8.1L Fuel Improvement/power upgrades
10-17-2012, 09:15 AM
#12
TECH Apprentice
Join Date: Apr 2012
Location: thurmont, maryland
Posts: 340
Likes: 0
Received 0 Likes
on
0 Posts
hell i have 4.56 gears and before motor rebuild and whipple supercharger i got 13 highway with 305/70/16's and 6-8 towing 16k camper. 6-8 depending on hills i was going up.. i would love to have a 6 speed and be able to drop 300-500 rpms on the highway. i sit at 2500 rpms at 70 mph but it doesnt hurt my mpg at all.
10-22-2012, 08:27 PM
#13
On The Tree
Join Date: Aug 2012
Location: Salt Lake
Posts: 137
Likes: 0
Received 0 Likes
on
0 Posts
Mine has the 5 speed ally and the only difference with the 6 speed is an extra overdrive so why re gear just drop it down to 5th. Im at 2500rpm at 75 with 245s and 410 gears I wish I had the extra overdrive and it can be swapped in with a valve body change. I get 12 empty highway 10 around town and 8 pulling 7k
06-03-2018, 07:32 PM
#15
Registered User
Join Date: Jun 2018
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Whippled 8.1.
Guys I'm posting for my uncle on this, he tows goose neck mobile trailers from Indiana to all parts of the country and he has the 8.1L w/ the 6 speed allison tans and 4.10 gears. This is his second truck the first one was the same truck with the 5 speed allison. On the first truck he mentioned he put in a KN cold air intake and it destroyed the the MAF sensor. I asked him if he installed it on the new truck and he said no b/c of that reason.
So question, what bolt ons can be done that would improve fuel economy and gain horsepower. He is thinking of upgrading the 4.10 to 4.56's.
So question, what bolt ons can be done that would improve fuel economy and gain horsepower. He is thinking of upgrading the 4.10 to 4.56's.
hell i have 4.56 gears and before motor rebuild and whipple supercharger i got 13 highway with 305/70/16's and 6-8 towing 16k camper. 6-8 depending on hills i was going up.. i would love to have a 6 speed and be able to drop 300-500 rpms on the highway. i sit at 2500 rpms at 70 mph but it doesnt hurt my mpg at all.
what at is your mileage after the Whipple supercharger. And where did u get your setup
Thread
Thread Starter
Forum
Replies
Last Post
GrooveCityZ71
GM Engine & Exhaust Performance
7
08-31-2015 12:05 PM
