Changing Gears

[mdross1]

I can cruise in 5th (.68) at 1500 rpms and not have a trailer hitch jerk. Hiway speed 70 to 80 I'm about 2000 rpms.

The only way to go for most of us.Have tried twice with peaky engines no doubt they are fun when used they way they were intended to be used but trying to chug around town or in stop and go they can be a real pain.
The very reason why I have been running big blocks since the early 70's.
Course I'm speaking for myself and other like minded enthusiasts.

[AL427SBF]

I'm car number 4 in the video, yellow Cobra with Alabama tag. I have 3:55 gears with 26" tires and a small block with a lot of low end torque. TKO 600 with the 2.97 1st gear. I sold my TKO with a 3.27 because first gear was useless.

There is no way I could use 4:10 gears in my Cobra. NO WAY

TKO 600 has a 2.87 1st, 3.27 rear was useless because? ... too tall?
Just curious as your 3.55 is going toward the short side.

[D-CEL]

TT SAID:
"D-cel, to be fair, part of the reason your tires work so well for you (besides being sticky and wide), is that they are 28" tall, which significantly changes the true ratio."
Circumference is 80.73 vs 87.96 roughly 10% $HOOT you are correct! I should be running 4.56s!
“ I have 275/17 drag radials (25.7" tall), which are pretty common, and there is no chance in hell I would hook with 4.10's. Cheers.”
Your Cobra makes a boat load of power and runs like a Democrat at the NRA convention. But Last time I looked the 275 DR guys were deep into the 7.50s @ over 180mph. Im pretty sure you could easily hook the added torque of 4.10s
D-cel

[itstock]

[joyridin']

I am not sure how much the OP has checked into this, but as far as I can tell, a 4.10 ration isn't even made for the 7.75 GTO rear end. 3.91 is as high as you can go.

If you really want a good set-up, you may want to go this route:

GTO - Store

[rgnbull1227]

Originally Posted by joyridin'

I am not sure how much the OP has checked into this, but as far as I can tell, a 4.10 ration isn't even made for the 7.75 GTO rear end. 3.91 is as high as you can go.

If you really want a good set-up, you may want to go this route:

GTO - Store

Actually I did. Realized yesterday 3.91 it is.

[joyridin']

Did you see the pricing? Some places are $750 for a ring and pinion!! Holy cow!

[Mother]

Im using 3.55 finals with a 460 BB. 740/680. Nitto NT555 tires, 25.9 tall, 285 40r 17's, and 235 45R 17 fronts. Finals are case hardened Richmonds. Cost $255.00, 31 strange splines, and an Auburn ratchet spool. Large Titanium yoke, and solid aluminium shaft, with a narrow ratio TKO 600 5 speed. Unit is a crusier. I have way too much coin in the toy to drag it at track. But for pure fun driving, its a blast. I don't need to prove anything. Spent way too much time wanting this car to even consider trying to find it's "limit". I have driven heavy trucks all my life. I'm into the sounds, smell and torque. I will pass on a happy man.

[itstock]

Originally Posted by Mother

Im using 3.55 finals with a 460 BB. 740/680. Nitto NT555 tires, 25.9 tall, 285 40r 17's, and 235 45R 17 fronts. Finals are case hardened Richmonds. Cost $255.00, 31 strange splines, and an Auburn ratchet spool. Large Titanium yoke, and solid aluminium shaft, with a narrow ratio TKO 600 5 speed. Unit is a crusier. I have way too much coin in the toy to drag it at track. But for pure fun driving, its a blast. I don't need to prove anything. Spent way too much time wanting this car to even consider trying to find it's "limit". I have driven heavy trucks all my life. I'm into the sounds, smell and torque. I will pass on a happy man.

"740/680"

don't need to prove it

"...spent lots of money and built the car to be able to take what it's given..."

won't drive the car to the point of even testing limits

I just don't get it.

[AL427SBF]

Originally Posted by itstock

"740/680"

don't need to prove it

"...spent lots of money and built the car to be able to take what it's given..."

won't drive the car to the point of even testing limits

I just don't get it.

WTF?
If you carry a big stick, most often you don't need to prove it. The challenges usually come from wannabe chumps in 4WD Subarus - they don't deserve the time of day let alone a demonstration

"...spent lots of money and built the car to be able to take what it's given..." the quote no where to be found in Mother's post, not adviseable to put words in peopl'e mouths.

How would you test the lmits of a 2500 lb roadster with 740 HP/640 lb-ft Torque, please do tell lol.

Agree, you clearly don't get it.

[twin turbo]

Originally Posted by D-CEL

TT SAID:
"D-cel, to be fair, part of the reason your tires work so well for you (besides being sticky and wide), is that they are 28" tall, which significantly changes the true ratio."
Circumference is 80.73 vs 87.96 roughly 10% $HOOT you are correct! I should be running 4.56s!
“ I have 275/17 drag radials (25.7" tall), which are pretty common, and there is no chance in hell I would hook with 4.10's. Cheers.”
Your Cobra makes a boat load of power and runs like a Democrat at the NRA convention. But Last time I looked the 275 DR guys were deep into the 7.50s @ over 180mph. Im pretty sure you could easily hook the added torque of 4.10s
D-cel

Too funny. I have trouble hooking as it is with 2.73 rear gears on the street. Cheers.

[itstock]

Originally Posted by AL427SBF

WTF?
If you carry a big stick, most often you don't need to prove it. The challenges usually come from wannabe chumps in 4WD Subarus - they don't deserve the time of day let alone a demonstration

"...spent lots of money and built the car to be able to take what it's given..." the quote no where to be found in Mother's post, not adviseable to put words in peopl'e mouths.

How would you test the lmits of a 2500 lb roadster with 740 HP/640 lb-ft Torque, please do tell lol.

Agree, you clearly don't get it.

Sorry for the oversimplification of my paraphrasing. He stated that he spent lots of money on the car to build it right, but since he knows it's built right, there is no need to prove that it's built right. Again, paraphrasing.

And how do you test limits? Bring it to a track, try it out. Give it some throttle every once in a while. Why build a car to not break parts at that power if you aren't going to drive it in any way that is going to break parts anyway? Besides, according to DCEL, all he has to do is put a 275 drag radial on that car and it should hook just fine!

[AL427SBF]

FYI, you put something in "quotes" then it's not paraphrasing, and now you equate testing something to its' limits as testing to failure? No need to continue, we're done here lol.

[itstock]

Sorry, next time I will use the correct citations. lol

And I guess turnabout is fairplay for you putting words in my mouth, since I never equated testing to limits meaning failure.

[twin turbo]

Rgnbull, did you ever end up putting in the 3.91 gears?

[G-Pete]

26.5 inch tires, T45, SVT rear pumpkin with 4.10 gears.....just a ton of fun.


First ride (gocart) 289 Shelby Cobra --- Scratch build. - YouTube