Lean Burn 1991 Talon AWD Auto

[pgfpro]

Well I'm finished with my wife's Del Sol and now its time to start the build on my car.

Its a 1991 Eagle Talon AWD w/automatic transmission.

I use this for rally driving (on and off road), drag racing, road racing, auto x, rally x, and daily driving and its my main vehicle for winter.

My plans are to build my back-up engine this winter.
.020 2g pistons that will be thermal coated.
1g stock rods with arp rod bolts.
new oil pump.
after market cams with adjustable cam gears.
My home built Lean Burn Prechamber with head modifications.
stock intake
FP 2g exhaust manifold.
EVO III 16g turbo with O2 housing mods to induce boost creep.
FMIC with a by pass system for extreme WAI.
ECM Link engine management for tuning and data logging.
Programmable TCU for adjusting line pressure and shift points.

I went with an automatic because of its reliabilty and no shifting when I'm rally driving off road. Plus I want to do some experimenting with light to mid load lean burn driving. So far my best is 31 mpg @ 60mph.

Goals:
40MPG @ 65 MPH running pump petrol
10 sec. @ 125+mph 1/4 mile running E85
0 to 60mph in under 4.2 seconds running E85
rally the car without crashing.LOL

[pgfpro]

Off to a great start. Finished some tuning today and got 35mpg @ 62mph.

The biggest problem I can see with this car is in town driving. There's just to much mass and parasitic drag to get the car up to speed.

[pgfpro]

Well I had to cancel my test run today due to rainy weather.

Made some minor adjustments to timing maps and fuel maps to try to achieve my 40mpg goal, but it looks like it will have to wait until next week.

I did confirm that running my new Bridgestone WS70 Blizzack tires I did not increase or decrease over my previous tire in fuel consumption.

[HeadlessNorseman]

extremely interested in whats been done to the engine/tuning for lean burn!! Ive wanted to do this with a standard dohc motor, add swirl by different intake cam profiles or whatever i can do! any pics?

[imzjustplayin]

"lean burn" isn't going to function well unless you can make sure the fuel mixture is homogeneous. Does this car have 2 or 4 valves? Maybe you could copy the civic VX/HX valve timing by turning one of the cam lobes so that it opens only a little bit for one of the intake cams but the other cam lobe continues to open the same.. This way you would "induce swirl" providing for a more complete combustion.

[pgfpro]

Originally Posted by HeadlessNorseman

extremely interested in whats been done to the engine/tuning for lean burn!! Ive wanted to do this with a standard dohc motor, add swirl by different intake cam profiles or whatever i can do! any pics?

Thanks. I will have a build thread on the new engine with the prechamber later this winter.

I'm not using anything unusual when it comes to the cam profile. The turbo is the key to my fuel atomization process.

My new personal best so far is 37mpg. So next year during the warmer months it should be able to get to my goal of 40mpg.

[pgfpro]

I got to do some unseasonal warm January testing today. It was 53*F. with a 4 mph head wind. I trimmed my "fuel fat" by another 4%. Zero counts of knock. Drop my in Hg by 1.6 points with a 2% increase in throttle angle.

This should be enough to get to my goal of 40mpg freeway.

[pgfpro]

Did some more testing on my posted 45mph prairie route. Its a nice road that I can run at 40,45 or 50 mph and not have traffic to deal with.

Had some strange results. The slower speeds 50mph,45mph and 40mph are not improving over my steady state 60mph Freeway numbers. This is where my Honda has major improvements.

Its like the auto-trans. is over loading the engine at the slower speeds. I think it also has to do with the 4G63 1g head and its large ports. The fuel is not atomizing at the lower rpm like it should.

[theholycow]

Could be that the lower speed results in keeping the TCC unlocked vs. locked at higher speed. That'd be a big waste.

[pgfpro]

Originally Posted by theholycow

Could be that the lower speed results in keeping the TCC unlocked vs. locked at higher speed. That'd be a big waste.

That could be a lot of it. Especially since my 1G Talon comes with a
non-lockup torque converter. Its probably just making a bunch more heat at the lower rpm.