im rockin 80 basically stock 4 spd tranny and get ok mileage under 55 but i was wondering if possibly a 5 spd t5? could possibly/reliably work to achive freeway speeds with better mileage?
will it fit up?
will there be problems with the ratio's and different torques?
What are you getting for mileage right now?
My 78 has your eng / trans combo and I get a consistent 20 in the city, even in bad tune and being heavy on the go-pedal.
Many years ago, it would get 30 when doing lots of highway driving during college years. Cruising speed averaged 65 or so.
Not sure if the increase in mileage would be worth the effort / cost in the tranny swap...
i dont see how it wouldnt help. youd go from 1:1 to around .8:1 in high gear. there were a few overdrives in t5s and i dont know them off th top of my head. i think one was .82, one was .7X and another was .6X. plus no crappy screw in shifter and easy to find parts. your input shaft yoke on your driveshaft will have to be changed. i also had to cut my driveshaft down. not much, i dont even think it was an inch. youll need a cable clutch bell housing for a t5. youll have to notch out the tranny crossmember where the mount bolts and flip it backwards. a regular mustang mount is what you need. if you get the bellhousing with the bellcrank, and not the straight pull, you have to make some mods so the cable doesnt hit the crossmember. or not and let it rub. the shifter is also roughly 2 inches farther forward and your floor has to be cut to allow room. pending on how tall you are you may have to change the angle of the shifter or figure out a way to move it back to a comfortable reach. you also may need to change the speedo gear. i dont know how many teeth are on the speedo drive in the tranny on either 4 or 5 speeds. i used the 3.55 cable gear from the turbo coupe i stripped with my 3.40 geard car. speedo wasnt off more then 5 mph. close enough for me.
as far as ratios. the 4 banger t5s have a low first at either 3.97 or 4.0X unless you find a certain year svo that has a 3.50 first. good for a freeway geard car to get away from a stop light fairly well.
bob
Quote from: 78txpony on October 15, 2009, 02:23:56 PM
What are you getting for mileage right now?
My 78 has your eng / trans combo and I get a consistent 20 in the city, even in bad tune and being heavy on the go-pedal.
Many years ago, it would get 30 when doing lots of highway driving during college years. Cruising speed averaged 65 or so.
Not sure if the increase in mileage would be worth the effort / cost in the tranny swap...
huh? i dont have a tac but i recon im about 5 or 6000 rpms around 60-65 mph and i dont like maintaining those speeds for very long plus to make it worse the 80's gas gague is a monster about just as big as the speedo up a hill on a freeway you can totally see that needle drop, anyway justlookin for ideas, what do you think about a hydrogen fuel cell feeding through the intake.btw i only know very basic mechanics
Quote from: kevin.s 80 on October 16, 2009, 01:08:23 PM
huh? i dont have a tac but i recon im about 5 or 6000 rpms around 60-65 mph
You heard right... Of course my car has the standard 2.73 highway gears and the tach shows 3000 at 70mph. If yours is way off, you might have some VERY low performance gears. :surprised: In that case, an OD would be a great addition.
My 2.3 has always sounded like it is running faster than it is - just the nature of the mechanics (the opposite of an Olds V8). Maybe it is time to install a temporary tach to find out what your rpms are.
I won't get into the hydrogen debate... ::)
I was watching one of my videos from my drive to Utah this spring, my speedometer showed 75mpg and my tach showed about 3000 rpm. My tach is off about 50 rpm or so, judging by what the computers showed at the emissions station I tested at this year.
I have a stock 4 spd transmission and 2.73 gears in a 6.75" rear, all behind a 2.3l motor.
78tx is right, these little 2.3s sound like they are running a lot higher than they really are when on the freeway. I hate taking mine over 55 because that's about where it starts to sound harsh. In all truth though, 55mph in fourth gear is actually the same RPM as 35mph in third gear which is what I drive around town.
A quick glance at my tach and my worries go away. :) Now cruising at 85mph gets me wirroied, regardless of RPM... :look:
Quote from: dave1987 on October 28, 2009, 01:36:28 AM
I hate taking mine over 55 because that's about where it starts to sound harsh. In all truth though, 55mph in fourth gear is actually the same RPM as 35mph in third gear which is what I drive around town.
My 78 was driven hard and fast a lot long ago - 70 - 80 cruising. It had to put up with some leadfooted teenagers for 10 years of its life. I had the speedo needle in the middle of the odometer once and it was really buzzing. Given the abuse it took, all still runs well. Going 60-65 should not be a problem - just change the oil every 3k.
I use 4th all the time around town. I shift to 4th at 35mph and it pulls fine with no lugging. Tough little engine for what it is!
5th in a 4 cylinder T-5 is .76 or .79 or .82
Stock 2.3's with carbs don't get the mileage of the newer EFI cars, never will either. best I ever got with one in good tune has been around 27-28, freeway with no horsing around. My 78 with 3.00 and a c-3 gets around 23-25 avg. And it hates the new E-10 fuel we have too. Dropped about 10% with that stuff. I've tried alot of jetting scenarios and it don't really seem to change mileage much. Can't wait to get my Turbo 2.3 and T-5 in and running. :2fast4u: