Which gears with my combo

[UpRise_5.0]

Hey,

I just bought a 1994 GT, 5 speed, with the mods in my sig.

The gears were not set up properly when installed when the previous owner had it.

Im going to get the rearend redone and put in new gears.

Should I stick with 3.55s with my combo, or go to 3.73s?

Right now im running 275/40/17 radials.

Im planning on either running nitrous on it, or possibly a supercharger.

Will 3.73s be okay? Will I run out of gear, or have traction problems with them. With the 3.55s im getting awesome traction at launch.

I ran a 13.5 at 103mph in the 1/4. Was my first time out so I know theres more. At 75mph im at about 2300 rpm with the 3.55s and in 5th gear.


Thanks

 

[BlackVert]

mostly street: 3.73:1
mostly track: 4.10:1

 

[Dino Dino Bambino]

As I suggested in my post on Corral.net:

Street: 3.55
Track: 3.90

 

[mojopony]

My combo is similar and I run 3.55's. Going to 3.73's won't be a huge difference unless all you do is race and are looking for any way to cut your ET.

BTW: How does that puppy idle with the E303?

 

[94-302-vert]

I ran a 13.5 at 103mph in the 1/4. Was my first time out so I know theres more. At 120mph im at about 2300 rpm with the 3.55s.

Thanks

How? I am at ~3300 RPM at 90 with my 3.73s. ... I am guessing that you should be about 4200 rpm at 120 with the 3.55 in OD...

 

[Grn92LX]

4.10 or 4.30's would be ideal for you if you wanted the most out of it on motor.

With the blower comming i'd just keep the 3.55's.

I personally run 4.30's in my pump gas street car and theyre great.

 

[The Green GT]

Alot of people go with 3.55's with they have forced induction for traction purposes.

But I know someone with 4.10 and a Vortech.

 

[final5-0]

Gears are mainly to optimize the power band :Word:

They multiply the torque and all that
but
From what all I've seen on these boards

A lot of focus has been on rpm at highway speeds and traction

The rpm thing has always amazed me
when I see confusion
as the E X A C T answer can be obtained with simple math
thus
hear say, opinion, or the unknown ... can be avoided ... totally

As for traction ..........
A steeper gear can make it easier to break em loose in the first place
but
You can regain control of the spin more easily with the pedal also

Using lower numerical ratios with Power Adder combos is
usually based with a focus on not running out of gear before
the end of the strip as opposed to having traction concerns.

Never ... Never ...
Try and use a stock Stang and a NA h/c/i Stang for an equal basis
on determining a ratio

On the h/c/i Stang ..........

Its all about how the power band has been shifted upward
and
The fact the power band has been extended

On the little stocker Stang ........

The power band is low and short as opposed to the h/c/i Stang

A general all around rule of thumb is ........
the stocker will not benefit from as steep of a ratio as the h/c/i Stang

Just a thought or two as I see it

Grady

 

[UpRise_5.0]

Opps im from Canada so put 120mph but meant kms, so I mean at 75mph in 5th gear im at about 2300 rpm.

 

[94-302-vert]

3.73s.

 

[UpRise_5.0]

3.73s.

How comes 3.73s?

 

[Dino Dino Bambino]

Opps im from Canada so put 120mph but meant kms, so I mean at 75mph in 5th gear im at about 2300 rpm.

That makes more sense. I did say your car is geared for 31.9mph/1000rpm in 5th in my corral.net post so I'll say it again; 3.55 for mainly street, 3.90 for mainly track. You'll see that I've already done the maths.

 

[Black95GTS]

That makes more sense. I did say your car is geared for 31.9mph/1000rpm in 5th in my corral.net post so I'll say it again; 3.55 for mainly street, 3.90 for mainly track. You'll see that I've already done the maths.

There is more to this then RPM. Tolerances are too tight and the pumpkin is not something to mess around with. OEM quality is not something to sneeze at. FRPP does not make 3.90s; your choices are 3.55, 3.73s, and 4.10s.

Pick the 4.10s and ditch the E303 camshaft. You should be running faster then 13.5 with an HCI and the appropriate mods / tune. You should be in the high 12s. You definitely need more gear and a camshaft that fits your combo.

Adam

 

[BlownFiveLiter]

I'd go anywhere from 3.55-4.10 gears, but it would depend on some things. First, what are my plans for the car? If I'm still using it to commute, I wouldn't go any more than 3.73's. If I wanted to see the track quite a bit, then I'd go 4.10's, but with the possibility of a supercharger, I may stick with a 3.55 or 3.73 for traction. As long as you don't spray the nitrous off the line, you could probably use any of the gears I've mentioned with no problem, should you choose that as your power adder. I also wouldn't recommend losing the E cam without seeing one of your timeslips. You may have run a 13.5, but you did it at 103, which is enough to get you a 12 with traction and driving. My old 90 GT ran a 12.89 at 104, so you're already within the possibility of hitting a similar time.

 

[UpRise_5.0]

I'd go anywhere from 3.55-4.10 gears, but it would depend on some things. First, what are my plans for the car? If I'm still using it to commute, I wouldn't go any more than 3.73's. If I wanted to see the track quite a bit, then I'd go 4.10's, but with the possibility of a supercharger, I may stick with a 3.55 or 3.73 for traction. As long as you don't spray the nitrous off the line, you could probably use any of the gears I've mentioned with no problem, should you choose that as your power adder. I also wouldn't recommend losing the E cam without seeing one of your timeslips. You may have run a 13.5, but you did it at 103, which is enough to get you a 12 with traction and driving. My old 90 GT ran a 12.89 at 104, so you're already within the possibility of hitting a similar time.

Thanks for the info. My plans are going to be either nitrous or a supercharger, and very light track use. Around 6-8 times a year I will go to the 1/4 mile. But I want to be able to have fun when Im driving on a back road too . But I will also be using the car for light commuting. Its sorta my daily driver, but I do have a another car.

My best time slip was as follows...

R/T: 0.602
60: 2.046
330: 5.696
1/8: 8.723
MPH: 81.90
1000: 11.349
1/4: 13.55
MPH: 102.5