Anyone running the new 278mm Circle D converter?

[gtp6515]

I am curious how this converter would behave on the street, and if there would be much of a gain at the track. Do stalled cars trap slower? I am thinking there would be less mpg loss around town than the 258mm.

[hagarr]

bump this...

[RichsGreyGT]

subscribed

[gtp6515]

Not looking good here. Figured this may potentially be a good seller.

[RichsGreyGT]

yeah that converter is only $500....the comparable Yank SS is $800.....

if the vendor wants to chime in, this would be a good time.....

[dmarple80]

I would like to know the difference between this one and the 258mm Pro II single disk that Chris recommended I get.

[Matt82]

Looks like a cheaper alternative. The main difference it looks like, is that it isn't a billet converter. No billet front or piston, and whatever other goodies the Pro series has.

[Matt82]

Here's what Chris posted in another thread.

Sorry, missed this post.....

The OE converter is a 300mm 12" converter, stall is about 1600-1800

278mm HP Series, 2600-3200 range, non billet - good for stock cam or very small cam and street use. - New CDS option.....

258mm Pro Series Billet. ~2500-3500 range. Good for cam, power adders, and street strip use.

245mm Pro Series Billet. ~2800-4500 range. Cam, NA, Small shot, better for more strip use.

Single vs Multi - single for regular cruising lock up, multi for WOT lock up.

And we also make all of our billet fronts in house now, single and multi. Forged and machined in the USA!!

More on those later though....

Chris

[gtp6515]

I guess my question is how do they behave/perform differently. They have some of the same rpm options.

[TLS]

I would think it would be slightly tighter being larger.

Back in the day all we had were sizes. Put a little Vega converter on a full size car and you had your hi-stall converter!

This non-billet sounds like a deal. I truly doubt most guys going for this low of a stall speed are pushing torque making billet a necessity.

If stock is 1600-1800, mine is definitely on the tight side of that! I'd settle for a 2000 to just get rid of the creep at a light! <----And I'm fully stock!

[RichsGreyGT]

who owns one of these GM 278mm HP 6L80 LS Torque Converters?

[GRRRR8]

My opinion is: If you plan on abusing the car.....get the convertor with the billet pieces. Using the wrong convertor for your application can wipe out a trans which ends up not saving you any $$$$ in the long run. I use Circle-D in all my builds. Never had a issue.

A 258mm with a 2800-3000 stall seems to be the best option for a NA G8 with 375-400 RWHP. Be honest with Chris when you have him build you a convertor. Power and TQ can change the stall speed of a convertor. So I guess the correct way to say it is you want to end up with about 2800-3000 stall in most daily driven G8s.

Remember if you have a gear and add a convertor your will need to address traction or lack of! :)

[KDRobb]

I may be a test dummy! I plan on ordering the HD converter soon, my thoughts are having great daily drivability with no pushy attitude at the stop lights. Hole shots and 1/4 mile times aren't a concern for me

[gtp6515]

Awesome...what rpm?

[KDRobb]

I'm thinking 2800

[gtp6515]

I chose gears over this mod and not sure i made the right call. Gl to you. Cant wait to hear. Wonder if this will hold up to over 400 whp.

[Matt82]

Wonder if this will hold up to over 400 whp.

That would be my concern. If you plan on modding the motor anymore, you'd be better off getting one of the billet pieces. That way you wouldn't have that weak link in the drivetrain.

[KDRobb]

Chris at circle d says it will be good, I Figure there's a lot of supercharged guys out there running stock converters yet, and this should be better than the stock converter

[TLS]

Heck of a lot of Big Block trucks with a ton of torque towing HEAVY that would put a much bigger hurting on a regular converter than a warmed over LS.

Billet, while I'm sure really strengthens things up, is probably overkill for 95% of the guys out there.

[Circle-D]

Sorry, missed this thread....

The beauty of the 278mm option is it uses the 12" full size clutch. So we do not have to upgrade to a billet unit to get good clutch in it. I use them mostly in trucks, good for a small cam and towing. But I think they are a good option for a G8 as well. Assuming stock or small cam and mostly a street car. It really depends on what you want out of your car....

Chris

[RichsGreyGT]

Sorry, missed this thread....

The beauty of the 278mm option is it uses the 12" full size clutch. So we do not have to upgrade to a billet unit to get good clutch in it. I use them mostly in trucks, good for a small cam and towing. But I think they are a good option for a G8 as well. Assuming stock or small cam and mostly a street car. It really depends on what you want out of your car....

Chris

what about a G8 with 450rwhp? is the 278mm safe or need to go with the 258mm billet?

[Circle-D]

what about a G8 with 450rwhp? is the 278mm safe or need to go with the 258mm billet?

I have the 278mm in a lot of heavy trucks with over 500RWHP on the 4L60/4L80/6L80 trans. So yes, I think durability wise you are ok. Performance might not be the best though, just depends on your setup and goals. Can you shoot me an Ask Chris or call me at the shop....

Thanks,
Chris

[RichsGreyGT]

I have the 278mm in a lot of heavy trucks with over 500RWHP on the 4L60/4L80/6L80 trans. So yes, I think durability wise you are ok. Performance might not be the best though, just depends on your setup and goals. Can you shoot me an Ask Chris or call me at the shop....

Thanks,
Chris

what is your email?

that is a preferred form of communication for me.

[Matt82]

what is your email?

that is a preferred form of communication for me.

askchris@circle-d.info

[Got 8?]

I should be running one in a heavy ass truck with ~400 HP in a few days but not in the G8...

[G8-4-Speed]

I used a 278mm in a 78mm turbo'd/cammed Camaro, worked great. That should be enough power to cover you N/A guys....

[Matt82]

I used a 278mm in a 78mm turbo'd/cammed Camaro, worked great. That should be enough power to cover you N/A guys....

That's probably making more that 90% of the NA guys on here.

[Circle-D]

Thanks for all the input guys... appreciate it!!

Chris

[KDRobb]

Finally got my TC ordered today!

[Got 8?]

Been running one in the wife's TBSS for a couple of weeks now...she likes it...I got the 3000-3200...only problem, if you wanna call it that, is now I got to remember to turn off traction control and Stabilitrac if I wanna have a little fun and stand on it from a stand still or when it hits second...took my brother for a ride the other day and floored it from a standstill...ROASTED the 275/45/20's until I got out of it heading sideways for a mailbox...LOL !!! I'm guessing we were moving about 25-30 mph with them in a cloud of smoke and my brother said he looked over at the speedometer for a second and saw ~105 mph so I definitely cooked 'em...LOL !!! Pulled my cargo trailer on a four hour drive in the hills and when the clutch locks up you can definitely tell (my wife asked if they added an extra gear when they rebuilt the tranny...LOL !!!)...so far I'm happy with it and the little woman even said we should take it to the track to see what it will do now...

[RichsGreyGT]

askchris@circle-d.info

a little too late matt. haha

[Matt82]

Hell yeah Rich, I know you can't wait!