Circle D 2C drive ability inquiry...

redfirepearlgt

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Hey guys,

I had a Circle D 2C (new out of the box 3200-3400RPM stall) installed a few months back. The tune according to the tuner "should need to be updated" for this modification.

Setup power is a 2014 Mustang GT making 550RWHP with a 2300TVS. 6R80 with the Circle D modification, one piece Aluminum DS, 3.15 standard factory diff gear. Car HAS 16000 MILES ON IT. HAS SEEN SOME PASSES AT THE TRACK ON T/T NIGHTS-- ABOUT 25 passes IN AN ENTIRE SEASON AVG OVER PAST 2 SEASONS -- SO I WOULD NOT CONSIDER THE CAR ABUSED OR BEAT ON EXCESSIVELY. JUST DRIVEN WITH SPIRIT AT TIMES.

Symptom concern - I am hearing some chatter/clatter in the higher gears (3 lightly, 4,5,6 mostly) ONLY during TCC lock up at lower RPM (1500 at 40mph in 5th gear as example) when I apply light throttle. Running steady throttle at this RPM/SPEED in these gears ther eis no noise heard. Only when load to the driveline is applied lightly to increase/maintain speed. The nosie was not there prior to the stall converter being installed. Fluid level is correct on the unit and verified before being taken off the lift just after the swap out. They showed me since the car has to be on the rack to check 6R80 fluid level from underneath and on a level plane.

I have had the car up on a rack at the speed shop and verified the control arm bushings are fine, gear lash is fine, U joints are fine, the DS loop is not interfering with anything, no exhaust noises, all clamps tight, no rubbing, etc. The shop owner has ridden with me and heard the noise and states he believes the noise is NVH being generated by the TCC in the converter which locks up harder (3 clutch vice 2 clutch stock system as I understand this) and this noise is transmitting down the one piece DS. He followed up a day later stating that his on line research indicates this is a somewhat common phenomenon after the install of a Circle D on cars with a more quiet exhaust system (OR H w GT500 mufflers and stock afterpipes) like mine. I'd love someone with a stall converter in their 11+, with 3.15 gears, and 1 piece DS, first tell me if they have this problem or would be kind enough to try to duplicate the driving condition to see if they get a similar noise.

The noise arises in drive or with a higher gear manually selected and the TCC locked up. Conditon - Level road, rolling at 40MPH in 5th gear (1500 RPM with a 3.15 diff gear) and apply light throttle up. Not so much the TCC unlocks, just enough to raise RPM in maintaining speed or beginning a slight uphill climb.

I would appreciate the feedback. I am just trying to discern if it is simply increased NVH due to a performance item being added or if there is actually a potential problem. The datalogs I have made and had looked at indicate that the TCC is locked up when this happens but no one has told me if the clutch is slipping at lockup causing this or if it is suppose to lock up. I have called Circle D and tried to describe the noise and they of course simply want to write it off as being transmission related......like I am surprised. So not fully impressed with the tech support from these guys for a $1200 part.

Thanks for the help in advance.
 

redfirepearlgt

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grammar correction in opening statement - Tuner said TUNE SHOULD NOT NEED TO BE UPDATED for this modification. SORRY! I suck at typing.
 

redfirepearlgt

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I'll conclude from the silence that this indicates that the Circle D is likely defective as I have been suspect since there are no remarks from anyone experiencing a similar issue after installing one. Will find out for sure when it comes out and I ship it back to Circle D under warranty for inspection before selling it. Thanks for the help.
 

RocketcarX

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I'm with you on suspecting the converter has an internal issue, especially since the issue did not exist prior. On the other note it sucks the way the forum participation fell off. I really enjoyed spending my evenings here in conversation.
 

redfirepearlgt

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I'm with you on suspecting the converter has an internal issue, especially since the issue did not exist prior. On the other note it sucks the way the forum participation fell off. I really enjoyed spending my evenings here in conversation.

I'll find out soon enough when it comes out and goes back. I'll probably run the rest of the season stock, and then save up over the winter and do the exedy clutch and intermediate shaft upgrade next spring and maybe put it back in then. Or I'll just gear to a 331 or 355 as has been previously suggested. That 10R80 has a 4.6X 1st gear compared tot he 4.17 1st in the 6R80 and Ford is offering a 355 diff option on the 18+.

Hopefully lack of participation indicates no one is breaking and most are having a good season.
 

SouthernCyclone

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Hey guys,

I had a Circle D 2C (new out of the box 3200-3400RPM stall) installed a few months back. The tune according to the tuner "should need to be updated" for this modification.

Setup power is a 2014 Mustang GT making 550RWHP with a 2300TVS. 6R80 with the Circle D modification, one piece Aluminum DS, 3.15 standard factory diff gear. Car HAS 16000 MILES ON IT. HAS SEEN SOME PASSES AT THE TRACK ON T/T NIGHTS-- ABOUT 25 passes IN AN ENTIRE SEASON AVG OVER PAST 2 SEASONS -- SO I WOULD NOT CONSIDER THE CAR ABUSED OR BEAT ON EXCESSIVELY. JUST DRIVEN WITH SPIRIT AT TIMES.

Symptom concern - I am hearing some chatter/clatter in the higher gears (3 lightly, 4,5,6 mostly) ONLY during TCC lock up at lower RPM (1500 at 40mph in 5th gear as example) when I apply light throttle. Running steady throttle at this RPM/SPEED in these gears ther eis no noise heard. Only when load to the driveline is applied lightly to increase/maintain speed. The nosie was not there prior to the stall converter being installed. Fluid level is correct on the unit and verified before being taken off the lift just after the swap out. They showed me since the car has to be on the rack to check 6R80 fluid level from underneath and on a level plane.

I have had the car up on a rack at the speed shop and verified the control arm bushings are fine, gear lash is fine, U joints are fine, the DS loop is not interfering with anything, no exhaust noises, all clamps tight, no rubbing, etc. The shop owner has ridden with me and heard the noise and states he believes the noise is NVH being generated by the TCC in the converter which locks up harder (3 clutch vice 2 clutch stock system as I understand this) and this noise is transmitting down the one piece DS. He followed up a day later stating that his on line research indicates this is a somewhat common phenomenon after the install of a Circle D on cars with a more quiet exhaust system (OR H w GT500 mufflers and stock afterpipes) like mine. I'd love someone with a stall converter in their 11+, with 3.15 gears, and 1 piece DS, first tell me if they have this problem or would be kind enough to try to duplicate the driving condition to see if they get a similar noise.

The noise arises in drive or with a higher gear manually selected and the TCC locked up. Conditon - Level road, rolling at 40MPH in 5th gear (1500 RPM with a 3.15 diff gear) and apply light throttle up. Not so much the TCC unlocks, just enough to raise RPM in maintaining speed or beginning a slight uphill climb.

I would appreciate the feedback. I am just trying to discern if it is simply increased NVH due to a performance item being added or if there is actually a potential problem. The datalogs I have made and had looked at indicate that the TCC is locked up when this happens but no one has told me if the clutch is slipping at lockup causing this or if it is suppose to lock up. I have called Circle D and tried to describe the noise and they of course simply want to write it off as being transmission related......like I am surprised. So not fully impressed with the tech support from these guys for a $1200 part.

Thanks for the help in advance.

So what was the verdict?
I’m experiencing the exact same thing on my Mustang with a Circle D converter.

I couldn’t pm you about it because you have you profile limited.
 

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