Out of curiosity.........anyone know the difference in horsepower, torque and MPG of a stock 305/350 TPI engine vs. a stock 305/350 TBI engine?

Wm

 

It varies over the years. Go to the thirdgen index page and use the camaro/firebird tech data links in the left navigation bar and it'll list it all.

 

that's right but it won't give you any MPG ratings. you could still use http://fueleconomy.gov/ which i believe will show you the official mpg-rating of any car, but mind you, of course milage will also depend on the car's options and transmission..

 

Thanks for the links guys. I found all of the HP/TQ ratings for the TPI/TBI 305 and TPI 350 but nothing on a TBI 350 (I'm assuming that was never an offered option). MPG ratings for the TPI 305/350 are pretty close, ranging from 15 mpg city and 22-24mpg hwy.....there was no listing for TBI systems though.

I'm still on the fence with this project, I have a 327ci from a 67 Camaro and I'm looking to upgrade to EFI for better mpg and performance......but can't decide on TBI or TPI.

Wm

 

TBI would probably be easier, but TPI would be nicer.

 

imho a decision whether to go tpi or tbi shouldn't take MPG into the equation, as this is more a matter of how radical your specific engine is built, where and how peaky the power band is, what ratio transmission and rear gears you are using, etc...
if you are starting from scratch it's probably a matter of funds as tpi would run you quite a lot more imho, even more so if you need modifications to accomodate the airflow for a higher performance engine.

 

just for info. , a 305 TBI that is well tuned gets great hwy.mileage . i have got as high as 29.43 mpg. on the hwy. . i am not the only one , many others have done as well .

 

My logic suits my situation and plans......not everyone has the same agenda.

Wm

 

id buy a conversion kit. an edelbrock pro flow, or holley setup. and if i chose between the two id take the tpi.

 

Regardless of what route I take, I'll wind up using a GM system.....they've spent more on research and development than Holly and Edelbrock combined.

Wm

 

You can get complete TBI setups at a junk yard all day long fairly cheap. The TBI 350 was an option in trucks, and they made a whole lot of them.

As far as mileage goes here's what I've personally recorded with different combos in the same car:

305 TBI/700R4/2.73--24-26 MPG

305 TBI/T-5/2.73--28-30 MPG

305 TBI/T-5/3.27--23-25 MPG

355 TBI/T-5/3.27--21-23 MPG

These numbers are all mixed driving. I drive the car 70 miles round trip every day to work and back. Out of the 70 miles a day about 25 is in the city.

 

Thanks for the data FYRCHKN, those are some pretty impressive numbers. Since I'm putting this system on a 327 I'll wind up looking for the setup from a 350.....hopefully I can scrounge one up. lol

Wm

 

i used to get bout 18`city and 30 on the hwy with my LO3 and 700R4...with open 2.73 on 87 octane

now ive swaped to a LSD 3.23, advanced timing to 8* running on 93,so still unsure on its milage yet.