🔧 BUILD strtcar 1967 Coyote Swap Mustang

General Information

Finally after almost 3 years in the making I started my 67 mustang this weekend. Excited to get her on the road, but still ton of work to do.

1688936593571.png


Gen 2 Coyote
PMAS CAI

CJ Intake
VMP twin 67mm Throttle Body
Lund Tune, will be on E85

4r70w w/Circle D 5c converter
Strange 9"




Pressure Ratio

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Nov 11, 2005
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Glen Ellyn
What is your 60' times?

Does the converter lock-up down track?

Do you have a trans brake set up?

I think a normal Gen 2 GT intake motor makes peak torque at about 4,200. With the CJ intake, it may be slightly higher. Usually in a drag racing application, you want the stall speed to be about 500-700 below peak torque. A looser converter would probably benefit the ET. With lockup, you can get away with a higher stall speed and have good trap speeds. As well as good street manners. You may not want to go to a 3,500-3,700 stall speed. But increasing it from where you are now may help out. It would be worth a call to Circle D to see what they say.
 

strtcar

Regular
Oct 28, 2007
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What is your 60' times?

Does the converter lock-up down track?

Do you have a trans brake set up?

I think a normal Gen 2 GT intake motor makes peak torque at about 4,200. With the CJ intake, it may be slightly higher. Usually in a drag racing application, you want the stall speed to be about 500-700 below peak torque. A looser converter would probably benefit the ET. With lockup, you can get away with a higher stall speed and have good trap speeds. As well as good street manners. You may not want to go to a 3,500-3,700 stall speed. But increasing it from where you are now may help out. It would be worth a call to Circle D to see what they say.
It is a circle d like 4200 rpm converter, but more so my brakes start to not hold the car above that 2500ish rpm range, but honestly havent worked much on trying to launch higher. I've actually never tried to lock the converter at WOT, always thought about it but never actually tried. It is a triple disk so I should be able. 60's are always in that 1.6x range.
 
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Pressure Ratio

....
TCG Premium
Nov 11, 2005
20,305
11,730
Glen Ellyn
It is a circle d like 4200 rpm converter, but more so my brakes start to not hold the car above that 2500ish rpm range, but honestly havent worked much on trying to launch higher. I've actually never tried to lock the converter at WOT, always thought about it but never actually tried. It is a triple disk so I should be able. 60's are always in that 1.6x range.

You can look into trying to foot brake it at different rpm. See if a lower foot brake rpm will allow it to flash the converter higher. Even try it off idle. See what lt likes best.

A trans brake is the best way to get the max stall speed out of the converter. But that is a valve body replacement which isn't cheap. But could help the car launch much better.

You can also add a second caliper to the rear brakes. Or a brake upgrade over PBR calipers to get more braking power to get more stall speed. But try different launch techniques to see if the car reacts better with a different launch. It's free other than paying to go to the track and a few wasted passes if it goes slower.
 

01bluesnake

D Mark Performance
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It is a circle d like 4200 rpm converter, but more so my brakes start to not hold the car above that 2500ish rpm range, but honestly havent worked much on trying to launch higher. I've actually never tried to lock the converter at WOT, always thought about it but never actually tried. It is a triple disk so I should be able. 60's are always in that 1.6x range.

Try bringing the rpm up to 1500, then going wot right as you let off the brakes. That will build less heat, and should allow the converter to flash higher helping the '60. You always want lock up at wot, if the trans and converter can take it. Lock up acts as a 1to 1 gear, or a manual trans with a clutch in a sense, in that it stops power loss through converter slip. Finding when to lock it up is trial and error, but it's gonna be up top, i would shoot for the 7500 area, see how far the RPM drops. Depending how loose the converter is, will determine how much rpm comes down once locked.
 

strtcar

Regular
Oct 28, 2007
489
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Try bringing the rpm up to 1500, then going wot right as you let off the brakes. That will build less heat, and should allow the converter to flash higher helping the '60. You always want lock up at wot, if the trans and converter can take it. Lock up acts as a 1to 1 gear, or a manual trans with a clutch in a sense, in that it stops power loss through converter slip. Finding when to lock it up is trial and error, but it's gonna be up top, i would shoot for the 7500 area, see how far the RPM drops. Depending how loose the converter is, will determine how much rpm comes down once locked.
Drew, are you familiar with the quick4 tuning on a 4r? I'm assuming it would look something like this then, lockup 2,3,4 (I disable overdrive anways), then play around with lockup RPM or TCC On?

1684893586378.png


1684893626309.png
 

strtcar

Regular
Oct 28, 2007
489
2,381
You can look into trying to foot brake it at different rpm. See if a lower foot brake rpm will allow it to flash the converter higher. Even try it off idle. See what lt likes best.

A trans brake is the best way to get the max stall speed out of the converter. But that is a valve body replacement which isn't cheap. But could help the car launch much better.

You can also add a second caliper to the rear brakes. Or a brake upgrade over PBR calipers to get more braking power to get more stall speed. But try different launch techniques to see if the car reacts better with a different launch. It's free other than paying to go to the track and a few wasted passes if it goes slower.
I don't think anyone has the 4r trans brake with Auto figured out yet. I think FB does but Darrin (BCA) says it dont last.
 
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01bluesnake

D Mark Performance
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Jul 8, 2009
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Drew, are you familiar with the quick4 tuning on a 4r? I'm assuming it would look something like this then, lockup 2,3,4 (I disable overdrive anways), then play around with lockup RPM or TCC On?

View attachment 163709

View attachment 163710

I am, i have done a decent amount of auto swap cars with them. Yeah, and it will take a bit of trial and error to see what the car likes.

I don't think anyone has the 4r trans brake with Auto figured out yet. I think FB does but Darrin (BCA) says it dont last.

I ran a VB from Darrin years back when i did a 4R conversion in my 01 cobra. I used a mach 1 auto pcm to control it, but worked flawless. I did however build my own trans. I believe it was a PA valvebody. I ended up selling trans after running it for a about a year and a half, under power of my F1 blower with no issue. The guy i sold it to went high 9's with the trans, didnt really keep contact to see how it lasted.
 

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