DomesticViolence

http://mavness.com/camarozach/trans.htm

camaro_zach on firebirdV6.com

Bliggida

I'd skimp on the 700 dollar GM robbery. That'll lower your costs quite a bit.

V6Bob

"Yea...seeing how funny cars don't even have transmissions!!!"

"Yeah, so funny...because they do have transmissions, they are manual.
I suppose the clutches they have to rebuild every 1 to 3 runs aren't for the transmission right?"

You're both right.

Some do have transmissions, some don't. The ones that don't still need a clutch to get off the line, but the only gears are the rear end gears. This link:

http://wizardswarehouse.com/raceteam/car.htm

says the "transmission" is high gear only. There's really no transmission, it's just a solid shaft.

This link:

http://www.mikeetter.com/html/car_specs.html

says this alcohol funny car uses a 3 speed Lenco.

A 1993 book I have (The Anatomy and Development of the Top Fuel Dragster) says:

"Put simply, current Top Fuel Dragsters are powerful enough to use a direct drive system. Transmissions are not needed."

Earlier Top Fuel cars did use a two speed transmission.

Some do, some don't.

Bliggida

Could be, honestly, I haven't turned wrenches on dragsters in years. Some stuff may have changed. With 6,000 horsepower, its not a question of them being powerful enough, its do they have the gearing???

For a 36.62 inch tire, and a 1:1 direct drive ratio, that means you've got to run a 2.50 rear end gear to go 300 MPH at 8,000 RPM. Now, yes a 6,000 horsepower dragster will certainly pull that high a gear, but it doesn't sound right. I'm use to seeing a 3.20:1 gear in the differential on a dragster. Which means you need at the minimum a two speed transmission, which is what most of them use. That combined with how the tire grows on down the track, by the end at 8,000 they are breaking 300+ MPH.

Also you mentioned a Lenco based transmission, as if they aren't manual. As stated, they have a lever for each gear, they are fully manually shifted, and they have a clutch - how are they not manual transmissions???
When the guy talks about only having the high gear...high gear of what, a direct drive? Direct drives don't have more than one gear which is a one to one ratio. If it has more than one gear it has to be a transmission even if only by techincality. He has a Lenco, and using the high gear of it. Still a tranny.

JaysZ

This is confusing. How can a car (or a drag racer) not have a clutch? Even if a car has an automatic transmission it has a torque converter which acts like a clutch, right? I mean, a car can't be in gear all the time. How would you start it up? How would you push it around? Even if there is only 1 gear there has to be a clutch (or something that engages the gears)- or am I missing something?

V6Bob

Geez, you're a hard man to convince. That's a challenge I can't refuse. This will be overkill.

"For a 36.62 inch tire, and a 1:1 direct drive ratio, that means you've got to run a 2.50 rear end gear to go 300 MPH at 8,000 RPM. Now, yes a 6,000 horsepower dragster will certainly pull that high a gear, but it doesn't sound right. "

It is exactly right. The clutches are called "slipper clutches" and are designed to slip enough to not bog the engine down at the start of the run.

From an NHRA Top Fuel article:

[Unquestionably, the clutch is the most crucial element for Top Fuel success, so much so that the Schumacher team has added a dynamometer specifically for developing this component. The car has no transmission, so the five-disc clutch is set up to slip just enough to keep the tires from breaking traction. ]

"When the guy talks about only having the high gear...high gear of what, a direct drive? Direct drives don't have more than one gear which is a one to one ratio. If it has more than one gear it has to be a transmission even if only by techincality. He has a Lenco, and using the high gear of it. Still a tranny."

"Direct drive" means just a shaft. If you're not going to shift, you wuldn't run thousands of HP through gears which could break just for kicks.

From a couple of UK Funny Car sites:

[Next year we're moving to direct drive. We're the only car left with a two-speed. Direct drive makes a big difference, the car feels more powerful. With the two-speed we have at the moment, it's like the old days when I ran 6.0s, but I think we should be able to get it into the fives. ]

[Spuffard pedaled the Showtime Funny Car to a 6.01, whilst Gordon Smith ran a 6.53 in the Shockwave car. Gordon has switched from a transmission setup to a direct drive system, and this first pass looked clean, straight, and strong.]

From a dragbike site:

[About the bike
*ProDragster
*114 cubic inches
* 5" stroke
* 3 13/16" bore
* Burns carborated nitro-methane for fuel
* No transmission-direct drive with a centrifugal clutch]

Convinced? Some use a transmission, some don't.

"This is confusing. How can a car (or a drag racer) not have a clutch? Even if a car has an automatic transmission it has a torque converter which acts like a clutch, right? I mean, a car can't be in gear all the time. How would you start it up? How would you push it around? Even if there is only 1 gear there has to be a clutch (or something that engages the gears)- or am I missing something?"

You've got it exactly right. Everyone has a clutch and rear end gears. Some have a transmission in between and shift, some have a solid shaft, aka "direct drive" and don't.

WhoBetter?

your all idiots, now shut up. Again, if you want a manual that badly just go and look for a trade, your might have to pay a little bit on top and some taxes, but it will be cheaper and a lot less frustating than converting your car.

ibanez6rg

I never stated that, that's not what direct-drive means. And I said the pressure plates melted together, not the "gears" in the "transmission"



Yea, I bet everyone is aware

Bliggida

Eh Bob. Just needed to make a few changes.
I earlier said that it would take a 2.50 rear gear with a 36.62" tire at 8000 RPM if you have a 1:1 gear. And that is incorrect. I inadvertently changed tire diameters, and my earlier calculations were for a 32.26" tire.

Dragsters do run a 36.xx" tires, they do have a 1:1 gear, and the rears are 3.20's. That in math will equate to 274 MPH at 8,000 RPM, but you've got to figure in tire-swell, and that can easily add 12 inches to the tire diameter. So all said and done and the south end of the track they post just over 300 MPH at 8,000 RPM before shutdown.

As I said before, Its be a long time, things have changed. When I was in the pits, we had more than one gear.

nikkev

Wow,this thread got waaaaaay off topic.We're talking about V6's here guys,not 8,000 hp top fuel dragsters!For normal cars like ours,driven by normal people like us.You WILL get better times at the track on equally modded cars if you are an average everyday driver.Plus that HUGE 5% difference ya'll keep talking about is only like 15hp on a 300hp car.That can be made up by 1 or 2 bolt-ons,or even factory tolerances.You WILL get a better launch with an auto,therefore unless your manual has gobs more power,you will get beat.Especially on the SAME car.Let's say his car has 200rwhp.That's only 10hp at the wheels.With a MUCH better 60',he'll more than make up for that 10hp.
Kevin