HOME FORUM RULES CONTACT
     
   
   

Go Back   CLASS RACER FORUM > Class Racer Tech > Support Tech


Reply
 
Thread Tools Display Modes
Old 01-05-2021, 06:33 PM   #11
FED 387
VIP Member
 
Join Date: Jun 2006
Posts: 3,347
Likes: 309
Liked 279 Times in 149 Posts
Default 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
FED 387 is offline   Reply With Quote
Old 01-05-2021, 11:37 PM   #12
Tom Meyer
Senior Member
 
Join Date: Aug 2003
Location: Pierce NE
Posts: 899
Likes: 49
Liked 298 Times in 104 Posts
Default 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 ???
Tom Meyer is offline   Reply With Quote
Old 01-06-2021, 11:58 AM   #13
FED 387
VIP Member
 
Join Date: Jun 2006
Posts: 3,347
Likes: 309
Liked 279 Times in 149 Posts
Default 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
FED 387 is offline   Reply With Quote
Old 01-07-2021, 09:01 AM   #14
Bob Don
VIP Member
 
Bob Don's Avatar
 
Join Date: Oct 2002
Location: Greater Boston
Posts: 1,476
Likes: 974
Liked 778 Times in 175 Posts
Default Re: Chevrolet 8.1 Vortec advice

Quote:
Originally Posted by C29404 View Post
Bob, was your pick-up stock and did it hunt between gears when towing at highway speed?
Pick up was stock. No gear hunting on highway except for going up hill.
__________________
Bob Don 128 SS
Bob Don is offline   Reply With Quote
Old 01-07-2021, 06:32 PM   #15
C29404
Junior Member
 
Join Date: Dec 2016
Posts: 20
Likes: 0
Liked 0 Times in 0 Posts
Default Re: Chevrolet 8.1 Vortec advice

55 to 60 miles per hour its around 17 to 1800 then at 70+ 2200 and up.
I currently have a 285/70-17 wheel and tire combo on it, when I bought it it had the 245/70-16 wheels and tires, changed them for towing stability not so much for looks. I've also got a camper shell/cap on the bed. I have looked at the profile of the truck versus the trailer and there is a lot of flat trailer showing around the edges, one of those bubbles may be in the cards. I also stumbled across the manifold modification a while back, if I can find another manifold to modify i'll give it a try. I appreciate all of the input I have received on this matter and I am going to give some of this a try. Thanks
C29404 is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:37 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.