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My 89 Z24 seems to rev high, it's past 3250rpm in 4th going rpm in 45mph, in 5th I'm over 3500rpm going 65mph on the highway.
any one else rev like this or have suggestions? is this normal?

peace
 

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This may sound weird.. but get your transmission checked out to see if it is a Getrag or Isuzu....

Isuzu will rev alot higher like you are describing.
 

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Mine runs similar engine speed on the highway. 3800rpm going 72 mph in 5th gear. How do i find out which transmission i have (Getrag or Izusu)? It's an '88 Z24 w/ the 5spd.
 

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all the second gen z have the izusu the newer cavs have the getrag.
 

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I'd get the speed sensor checked out also!!!

Try having one of your friends in a stock car, at least stock tranny and sensor and check his speed.

I've swapped my getrag 5sdp for a Isuzu 5 spd, and there is 500rpm difference between the 2 in 5th. At 75 mph, with the Getrag, engine rpm was at 2500 rpm, with the Isuzu, it's at 3000 rpm.

So I suppose that at 3850rpm, you are going at about 100mph!!

And all 2nd gens with the V6 engine came with the Getrag. I4 came with the Isuzu.

Both can be swapped with minor mods...
 

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In an '88 issue of Car and Driver, the Z24 they tested ('88 w/ the 5spd) had a Getrag, so all 2nd gen couldnt have Izusu. I always thought all the 5spd were getrag. Whats the difference between the two?

Also, I think the final drive ratio on the 5spd is 3.61:1, not 3.18:1 like in the info section. I could be wrong though.
 

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If my memory is correct, on the Isuzu, where the shift levers are, there is a bolted on plate, or where the shifter shafts go in it's a bolted on plste. Getrag does not have this.

If I could have both side by side, I could tell you, but one is in my car, the other is sitting in storage 50 miles away, waitin for the clutch fork!
 

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firenza,
I get a code on the computer that says somethings wrong w/ the vehicle speed sensor (Code 24) and it says to check the tps. Maybe my tach could be off by a little too, not by much though since power dies off after like 5500rpm. I dont know how you can run at such low rpm going 75. Mine should have the same setup yours did w/ the getrag.

I got the car used so is it possible the previous owner put different gears in it?? it's relatively easy to swap gears on rwd, but i've never heard of doing it on FWD cars.

Jim
 

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It is quite possible that the VSS is off, but I'd go with the wrong sensor in.

Do you have the digital dash?

As for 5500 rpm, I can't really go there in 5th... Hit the cutoff at around 5300rpm at 120mph...
 

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yeah, i have the digital dash.

when i said power starts to die down after 5500rmp, i meant in general. I never took it that high in 5th.
 

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Hmm... reduces the possibilities!!!!

Digital dash can only have 2 speed sensors on the tranny, but will not give that big of a difference.

Are you sure the right tach is in the dash? You could have the 4cyl one in the dash, and that could give you a reading way off like you have!
 

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Ryan, it won't help...

I've got a 1986 I4 2l Isuzu 5spd tranny on a 1989 V6 2.8L....

They can be swapped with little trouble....
 

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i have stock tire size on. And my speed is pretty accurate when i pass those radars on the highway, so i dont think the vehicle speed sensor has anything to do with it.

I think that only leaves for my tach to be off (assuming the trans are the same in the 5spd cars)? How would i go about calibrating that?
 

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Wish I had the damn 5 spd...at 80mph mines chillin over 4 grand :(
 

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uuummmm.....not sure but im assuming that performance parts might also have to do with higher speesd at less rpm, think of that? :roll:
 

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a.slow.89z said:
uuummmm.....not sure but im assuming that performance parts might also have to do with higher speesd at less rpm, think of that? :roll:
ummmmm..... is 350000 km considered a performance improvement? :)
No mods has been done on my car for performance, unless you consider the 5spd Isuzu tranny that I had to install to replace the Getrag one!!!
 
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