Chevrolet 8.1 Vortec advice

Glenn Briglio · 01-05-2021, 01:14 PM

Quote:

Originally Posted by C29404

I have a 2007 3/4 ton pick-up with the 8.1, its 2wd with 4.10 rear and the 6 speed Allison trans, does any one have any advice on improving towing mileage? I tow a 26 ft Gold Rush with a 2700 lb car and race day stuff, it currently has a Voliant cold air and a Black Bear tune through EFI Live. Any additional input is appreciated.

What engine rpm is it running at what mph?

FED 387 · 01-05-2021, 06:33 PM

supposedly the OEM air induction system(filter ,tubes ,air cleaner box) is more than adequate to handle the 8.1 it's the opening for the throttle body that is the restriction---the cold air actually makes the engine WANT more fuel so with an increase in fuel consumption AND power while you get a decrease in MPG. Second use lots of synthetic fluids in the rear , trans if you can and engine oil.---third put a tonneau cover or a cap on the bed to help smooth out the air flow over that open bend---maybe put a chin spoiler under the front bumper to help smooth that area out-----then change to a 3:73 rear from that 4:10 to cut down on RPM 's at cruising speed --and finally maybe either a nose cone on the front of the trailer and or a spoiler on the top of that cap to move the air up and over that flat front of the trailer---FED 387

Tom Meyer · 01-05-2021, 11:37 PM

Cruse rpm 2300 to 2500 65 to70 mph peek torque was at 2500. Taller rear tires can help with gearing. We have over 200 k on the clock still going strong. The hole in to floor of the intake floor is the restriction, Tom

FED 387 · 01-06-2021, 11:58 AM

yes taller tires will help cut down the rpm---depends whats available might only lower it a smidge to say a 4:00 not much but it will be better than what you have now

01-05-2021, 06:33 PM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,416 Likes: 522 Liked 330 Times in 178 Posts	Re: Chevrolet 8.1 Vortec advice supposedly the OEM air induction system(filter ,tubes ,air cleaner box) is more than adequate to handle the 8.1 it's the opening for the throttle body that is the restriction---the cold air actually makes the engine WANT more fuel so with an increase in fuel consumption AND power while you get a decrease in MPG. Second use lots of synthetic fluids in the rear , trans if you can and engine oil.---third put a tonneau cover or a cap on the bed to help smooth out the air flow over that open bend---maybe put a chin spoiler under the front bumper to help smooth that area out-----then change to a 3:73 rear from that 4:10 to cut down on RPM 's at cruising speed --and finally maybe either a nose cone on the front of the trailer and or a spoiler on the top of that cap to move the air up and over that flat front of the trailer---FED 387

01-05-2021, 11:37 PM	#3
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 936 Likes: 78 Liked 351 Times in 120 Posts	Re: Chevrolet 8.1 Vortec advice Cruse rpm 2300 to 2500 65 to70 mph peek torque was at 2500. Taller rear tires can help with gearing. We have over 200 k on the clock still going strong. The hole in to floor of the intake floor is the restriction, Tom __________________ Tom Meyer 5240 SS Stock ???

01-06-2021, 11:58 AM	#4
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,416 Likes: 522 Liked 330 Times in 178 Posts	Re: Chevrolet 8.1 Vortec advice yes taller tires will help cut down the rpm---depends whats available might only lower it a smidge to say a 4:00 not much but it will be better than what you have now