35 MPG 1966 Chevelle

[2000mc]

Automobile-catalog.com estimates 66 chevelles had a .52 cd

[darcane]

Originally Posted by spacemanspif

I was under the assumption that the new Camaro aero was pretty terrible so I thought that the Chevelle might not be much worse. With an air dam to reduce under car turbulence I think the gap closes ever farther. I really didn't think old cars were THAT bad in the aero department.

GM built the first full-scale wind tunnel in North America, but that wasn't until 1980.
General Motors' wind tunnel turns 30, more important than ever
GMWindTunnelBrochure.pdf

Now it runs almost constantly and modern cars get hundreds of hours in the wind tunnel.

Before that, they tested using scale models, but clearly they had a lot of room for improvement.

[Frank Lee]

I've read the first car GM aero tested was the '59 Chevy. But that was after the styling and perhaps tooling was done. I've seen a vintage action pic of a '59 covered with yarn tufts.

[67-ls1]

I do realize that 35 is a lofty goal. I could have shot for 25 and nailed it easy, but that's no fun.
If I get 30, that's cool. Still way better then the low to mid teens the Chevelle used to get.
I am going to add a large air dam in the front. Are there other ways to keep air out from below the car, ie, hood vents above the radiator fans, skirts along the lower body sides, etc.
I'm willing to try things that can be undone if they don't help and detract from the classic lines.
I will start browsing the other forum sections for info.
Thanks,
Dennis

[2000mc]

Belly pan, rear wheel spats, block heater (convenient hidden plug-in would be the tricky bit though), higher ratio manual steering gear or electric (guessing electric would be a pain unless someone makes a kit to do it) there seems to be enough 3.6 variants out there that coming up with a non p/s belt routing option should be doable

[spdfrk]

35 should be doable as long as you keep it under 60 mph. Underbody aero will save you if you do it right. Use the Amsoil low viscosity ATF if your transmission is spec'd for dexron vi. That stuff is amazing. I managed 30 us mpg out of my 1990 1/2 ton rwd Silverado with 3.08:1 final drive (silverado30mpg) and not quite 50 us mpg out of my 2005 Malibu LS v6 with 3.05:1 final drive (05ls).

Have fun!

[67-ls1]

2000MAC,
I thought about manual steering (I even bought the box), but I already had to redo the front belt drive to eliminate the AC (compressor would not clear the frame). Because this is a serpentine system, dropping another pully may be tough.

I did notice that the engine has a 135 amp alternator on it. The Chevelle doesn't have near the electrical load the Camaro had, so could use a LOT less alternator capacity. Considering that the alternator will be almost idling after charging the battery following a start, should I change to a smaller out put alternator? Would there be any savings?

Thanks,

Dennis

[Frank Lee]

You could get by with a smaller alternator AND put a big pulley on it to slow it down: http://ecomodder.com/forum/showthrea...ork-20558.html

[2000mc]

i think the camaros ecm will put the alternator into a fuel economy mode (voltage to match open circuit voltage of the battery) when appropriate. unless you wanted to go alternatorless, i dont think there is going to be much gain to be had.

to drop another pulley the alternator might have to be put where its located in FWD vehicles then you could go from the crank to the tensioner, to w/p, to alt... i dont know if you would have to have the idler to keep the belt from slipping at the alt, and the belt might not clear the tensioner, if it was going from the idler to the crank. might just take the perfect length belt to keep the idler pulled enough, or just go straight from the alt back to crank.

i think the bigger issue might be that the would be alternator mount is used in part by the oil filter housing mount. i think the alternator could be cut to accommodate that, but i dont know if the rest of the alternator might be tring to get into the filter housings space. craptastic work around would be to take off the filter housing and use a spin on filter, but i think access will be awful, and make a heck of a mess when you change your oil.


edit: heres a better pic... basically this minus the ac, i think thats the long engine oil filter on there, so that might help guess if you have space to go for a spin-on

[spdfrk]

Going with a smaller alternator might make a difference but as someone else mentioned, GM has some pretty smart technology for how it engages the alternator. My '05 Malibu has the same technology. You could reduce electrical load by getting LED headlights. They'll be tons brighter too depending on what you go with.

:-)