how much HP/torque will a C4 take?

[fe66comet]

Thinking of using a C4 behind my 445 FE. How much can a C4 be built to handle in a 4/4 with big tires and a healthy engine?...... Jon

[machoneman]

About a 1,000 hp. Most premier C-4 builders rate their top of the line trannys at/near 1,000 hp as well.

http://www.performanceautomatic.com/products/ford-racing-transmissions/c4-transmissions/

[cjshaker]

BUT, if it's stock it won't handle it for long if you mud or do any pulling with it. 1000hp only applies to the modified ones.

[JamesonRacing]

I'm using a Paquet C4 in my drag car with around 750hp, but that's a lot different than a 4x4.  I think I'd be looking really hard at a C6, as it should take quite a bit more beating for much less investment.

[fe66comet]

I planned on building from scratch and using a hardened input shaft, heavy duty drum, heavy duty clutches and a modified valve body. The main issue I have is space, I am stuffing it in a Jeep Wrangler do I need something compact. I was going to use a T350 but the C4 bolts up and I have a rebuilt one already. It was converted to a Bronco II transfer case but I can get a Atlas to bolt right up. My engine is nowhere near that sort of HP so I would definitely in the safe range there. Thanks guys.......Jon

[fe66comet]

Another question? Where do you get a high performance torque converter that has a 1.850 pilot or a bushing to 1.375 . Everything I see is 1.375 pilot for the converter......Jon

[JamesonRacing]

I used the same converter that I had for a C6, with a simple spline adapter than several of the performance shops offer.  Another option would be to use the smaller pilot and make a simple bushing...most any machine shop should be able to knock something like that out pretty quickly.

http://www.performanceautomatic.com/products/parts-and-accessories/c4-race-parts/c4-spline-adapter.html

[hbstang]

i think jay may have some input on this.wasnt his galaxie that he ran in drag week equiped with a c4?i have a very good friend who has been doing trans work for 40 years,and hes a ford guy.his name is dana sniff,hes in irvine ca.he is on face book if you want to look him up.he built a c4 that ran 4th in class in the baja 500 recently.

[fe66comet]

I found converters from performance automatics that have big or small pilots for C4s. Also the bell housing to hook it up, pricey but it is a better option than A T350 or C6 as it is the smallest and shortest of the bunch. In order to build it bullet proof and bolt in it will run a little over 2700 with the starter and adapter to an Advance Adapter Atlas four speed transfer case. It does guarantee no breakage at my power level to have the Pro Max rebuild kit, roller bearing conversion, six pinion planetary set, Pro pump, hardened input shaft and six clutch high gear drum. Also going with a 2500-3000 stall converter and heavy duty flex plate with the Bell housing kit. I was told by Performance Automatics this would give me a 60% easy boost in strength and greatly improve torque output at the rear wheels.....Jon

[jayb]

i think jay may have some input on this.wasnt his galaxie that he ran in drag week equiped with a c4?i have a very good friend who has been doing trans work for 40 years,and hes a ford guy.his name is dana sniff,hes in irvine ca.he is on face book if you want to look him up.he built a c4 that ran 4th in class in the baja 500 recently.

My Galaxie does have a C4, and it is no small feat for a C4 to live behind a 900+ HP SOHC in a 3900 pound car on slicks LOL!  Unfortunately automatic transmissions are something I'm just not all that knowledgeable about.  I know that the trans in the Galaxie has cryo-treated input and output shafts, red clutches, and a Performance Automatics valve body and servo valve.  Other than that, its pretty much a mystery to me.

[fe66comet]

Sounds like the.same deal they recommended for me, what kind of shifters are you guys running? I had a B&M cable shifter, it worked well except I went though burned cables on the exhaust. Then I had a lokar with mechanical linkage that is mounted to the top of the trans housing on my T350. It placed the shifter in the perfect spot but all the C4 shifters appear to be mounted on the tail shaft or the floor, I will have a transfer case and that is way too far back for where I need it. The floor mount has me concerned about linkage movement and bind in rough terrain. Any ideas guys? Thanks......Jon

[rockhouse66]

This is the C4 setup that came in the Mustang I bought.  The cable makes a U-turn behind the shifter tower and then goes forward under the floor.  Maybe you will recognize the components?

[fe66comet]

Kinda hard to see in the pick but looks like a TCI Quarter stick to me. Full competition just like your car, I dig the interior it has nice metal work..... Jon

[rcodecj]

I am under the impression that for the C4 to handle 1000 hp it would have to be a full manual valve body.
Does anyone know how much hp they will take with a regular valve body (leave it in drive, car shifts itself)?
I like the idea of using a C4 but I want to leave it in drive when I drive it or race it, and also just use the factory shifter.

[jayb]

I think it is correct that a manual valve body is required for really high horsepower from a C-4.  I think Performance Automatic told me that their non-manual C-4s were good for 750 HP.  In fact, when I first put the C-4 in my Mach 1 it had the normally shifting valve body, and the engine was the 706 HP 511" FE that I ran at Drag Week in 2005.  I had the same thoughts as you; I didn't want to mess with manually shifting the trans.  But I never could get the transmission to shift right, and in the end it turned out that the engine just didn't have enough vacuum for the vacuum modulator on the transmission to work properly.  So sometime during the summer of 2005 I swapped my valve body out for the manual version.  Shifting manually turned out to be no big deal, and I have never thought of going back to an automatic shift on that car, or any of my automatic cars.  Also, I have been able to retain the stock shifter; it requires a  certain touch on the track, but again I was able to get used to it pretty quickly.

In short, I wouldn't let the requirement for a manual valve body keep you away from the C-4...