Best MPG with fuel injection? and turbo?

MalibuAB

Daily Driver
Aug 4, 2009
19
0
0
Ft. McMurray AB, CANADA
just wondering if anyone has noted any numbers with their efi swaps. Thinking about what numbers are attainable with an LT1, possibly turbo charged. Already built a strip car but im looking for a different challenge now. I was thinking eventually of course turbo LT1, 700R4, 3:50''s out back ? Try to get the highest MpG possible! Think that would be kind of a challenge plus would be fun to drive as well!
 

StreetBu

MalibuRacing Junkie
Mar 21, 2004
4,158
3
38
Upstate NY
It's possible to get decent mileage from an LT1, turbo, wont help that much though, too hard to keep your foot out of it. FYI, My dad bought a 78 Regal brand new, matter of fact he ordered it. 305 4bl, automatic, 3.08 posi, Knocked down consistent 23-25 mpg EVERY week. He drove 33 miles one way to work, 6 days a week. Quadrajet 4bl WILL get better gas mileage than a 2bl, (smaller primaries :D ) as long as you keep your foot out of it. If you really want mileage, go for a LSX swap though, Plus will react MUCH better to a turbo. JMO
 

MalibuAB

Daily Driver
Thread starter
Aug 4, 2009
19
0
0
Ft. McMurray AB, CANADA
:) 23-25 is pretty good i would say, your are right it really depends on how you drive. would 40 mpg highway of course, be out of the question for a v8. LS or LT1 would probably get 28 and up from the factory if tuned up, but has anyone swapped in a cam for economy ? Or any other mods that have really brought the numbers up. Other than buy a toyota preaaz of course!
 

StreetBu

MalibuRacing Junkie
Mar 21, 2004
4,158
3
38
Upstate NY
I dont think you'll get 40mpg out of it, simply because of the aerodynamics. With a 4.8L lsx, proper gearing, tire size, trans ratio's, you may be able to get 30-35 though.
 

MalibuAB

Daily Driver
Thread starter
Aug 4, 2009
19
0
0
Ft. McMurray AB, CANADA
30-35mpg would be pretty damn good for a malibu, if better than alot of vehicals on the road right now. cool thanks for the input still a while before this ball starts rolling but right on.
 

v8power

Frequent Racer
Jul 24, 2008
511
0
0
okc
lsx power for sure. in my friends 2002 silverado, i cleared the factory long and short term fuel tables and leaned it out allot. they come so rich from factory. but in a ext. cab 4wd and beating on it we got average 17.3 mpg. so i think there is allot of potential with the lsx engines
 

MalibuAB

Daily Driver
Thread starter
Aug 4, 2009
19
0
0
Ft. McMurray AB, CANADA
yea i had and 03' chev 2wd with a 5.3, that truck was pretty good on fuel. i guess the LS series replaced the LT1's for a reason eh. I think ill look into both swaps still. i have a 700R4 that i would like to use with whatever combo and the LT1 would an easier block to bolt that too would it not ? im not familiar with what the caprices and other LT1 powered cars got for milage either?
 

Doober

Moderator
Jun 2, 2003
14,704
1
38
Catalina, AZ
www.cardomain.com
If you get down to the internals, the port/valve configuration and cam specs come into play quite a bit, because the lower RPM the engine turns, the less fuel it will call for, but to get the torque you need at that lower RPM, you also need a high velocity going into the cylinders, otherwise the torque just won't be there. That's one reason the TBI motors were better on torque down low, they have the ramps in the intake ports that were great for torque, but fell flat on their faces by 4000rpm. Part of the magic with the LS motor is the general head design they all share, plus they added some of the electronic goodies (variable displacement, vvt, etc.) down the road.
 

MalibuAB

Daily Driver
Thread starter
Aug 4, 2009
19
0
0
Ft. McMurray AB, CANADA
Sooo, if a guy could build a torque monster out of an LS block like a 5.3L stroker? if that is possible. Long rods etc. then throw a cam that would trow the best torque numbers at low rpms like 1500-3500 or something. then add 8-10 psi boost you should have a very effiecent engine. That would pretty much be a diesel. haha :roll:
 

v8power

Frequent Racer
Jul 24, 2008
511
0
0
okc
the 5.3 cams are actually pretty good cams for torque if you are on a budget.
 

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