this is just for a future reference but what improvements can i do on a 420a engine that will keep my mpg around 25 but give me the most whp
any info you guys can provide would be greatly appreciated

 

Absolutly nothing you can do : )

 

all i can say is, dont expect to get much for whp on that car without a turbo....And anything you do besides a turbo is not gonna affect the MPG that much

 

well i want about 250 horsepower what can i do to get to that number

 

whp? turbo thats about all you can do.

or you could drop a LS1 in it lmao!

 

how mutchpsi can a 420a handle

 

Safely , daily driving.. About 8-10...

 

you are gonna need to spend $2k+ to get to that mark

 

if you are wanting to get better fuel economy, stop using the throttle.
If you are wanting to make that much power, the theory on a N/A motor goes like this, CAI, Header, Exhaust, high flow cat, new o2 sensors, reprogrammed ecu, lightwieght flywheel, new clutch, lightwieght wheels, In order to keep your fuel economy high, you are going to take all the fun out of your new parts, cause you wont be able to use them.
on the flip side, fuel economy is directly related to how much weight you are pulling. you could do everything listed above, and then drop about 200lbs from your car, and that should do it.

 

hes not gonna get 250 whp on those mods, you need a turbo