I Got The 60ft Hook Up..Holla If You Hear Me!!

[DEFIANT 7M]

A drag race is won in the first 60ft..I have said it before and not to many if any have paid attention. Plus after going over Outofstep's thread http://www.supramania.com/forums/showthread.php?t=14479. Which goes far beyond what I saying, nobody is paying attention. Face it MkIII numbers at the track have been lack luster at best. Check this out...

Suppose a mythical Supra(turbo/auto) made 400 lb-ft of torque @ a launch of 4,700 rpm and has a 3.90 final drive. But has an auto tranny with a 2.80 first gear. How many (g's) do you think it can pull out the hole? Hear is the formula (source MMFF Aug2005) 2.80 (First gear) x 3.90 (final drive) x 0.87 (drivetrain efficiency) x 400 (lb-ft of torque @ 4700 rpm) / 1.1 (rolling radius of a tire) = 3454.70 pounds of thrust. Okay know divide that buy the famous MkIII weight say 3200 lbs, 3454.70 / 3200 = 1.08 g's of acceleration.

My aguement is that the gearing of the MkIII is not what it should be for drag racing. Or should I say for each set up. For N/As I feel a great set up is a R154 tranny with the 4.56 with a modified fifth gear.http://www.4x4wire.com/lists/toyota/200008/msg00338.html Let's plug in the formula 3.25(R154) x 4.56 x 0.87 x 275 lbs-ft of torque (nitrous 150 shot) / 1.1=3223.35 pounds of thrust. 3223.35 / 3200 = 1.01 g's!! OH MY!! 1.08 g's vs 1.01 g's. A "typical" MkIII turbo car does not make 400 lb-ft torque. Do you N/A guys hear me yet???

Okay lets make it tranny for tranny
turbo-3.25x3.73(gear for MkIII turbo)x.87x400=3835.12/3200=1.2 g's (thats strong)

But a typical N/A to turbo swap or just a turbo with upgrades 350 ft-of torque will generate 1.1g's. The answer is lower your ride weight and do all the bolt on mods, or even a bigger shot. Get your torque NOT hp up. This is just a basic idea it can be pushed further.

 

[Nick M]

Agreed. More grunt, more gear, more tire.

(source MMFF Aug2005)

 

[Fuzz420]

Very Nice info.I changed the equation to fit me. My goal is na-t, with around 300hp and 300fttq. I couldnt find the first gear ratio for the w-58 so i did the math assuming i have the r-154 with my pre-existing 4.30 lsd gear. 3.25*4.30*.87*300=3,647.47thrugst /3200=1.13g's. Now using 250fttq as the base point it worked to .94 g's.Not as good as the n/a with nitrous with less torque but still more than a full turbo with 100ft/tq more.

*edit i didnt divide by the 1.1 tire ratio: 3.25*4.30*.87*300/1.1=3,315/3200lbs=1.03 g's

 

[DEFIANT 7M]

W-58 first is 3.29. Check this out http://www.supramania.com/forums/showthread.php?t=1084&highlight=gear+ratio

 

[DEFIANT 7M]

Now on a 200 lbs diet vs 400 lbs-ft torque turbo
3.25 x 4.56 x .87 x 275 /1.1 =3223.35 / 3000 = 1.07g's. Looks like dead up out the hole assuming you got good traction.

 

[DEFIANT 7M]

Very Nice info.I changed the equation to fit me. My goal is na-t, with around 300hp and 300fttq. I couldnt find the first gear ratio for the w-58 so i did the math assuming i have the r-154 with my pre-existing 4.30 lsd gear. 3.25*4.30*.87*300=3,647.47thrugst /3200=1.13g's. Now using 250fttq as the base point it worked to .94 g's.Not as good as the n/a with nitrous with less torque but still more than a full turbo with 100ft/tq more.

Going back thru my notes, I type 250 fttq instead of 275 fttq. I think a 150 shot plus all available mods a N/A could make at least 275 fttq.

 

[Fuzz420]

3.29*4.30*.87*300/1.1=3,356.6973/3200lbs=1.04 g's

with the w-58 i would gain .01 g's if all else is the same. Now if i plug the w-58 in with your tq and weight numbers, with stock gearing:

3.29*4.30*.87*275/1.1=3076.97/300=1.02 g's a loss of .5 g's. So on paper it would seem the 4.56 out back really helps

 

[DEFIANT 7M]

3.29*4.30*.87*300/1.1=3,356.6973/3200lbs=1.04 g's

with the w-58 i would gain .01 g's if all else is the same. Now if i plug the w-58 in with your tq and weight numbers, with stock gearing:

3.29*4.30*.87*275/1.1=3076.97/300=1.02 g's a loss of .5 g's. So on paper it would seem the 4.56 out back really helps

Yea it does..the 4.56 comes from the 4x4 world the ring and pinions are the same size as the Supra. You can go higher!http://www.4x4wire.com/toyota/tech/supra_lsd/

 

[1TuffSupra]

but good lord a 4.56 rear would be a pain in the ass on the highway.

 

[DEFIANT 7M]

but good lord a 4.56 rear would be a pain in the ass on the highway.

No...not if you swap the fifth gear. http://www.4x4wire.com/lists/toyota/200008/msg00338.html

Modified R154(for a 4.56): the R150 or 151 overdrive gears (0.565) in my R154 its
1.117 x 0.565 = 0.63 overdrive.

Stock R154: R154 has a cluster ratio of 1.117 and an overdrive gear ratio of
0.674. Therefore, 1.117 x 0.674 = 0.75

 

[DEFIANT 7M]

Check this out.

http://www.geocities.com/MotorCity/Pit/9975/dataBySubject/Gearboxes.html

 

[1TuffSupra]

No...not if you swap the fifth gear. http://www.4x4wire.com/lists/toyota/200008/msg00338.html

Modified R154(for a 4.56): the R150 or 151 overdrive gears (0.565) in my R154 its
1.117 x 0.565 = 0.63 overdrive.

Stock R154: R154 has a cluster ratio of 1.117 and an overdrive gear ratio of
0.674. Therefore, 1.117 x 0.674 = 0.75

You know I forgot that you said we should change the 5th gear out. That is my biggest complaint with the 4.3 now is the rpm level while cruising on the hwy, it makes gas mileage suck monkey balls. This is something to look into