Through hours of long studying and modifications I've decided that strapping a roots blower on top of an otherwise high-perf. low-economy engine can actually give you better gas mileage... somtimes much better. My car was getting 3 MPG with its 420 horsepower street engine, and by adding the blower, and better cam, and a ton of carb tweaking, Im getting 18 MPG with a TH350 and 3.08 gears. Oh, and Im making over 550 horsepower too.

I'm thinking of making some kind of tech article on this subject, but only if alot of people will benefit from it. Theres alot of misconception about roots blowers and how they work... But its pointless to write a 10 page essay if no one will read it right?

Tell me what you think, would this be worthwhile to Thirdgen.org as a roots blower / economy street car reference guide?

 

I'm interested for sure. I just bought two books to learn as much as I can about Roots blowers. However these books are mostly theory and formulas and lack {real world} knowlege. I can grasp the math and the concepts of physics of how and why its beneficial to use a Roots supercharger, but nothing beats {been there done that} stories!

Jay

 

I love roots blowers and all but I don't suppose that going from 3mpg to 18 might have something to do with "a ton of carb tweaking"?

 

well THATS a long story in itself, but heres the short story:

3 MPG:
3800 RPM Stall converter; Holley 650 running super rich; crappy blazer cam; 9.5:1 compression; 34* total timing; Zero rear wheel horsepower = incentive to buy a blower.

18 MPG:
2400 Stall converter; Holley 885 - blueprinted, heavilly modified; 17:1 air/fuel ratio highway; 51* total timing; 9:1 compression; blower (free atomazation woohoo!); More conservative (ok more radical but still...) cam....

so you see, it wasnt just the carb mods... other things played a part as well, but those are the sorts of thing people need to be told... running 51* total timing is a No-no under boost, and even when not under boost... timing controls are necessary to achieve and specific dial in proceedures come to mind.
Like Jay4speed said, the books all tell how it works, but what works and what doesnt is another story. it took me 10 hours of drilling and thinking just to reference my power valve through the metering block... instead of through the throttle body. 10 hours and my result was more power, and 4-5 more MPG. that was only 1 out of 7-8 mods, I used the book by "SA Designs" and followed their proceedures, but some didnt work out like I expected, and Im sure people would like to know whats what. Anyways, I think im getting famous for super-long posts by now, im goina cut it short. If this sounds like an interesting piece of work I can do it right, And Im just wondering if it would be a worthwhile investment / contribution to thirdgen.org's database.

People that want power AND fuel economy are common, people that HAVE power and fuel economy are rare. Even Rarer are people that have power AND fuel economy and didn't have to spend $3500 on an EFI setup for it. I spent $82~ on my carb mods, and $60 of it was to get the metering plates and throttle body air bleeds blueprinted, and THAT was only because the carb was like 4 years old lol.

 

It would be worth while to me, I'm in the middle of finishing that same SA designs book. I encourage you to write the tech article I know of one person that it will help out, me!

 

been away for a while... im moving to miami, wont have a computer for a week or two. cya then