C6 converter

[John Poling]

Since this is the Tranny Talk section, does anyone have an interest in a higher stall (3200rpm) converter for a C6? I have one with about 200 (two hundred) miles on it and had to swap it out because it was just too much stall for what I am intending on using my Cobra for. I have it listed on the "Parts for sale" section to no avail. If you know of anyone please send them my way.

Thank you.
John

[Harris]

John,
In your post you mentioned the 3200 was "Too much stall" What was the car doing. I'm putting a 3000 in a built C4 and I would like your impressions.

Thanks
Harris

[John Poling]

Good Morning Harris,

My problem is that my 3.50:1 gear and 25.7" tall rear tires were not a good combination for that much stall on what I intend to use my car for. My 65mph highway cruise speed is just at 3000 rpm which in turn is just below where my torque converter is in its "engaged" status. Basically, for any cruising it was just free wheeling unless I was in the throttle. For the city streets and racing it would be okay but I intend to drive it more on a daily basis during the summer, therefore I have swapped it out for a more mild mannered 2000rpm stall. Keep in mind it's not how "built" your xmsn is that matters when it comes to the converter you need, rather your intended use and the power output and rpm range capability of your whole drivetrain.

Hopefully this answered your question, but if it didn't please ask more.

Thank you.
John

[TonyMadrid]

Hi John & Harris. Seems you guys are apparently the people who I may need to speak with. I am building a kit and intend to use a C-4 or a C-6 (probably the C-4). I don't plan to race it but I still want it to have some guts for the street. Whay do you guys recommend as far as what converter to use and how should I determine what stall speed would be adequate.

Also Harris, what is the best way to beef up the C-4? Am I better off buying one from a company that sells high-performance trannies, or should I buy one from the boneyard and have a shop beef it up?

Tony

[John Poling]

Good Morning Tony,

For what you say you are intending on using it for, you will not need a C-6.I personnaly would not have chosen a C-6 because it is just plain overkill for the weight I am pushing, but I bought this kit started by someone else and they thought that the C-6 was the better choice. I know a lot of people that are using a built C-4 behind high power small blocks and one or two people that are using a C-4 behind a big block and they have not had problems. Most of the people are running these combo's in Fox bodied Mustangs which are heavier than most all Cobra's out there. As far as determining the required stall speed there are all kinds of things you need to consider, you will need to take into account big block or small block, power/torque output, grind of cam, weight of car, rear gear, cruising speed on the hiway at 65mph (for a street car not race) etc... Keep in mind that you are not going to be pushing around nearly as much weight in a Cobra as you would in an old Mustang, so theoretically your stall speed will be lower in a lighter car.

As far as choice of where to purchase, that is completely up to you depending on your financial and mechanical abilities.

Did this help? If not, please reply with more questions.

John

[Wild Thing]

Hi everybody,

as far as I know, you get the best result when the stall speed meets the revs where your engine has the maximum torque ?

[John Poling]

Wild Thing,

I would agree. Of course the only way to know this is to either have your engine run/tuned on a dynomometer be it chassis or engine.

John