I've been searching for an answer to this question for a while now and so far I haven't found one. Sorry if this is the wrong place but I didn't want to post it in the drag thread because its not really drag related.

My question is what will a L69, 5 speed, 3.73 geared car run at the top end bone stock. I am suspecting it will at least do a honest 130 MPH (I have a friend who got an Integra up to 132 with less HP and they weigh a couple hundred lbs less) I recall Dad saying he suspected the TA could get up to 140. But I don't see it with 3.73 gears.

Again, a bone stock L69 (305 HO) with a T-5 (5 speed) and 3.73 gears, what are we talking top speed wise? Due to that cursed 85 mph speedo I will have no idea how fast I will be going if I do open it up.

Thanks

 

It could probably do 140 if in good condition. However, with the 3.73 you will be close to red line in 5th gear at that speed.

 

It's an easy calculation. I need to know your tire size and RPM redline first, though.

 

Here's an example:

Redline: 5200 RPM
5th gear: 0.73:1
Rear end: 3.73:1
Tire size: 245/50-16

Top speed: 133.23 MPH

 

Here are my figures
Redline: 6000 RPM before full red.
Rear end: 3.73:1
Tire size 215/65R15
5th gear: 0.73:1 (I suspect its the same as the above I will need to dig around for the ratio.)

What is the formula for that anyway?

 

Also this is assuming your car has the power to run 6000 RPM in 5th gear... most don't!

 

I know that. LOL but if IIRC back when the car was on the road I remember dad shifting at about 5500 a couple of times. Still felt like it was pulling. Naturally, those shifts were in lower gears. I know 60 is easily attained early in third. Not sure. LOL its been a long time. Ofc, I probably don't have the power at the moment because I downgraded the motor to get it back on the road. I do know the L69 had a slightly higher redline than the LG4. This is all theoretical of course. I've been trying to nail down this car's top speed for a while now. It would be great to have numbers for the 1:1 4th as well. It would also be great to have the formula for future reference.

 

Here you go:

mph =

(rpm)(60)(tire diameter in inches)(3.14159)
-------------------------------------------
(5280)(12)(rear end ratio)(trans gear ratio)


mph =

(6000)(60)(26.0)(3.14159)
--------------------------
(5280)(12)(3.73)(0.73)

mph = 170.44 (assuming enough hp / guessing on tire diam)

 

wow....so the gearing and tires are probably good for 170. Any way we can incorporate the stock 190HP and car weight of approx. 3300lbs into that? I know it won't do 170 with 190 HP unless the 305 HO was grossly underrated. If I do get that high then I will be letting ya'll know from a jail cell.