chadroosa

iTrader: (14)

i have a 98 z28 with rebuild trans and 3200 stall, 2.73s as of code in glove box, when im on highway and cruising at 70 mph, its running at 2350 rpm.. does that sound about right to you guys?? thanks in advance

Gilbert@Ace Racing

That does not sound right. It should be in the high teens, low 2k range. If I had to guess I would say that your torque converter is not locking up. What can you tell me about the car? Any repairs recently, any other issues that have been addressed? Any changes to the tune?

What is the fluid condition?

g

chadroosa

iTrader: (14)

no recent repairs, i dont know how it should be the day after i bought car the trans went out, so i didnt really notice if it was different. i havent tuned car.. fluid is clean, car had a shift kit installed when i got it, the 3/4 shift accumulator springs and piston where set up different from the way my A.T.S.G. book was, i asked bout it on here and people said to put it back the way it was.

JRENIGAR

iTrader: (37)

Thats 3.23 gear territory...

chadroosa

iTrader: (14)

im pretty sure the rpo code was for the 2.73s

FirstYrLS1Z

iTrader: (4)

that's what my 3.23s' were running.
GU2=2.73
GU5=3.23

Gilbert@Ace Racing

If the fluid condition is good, and it is full... then take it out and get it up to highway speeds. While holding a constant throttle pressure lightly apply the brake pedal. Not enough to slow the car down, just enough to engage the brake switch. Simultaneously look at the tachometer. If the engine rpms go up, then it is what it is, meaning that 2,350 rpms is due to the final axle ratio.

However, if the rpms do not go up and then back down when you release the brake pedal while holding the throttle steady then your torque converter is not locking up.

If you have access to a scanner or tuning software that can show you if the converter is being commanded to lock up that would be great. But the test I just mentioned will definitely confirm converter clutch operation.

g

chadroosa

iTrader: (14)

ok cool ill try that tonight i have snap on scanner at work ill have to see what happens thanks alot

tested on way to work when i press brake pedal, rpms go up to about 2500, so the must be working, double checked code says GU2, wondering if rear end has been changed before

HuggerOrangeZ

That seems to be where I am with my 3.42's at 70mph. I'll have to double check on my way home tonight.

With 3.42's at 70mph the rpm's are at 2230. (Locked converter)

chadroosa

iTrader: (14)

pretty close.. is there anything else i could check into??

camaroz28lt1at

iTrader: (16)

Take the cover off the rear and figure out what gears you actually have since you obviously dont have 2.73s

LS1121

iTrader: (17)

I have a 98 Z28 with 2.73's and when I'm on the highway at 75 mph my tach is at 2000 rpm's.

Stew215

iTrader: (1)

my 3.42 put me around 2200

chadroosa

iTrader: (14)

prolly have to do that

Badazz 97 TA

iTrader: (18)

You can also put the rear of the car in the air, put it in neutral, put a mark on the driveshaft with a sharpie, spin the tire exactly one revolution and at the same time count how many times the driveshaft turns. that will give you your gear ratio

chadroosa

iTrader: (14)

[QUOTE=Badazz 97 TA;15482026]You can also put the rear of the car in the air, put it in neutral, put a mark on the driveshaft with a sharpie, spin the tire exactly one revolution and at the same time count how many times the driveshaft turns. that will give you your gear ratio[/


thought about doin this as well be cheaper and easier