30MPG is the Goal

[Gary]

It was a 12" pusher from Summit. Flex-o-something or other.

Edit: Flex-a-Lite Model FLX-110, 12" dia, 2 1/4 deep, 1250CFM

[Gary]

Fan is all set. Thanks to Deaner and Bello (I have the dimensions for the clutch fan washer in my camera)

Hooked up the 2" pipe to a 16" magnaflow muffler. (Should have bought the 14") Nice sound, throaty but not too loud. Had problems with the over the axle pipe so the car goes to the muffler shop next.

The good news. Took it out for a 2 mile trip. What a difference from before!!! Very noticeable when accelerating. There is a lot more power. Idle is dead smooth and it shuts down like it had high comp pistons.

If the weather holds out and the exhaust gets finished Monday. I hope to start using it next week.

[jvandyke]

Originally Posted by RallyBob When I drove my Ascona from CT to Mid-Ohio racetrack back in 1995, I got 28.5 mpg for the entire trip. And we all know the Ascona is a brick aerodynamically. That was with a Getrag 240, 3.89 gears, very wide tires (245/50 -13's!), and 300 lbs of stuff in the trunk (spares and luggage), and a constant 72 mph for 11 hours each way. Oh, and the engine was the same one I loaned you for your old blue wagon, with a 38 DGAS and ported intake, so it was making 97 hp instead of 65 hp stock. Considering the extra weight, aerodynamic and frictional drag (tires), and the addition of 50% more power, it wasn't too shabby. And that car was only rated for 24 mpg from the factory... Bob

What would acceptable MPG for 2,0 and a 38? I mean, you can live with anything your wallet will accept but with my old Holley/Weber 32/36 I was getting low 20's and the timing was off and what not.
Now that I'm "getting there" with a 38 and timing and all that, I'm getting somewhere near 17 and that's kinda low, no?
At what point do you figure something is really wrong?
Thing runs great and plugs look good to me so I don't think I'm super rich.
Ouch.

[opelwasp]

I am getting 25 mpg with my 2.4l LS,38 DGES, combo cam, 2.0l valves, 5 speed tranny, and a heavy foot.

[jvandyke]

I've got the same carb and the same foot but different results.
Oh well, I'll address that down the road.

[Gary]

After 4 tank fulls my mileage is actually slightly less than it was last year.
Getting just about 20mpg with combined highway, traffic jams, city driving. Best was last year on a 95% highway run.

Attached is an Excel spreadsheet for those who want to use it for their own tracking.

[thetourist]

Bummer on the MPG. I played with this several decades ago. I routinely got 30-32 mpg with my Manta. I had to work to get it below 25.

My tricks.

Block the grill. Put lexan across the nose of the car from the outer edges of the headlights to several inches into the plastic grill piece. Look at the hole inside. It's small at the grill and opens toward the rad.

A huge airdam. My car was used for rally and was raised 2 inches. I had a 14 inch airdam attached behind the bumper. Totally vertical and flat. It wrapped around to the wheel arches.

Dechrome the sides. toss the right mirror and antennae.

165 tires...44 psi.

Skid plate (body pan?) to the rear of the transmission.

Solex stock carb.

Lightly tuned distributor.

Cut the fan blades down. Or go electric.

Big exhaust with glass pack. Later a header with same.

4-speed with 344 gears.

This was a small bumper manta. Probably the slickest of our Opels.


I did some coasting and tufting tests. I still had a pressure area at the base of the windshield, so the heaters/defrosters worked fine.
Coasting off a nearby mountain from 50mph netted a 15 mph increase at the bottom. I was impressed with the results.

Of course it all seems trivial now. Gas was 50 cents then.

[jvandyke]

Well, I filled up and did the math and it's not as bad as I thought. 21. Might be as good as I'm going to get with the 38.

[George]

I remember my father telling me that you could increase the gas mileage by using brass window screen under the carberator.I have no idea what this was supposed to do or if it worked as gas was cheap and I never tried this.He also had what he called a Fish carberator with one moving part that was supposed to get great gas milage.

[Gary]

On the trip to Carlisle the wagon got 26-27 MPG on the highway. It's up to close to 22 combined. (40 mile/day commute, 80% highway with 5-20 minute traffic delays, top speed 70-75)

Small tires and acetone did not make much of a difference. Next up swapping the 32/36 for a Solex.

[opelwasp]

Gil gets about 35 hwy in the blue GT. 2.2L EFI on 16" tires with a 5 speed.

[Gary]

Solexed it last night. Need to set the idle and mixture. Opels on the Lawn this weekend may be a quick test to see if highway mileage improves.

[RallyBob]

Originally Posted by Gary Solexed it last night. Need to set the idle and mixture. Opels on the Lawn this weekend may be a quick test to see if highway milage improves.

Other than a Getrag 240, the best thing would be a 3.18 rear axle and 4-speed swap. The automatic, especially at higher speeds, just sucks the life out of the mileage. Plus there's the additional 300 +/- rpms of slippage from the converter alone.

[Gary]

Originally Posted by RallyBob Other than a Getrag 240, the best thing would be a 3.18 rear axle and 4-speed swap. The automatic, especially at higher speeds, just sucks the life out of the mileage. Plus there's the additional 300 +/- rpms of slippage from the converter alone.

Bob, Which models had the 3.18's?

[RallyBob]

Originally Posted by Gary Bob, Which models had the 3.18's?

Kadett wagons generally, although it was apparently an option for other Kadett models with the 1.9 engine. I sold some NOS 3.18's to a west coast circle track racer a few years ago for cheap. Got them from Frank Lundholm in 1991 or 1992. I never used them so I figured they'd go to waste. Wasn't counting on $5 per gallon fuel prices back then however!