speed Transmission?

Transmission to Rear-end

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predator
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speed Transmission?

Post by predator » Mon Jul 06, 2015 11:10 pm

8 Speed Transmission.

What I want to know, is Who Makes one?

Brian P
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Re: speed Transmission?

Post by Brian P » Mon Jul 06, 2015 11:39 pm

Manual or automatic?

Manual: the only way I know of this being done is via a 4-speed with an auxiliary hi-lo range box or an overdrive.

Automatic: ZF (and Chrysler, same unit built under license from ZF), GM, Aisin (Toyota/Lexus), Hyundai. These are all OEM transmissions in current-model cars and trucks. There may be others but those are the main players. All use full electronic control.

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Re: speed Transmission?

Post by peejay » Thu Jul 09, 2015 7:26 pm

Quaife makes or used to make an 8 speed transmission for low powered circuit cars... it was a 4 speed that also had a shiftable transfer gear. So you had a 4 speed H pattern and you could split those gears by rotating the shifter 90 degrees to change the transfer gear.

I think the ratios involved were still closer than a close ratio 4 speed - first gear was in the 2:1 range and top gear was maybe 1.1:1.

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speed Transmission?

Post by predator » Sun Jul 12, 2015 12:19 am

Well, I need to find-out more about these Z-F Transmissions. You guys see I want to have good gearing all the way from a stop to 200 M-P-H. Over-drives are, and sound pretty cool. But, there is always a But, But right now my Car has 4.88 rear-end Gears. My Car also has a Torrque-flight with a Gear-Vendors Over-Drive. I thought for a brief time about adding sa SECONSD g-V OVER DRIVE. i know you guys have already figured out my logic here. 4.88 X .72 X .72 = 2.52 But, There's that BUT again. While I guess here on my computer Board, it Would work. My Drive shaft would be spinning at near Hyper-sonic speeds, at 200 M-P-H.

No, no, NO. I think I need to put a taller gear in the rear. Then I can get the gearing I will need in order to accellirate the car stronly through-out the intended Speeds I hope to runthe Car. Iknow, I know that you Guys must think that I am Whacked. But I am having fun.

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Re: speed Transmission?

Post by peejay » Sun Jul 12, 2015 9:34 am

I drive a 4.78 gear on the street with 24" tires.

Driveshaft speed is a major issue for me. U-joint angles are absolutely critical and the slip yoke and transmission bushing are regular maintenance items regardless. So is the pinion seal but I would rather just keep adding gear oil and deal with the mess.

And this is keeping speeds 80mph sustained, nothing crazy like you're describing. I have "only" about 5400 driveshaft RPM! Scary to think about that front U-joint six inches from my hip.

Get the driveshaft speed down! There's a good reason why the Euro automakers prefer relatively tall rearend ratios and no overdrive. And Guibo couplers instead of U-joints. (They soak up drivetrain-killing harmonics) Or just saying piss on it, put the transmission in the back.

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Re: speed Transmission?

Post by predator » Sun Jul 12, 2015 11:28 am

Well, just as peejay says: I need to keep Drive-shaft speed down! Guys, I am very-much concerned about having experiencing my Drive shaft exiting my vehical when it is spun up at Hyper-sonic speeds! You know just because I can do something mechanically, such as adding a second O-D, does not mean that I SHOULD do something like that.

No, I think to acheve my goals: I think the answer to my drive-line requirements, lies with aquiring a Transmission with more gears in the Case. Then I can go to a Taller Gear in the Rear-end.

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Re: speed Transmission?

Post by Supershafts » Sun Jul 19, 2015 9:10 pm

8800 isn't hyper sonic. putting the trans in the back like some euro cars and the vette puts the shaft at whatever rpm the motor is at in EVERY gear.
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predator
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Re: speed Transmission?

Post by predator » Sun Jul 19, 2015 10:26 pm

OK Guy's, here's the deeal: I have a B-body mopar, a 71 Plymouth Road runner. 440, torque-flight.Gear Vendors Over-Drive.
4.88's. I really am thinking that I need to put the gear back in inside say a Transmission. So here I go with my direct to the point
question: What Transmission is offered out there, and more to the point: Who is the Manufactorer of said transmission that will allow me to put lower gears in the rear-end while still being able to accellerate the car wheather ity's down the Quarter mile. Or if it is being able to run 200 Miles an hour?

Yes i want it all.

See Ya Predator

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Re: speed Transmission?

Post by Supershafts » Tue Jul 21, 2015 9:23 pm

See ZF for a 8spd...

So you know what you're doing isn't a problem for the shaft.... also so you know if a shaft breaks at 5500 rpm its just as violent as 8800
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Re: speed Transmission?

Post by iadr » Sat Aug 01, 2015 8:36 pm

Don't bother with the 8 speed transmissions- they aren't what you need.

Look more at what late model diesel trucks are running - or even gas 3500-series.

If I had to do it I'd find a hybrid bellhousing and do a Ford 4r100 ( C6 overdrive, with 2.71 1st , and a 0.71 4th) and an aftermarket "box"(controls) put a GV behind that. And, run right around 4:00 rear gears. Why do you need 4.88's with a big block?

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Re: speed Transmission?

Post by Rizzle » Wed Aug 05, 2015 9:29 pm

iadr wrote:Don't bother with the 8 speed transmissions- they aren't what you need.

Look more at what late model diesel trucks are running - or even gas 3500-series.

If I had to do it I'd find a hybrid bellhousing and do a Ford 4r100 ( C6 overdrive, with 2.71 1st , and a 0.71 4th) and an aftermarket "box"(controls) put a GV behind that. And, run right around 4:00 rear gears. Why do you need 4.88's with a big block?
Be careful with running Diesel/HD style parts/transmissions - many are not rated for high input RPM, they are built beefy to handle the torque, and thus not designed to see very high input speeds.

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Re: speed Transmission?

Post by Mohr HP » Mon Aug 17, 2015 9:41 pm

I have a dual purpose land speed/street car, have been 205 at Wilmington. I use a TH400 w/ switch pitch converter AND Gear Vendors overdrive. 3.23:1 gear. revs about 6500 at 200 MPH. Using a Gear Vendors OD under load at the power levels needed to go 200 in a mile, puts it close to its designed torque capacity. I destroyed the clutch in mine, exchanged it for their hopped up one rated at 2000 HP. Those guys on drag week don't use the overdrive while racing, only while putting from track to track. The car can leave hard enough to drag race, with the stall at 4500 RPM. Flip the switch and it's at 1300 RPM.

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