Author Topic: what Trans for over 250 MPH  (Read 10666 times)

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Offline SPARKY

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Re: what Trans for over 250 MPH
« Reply #15 on: October 05, 2008, 02:34:53 PM »
Direct---no control other than gearshift..
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Offline racergeo

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Re: what Trans for over 250 MPH
« Reply #16 on: October 06, 2008, 03:53:26 PM »

      I use a glide. It is 17in. long and is a direct drive with no fluid dump. Push it off in neutral and when you get to about 40 put it in low. I am probable giving up a few mph by not having 1 or 2 moe gears, but when you get in the 5th mile if you have any power your still going to go fast. I have a old Hot Rod book somewhere (50's) that has a front wheel drive roadster built by the guy that started CAE. It has one of his first in and out boxes he ever built and direct drive with a clutch (no trans !) and he ran 215mph first time out. His power was an old 354 hemi with injection!

Offline Stan Back

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Re: what Trans for over 250 MPH
« Reply #17 on: October 06, 2008, 04:29:27 PM »
Betcha the gas "smelled funny".
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Offline panic

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Re: what Trans for over 250 MPH
« Reply #18 on: October 06, 2008, 05:37:10 PM »
If the low number of ratios, wide RPM drop and low torque multiplication are acceptable compromises, the PG offers a big advantage: wouldn't it be nice to delete the entire "clutch question" (weight, spares, throwout bearing, inertia, linkage, leverage ratio, room in the cockpit for the control, less things for the driver to think about)?

I never thought I would say this back when I was young, stupid and completely broke (now I'm old, senile and almost poor) but any problem I can solve by buying something commercial (viz., known quality product, spares available by FedEx, does what I want) rather than make another fabrication project out of it... I'll just pay for it.
There's always something else I can't buy that needs my time and energy.

Offline Milwaukee Midget

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Re: what Trans for over 250 MPH
« Reply #19 on: October 06, 2008, 07:18:59 PM »
For really fast cars that will be traction limited: how many have used (or plan to) a Powerglide built for oval track?

I recall seeing John Greenwood's IMSA 'Vette compete at Brainard International in the early '80's.  He was running a modified powerglide at the time, and in a downpour that proved to be extremely traction limiting, (standing water in spots) he was able to smoothly apply power and moved up numerous positions on the rest of the field.  On parts of the track where other cars would bust loose, JG just rolled right along.

Applicable to salt? :roll:
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline panic

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Re: what Trans for over 250 MPH
« Reply #20 on: October 06, 2008, 07:22:16 PM »
I suspect he was using converter slippage as a buffer/traction aid, and it's possible to adjust stall underway using an adapted Super Turbine dual-pitch converter - IIRC it's what Jim Hall used in the 2J Hoovermatic car.

Offline Racerboy

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Re: what Trans for over 250 MPH
« Reply #21 on: October 10, 2008, 11:36:04 PM »
I found a G Force 4 speed (Tex Racing) that I think will be a better fit and I can still get it with a 4 gear overdrive (.91). Can Anyone suggest some gear ratios  The car is a  C fuel Comp coupe and I will be running both B ville & El mirage
Long Live the Comp Coupe's

Offline bvillercr

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Re: what Trans for over 250 MPH
« Reply #22 on: October 11, 2008, 12:08:35 AM »
I am thinking of using a new Muncie 4 speed with a .86 overdrive (4th gear) in my new B comp coupe.

Did you change your mind on the motor size and when are we going to see a picture of your comp coupe? :-D

Offline Racerboy

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Re: what Trans for over 250 MPH
« Reply #23 on: October 11, 2008, 12:15:52 AM »
I will be running a C motor to start with then my B motor and a D motor along with anything else I can find around the shop
Long Live the Comp Coupe's

Offline Sumner

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Re: what Trans for over 250 MPH
« Reply #24 on: October 11, 2008, 09:42:22 AM »
I found a G Force 4 speed (Tex Racing) that I think will be a better fit and I can still get it with a 4 gear overdrive (.91). Can Anyone suggest some gear ratios  The car is a  C fuel Comp coupe and I will be running both B ville & El mirage

We have a G Force and love it and actually I think that G Force actually makes a lot of the Tex Racing transmission not the other way around, but I could be wrong.

We run the highest 1st that they could put in it (1.923) and I wish we could go higher than that.  If you have any power at all and a good push vehicle you can use a high first to drop the rpm drop going into 2nd.  We can still only use about 30%-50% in first and that is with the car weighing 5000 lbs and we are probably making 850-900 HP at the crank.

2nd is 1.331 and we still can't run WOT in 2nd either.

3rd is the 1.00 and is actually the normal 4th gear.

4th is .931 and is the normal 3rd run as an overdrive 4th like what you have.

You don't mention what your rear gears are, tire size and power/torque range.  Maybe run it like it is the first year and data log rpm and tps and what ever else you can and then look at where you want to go from there with gears.

c ya,

Sum

Offline Randall Parker

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Re: what Trans for over 250 MPH
« Reply #25 on: October 11, 2008, 10:50:46 AM »
Sumner you are a genious.
The Faster you go the longer you live...it's just physics.