Circle "D" 4K stall converter install!

[Poppacapp]

I can only get about 2,500 rpm's against the brakes when I stage at the track on drag radials. After that, the car will push through the beams. Car launches best when I hold about 2,000 rpm's against the brakes at the line.

When I let off the brakes & mash the gas pedal to the floor, the converter instantly flashes to 5,000 rpm's and away I go - typically pulling 60' times in the 1.59 to 1.64 range. And, when the trans upshifts, the rpm's never fall below the 5,000 rpm flash speed, keeping me right in the powerband the whole way down the track.

Gotcha. i appreciate the explanation. :cheers:

I'd suggest trying to find somebody locally that has a converter in their car with a 6R80 and have them give you a ride this way you can see for yourself before committing to this, but in my opinion these cars need more stall badly, how much is depends on your goals. You can always have the converter reworked to get more or less stall...Circle D has more info on their site.

Yeah, I would like to ride in a converter S550 to see how it is. I DO drive my car alot, and don't want to sacrifice too much in the way of street manners.

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[Five Oh Brian]

I wanted 4.10s but couldn't locate them...are yours from the Cobra Days and if so which posi did you use so the ring gear could mate up with the pinion gear?

My car is a '14 GT with the solid axle, so any gear ratio easily swaps in from 2.73 to 5.14. Sounds like the '15 IRS is a little trickier to get the ring & pinion swapped.

 

[kcc0521]

I'd suggest trying to find somebody locally that has a converter in their car with a 6R80 and have them give you a ride this way you can see for yourself before committing to this, but in my opinion these cars need more stall badly, how much is depends on your goals. You can always have the converter reworked to get more or less stall...Circle D has more info on their site.

What is the drop in gas mileage from the converter swap? I am contemplating trading my GT PP car for an auto. I love to drag race and I think the auto would be way better on parts.

 

[Five Oh Brian]

What is the drop in gas mileage from the converter swap? I am contemplating trading my GT PP car for an auto. I love to drag race and I think the auto would be way better on parts.

I only lost about one or 2 miles per gallon over all with the converter swap.


Sent from SYNC in my '14 Mustang GT...

 

[RBS550]

What is the drop in gas mileage from the converter swap? I am contemplating trading my GT PP car for an auto. I love to drag race and I think the auto would be way better on parts.

Sorry I haven't responded sooner, I've been on a 3K mile True Street vacation with my 4K stall Circle D converter! To answer your question I think you would only notice a mileage drop in the city as the converter locks up later on in 2nd gear and locks up immediately from 4th gear on. To recap I have 3.73s and the 4K stall and pulling my 4'x8' utility trailer with tools and spare tires ect... at 72+ mph a/c on I get 21+ mpg. Had I kept the 3.15s I'd still be real high 20s, like 28-29 mpg.

 

[esacteksab]

Sorry I haven't responded sooner, I've been on a 3K mile True Street vacation with my 4K stall Circle D converter! To answer your question I think you would only notice a mileage drop in the city as the converter locks up later on in 2nd gear and locks up immediately from 4th gear on. To recap I have 3.73s and the 4K stall and pulling my 4'x8' utility trailer with tools and spare tires ect... at 72+ mph a/c on I get 21+ mpg. Had I kept the 3.15s I'd still be real high 20s, like 28-29 mpg.

I love this picture!! How'd the car run? Did you do any racing?

 

[RBS550]

I love this picture!! How'd the car run? Did you do any racing?

Heck YEAH! If I had not shown up there would have been no S550s in True Street. I'm not the kind of guy always expecting to be the fastest, I just want to make sure the public knows what the current Mustang can do. I view it as my job to promote FORD and the aftermarket to keep us ahead of brand "X". And remember many Mustangs were the current ones in their day. Now it's the S550's job to carry on the torch. We need S550's to show up in True Street and else where.

 

[esacteksab]

That's awesome!! I love your car!

 

[Excelerater]

Pretty neat, if you had a data logger on your car you cold see
what the converter is really doing..(slip,shift drop,lock up etc)

I know the factory conv is way too tight to get any 60ft
even with 2HP per CID which some guys are making.. I know Pro torque is
working on a unit for the GT along side a pretty well known tuner and im pretty excited to get one when they are ready..

 

[RBS550]

Pretty neat, if you had a data logger on your car you cold see
what the converter is really doing..(slip,shift drop,lock up etc)

I know the factory conv is way too tight to get any 60ft
even with 2HP per CID which some guys are making.. I know Pro torque is
working on a unit for the GT along side a pretty well known tuner and im pretty excited to get one when they are ready..

I do data log, but only when I'm racing, I've never data logged in normal driving. When street driving normally I do find it's much better to manually shift first and second, you hardly notice the stall that way.

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