C_Rules

iTrader: (7)

i went to the track this weekend and had some shifting issues on my 4l60e. i logged the trans with datamaster and found the following. if i leave the car id overdrive or drive and take it down the track this is what happens (keep in mind all my rpm kickdown points are set at 6200 and my rev limiter is at 6700):

1>2 shift at 36 mph 5014 rpm
this leads me to believe that the car shifts at whatever comes first the mph table or the rpm table. my mph 1>2 shift is set at 36.

2nd gear: rpms keep rising from 5014 to 5944 before they drop to 4746. why do the rpms keep rising after the car has shifted before dropping?

2>3 shift at 73mph 5423 rpm
again this tells me the car shifts at whatever comes first mph or rpm. my mph 2>3 shift is set at 73.

3rd gear: rpms keep going rising from 5423 until they smack the revlimiter (6700 rpm) a couple of times. the rpms finally settle down to about 4024. again why do the rpms keep rising after the car has shifted before dropping?

all i want is for the car to shift at 6200 rpm in each gear until i find out what my optimal shift points are. if i raise the mph to a very high value will the car shift according to the 6200 rpm i have set? i figure that since the car looks like it is shifting to whatever comes first the mph or the rpm setting the mph real high will cause the car to shift at the rpm setting which will come first. anybody have any ideas as to what is happening?

DrkPhx

iTrader: (15)

For the LS1 F-bodies, you need to lower the mph value in WOT Shift tables, not raise them. I assume the LT1's are the same, including the OBD-I cars.

C_Rules

iTrader: (7)

thats what I've heard. I will have to try to see what happens. I figured since it looked like the car was shifting according to whatever came first mph or rpm i would det the mph high so that is would shift by the rpm. I didnt' want to lower the mph and then have the car shift way too early. especially since the mph shifts are already set so damn low from the factory:
1>2 36 mph
2>3 73mph

C_Rules

iTrader: (7)

well i found something out that might be helpful. my cousin who has an LS1 has his car shifting at 6200rpm. he's not having the problem I am with my LT1 so I asked him what his mph was set at here is what i found out:
Mine His
1>2 36 45
2>3 77 88

So I have increased my mph to see what happens. It makes the most sense to raise the my mph since it looks like the car is shifting according to mph anyway which is too early. The 2>3 shift kept smacking the limiter so I don't know if raising the mph will fix that but we'll see. I think the problem with the 2-3 shift is that the mph and rpm settings are conflicting with eachother and freaking out the transmission.

Frost

iTrader: (45)

usually if it's on the limiter, the MPH has not been met since obviously the limiter is set higher than the shift-point in RPMs.... though this is not always the case, particularly if the two are close, since commanded RPM may not be the same as actual. In an LS1 car the MPH must be met and then the RPM for the shift. I have had to command as high as 6900 to get a 6400 RPM shift before with a built tranny behind a H/C setup.

Ed Wright

iTrader: (1)

Shift it by RPM, forget MPH. Most stock-to-mild LT1 F body cars need "led" about 400 RPM. If you want to shift it at 6200, start by setting it to 5800 and go from there. The 2-3 shift often needs "led" about 50 more than the 1-2. Like 5750 for the 2-3. Seems to vary some the shift kit and how it is set up. Should get you pretty close, unless you are spraying it. Might need more lead then. Depends on how fast it revs. I had to fudge my 383" 1000 & 950 RPM to get it to shift on time. I often set the WOT Upshift MPH 1 MPH higher than the WOT down shift with very loose converters.

Good luck, Ed

C_Rules

iTrader: (7)

i tried it all today. lowered my mph by 10 across the board and i still smacked the limiter. raised my mph by 10 still smacked the limiter. lowered my rpm and mph back to stock and still smacked the limiter. i was paying close attention and when the car is should be shifting and is on its way to smack the limiter i hear a shhhhhhhhhhhhhhh noise.

C_Rules

iTrader: (7)

could the tps sensor be causing shifting issues. my tps voltage is slightly high at idle .86 and reaches 4.57 during WOT. could this be causing my issues?

Ed Wright

iTrader: (1)

4.57 volts should show 100% throttle angle, that should not cause a problem. If it showed low at WOT, it should shift sooner, not later.

What stall speed is your converter? Over 2800?

jaybob

The car will shift when both parameters are met. Whichever comes last will be the point at which it shifts. As long as the speed is met at any time before the the RPM, then the RPM will be the deciding factor of when the car shifts. If it is shifting right on the MPH then you have already surpassed the set RPM. How are you determining the RPM in which the car is shifting?

C_Rules

iTrader: (7)

3000 stall w/lockup WOT shows 99.6%

C_Rules

iTrader: (7)

when i pass the mph datamaster shows the gear change however the shift doesn't happen until i reach the desired rpm. however, on the 2-3 it goes right past the set rpm and smakcks the limiter. i tried determining what rpm the car shifts at by doing a little research. i set it at 6200 and as low as 5000 and no shift. i tried adjusting the shift lever linkage but still no go. tranny shop said they didnt smell burnt cluctch and the fluid was fine. the car will shift at 3/4 throttle but not WOT.

C_Rules

iTrader: (7)

anybody else have any ideas?

Ed Wright

iTrader: (1)

So, you have the 2-3 MPH set low in both the WOT shift MPH also the higher throttle angle end of the part throttle tables, and the RPM set low, still no WOT 2-3 shift? Anytime I have seen that is was the tranny. If the scan tool shows the shift commanded, and no shift, in my experience it has either been low fluid levels or a smoked 3-4 clutch pack. 1/2 quart low will often cause WOT shift problems.

Good luck, Ed

C_Rules

iTrader: (7)

yeah i had set it at 63mph and 5000 rpm and no 2-3 shift at WOT. did a couple of tries like that then checked and smelled the fluid it was fine good level and had no burnt clutch smell at all. i know if it was burnt clutches the fluid wouldn't be as pink as it is and i would get that smell. car wil shift fine at 75% throttle or if i back off a little when i see it revving too high at WOT. the clutches aren't slipping anywhere else. i did notice very high slip rpm #s on both the 1-2 shift and the 2-3. don't know if thats normal with a 3k stall.

C_Rules

iTrader: (7)

okay so it appears that the tranny is fine as far as clutches, bands, and servos go. the problem seems to be valve body related. they are currently going over it to check for internal leaks and valve issues. will keep everyone updated.

1lejohn

iTrader: (9)

You might change out the VSS on the trans,or at least check the wire and harness. I had problems with my trans not shifting on the 1 to 2 at the track. On the street it would shift fine. I found the connecter on the VSS to be bad.It would make some time and open up other times. It never fired a code.

C_Rules

iTrader: (7)

I'm not doing the tranny the guys who built it are looking at so I'm not familiar with what the VSS is. Whats is that?

EasyRider

I am having a problem with my 2001 Camaro SS (LS1) and could use some help, when I drive my car it shifts fine, It has a 500 over factory stall, thicker clutches and shift kit, when i mash the gas and it shifts from 1st to second it falls flat on its face, or when i am running in 3rd and kick it, it does the same after it shifts down into second. Is this a tranny problem or something else ?

cookietime

http://www.f-body.org/gears/
try plugging your car into this, with correct gears, tire size diameter(not wheel size) and set you revlimeter just above where you want be, i think you said 6200, so maybe 6400 to 6500.
this will give you a good starting point to satisfy mphg shifts.
and in my experience the lower values , mph shift points will happen before rpm shift points, rpm shift points take 400 to 500 rpm beyond setting, depending on the health of your trans.
again this is MY experience only! but is a good starting point

Just a note:
with tuner cat obdi tuning software, one of the first items is speedometer calibration, that involves tire size,(or diameter) and rear end ratio. these values need to be correct to accuraterly predict mph settings and rpm settings.
and with tuner cat just plug in those values and calibaration is is figured for you.
obdii im not familar with but should be similar.

keep us updated