Best Auto Setup

[danc30]

I am going to use an auto in my hurricane (soon to be purchased). I know, what a weenie (medical reasons).
I am going to use a Rousch 427(351W bored) with 550HP and 535ft/lbs torque.
I will be mainly cruising and want decent off the line acceleration (as well as causing smoke-screens when desired).
Here are my wants and questions:
1- I want to be able to cruise at 65 at around 2200 RPMs.
2- Have good "streetability". (No motorboat sound yet real good accelleration)
3- I want to be able to manual shift most of the time. (If not all of the time).
4- Want to be able to downshift the auto in all gears. (if possible).
5- I will be using Yoko S/T 295/50/15 rears
6- What would be the best rear gear/tranny/torque converter combination.
7- What shifter would you recommend?
8- How hard are the Lentechs TV cables to get "right"?

Any help all you more experienced builders can be is appreciated.

[danc30]

Any input is appreciated. If you have an automatic tranny in your Cobra Replica, what is your rear gear and tranny.

Please help, trying to make a decision on my set-up before ordering.

[GREENSNAKE]

My old cobra i sold was B&B. I set it up with a C-4 Manual valve body,Hughes 2200 stall converter, Transgo Shift kit, the rear end was a 8.8 327 gears the car went high 12s at 107 mph 302 carbed great for street did 65-70 mph at 2200- 2300 rpm great for a 3 speed you might want to consider a AOD if you want that xtra gear . Hope this helps! Lonny

[ItBites]

I run a chevy TH400 with a 3.08 rear. The top speed is north of 160. Quarter mile 12.0 at ~116mph (still in second gear - I shift at 7400 rpm).

Tranny was built by Hughes and I use a Hughes 3000 stall converter.

If your rear end can handle the torque, I'd go lower in the rear gears. I don't want to destroy my aluminum C4 vette rear setup, so have never changed to lower gears.

[danc30]

Thanks to both of you for your suggestions.

[Ken Bisconti]

I have a C6 Trans and a 390FE in my Hurricane. It fit fine, so you should have no problem with a C4. Used Lokar Linkage. Lokar kick down. 325 Rear end gears. I like it just fine. I had 351 gears in my old Cobra and was a little high reving at 80 mph for me. ken HM 1007

[TonyMadrid]

I had a C-4 behind my 351W and 3.50:1 rear end gears. To go 60-65 the engine would spin at about 3000RPM. I swapped the C-4 out for an AOD and now to do the same 60-65 the engine only spins at about 2000RPM.

When you do the math, the logic is easy to understand. The C-4 or the C-6 for that matter has a final tranny output ratio of 1:1, meaning that for every rotation of the output shaft the engine has to spin once. With the AOD, the final output shaft speed is .67:1 (overdrive gear), meaning that for every rotation of the output shaft the engine spins 1/3 less than with the C-4 or
C-6. This translates to bringing the RPM's down by a third, 3000RPM's down to 2000RPM's.

With the 3.50:1 rear gears you'll still have the low end punch.

With respect to the TV cable, it is very important to adjust it correctly. If you have too little throttle valve pressure you will fry the tranny. What happens is that the clutch plates try to engage but with insufficient pressure they cannot fully engage so they just spin against each other and wear right down. If you have too much TV pressure the trannny will shift like a kicking mule. In order to correctly set the TV pressure you will need a pressure gauge to corrrectly set the TV pressure at idle. It is best to err on the side of too much pressure and then if it shifts too hard, you can gradually back the adjustment off.

I used a TCI AOD that I got from Summit and the techies at TCI were more than helpful walking me through the TV pressure initial adjustment and setup.

Hope this helps you out.

Tony

[danc30]

Thanks. This is very usefull information.

[WV66AC]

I agree with what Tony says -- three speed no overdrive -- 3000 rpm at 65 mph -- it beats you to death if going for any distance. Light cars --- if not accelerating hard - you hit third gear early. I enjoy puttering around at low speeds -- theraputic to be sure. Good luck with your choice of tranny.