TheSamba.com :: View topic - Gas $5.00/gal. - What kind of mileage motor should one build

Sun Jun 17, 2012 11:09 pm

OK, a stock 36 HP in a late model sedan, (pre freeway flier), a 6 volt starter with an adapter bushing and 12 volt solenoid, and a rewound generator ti 12 volts.

Any thoughts?[/quote]

My thoughts are:

All your doing there is choosing one of the best mpg engines vw produced as stock.

If were building an engine is 2012 and we can do a bit better than that :wink:

Mon Jun 18, 2012 7:07 am

manxcraig wrote:
OK, a stock 36 HP in a late model sedan, (pre freeway flier), a 6 volt starter with an adapter bushing and 12 volt solenoid, and a rewound generator ti 12 volts.

Any thoughts?

I'd loose the freeway flier transmission. Dropping the RPM's so the engine is out of its powerband so it's lugging around is a sure-fire way to loose MPG's.

My 31.1 mpg bus did that at 65mph doing 4000 rpm. My 40mpg 2276cc engine able to make 200hp did that at 3600rpm. You want to cruise where your engine is making power. That's where the engine is running efficiently.

Mon Jun 18, 2012 7:27 am

2276cc making 200HP and still give 40MPG??? What the hell the engine inhaling?? Peroxide?? That is one for the record books, don't you think??

Even the Izusu I-Mark Diesel did not get that much in the street. And that thing will give 65MPG hwy back in the day.

Mon Jun 18, 2012 8:24 am

nsracing wrote: 2276cc making 200HP and still give 40MPG???

Megasquirt noobs are easy to spot on these forums... :lol:

Mon Jun 18, 2012 8:35 am

nsracing wrote: 2276cc making 200HP and still give 40MPG??? What the hell the engine inhaling?? Peroxide?? That is one for the record books, don't you think??

It wasn't built for mpg's either. FK89, 48x38 CE heads, 12.5:1, 1.4 rockers, 1 7/8" exhuast, 3" magnaflow muffler. It was my drag motor with a custom intake system (single throttle body, cold air induction).

Last summer I just wanted to see what it could do for MPG's if I took the time to tune the EFI and ignition tables. I used a knock sensor to get the ignition maxed out, you wouldn't believe what the ignition table looked like when I was done!

All figures were done with GPS, I held 70mph on a 70 mile drive and it used less than two gallons of fuel after the entire drive. There's a picture posted somewhere of the GPS trip meter being held in front of the gas pump numbers. Oh yea, 91 octane too. lol

I see no reason why a properly built VW engine and car couldn't achieve 60mpg at 60mph and make over 60hp. If I had the time and money to do it, i'd build this 64 in my garage to do it. If someone bought my drag car, i'd do it. :wink:

Mon Jun 18, 2012 8:53 am

Laws of Physics do not apply where you are at, Mini?? You must have an aircooled engine that can run way leaner than stoich and not ping.

Unless that thing is set up sequential-fire, and inhaling fumes only, it is very much one heck an engine if it does all that and still have 200 ponies foaming at the mouth.

Awesome!

Mon Jun 18, 2012 8:54 am

You are an inspiration Eric! You should post your stuff in the Engine Combo sticky.

FI can do amazing things if the tuner is talented and patient enough to work with it.

Mon Jun 18, 2012 9:02 am

I just love the look of dual 48mm IDAs on tall stacks mounted on an aircooled VW engine. They look much sweeter that way. :lol:

Mon Jun 18, 2012 9:07 am

Eaallred wrote: manxcraig wrote:
OK, a stock 36 HP in a late model sedan, (pre freeway flier), a 6 volt starter with an adapter bushing and 12 volt solenoid, and a rewound generator ti 12 volts.

Any thoughts?

My 31.1 mpg bus did that at 65mph doing 4000 rpm.

Please, let us in on the recipe!
Iam in the process of building a 2276 for my bus with megasquirt efi and ignition control. I really thought dropping the rpm was a sure way to better mileage!

Mon Jun 18, 2012 9:16 am

DarthWeber wrote: You are an inspiration Eric! You should post your stuff in the Engine Combo sticky.

FI can do amazing things if the tuner is talented and patient enough to work with it.

Thanks! Lately I have more interest in a ultra-high mpg VW street car than I do the drag racing stuff anymore. People think i'm joking, but if I could get my money out of my drag car by selling it, i'd do it in a heartbeat and start chomping on the MPG stuff big time.

To put my goal in perspective, I could (on fumes) almost drive from my house here in Northern Utah, to Sacramento Bugorama on a single tank of gas in a bug. 21.5 gallons round trip for 1,292 miles. Except Donnor pass would kill the MPG. Better stop in Reno for gas. :wink:

Mon Jun 18, 2012 10:27 am

nsracing wrote: Laws of Physics do not apply where you are at, Mini?? You must have an aircooled engine that can run way leaner than stoich and not ping.

Unless that thing is set up sequential-fire, and inhaling fumes only, it is very much one heck an engine if it does all that and still have 200 ponies foaming at the mouth.

Awesome!

Stoich is used by production cars as its whats catalytic converters like to produce the least emissions.
No smoging means you can run 18/17 to 1 and get way better MPGs than a modern car trying to pass the smog regulations. (this is how them tunign chips get better mpgs)

I dont actually think sequential is better for Mpgs than batch, with sequential you have to use larger injectors because your firing them much later.

Mon Jun 18, 2012 10:29 am

Eaallred wrote: DarthWeber wrote: You are an inspiration Eric! You should post your stuff in the Engine Combo sticky.

FI can do amazing things if the tuner is talented and patient enough to work with it.

Thanks! Lately I have more interest in a ultra-high mpg VW street car than I do the drag racing stuff anymore. People think i'm joking, but if I could get my money out of my drag car by selling it, i'd do it in a heartbeat and start chomping on the MPG stuff big time.

To put my goal in perspective, I could (on fumes) almost drive from my house here in Northern Utah, to Sacramento Bugorama on a single tank of gas in a bug. 21.5 gallons round trip for 1,292 miles. Except Donnor pass would kill the MPG. Better stop in Reno for gas. :wink:

If you dont mid letting a coupld of cats out of the bag, whats the leanest fuel air mix and most advance on your spark table?

Mon Jun 18, 2012 12:16 pm

true words were never spoken . i got out of drag raceing about a 2 year ago. i still drag race but not a all out race car. oh i use my friends race car to test motors but his is now up for sale . hes done. way to much money . cost of parts going up up . money for gas . hotel rooms. food . money money spent at the drag strip . its not fun for me any more. i have a nice street bug and all it needs is a wash and wax put some pump gas in off i go. if i want to drag race i just run my street bug now . i would like to have back all the money i spent on race cars and motors over the years lol oh i had fun what the hell lol the raceing i like best is when i raced mazda speed miatas that was fun when it needed fixed mazda fixed it for the next race lol spencerfvee Eaallred wrote: DarthWeber wrote: You are an inspiration Eric! You should post your stuff in the Engine Combo sticky.

FI can do amazing things if the tuner is talented and patient enough to work with it.

Thanks! Lately I have more interest in a ultra-high mpg VW street car than I do the drag racing stuff anymore. People think i'm joking, but if I could get my money out of my drag car by selling it, i'd do it in a heartbeat and start chomping on the MPG stuff big time.

To put my goal in perspective, I could (on fumes) almost drive from my house here in Northern Utah, to Sacramento Bugorama on a single tank of gas in a bug. 21.5 gallons round trip for 1,292 miles. Except Donnor pass would kill the MPG. Better stop in Reno for gas. :wink:

Mon Jun 18, 2012 3:10 pm

Oh come on, Spence. The smell of that race fuel when you fire up that motor was exhilirating, intoxicating! Nothing like it when you see that engine roar w/ the double stacks of IDAs. The 2 1/4 inch pipes nicely wrapped around that drag motor... MSD ignitions...

It is so good seeing that car peel out of the waterbox. :lol:

Mon Jun 18, 2012 3:14 pm

nsracing wrote: Laws of Physics do not apply where you are at, Mini?? You must have an aircooled engine that can run way leaner than stoich and not ping.

If you tune for stoich, you're not just a Megasquirt noob- you're also a tuning noob. :shock:

My 1915 turbo makes ~170 hp at the crank, getting close to 29mpg when not boosting. 16:1 AFR, 42* of advace will get you there.

Mon Jun 18, 2012 3:19 pm

krusher wrote: If you dont mid letting a coupld of cats out of the bag, whats the leanest fuel air mix and most advance on your spark table?

It all depends on what spot of the map I was driving in.

One thing I will say, I did end up running less advance at part throttle than I did at full throttle. Engine knock wouldn't let me run more than that, lol. I guarantee it wouldn't have passed emissions, NOX would have been way too high I bet.

My 31.1mpg bus was a 1600cc single port, stock exhaust, stock intake, carb, oil bath filter, and was still a 6 volt system. All I had was distributors and jets to play with to get that one dialed in. That was with me running it floored against the stock governor between the carb and the intake to make it hold 65mph the whole way. I would have kept that bus if it weren't a panel.

Dang it. I may have to put my car up in the classifieds. I get way more excited about this than racing. lol

Mon Jun 18, 2012 4:30 pm

buy his car spence!!! beleave me, you will miss it. it,s hard for me to even go watch.

Mon Jun 18, 2012 4:44 pm

You know, Mini you can bring that car of yours to our next BugOUt here in VA if you want to race. I don't mind taking lessons from the likes of you.

I can have a car run in the Pro or Super Pro or street car if you are up for it.

Just saying.

Mon Jun 18, 2012 4:55 pm

Not gonna win if you tune for 14.7 AFR. :lol:

Mon Jun 18, 2012 5:33 pm

I only tune w/ EGTs. Surely you don't mind that.