When i had my na setup i went from 60e to 80e and ran the same times but one mph more with the 80 and weather was hotter.

 

This is good info....excellent work. Would love to see the swap done with the same converter setup. Meaning same rotating mass and locked. Eliminate another variable in the equation.

Chris

 

You'd be suprised. It may even pick up .2 The different gearing in the 80e may factor into that.

 

Very cool ! there has been allot of debate around the shop and my choice to include a 4l80 in my 6.0 swap and the "POWER LOSS" looks like I made the right decision Thanks for the info

 

I bet the the combo of the weight, taller first gear, and the now known (thanks to NicD) 15hp loss equals 30ish HP feel....

 

No Doubt the ratios make it feel different but its nice to see actual prof.

 

That Tahoe Is a beast!!! Glad to see you join up over here.

 

Now that I've been driving it around for a while I'll share some more impressions on the swap from the 60 to the 80.

Since I used stock torque converters on both I have noticed that the 80 converter is certainly looser than the 60. The longer first gear in the 80 and it feels kind of like a turd down low comparably speaking. My mileage has gone down by almost 1 mpg (when I can stay out of it) because the converter slips more and when it is locked up like on the freeway it's spinning another couple hundred RPM because the overdrive gear is shorter in the 80.

Now even though 1st gear definitely feels worse I don't think it really performs worse because once it gets moving the RPMs don't drop nearly as much on the 1-2 as it used to with the 60 and it just keeps going. The slightly looser factory 80 converter seems to make up for the longer gear by just a little bit with the closer ratios working their magic once you are under way making up the rest. Weight is obviously a factor as well since the trans/converter is heavier but it seems minimal. It really just has a different feel all around to it and at least with my combo it helps my rear tires not completely get destroyed when I'm all in from a dig. LOL

 

i love the 80E even if it does rob power, the gearing is perfect and its only a .75 OD vs .70..
the way it shifts is so nice.

 

thanks for the info that answered alot of my questions with facts always heard they lose alot but no facts to back it up good thread!!