c4 vs 5 speed

Has anyone read the February issue of MM&FF?...They have a great article (in my opinion) on the comparison of an allout race prepped c4 transmission vs a 5 speed.

The gains or lack there of are sim to what I have seen in my cars in the past. Wondering what the thoughts are of those who read it if anyone. Can lead to some good discussion

i read it, i was suprised, i was expecting the c-4 to be quicker

well who was driving the 5spd in the comparision? If its a professional driver then its understandable because thats not like the average joe running his modified car at the track

at the track it was what i expected. car was not extreme enough yet. so make a non-modified 5 spd hard to drive.

on the dyno it was different then what i see all the time

on the dyno it was different then what i see all the time

Click to expand...

Matt,

Same here...I was expecting to see considerably less HP, not a small increase in HP when switching to the auto.

David

BTW I wasnt talking about gains or losses in HP or TQ in case there was any confusion.

Keep in mind that the power loss between a c4 and a t5 isnt nearly as great as between a t5 and an AOD or AODE.

What I was alluding to is that on the cars I have swapped for myself and freinds in the past have always shown similiar results. But I'm not talking 8 second cars..I'm talking 10's. This was also never with an off the shelf converter. Always a custom built one for the particular setup

And it was always for consistancy not to be faster or quicker

In the article they used an 8 inch 4,700 stall. I've personally never used anything that small.

I just thought the article to be interesting as rarely do you see back to back testing of this nature

im most mid 10 sec cars we do. when we swap to a C4 we drop 2-4 tenths. from the 5 spd.

Transmissions can vary so much. "An all out race prepped C4" doesn't mean anything. Unless it was a completely full roller bearing transmission meaning there's a roller bearing in every possible place that had a frictional contact, aluminum drums, gundrilled mainshaft, and a custom machined 36 first gear sprag from a C6 to fit, then I wouldn't call it much of an efficient "race" transmission.

Same thing with the converter. Going from Coan's best converter to my transmission guy's converter, I gained a tenth and a half. Going from "an all out race prepped TH400" from Coan, to the one I have now, I gained another two tenths.

Transmissions can definitely vary. This is what I wanted to hear. I have always had the experience of just about the same performance. Of course the stick driver needs to be on top of his game otherwise numbers will suffer moreso as well. I have always used Dynamics Mighty Mite c4 which is what they consider fully rollerized. I personally think there is more to be had in converter selection then the tranny at this level.

I haven't read the article since I don't read MM&FF as a rule.

The reasons given by most around here for their switch to C4 are the usual concerns for consistency, but also a lot say they did it for reliability too.

One case in point, an 84 that had run 11.0's/120 with a nitrous fed 302. The 5 speed wasn't a problem at all and the owner was a die hard 5 speed fan. The 302 eventually blew up so in went a 351. First pass killed the T5, and the next one, and the one after that. A Tremec was purchased and went longer but still failed for one reason or another within 10 or so passes. The car was now a solid 10.20/130 performer when it had a trans in it. Also, around these trans failures were multiple clutch failures, and every one was a total PITA as getting the scattershield out required removal of the headers.

The owner finally had enough and bought a used, rollerized, manual valve body w/'brake, C4. It took a little shaking-out, like where we found that rollerized isn't necessarily a good thing, but the car did gain just about 2 tenths and was running 10.0's. It eventually went 9.67/139 as it's quickest but was consistent in being around the 9.70's for whole seasons without a tranny failure until the owner grew tired of Mustangs and moved over to Turbo Regals

I never ran a good 5 speed. My turbo v8 car when it was a supercharged v8 car used to eat up 5 speeds albeit all stock world class T5's. I know people having great luck with the good tremacs and modified T5's. However the shock of dumping a 5 speed at 5,000 is alot greater then that of a c4 with a 5,000 stall and a transbrake.

Consistancy is definitly key and after awhile reliability of cranks, driveshafts, axles.....

One thing I didnt mention is that I would freshen up my rollerized tranny every year as I heard a few horror stories of the bearings going prematurely.

We treid running a C4 in my buddies stang but he kept exploding them..Currently we have a poweglide in there and crossing our fingers it launches like a mofo and goes straight..In one peice!

My Mustang went from 12.80's with a 5 speed to consistent 12.20's just from going to a built C4 with a 4200 stall.
I must admit I am not the hottest 5-speed drag racer out there...