23 replies to this topic

[Steve220]

Regards mpg. Is that because of the lower CR you have to run with charged engines. Or simply because you are turning the charger

It's because your engine is receiving positive inlet pressures and would begin to run lean.

[Turbo Phil]

Regards mpg. Is that because of the lower CR you have to run with charged engines. Or simply because you are turning the charger

Both, plus the supercharger makes boost vs rpm so you’re generally boosting from very little rpm.

Phil.

Edited by Turbo Phil, 14 June 2019 - 09:16 AM.

[luismx123]

Regards mpg. Is that because of the lower CR you have to run with charged engines. Or simply because you are turning the charger

also more power needs to come from more mixture. i.e more air=more gas needed

[IronmanG]

If you could run a 10.1 CR how much would that offset the negative points.
So a 1275 might get 40mpg. A turbo might get 35 and a super 30?

[Steve220]

I'd you're boosting a mini, I wouldn't start worrying about mpg.

[IronmanG]

Just a curiosity

[Magneto]

I think the mileage drops because it's so much fun to put your foot in it!  

[REDICE]

Dont : Just slap one on as cheap as you can

Do: Research and think it out. You will have to spend probably more than you want to..

Do it right - do it once

[mini13]

yeah thats not far off, i think a turbo and NA might be closer with a charged one lagging behind a bit more,

 

one main reason is you are always using a bit of power to churn over the supercharger, as its pretty much always trying to boost, as a scnario at cruise the charger will be blowing against a part open throttle and consuming maybe 1-2hp , and the total needed to drive the car forward might be 8-10 hp so its a fair percentage of consumed power (total guesstimate on those figures by the way) where as a turbo wont actually consume anything until its making boost, and even then a lot is coming from "lost exhaust heat" but thats another discussion....

 

 

 

 

 

 

 

If you could run a 10.1 CR how much would that offset the negative points.
So a 1275 might get 40mpg. A turbo might get 35 and a super 30?