For those of you with superchargers, does it effect your gas milege(sp) alot? if you could throw some numbers out of what u get per gallon thatd be great!

thanks in advance

 

An engine needs 0.40-0.5 pounds of gasoline to make 1 HP for 1 hour, supercharged/turocharged engines run additional fuel for cooling the components say 0.52-0.58 pounds per horsepower hour. {BSFC}

At idle and cruise the pressure is [should be] bypassed so other than the added drag from turning supercharger say 5 HP at no boost [>25-35-45 HP depending on supercharger at max boost], the engine acts as normal [fuel consumption wise].

Cruise might decline by 5-10% from supercharger addition........Some oem systems have a supercharger clutch to save parasitic horsepower drain druing idle and cruise [low power demand].

If you require 30 HP to cruise at 60 mph [tire drag air drag] 30 x 0.45= 13.5 pounds per hour/6.2 pounds per gallon= 2.18 gallons per hour or 60/2.16= 27.65 mpg.

Thermodynamically, the engine is less than 30% efficient [less than 30% of gasoline heat gets to flywheel as power], then less than 25% gets to road to actually move the car. Gasoline has the ability to create 115-125,000 BTU per gallon [diesel can be as high as 139,000 BTU per gallon].

http://www.prime-mover.org/Engines/GArticles/bsfc.html
http://www.westechperformance.com/pa...ding/bsfc.html
http://www.holley.com/HiOctn/TechSer...l/Artcl07.html

 

So... without a difinitive answer... thanks for the info. My college professors would have eaten you alive Q!

After running the above post through babblefish, the answer that spit out was that the car will lose a tiny bit of mileage under normal driving conditions due to the additional losses the S/C adds to the drivetrain.

 

yea i know that, but would i notice it? what about driving agressive? would it suck alot more when driving agressive?

 

Yes it will suck a whole lot more.

 

like would it go twice as fast? or would i just have to refill it every monday and firday insted of every monday?

 

You kill me neff

 

My car got killer milage on the highway, as boost makes the engine run more efficently. I would see upwards of 26mpg. However, around town (heavy on the throttle) I would see about 15mpg. Now that my engine is messed up I get about 12-13 mpg in the city, and about 20 on the highway.

 

wow 26.......did u have a bigger fuel pump? how did u screw up your engine?

 

Yeah, I have a Walbro 255 and PE 380cc injectors.

The car was tuned completely wrong.

www.KPtechnologies.com/dynos/dyno.htm

Check out that a/f! Unfortunately, these were from AFTER the damage had been done.

 

wow. 62 psi!!!! didnt it come with the bigger fuel pump? u could take your engine all apart and get it bored, then have fresh, full compression engine. how much boost are u running? 15psi? for 380 hp...

 

I didn't use ANY of the engine management supplied by ATI. I tried the TS/injector method. Unfortunately, I was one of the first to go that route, and they didn't have all the bugs worked out. I'm hoping the damage was only done to a piston ring and that the block won't have to be bored more then .020". If there is any cylinder wall damage beyond that I'll scrap this block and go with the spare VQ35 I have sitting in my garage. I like to be prepared....

 

now that your rinning how it should be, whats your gas miledge?

 

Its not running right. After I found out the engine was damaged I quit messing with it.

Its in the shop right now having the motor rebuilt.