80 a try in an upcoming project, and hopefully it won't disappoint us. We looked at the TH400 with the Gear Vendors kit on it but that was alot more expensive.

How much do the run for and what are gear venders. And who is Frank Cahall.

Frank Cahall (12SCNDZ on these forums) is the owner of Cahall Performance Transmissions, which the best 4L60E shop, period. CPT is a supporting vendor of these forums (as is Victory Racing Engines, and I certainly wouldn't be ignoring Eric's comments either -- VRE knows their ****). 4L60E is the transmission found in A4 fourth-gen F-bodies.

Gear Vendors sells an overdrive unit which mounts behind the transmission and adds an overdrive ratio to a transmission that doesn't already have one. Adding this to a TH400 would allow you a ratio around 0.75:1 (I don't know the exact overdrive ratio of the GV product), which is approximately the same as 5th gear on an M6 F-body.

At about 2400 dollars (depending on model) the GEAR VENDORS is not the cheapest way for you to get overdrive but is by far the best. A Gear Vendors will handle more horsepower, deliver bigger performance gains, give you guaranteed trouble-free performance, and install easier than any other overdrive available. A GEAR VENDORS will handle 1200+ horsepower reliably and is under warranty even at the dragstrip.

Seems like alot of money to me.

How much do the run for and what are gear venders. And who is Frank Cahall.

So Im kinda confused, is gear vendors a full tranny or just a add on part for a tranny.

Off topic, thanks Victor. You are my new hero. You have totally helped me with everything, and made my mind up on what Im going to do to my car. I should be contacting you about doind my motor very shortly.

Just an overdrive addition to your TH400

Why is that so addition so expensive

Because they are basically the only people to that kit, and allow TH400 user to retain overdrive. The other option being a 4L80, but you will need a controller for it which is an additional $600.00.

I vote for a 6L80 swap. :D

(6L80 is GM's new six-speed automatic. It bolts up anywhere a 4L60 will, and is the same size. You'd need a controller for it just like you would for a 4L80, but it'd be really cool.)

well is the 6L80 a proven contender for strip cars. I have never heard of it being very good. I think im going to get a th400. Just need to find one beefed up enough for me ready to bolt on.

No, it's not a proven contender, because it's too new and I don't think anyone who knows what they're doing has tried to build a real strip car using one yet.

So it's not a proven combo, but that doesn't mean it can't work. You'd just be the first.

The least expensive solution is a stock T56. It will hold up pretty well. How long it lasts is variable and depends on how often you launch hard with sticky tires on a prepped surface. Obviously is very streetable. You will need a Street Twin clutch and flywheel for about $1,200 but other than that it's "free". The problem with it is that in stock form it can't be speed shifted and will therefore be giving up some ET. You can have a T56 built up to make it pretty bulletproof and so that you can speed shift it. But that gets very pricey - in the $4-5,000 range plus the clutch.

You mention "drag car". I am not sure what kind of drag racing you're referring to. If you mean bracket racing, any manually shifted tranny (even a manually shifted automatic) will put you at a big disadvantage. The only way to be consistent enough to win against tough competition on a regular basis is to have a tranny that is shifted with an air shifter or an electrical equivalent. IOW, an "automatic" with a manual valve body and an air shifter to shift it "automatically". Sounds stupid, but that's the best way I could express it. A Lenco or other "clutchless" manual can also be shifted mechanically.

The problem with a TH400, as has been mentioned, is the lack of an OD. This will kill your car for serious street use. The TH400+GV solves this but is expensive. I think the cheapest "best of both worlds" solution is currently the 4L80, though not enough people have done it to make it "plug and play". This is not cheap by any means either - remember that with any auto you also have to buy a converter, which to be appropriate for this kind of use will run close to $1,000 and a shifter for another couple hundred.

If I still wanted to use my 800+rwhp car at the track, I'd go for the upgraded T56. A T56 + big power is a joy on the street. An auto, even with OD, is not due to the high stall converter needed. Of course, my track use for the Camaro was never brackets. It was test n' tune and grudge racing. As it is, I am using a stock T56 - it lasts fine on the street as traction is so limited compared to sticky tires on a track. And I don't do "hole shots" on the street. I will upgrade it as needed.

If I had an unlimited budget, I'd do up a 5-speed Lenco with a 2.73 rear end. What with the cost of the parts and all the custom work needed that would be in the $10K range though.

Rich

Wow, you made my choice even harder. lol. Thank you for int info, but damn. Im back at square one. If i knew this was all so hard, I would have a different hobby. I can just imagin what problems Im going to have when i start draining my bank acount though.

As far as which tranny, still Im not very familar with them. Like the air shift etc. I dont know what kind of racing I will get into, b/c I still have the same car i started with. Most likely I will start off going to the track and getting to know my car and then decide from there. I wont lie, Im leaning torward the proven th400. I have a m6 now and even with 350-400 rwhp, it has problems, and i have the carbin internals. Before I sell it i will rebuild it myself.

I think you will be happy with the Th400, and if you find that you miss overdrive it can always be added.

How much do the run for and what are gear venders. And who is Frank Cahall.


go with Rossler or probuilt, learn from my Mistake

go with Rossler or probuilt, learn from my Mistake

Had a probuilt and it lasted maybe 2 thousand miles and then turned into a huge paper weight.