Is it possible to "tame the beast" while you're driving and get up to 40mpg and then "release the power within" when you go to the track?

The only thing I can think of is a turbo set up that can be actively changed on the fly or while your car is cruising, it adjusts to give you better economy..

Other than an active fuel management system, what else is out there?

 

buy a Prius....

The only way I could see this being feasible would be to gut the weight of the car, throw on some form of boost and then limit the number of cylinders that fire. Even then I doubt you'd see 40mpg

 

There was another guy posting about this... I dont understand why you would want to get 40mpg in a 300+hp muscle car, they get decent mpg as is. Why dont you just buy a daily beater like a honda or something and enjoy your camaro on weekends... Just a waste of money to try to do something impossible...

 

I have a ls1/t56 in a 93 rx7. bolt ons only with a stock cam/heads that runs 12.1/12.2 and gets 35mpg highway @60mph...

 

You could probably get 40 with a gutted car and a stock motor if you went really slow. Some narrow, light weight wheels and a leaner tune would also help. People claim to get 30 now in 6 speed cars

 

completely gutted he wouldnt get 40 cause in my 2750lb rx7 with a ls1/t56 i only get 35... he would be lucky to reach that number (maybe possible cause i have a 3.90 rear gear).

Any set up that could come close would destroy the point of having a trans am. skinni tires? driving slow? think id rather **** the fat, hindu, gas station clerk for a free tank than ruin my car....lol (well... maybe not that far...)

 

I know this man. He was asking "if" it was possable.

 

Not possible. Just embrace the power!

 

Didnt we just have a thread like this? I really dont think its gonna happen. Maybe 30-low 30mpg manual?

 

Actually we haven't had this thread in days - about two

https://ls1tech.com/forums/new-ls1-o...-trans-am.html

 

Oh my bad. My thread calculations are off for the hour

 

ya this is a double post buy the same guy.... simple answer is NO you will not get 40mpg out of an ls1/ls6 if you are so concerned with mpg get a 6cyl f-body with an M6 with some head work 2.xx gears, gut the SOB and you might get to 40mpg other than that you need to trade you ***** in and go get a prius or some **** like that. not trying to be mean or anything im just saying.

 

I would just get a honda civic beater like mine. 30mpg all day

 

I think our cars get pretty good mileage considering what they are. Stock they're low 13 second cars and even with an auto can get 16-17 around town and 25 on the highway. I regularly average 19 MPG.

Although I'm tempted to see what kind of mileage I can get by bumping up the compression. Some milled 243s/799s might net a couple more MPG in addition to more power.

 

You need tuning software. It's not 40, but, I can get 33mpg highway running her @ 16.8-17.2:1 A/F ratio under normal driving conditions. Main problem for guys w/ cats is that you can't do this without killing the cats. cats need to dither around stoich, 14.63:1. (Before someone tells me how dangerous running this lean is, I have done it for years & looked @ internals...everything is fine).

Specs; 11.9:1 SCR, cleaned up AFR 205 heads, 224/228, .581/.583, 112 LSA on 110 CL, 1.75" long tubes through bullets dumped prior to rear differential. Car weighs 2600# + passenger(s).

Normal driving SCR is 17:1 (as noted), @ WOT is 12.5/13.0:1 up t0 6700 RPM. Makes over 500 BHP.

This information can be added to the baseline archives as to what is possible while making approx. 500 BHP without cats. IMO, w/ more effort, weight & set up effort + granny stile accelerations, 40 mpg is possible @ 500 BHP +, because the driver isn't using the HP & most street cars are not gonna be using much more than 12:1 SCR heads.

 

Lsx swap into a Prius might get u close. something like a turbo 4.8... Problem is weight. In order to get a ls motor to 40mpg, it will need to be in a car thats 2500lbs or less.

 

Finally some info I can use. I'm sick of people just trolling the thread and telling me its not possible bla bla blah. Thanks for the specs. I'll get started on the tear down and build.
I'll also keep everyone updated on the so-called impossible feat.

 

Google "gasoline direct injection" and read up a little . The basics are they increase fuel pressure to about 2000lbs. and inject the fuel right as the piston reaches tdc and at moderate accelerations the spray pattern is into the middle of the cylinder keeping fuel away from the cyl walls . They claim something like a 25% mileage increase . Of course You'd have to fabricate You're own set up for an LS engine .

 

When I had my 2001 WS6 6spd, I would get 28-32 mpg cruising and city was 22-25. That's all about non aggressive driving and what not. All depends on speed, flat or hill roads, down hill or uphill, wind, rear end gears, tuning, intake, exhaust, so much comes into play.

 

Thanks chris frost. Im not all that experienced in machining or fabrication like that so im not sure where to even start on all that