Best upgrade: Fuel Injection or 700R4?

[MaineShark]

I'm trying to plan for the next year or so, and I'm wondering which is the best driveability upgrade: fuel injection or a 700R4?

Both are fairly similar in price, I believe.

Joe

 

[cruzer99]

If you go with the tranny, you need to look at what rear-end gear you have. With the 700R4 you can/should run a tall gear because the tranny has an extra gear (4), that will make better use of the engine HP and yet is great for cruzin the highway and good gas mileage. The 700R4 also has electronic torque converter lock-up controled by a computer in the newer cars. I think most people who switch over to the 700R4 by-pass this and lock the converter which means it doesn't free-wheel when you let up on the gas or hit the brakes.
Some other people who know more that I do can put more light on this for you.
You could go for both and get a wiring kit and computer from painless and have everything. Last year I bought the complete TPI engine, 700R4, and all of the electronics out of a 91 TA for $1000 and put it in a 34 3-window. This kept the cost down for me. Just a thought.......

 

[mmvette80]

I did the 700R4 swap a few months ago. The car is much faster from a dead stop. Fuel economy is better but only on the highway. If I cruise at 70mph im doing 2000rpms. Stock 3.08 rear.

 

[BigBrakeFuelie]

MMVette80-I think you just sold me on the 700R4.That`s exactly what I am looking for.I have the same 3.08 and I don`t like the off the line performance.Have you shaved at least a second off your accelaration time?

 

[BB wowbagger]

I would go for a Fuliesetup..Those things are soooo damn cool

 

[mmvette80]

I would think it took a second off. The tranny came with a 2200 stall converter. I drive my Vette on long trips mostly so the tranny is like an engine saver. I save 1000 rpms at 70 mph.
As for fuel or the tranny I would go with the tranny first. The way the 700R4 multiply's the engines torque to the rear wheel is like changing the 3.08 rear to a 3.73.
I bought mine from www.700R4.com
$1900 with everything to my front door. (I installed it myself)

 

[BigBrakeFuelie]

Thanks Bro I`ll check it out.

 

[mmvette80]

BigBrake- What color car and what options?

 

[page62]

Do your mods in this order:

1. Transmission
2. Transmission
3. Transmisson
4. Transmission
5. Transmisson
6. Transmission
7. Transmission
8. Transmission
9. Transmission
10. Transmission

If your carb is rough, replace it with an Edelbrock QJet. (Been there, done that.)

Fuel injection can wait till next year...

 

[mmvette80]

The one cool thing about owning a 1980 is its the last year before a computer. It seems like much less of a headache. I dont think ill ever switch over. With the 700R4 I went from 16 mpg to approx 21mpg (hwy). Thats good enuff for me.

 

[MaineShark]

If you go with the tranny, you need to look at what rear-end gear you have. With the 700R4 you can/should run a tall gear because the tranny has an extra gear (4), that will make better use of the engine HP and yet is great for cruzin the highway and good gas mileage.

Well, my owner's manual says 3.55 rear ratio.

The 700R4 also has electronic torque converter lock-up controled by a computer in the newer cars. I think most people who switch over to the 700R4 by-pass this and lock the converter which means it doesn't free-wheel when you let up on the gas or hit the brakes.
Some other people who know more that I do can put more light on this for you.

Wiring it to unlock with the brakes is pretty easy, since there is already a sensor on the brake pedal (for the brake lights). I'm not sure about a throttle connection to the TCC, though. I can't recall that being mentioned in any description I've read. The only throttle connection I know of is the TV cable.

You could go for both and get a wiring kit and computer from painless and have everything. Last year I bought the complete TPI engine, 700R4, and all of the electronics out of a 91 TA for $1000 and put it in a 34 3-window. This kept the cost down for me. Just a thought.......

If I manage to find a deal like that, I'll be set. I figure the better mileage will probably save me about $100/year on fuel (just a rough guess), so it would take a while to pay for itself, at that rate. Of course, no one said 'Vettes were supposed to be practical

I do a lot of highway driving, though, so the savings of the overdrive might be more noticeable than the savings of a EFI system, if I have to choose based on that.

Joe

 

[BigBrakeFuelie]

MMVette80-I have a dark blue vette with T-Tops and dark blue interior.My tranny is the auto TH350.I have a built up 350CI replacment non original engine about 290hp.This is the California version of the Corvette in 80 so it came with the 305 originally.It also has a computer.the California 80`s had the orginal computer.Also have a new hi-flow Cat, and flowmasters.

 

[page62]

MaineShark, if you buy a 700r4 or 2004r from Bowtie, it comes with a non-computer lockup system preinstalled. All you do is add wiring to the brake switch so that it unlocks the converter when you press the brakes.

Without a computer, I find I have to keep the car in 3rd for city driving. The tranny is too eager to drop into 4th. You get used to it pretty quick.

Finally, with a 3.55 rear end, Bowtie recommends a 200-4r transmission. It doesn't have that really low first gear like the 700-r4, as well as a slightly taller overdrive.