Ok, my '89 Vette has the manual 4+3 transmission, but I have some doubts about it...

Is the order to change: 1st, 2nd upshift, 3rd upshift, 4th upshift, 2nd, 3rd and 4th? Or is it: 1st, 2nd upshift, 2nd, 3rd upshift, 3rd, 4th upshift and 4th?

I know, I know, it is a pathetic question, but I am new with this kind of transmission and I am not sure. Think that this is not the way to understand the overdrive concept, right? Simply to assure

Also, I have still problems to change my shift ****! Some days ago, someone tryied to help me, but note that I am spanier and my english is for sure not perfect! Can someone explain it to me like to a stupid? Eh, eh...

Finally, if someone know where to find the car documentation for a '89 C4, please tell me!

Thank you!

 

You might want to double check the year of your Vette.
4+3 manual was only available from 1984 to 1988

 

How you use it depends on what you want to achieve.
If I am in a gas economy mindset, I leave over drive on and shift like a normal 4 speed.
If I am in an spirited driving mindframe, I turn it off and shift through gears 1 to four and then turn the overdirve on.

In my '88 the best way to turn it on and off is to use the tip of your thumb and psuh on the edge of the overdrive button that is closest to the dash board

 

 

What rws.1 said sounds perfect. With me, sometimes I'll cruiz in town in 2nd with the OD on then just hit the toggle on the shifter to lay the smack down! Maybe not the best thing for the tranny but its fun.

 

I am sure, my Vette is from the end of '89. It comes from Germany, so maybe there was still this kind of manual transmission for european owners.

 

What is the tenth digit of the Vehicle Identification Number?

 

Huh? A 4+3 in an '89? Agreed... what is the 10th VIN character?

 

Don't use all 7 speeds... some of the ratios are very close to each other, so it's a waste of time.

Go... 1 , 2 , 3 , 4 , 4OD

 

4OD for cruising at highway speed.

1989 Corvette was first year of the 6 speed standard transmission.

I looked at both vehicles side by side when I purchased my '88.

 

I use O/D a decent amount. On onramps its great. You can be in 2/OD cruising along the ramp's curve and then nail it when you need to merge utilizing the kickdown. Its also great for setting up an opponent.

 

The tenth digit is a "J", what it means? Note that the car was first registered in Europe on '89, I do not know if maybe it was made originally in the USA on '88!

 

I use mine like a 4 speed and the od when on the highway.

The manual says 1,2,3,4 od on back to 2nd , 3rd, 4 th.

When they are working correct I think they are great! However it was a pain to change the od fluid. The plug would not come out. I had to fill it through the cooling lines with a hand pump. Take care of it and it is great!

 

J = 1988 model year
K = 1989

You have an `88, cool year for Vettes.

 

Proper shifting for max accel is as follows on the 4+3:
1-2-3-4-3OD-4OD.

2OD is in between 3 and 4, closer to 4 though. Shift from 4th to 2OD and watch your competition go bye-bye ahead of you and your L98 hit its redline.

For top speed, 3OD is as high as anything near stock will be able to use. 150 mph is 5000 rpm in 3OD.

I like to shift out of 4th into neutral, while timing the push of the OD button a bit before the shift so it's in OD once I get into neutral. From neutral I shift into 3rd (OD) and be off before too long. It takes longer than a regular shift but it avoids gear tooth clash.

Once you're shifting from the end of 4th gear (at max, 120 mph or so on a stock L98) into 3rd OD, you've got a ride ahead of you. Find alot of pavement, it's gonna take a while to get up to "holycripes" territory, but it'll get there.

The only problem I have with the gearing is say you're doing 75-80 mph in 3rd OD, like 2200rpm or so. Do you go into 2nd OD or down to 4th or even 3rd? For max accel, you have to go down into 3rd gear and ride it to near 100. If you just go down to 2nd OD, the car just doesnt pull nearly as hard as if you jumped down into 3rd and then banged off 4th gear. Kinda hurts you in a roll-on race.

But in fairness to the 4+3, there's nothing like doing a steady 100 mph and having the tach loaf at 2500 rpm in 4th OD, makes the highway miles seem to fly by. When I ran the stock TPI fuel injection, I could get 30 mpg doing 100+ on flat interstate, no problem.

 

By the math, yes, in reality its a tossup. The time spent to shift back to 3/OD from 4 can be a nusance.

I can't agree with you here. You need to use 4OD as 3OD isn't strong enough to pull to 5000. Or if it is it will take a lot longer. 150mph is acheived at 4100 in 4OD which is at the top of the L98s hp peak. Even though the gear ratios don't make sense to use 4OD instead of 3OD it works out better being longer in the torque band with 4OD.