Best 1st gear ratio with 2.94 differential

-
b5cuda

b5cuda

Well-Known Member
Joined
Jun 30, 2007
Messages
224
Reaction score
33
Hey gang, looking for opinions on which 4-speed first gear is best with 2.94 rearend. I'm currently running a 2.44 first gear in my e-body project and it scoots - but I have to rev the engine and feather the clutch to start if there's a slight uphill. So I'm wondering whether a trans with 2.66 or 3.09 first gear would be the way to go? Running 26.5" tires, goal is a highway cruiser. Thanks!
 
I line in hilly country here in Nevada and when I lived in Pennsylvania.
This is just me but 3.09 might be better for not riding the clutch.
 
3.09 for sure. Multiply the gear ratio by the first gear ratio. The target sum should be as close to 10.00 as possible for arguably the best take off ratio.

2.44 X 2.94 = 7.17 - Not to great.
2.66 X 2.94 = 7.82 - An improvement, not so great though.
3.09 X 2.94 = 9.08 - Getting pretty nice here.

(Side note to what I’m doing later;
I myself will be using 3.55’s in the future with a OD manual trans which will end up at 10.959 calculated with the 3.09 first gear.
(Honestly I keep forgetting what the OE manual trans first gear is.)
The truck OD trans I have has the .71 OD gear. (IIRC)
Leaving me with a decent ratio for the Hwy @ 2.52 & a 245/60/15 tire at approximately 27 inches)
 
Last edited:
Sounds like a plan! Thanks guys, appreciate the confirmation of 3.09 as preferred ratio.
 
i ran a 3.09 in two different darts (64 & 65). one had a 3.55's with 25" tires and you'd be wanting to shift about the time you were thru a big intersection. the other had 3.23's and 26" tires and was a little more forgiving.

in a light weight, low powered car with low gears (numerically) that 3.09 1st really shines
 
I have a 72 Demon with a mild 360, 3.23 rear axle and 27" rear tire. 3.09 1st gear and it works really well. In the spring I'm either going to swap in a 2.94 gear or change to a 28" tire. Car is just a driver/cruiser.
 
3.23 X 3.09 = 9.98

That’s about optimal for a first year take off.

2.94 X 3.09 = 9.08. Still not to shabby.

It’ll still have a decent off the line acceleration and it’ll have a good Hwy cruise rpm. A pretty good balance IMO.
 
rumblefish360 said:
3.23 X 3.09 = 9.98

That’s about optimal for a first year take off.

2.94 X 3.09 = 9.08. Still not to shabby.

It’ll still have a decent off the line acceleration and it’ll have a good Hwy cruise rpm. A pretty good balance IMO.
Click to expand...
Height of rear tire comes into play also, but I can easily get the car moving without using the accelerator.....so I can get a little bit more out of the combo. I will probably change the tires first.
 
15.8 SLR for me. I don’t use the same metrics for SLR with a leaky slush box as I do for a stick car. Most guys are way short on SLR for their sticks.
 
Dan Brewer said:
Height of rear tire comes into play also, but I can easily get the car moving without using the accelerator.....so I can get a little bit more out of the combo. I will probably change the tires first.
Click to expand...
Absolutely! Coupled with the amount of torque from the engine…
LOL!

Newbomb Turk said:
15.8 SLR for me. I don’t use the same metrics for SLR with a leaky slush box as I do for a stick car. Most guys are way short on SLR for their sticks.
Click to expand...
What would you suggest for a SLR on a manual?
 
My 65 Barracuda originally had a 3.09 low gear in its four speed. That little 273 could keep up with SS396's and the like in low gear, but they would pull away in higher gears. Then I blew up the 273 in November of 72 trying to drive home from Charleston, SC to Cochran, Ga in second gear after I broke the 3-4 shift fork. Swapped in a 340 and now it would blow away the typical junior super car in low gear and pull away in the higher gears.

Fast forward a few years, and the trans main shaft got a large groove worn in it where the needle bearings sat on it (by this time, the car had well over 200,000 miles on it). I was told new main shafts were not available, so I got a junkyard 69 Dart four speed and put it in. That's when I first realized the difference in low gear ratios. The Dart trans had a 2.66 low gear. The difference was amazing. Before, I could just let out the clutch and go, now the only way to leave fast was to rev it up and dump the clutch. Otherwise, almost anything could beat it off the line (3.23 gears). Put up with that for a few years, then found out my original gears (which I had saved) would fit in the later case. Had a 3.09 low gear set ever since.

For the street, a 440 doesn't need the low first gear; a small block does.
 
rumblefish360 said:
Absolutely! Coupled with the amount of torque from the engine…
LOL!


What would you suggest for a SLR on a manual?
Click to expand...

If you google block magic clutches SLR chart you can see what I use as a pretty close guideline for 1st gear over all ratios.

I was pretty much stunned when I stumbled across that chart. Like I said, most guys don’t run enough first gear (according to the Black Magic chart) and proving it out has shown that chart to be pretty close.

I know when the Alston chassis book came out and then Morgan published his “Dooorslammers” books that both of them said a SLR from 9.0-10.0:1 was the ballpark, I’m sure they didn’t account for the less than (my guess here) 1% of cars using sticks.

I have to say in the last 10-12 years sticks have gotten more popular.

The issue is tuning a stick car is far more complicated than an auto car.

Then you have to find (and/or train) the driver. I always think about David Rampy. That dude is a drag racing god. Put him in a PS car (and considering those cars have a clutch but you don’t use it to shift for those who may not know that) and he wasn’t even competitive.

Thats how hard it is to find and train stick drivers. They just aren’t being made any more. Most people I know under 40 can’t even drive a 3 pedal car. My kid can’t. When he’s done with school for the year I’m going to get him to learn stick driving. He needs to know it. His mom can’t drive a stick for crap. I’m hoping he is more inclined to it than his mom.

And I’m not talking about drag racing or any of that. I’m just talking about actually driving with 3 pedals.
 
You must log in or register to reply here.
-

Back
Top