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-   -   So stinkin close to 40mpg (https://www.fuelly.com/forums/f8/so-stinkin-close-to-40mpg-10224.html)

jeep45238 10-20-2008 01:31 PM

So stinkin close to 40mpg
 
38.91mpg on the last fill up, about a 50/50 of highway/city. For years I've been using the Lucas Fuel Additive, getting between .5 to 1.5 mpg with it vs. without. Ran 4 tanks without it, got about 36 mpg like that, added the Fuel Additive and 1 tank later I'm at 38.91mpg - going to see if it stays consistent.

So aggravating being that close to 40mpg on a slipping clutch and 0 aero mods. Then again....the wallet's smiling more :D

Can't really complain considering almost everything has been maintenance, and the modifications I have done used duct tape and a hole saw to perform.

GasSavers_BEEF 10-20-2008 01:39 PM

seriously there is a guy (user name: lovmysan) and he has a saturn that is getting somewhere around the 60mpg range. I would copy what he has done. if nothing else, I think it would be an excellent starting point.

by your user name, I thought you did that in a wrangler. I was truely astonished. it is still really good in a saturn too.

jeep45238 10-20-2008 01:48 PM

I used to have a 95 YJ 4 banger stick (sold). Then a 94 SL2 auto (totaled). Then a 97 SL2 stick. Then a 93 K2500 auto (sold at a huge loss). Still driving around the '97 SL2, although I really want to put cruise control in it for long trips.

I don't see anything under that user name BEEF. I don't want to do HHO (don't see the gain to really be there from an engineering and financial side), and I need to replace the clutch and the bottom end before I go into any other modifications. The biggest thing I plan on doing is a 2 part formed kydex belly pan with 1/4 turn fasteners, and formed rear wheel skirts - but I'll worry about those later. I won't change out my overdrive gear - I do a lot of city driving and it's VERY hilly in Cincinnati, OH.

I figure after I do those two aero modifications, repair the clutch and bottom end (and switch to a 5W30 oil after the repair), I'll hook in a megasquirt 2 to tune the engine and I should be at 45-50 mpg without a problem. Few years off either way.

The senior design project that's planned for a little Saturn though - well, keep you eyes peeled in about 2 years, that's all I can say about it.

bowtieguy 10-20-2008 02:26 PM

i believe you're doing very well for 50/50 driving.

but here you go...

https://s75.photobucket.com/albums/i3...emysan/saturn/

i hope i have lovemysan's permission.

jeep45238 10-20-2008 02:38 PM

Ah, that - I've seen it before. The lip wouldn't last long - I drive down a dirt road once or twice a week that almost swallows my car. The rest of the modifications are what inspired me to start focusing on fuel economy on my car. Massive 180* turn compared to my previous project of a turbocharged saturn sedan dragster.

The bellypan would be done differently - 2 aluminum rails attached to the car frame, with 1/4 turn fasteners. The pan would be split down the middle to keep the thermoplastic from deforming from the exhaust heat, and then joining at the rear axle area. Kydex is cheap(ish), tough, and light, and doesn't have any problems like rust or oxidation. Heat it with a hairdryer and bend it to shape, and the 1/4 turn fasteners would allow quick removal for vehicle maintenance. Rear wheel skirts would be of similar fashion, without as many mounting points and no frame (yes, I love Kydex and 1/4 turn fasteners).

He does have one major benefit over my car - a single cam with more low end torque, and higher gearing. Kudos to his car, it's some impressive mileage.

theholycow 10-20-2008 02:49 PM

Quote:

Originally Posted by jeep45238 (Post 121931)
Kydex is cheap(ish), tough, and light, and doesn't have any problems like rust or oxidation.

https://en.wikipedia.org/wiki/Kydex
Interesting stuff. Where do you get it, and how cheap(ish) is it?

A google image search for kydex produces this as the first result (warning: NSFW):
https://www.survivalarts.com/images/k...ster_girl.jpeg

GasSavers_BEEF 10-20-2008 03:00 PM

sorry, my spelling is a little off. he has done crazy things to his car with huge payoffs.

not a huge fan of HHO either. people into it seem to put a lot of time into it and have results without gas logs. just heresay if you ask me.

have you done a grill block or a warm air intake. those cars react well to those too.

jeep45238 10-20-2008 03:07 PM

Kydex is easily found for about $4-6US per square foot in various colors and thicknesses (.028 to .250 inches thick). I've used it for making autobodies before - very light weight, and heat with a hair drier/heat gun and push to get it to conform. Let it cool and it stays put. I wasn't in charge of purchasing it then, but I'm sure there was a decent quantity discount. No, it's not as cheap as other options, but it's also not as expensive as other options out there. I'm looking at it from a long term solution without having to replace it short of a major accident. Captive 1/4 turn Dzus fasteners would hold it onto the vehicle, and keep the chances of loosing fasteners to practically nothing.

From my understanding, kydex is pretty abrasion resistant - but the limit of that testing for me personally is with firearm holsters in the shooting competitions I participate in (they do wear the finish off pretty good over time from the guns, but the holsters aren't effected). I don't have a doubt it will withstand scraping on the road, it's the impact that would worry me the most, but proper designing with some wiggle room at the ends and joints should give it the room to move it needs (yes, very technical terms here :P).

I'm personally looking at .040 thickness. A single custom sheet the size of my under body is about $350 from Formingrade - if I can find a local supplier I'm sure it will be cheaper. Not "cheap" up front, but long term - cheaper than some other options. Toss in the added stiffness and lower weight, and the need for extra support brackets is reduced quite a bit. Worst case scenerio use ABS sheeting - $50 for the same 4x8 sheet compared to $350 kydex.

jeep45238 10-20-2008 03:13 PM

Quote:

Originally Posted by BEEF (Post 121939)
have you done a grill block or a warm air intake. those cars react well to those too.

There's a plastic air intake silencer that goes above the radiator. I cut a hole in that, pointing at the header and sitting above the radiator. The radiator doesn't do that much considering i don't get over 173*F most of the time (I've hit 195*F ONCE in memory). I'll be running a thermal tube (don't know the technical name) that GM ran from their exhaust manifold up to the carb hat and be drawing air from the header. I'm a fan of simple and clean, so a heat shield will probably not happen.

I relocated the IAT from behind the headlight to inside the air box, duct-taped off the original inlet (temporary till I find the time to epoxy lexan on there), and with that hole cut (it's new source of air) the IAT's are up from ambient to about 100*F. Engine temps are up an average of 3*F. It'd be nice to hit over 195*F continuously so the thermostat stays open:rolleyes:

I haven't done a grill block yet. Due to some long-winded personal issues I may not have this car all that long (or a roof over my head), so I'm saving for rent money and a Saturn to rebuild and modify that. If I get to keep this car, I'll be doing those modifications to it.

jeep45238 12-20-2008 02:23 PM

Well, I revisited my intake tract setup and modified it a bit further.

I used cereal box cardboard and epoxy to seal off the original intake hole, and sealed the hole I drilled above the radiator hose so that the air has to come from the center of the radiator and a bit offset from the 300+*F header. I moved the intake air temperature sensor upstream from the airbox, near the throttle body, so the car has a very accurate depiction of how hot the air really is that it's ingesting.

I've started a new job, and am now traveling an extra 150 or more miles per week than I used to do. I'm mostly highway now, instead of 30/70 city/highway, and there is only one big hill (highway speeds this time instead of 25mph) for me to conquer, so it's a relatively flat commute for this area of the states.

I bumped the tire pressure back up to 50psi from the 44ish psi it's been at since there's no foretasted precipitation for a while.

Last tank cost me $15 even, and netted me 40.39 mpg. I'm sure it will increase if I ever get cruise control for the highway to use once I reach my desired speed.


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