dash94vert

Im sure many LT1 guys here have this but idk what this is about, my 94 z28's speedo only goes to 110 and i dont have the option of putting my car in first gear. ive tried searching but i guess i dont know what to put, so can someone just tell me why some come with the 150mph on the speedo and 1st, when mine and a couple others i know of just have 110 and 2nd

happysem

iTrader: (5)

Something to do with the options package I think.

Your factory tires were only rated to like 115 or something, so they didn't want people going faster than that, so its limited.

Also, its an auto...no need to shift it =P

dash94vert

well that sucks, i did buy it from an old woman so that makes sense lol..i wonder if i would be able to switch the speedometer with one of the 150mph ones. and sometime auto shifting is just that little feel of control you have

happysem

iTrader: (5)

I understand that lol, I used to do it in my V6 when I thought I was hot ****.

Its better to just leave it unless you are auto-x or something where you don't want it to shift.

You can swap gauges, but you won't be able to easily keep track of your miles, unless you get a set that had similar miles as your car lol.

dash94vert

aha i always thought it would be better to shift in short drag racing but it is much easier to just put it in D lol.. well then i'll be sticking with this one for awhile unless i get that lucky to find one with my mileage!

madhatter

Whats the mileage you have? I plan on swapping in my TA dash as soon as it cools down here. I will have my 150 mph cluster available.

dash94vert

well my speedometer reads about 138,xxx..but theres a newer motor in the car so i wouldnt be too sure. but would that matter that my current motor has less miles then the speedo because its pretty dead on anyway

MasterTomos

iTrader: (15)

The 155mph speedo, 1st gear selection, and Z-rated tires where an option in '93 and '94, then became standard in '95 for V8 cars, IIRC

spikester7878

iTrader: (1)

i just did the swap on my formy and its not hard to swap the odometer from the old gauged to the new ones just have to be careful when you remove it from the gauge cluster

madhatter

No ****? I am at 138,750ish haha. I will hit you up in a month or two to see if you are still interested. Just needs to be less than 100* out before I spend all day in my car doing a dash swap.

Irish350

iTrader: (14)

sounds feasible. I always thought the z28s came w that odo stock, but mine was a 95.

RedHotG8

iTrader: (1)

Buy a G8, the auto has a manual mode for shifting if you desire to. Also the speedo goes up to like 180mph.

dash94vert

haha alright.. where are you located

dash94vert

kind of hard to get a G8 when your just turning 18 with a horrible low income!!

lt11994

The inability to shift into 1st gear means that your car most likely has 2:73's. The other guys nailed it with the low speedometer, it was put in cars with different option packages, i.e. tire sizes, rear gears, etc.

99monguse

Ok...pull the shifter **** off. Now remove the consoles upper trim, exposing the actual shifter. Now, if you look very closely at the shifter, you will see a small buffer the blocks the engagement of 1st gear. If I remember correctly the buffer is rubber. Take a pocket knife or whatever and cut it off. I used an old steak knife and heated it up with a butane torch so the knife would cut through like warm butter. AND NOW YOU CAN SLAM THE SHIFTER INTO 1ST! WHOS THE ******* MAN NOW!

The speedo only goes to 150 if you have ZR rated tires. The 2.73 geared cars didn't have ZR tires. I had a 95 Firebird Formula with an automatic. I bought it brand new and it's tires were 235-55-16 and it had 2.73 gears and no 1st gear, at least until I modified the shifter.

Are you sure the car is a Z28; does it have a LT1 under the hood? I seem to remember my Formulas speedo going to 150 but the fuel shut off was at 118mph because the car didn't have 245-50zr-16 tires.

Brangeta

Topic starter-- You might want to check your RPO code sticker and make sure you have Z28 and LT1 on it. It sounds to me like you have a V6 Camaro with an engine swap.

Everybody else-- 1st gear was only selectable on cars with the performance axle ratio option, which is RPO GU5. You can check the RPO code section of my site for more detail about why 1st is missing. Standard ratio was RPO GU2.

This isn't true, because our '95 lacks the performance axle ratio (no 1st gear on the shifter), has the 155 mph speedo, and came with the optional 245/45R16 tires. We've owned it since '95, so I know nothing has been changed.

1995blacktattop

iTrader: (2)

I have seen V8 cars with 115 speedos and/or no first gear lockout.

IIRC there were 4 ways to order an LT1 fbody automatic.

1. base model 115mph speedo, non Z rated tires, 2:73 gears and no first gear selection
2. 3:23 gears and you're allowed first gear, non z rated tires 115mph speedo
3. 2:73 gears and no first gear selection but Z rated tires so 155mph speedo
4. 3:23's and Z rated tires = performance package w/ 155mph speedo and no first gear lockout (how mine is )

the tire size like someone mentioned is something like 235/55/16 for the base model tires while the performance tires were 245/50/16

I think i read somewhere that they never made the 3:23 gear and performance tires standard on the LT1's but that if you ordered an automatic WS6 T/A or formula or probably a camaro ss too that the GU5 3:23 was mandatory along with the performance tires (since they didn't offer non performance 275/40/17 tires)

99monguse

What I meant was...you will only get the speedo to go up to 150 if you have the ZR tires (or if you reprogram the pcm). My 1995 Formula was an automatic, 2.73 gears and had the 150 speedo but the speed militer kicked in at 118ish because it wasn't a ZR rated tire ooptioned car.

Brangeta

Hmm... I looked on ebay, and you're right. You could get a Z28 with the 115 mph speedometer. Found a '94 like that.

For reference, UB3 is the RPO for the gauges, and unfortunately, V6, 115 Z28s, and 155 Z28s all share UB3, so there's no code for just the different gauges. :-\

I decoded two cars and compared them. These two cars:
http://cgi.ebay.com/ebaymotors/1994-...US_Cars_Trucks
'94, 155 mph, GU6 (manual, 3.42 gears), QLC (245/50ZR16 tires)

http://cgi.ebay.com/ebaymotors/1994-...US_Cars_Trucks
'94, 115 mph, GU2 (automatic, standard axle ratio 2.73), QMT (235/55R16 tires)

Therefore the speedometer is definitely dependent on the tires and not the gears.

The shifter having 1st is 100% dependent on the gears. GU5 would have 1st gear selectable and have 3.23 gears.

That said, there is nothing bad about the 2.73 gears in my opinion. You get better gas mileage on the highway and when you're full throttle it's like being in a rocket ship as you'll be in first til about 45 mph, which I consider insanely fun.

I've never had the car going that fast, so I didn't know that. I never really thought about it.