Circle D
#21
I doubt that just a trans/converter swap will get you a whole second. Yeah, you went to a bigger converter, but the parisitic loss from that trans/converter will negate any (or most) gains from the higher stall.. You may pick up a small amount, but don't set yourself up for dissapointment by expecting a full second... Just being honest with you.
#22
Having held the stock 4l80e torque converter, I believe that's where the majority of the loss is coming from.....it's 20 lbs heavier than the 4l60e converter. 20lbs of rotational mass is a lot. That circle D unit should weigh about half of what the stock converter weighs
#23
Thanks for all the kind comments, very nice to read. Customer service is very important to me. The old golden rule idea, I am to please. It also helps that we manufacture one of the strongest converters in the market. If you are in the Houston area, stop on by for a tour.
I just signed up to be a sponsor on PT, so I hope to answer more questions for you guys on here.
Chris
I just signed up to be a sponsor on PT, so I hope to answer more questions for you guys on here.
Chris

I definately think you guys are going to get alot of the truck business now, or at least from members on this forum. Love your converter!
#24
#25
A billet converter isn't much lighter than a stocker of similar diameter, just tons stronger... Solid billet steel is heavy stuff. Not to mention the gearing difference, plus the trans internals are heavier parts.... Its not just the converter.
I didn't say he wouldn't gain anything, just not much/if anything...
Circle D makes a great product, I'm sure it will serve you well.
I didn't say he wouldn't gain anything, just not much/if anything...
Circle D makes a great product, I'm sure it will serve you well.
#26
A billet converter isn't much lighter than a stocker of similar diameter, just tons stronger... Solid billet steel is heavy stuff. Not to mention the gearing difference, plus the trans internals are heavier parts.... Its not just the converter.
I didn't say he wouldn't gain anything, just not much/if anything...
Circle D makes a great product, I'm sure it will serve you well.
I didn't say he wouldn't gain anything, just not much/if anything...
Circle D makes a great product, I'm sure it will serve you well.
The 245mm circle D converter is 35lbs. I'd guess the 258mm is about 5lbs more. Either way, that's still 20lbs lighter than the stock unit.
#27
#28
Unfortunately, the battery on my scale died, but the stock 80e converter is a beast. I've heard weights of 60 and 73lbs thrown around. It's somewhere in that range. It's also 310mm versus 300mm of the 60e
#29
I'm not saying its any kind of featherweight, just trying to extrude facts...
Sure a 9.5" converter will be lighter, but mostly what I'm saying is just because its billet, won't make it lighter, in some cases even heavier.
But as I stated before, the rotating mass of the converter isn't the only place power loss is experienced when going from a 4L6x to a 4L8x... There's a thread around here somewhere showing the sheer size differences... You don't think it would require more hp to operate a 60 than a 80?
Then we have the gearing issues, which can be overcome by a swap, or a bigger converter but usually costs you in the converters effeciency up top...
There's pros and cons everywhere you look. For a lot of people a built 60E is great, it was for me for a long time. But for others, with the vehicles weight and the outstanding amounts of power we make with this engine platform it requires a better design that will withstand that environment. But that strength also come with a price, not only in the form of dollars, but effeciency and hp loss...
Can an offensive lineman run as far and fast as a wide receiver??? Can a receiver take the punishment on every down that a 350+lb center can????
Sure a 9.5" converter will be lighter, but mostly what I'm saying is just because its billet, won't make it lighter, in some cases even heavier.
But as I stated before, the rotating mass of the converter isn't the only place power loss is experienced when going from a 4L6x to a 4L8x... There's a thread around here somewhere showing the sheer size differences... You don't think it would require more hp to operate a 60 than a 80?
Then we have the gearing issues, which can be overcome by a swap, or a bigger converter but usually costs you in the converters effeciency up top...
There's pros and cons everywhere you look. For a lot of people a built 60E is great, it was for me for a long time. But for others, with the vehicles weight and the outstanding amounts of power we make with this engine platform it requires a better design that will withstand that environment. But that strength also come with a price, not only in the form of dollars, but effeciency and hp loss...
Can an offensive lineman run as far and fast as a wide receiver??? Can a receiver take the punishment on every down that a 350+lb center can????
Last edited by silver-mod-o; Mar 8, 2009 at 04:52 PM. Reason: eye kant spel
#30
If you look back and read what I said ("I believe that's where the majority of the loss is coming from"), you would see that I do believe that there is more parasitic loss intrinsic to the 80 than the 60. How much loss is debatable. All I said though is that I believe the majority of the loss comes from the much heavier converter. Whether this is true or not I do not know. I believe the 2nd greatest perceived loss is from the much taller 1st gear, and finally 3rd is the extra power soaked up by the trans itself.
"Sure a 9.5" converter will be lighter, but mostly what I'm saying is just because its billet, won't make it lighter, in some cases even heavier."
That's true, but that has nothing to do with what I said. All I said is that the circle D converter will be significantly lighter than the stock unit. If my scale was operational, I would gladly weigh the converter I have sitting here.
This is kind of a pointless argument....we'll let the #'s and track times speak for themself.
The reason I am so interested and have a strong opinion on this matter is because I am going to be doing an identical swap to this in the upcoming months and am very interested in the results. When you say there will be none or very little gains coming from a 60e w/ stock converter, I will have to disagree with that.
"Sure a 9.5" converter will be lighter, but mostly what I'm saying is just because its billet, won't make it lighter, in some cases even heavier."
That's true, but that has nothing to do with what I said. All I said is that the circle D converter will be significantly lighter than the stock unit. If my scale was operational, I would gladly weigh the converter I have sitting here.
This is kind of a pointless argument....we'll let the #'s and track times speak for themself.
The reason I am so interested and have a strong opinion on this matter is because I am going to be doing an identical swap to this in the upcoming months and am very interested in the results. When you say there will be none or very little gains coming from a 60e w/ stock converter, I will have to disagree with that.


