road racing transmissions
03-14-2010, 02:48 PM
#1
Thread Starter
Join Date: Mar 2010
Location: missouri
Posts: 5
road racing transmissions
Hey guys, Im bulding my first track car and I would like some suggestions on what transmission would be best for my build. (or best bang for my buck)
The car is a 68 with a 289 and should be making around 350bhp
9 inch rear end, still haven't decided on the gears yet.
I have a 3 speed manual, but i've been breaking clutch linkages and bending my ho-po z-bar.
The car is a 68 with a 289 and should be making around 350bhp
9 inch rear end, still haven't decided on the gears yet.
I have a 3 speed manual, but i've been breaking clutch linkages and bending my ho-po z-bar.
03-14-2010, 03:59 PM
#3
5th Gear Member
Join Date: May 2005
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Posts: 2,445
For dragstrip, I'd go with a built C4. Manual valve body, and transmission brake.
"Kicking" the pedal when speed shifting a manual at the drag strip is pretty hard on clutch linkage, especially with one of the old H.D. 3 finger setups (Like the old Ram clutch).
for Auto-X, I'd go T5 with a 2.95 first gear.
For road course, Astro, or G-force T5 with an 0.80 5th gear.
Which ever manual transmission is used, one of the newer diaphram clutches, like a Centerforce, or FRPP King Cobra, will reduce the strain on the mechanical linkage, versus the old 3 finger style clutch plate. The mechanical linkage is my favorite when it's setup correctly using good quality parts.
Good luck,
"Kicking" the pedal when speed shifting a manual at the drag strip is pretty hard on clutch linkage, especially with one of the old H.D. 3 finger setups (Like the old Ram clutch).
for Auto-X, I'd go T5 with a 2.95 first gear.
For road course, Astro, or G-force T5 with an 0.80 5th gear.
Which ever manual transmission is used, one of the newer diaphram clutches, like a Centerforce, or FRPP King Cobra, will reduce the strain on the mechanical linkage, versus the old 3 finger style clutch plate. The mechanical linkage is my favorite when it's setup correctly using good quality parts.
Good luck,
03-14-2010, 04:49 PM
#4
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Join Date: Apr 2007
Location: California
Posts: 10,468
At only 350hp driven properly in a road racing setup, a stock WC T5 would be fine. So will the 8" rear, a 9" will just rob more power for extra strength that's not needed. Road racing is easier on drivetrain parts in regards to power, you do need good lubes though since there's more heat.
03-15-2010, 09:27 AM
#5
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Join Date: Apr 2007
Location: Texas Hill Country
Posts: 2,100
I know a bunch of those guys run Jericho trannys. They have straight cut gears, so they are loud, but are bullet proof.
If you are going to race it, I would stay away from Tremecs. They are going to be limited in how much power they can take, you don't need OD in a road racer, and after they canceled their T56 line including parts, I question their support for their products.
I do not know anything about the Richmond Gear trannys. I understand the NASCAR teams use a Richmond like setup.
If you are going to race it, I would stay away from Tremecs. They are going to be limited in how much power they can take, you don't need OD in a road racer, and after they canceled their T56 line including parts, I question their support for their products.
I do not know anything about the Richmond Gear trannys. I understand the NASCAR teams use a Richmond like setup.
03-15-2010, 10:33 AM
#6
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Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
mcleod sell those as well. I have one of theirs and am happy out with it
03-15-2010, 12:34 PM
#7
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Join Date: Apr 2009
Location: Tennessee
Posts: 70
If it were me, I'd pay very close attention to weight of the tranny. The bulk of its weight will be on the front tires, and keeping it light will help you corner.
Remember to design lightness in at the beginning of a build, not at the end.
I'd go with the stock WC T5 with the .8 OD.
Light, relatively strong, and silky smoothe.
Good luck...
Remember to design lightness in at the beginning of a build, not at the end.
I'd go with the stock WC T5 with the .8 OD.
Light, relatively strong, and silky smoothe.
Good luck...
03-15-2010, 05:00 PM
#9
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Join Date: Apr 2007
Location: California
Posts: 10,468
TREMECs are great for road racing, they handle massive amounts of power(over 1,000hp in drag racing, which is much harder on a trans than road racing) and they offer them with a 0.82 OD for road racing. NEXTEL Cup cars either run Jerico WC-4's or Richmond T-101's, but those are WAY overkill unless you plan on racing competitively, in which case you're going to need WAY more than 350hp and a whole crapload of driving lessons, along with a huge sack full of cash.
A standard WC T5 will be fine for a 350hp road racer, since if you shift properly you won't hurt the trans. They break because retards go to the track with them and powershift. Launching at the drag strip on sticky tires can also break them, depending on the clutch. An 8" rear and a WC T5 would be fine for your setup, and save you a lot of money that is better spent elsewhere.
A standard WC T5 will be fine for a 350hp road racer, since if you shift properly you won't hurt the trans. They break because retards go to the track with them and powershift. Launching at the drag strip on sticky tires can also break them, depending on the clutch. An 8" rear and a WC T5 would be fine for your setup, and save you a lot of money that is better spent elsewhere.
03-15-2010, 09:36 PM
#10
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Yeah, like other's here have said, the T5 would be a great fit for this application. Cheap, light, and exceptional aftermarket parts and technical support (thanks to all our Fox brothers and sisters, along with the GM faithful still running their T5s).
Astro Performance and G-Force have excellent parts and technical support for this transmission, and it see's a lot of track duty.
You can even get dog cut gears eliminating the syncros. A bit tougher to learn, but man does it shift fast! And tough as nails.
The close ratio box with 2.95 first and 0.80 5th is a great selection, allowing higher (numerical) rear gears. This makes that 350HP feel like 400HP, without running out of breath, or over-reving on the long straights.
Good luck with your choice.
Astro Performance and G-Force have excellent parts and technical support for this transmission, and it see's a lot of track duty.
You can even get dog cut gears eliminating the syncros. A bit tougher to learn, but man does it shift fast! And tough as nails.
The close ratio box with 2.95 first and 0.80 5th is a great selection, allowing higher (numerical) rear gears. This makes that 350HP feel like 400HP, without running out of breath, or over-reving on the long straights.
Good luck with your choice.