I have a 4spd auto (3spd w/OD) and am just curious if I still am gonna be pulling decent in OD/4th under boost? Since the PCM from the factory is set to never shift into 4th under WOT (Factory speed limiter is at 107, 3rd ends at 110) but I've changed it to shift at 105mph and speed limiter is set at 200mph, is there anything I can get it to do to tell it to pull harder in 4th/OD? Sorry if that didn't make sense, lot's of stuff going through my head.
"Vroom."
"Yo I wouldn't race him, there's not even an interior in his car man."
"Vrooooooom PSSSSHHH!"
"Oh sh*t. F*ck that, dude..."
Uhm.... OD is not a different gear. It is simply the torque converter locking in 4th gear.
As far as the answer to your question to if you're going to be pulling decent? Hard telling. Depends on how much power you have. At 100+ you're talking a lot of wind resistance on the car. Chances are that you're not pulling much over 100 in the 1/4 anyways, right?
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
SHOoff wrote:Uhm.... OD is not a different gear. It is simply the torque converter locking in 4th gear.
Unless he has the 3T40 transmission, this is incorrect. The 4Txxx transmissions all have 4 forward gears
It's the 4T40E. So at around 260fwhp should I be expecting good pulls in 4th with a gutted car???
"Vroom."
"Yo I wouldn't race him, there's not even an interior in his car man."
"Vrooooooom PSSSSHHH!"
"Oh sh*t. F*ck that, dude..."
Chris wrote:SHOoff wrote:Uhm.... OD is not a different gear. It is simply the torque converter locking in 4th gear.
Unless he has the 3T40 transmission, this is incorrect. The 4Txxx transmissions all have 4 forward gears
This is true, but the ECOTEC never came with a 3T40.
So i'm still right.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
SHOoff wrote:Chris wrote:SHOoff wrote:Uhm.... OD is not a different gear. It is simply the torque converter locking in 4th gear.
Unless he has the 3T40 transmission, this is incorrect. The 4Txxx transmissions all have 4 forward gears
This is true, but the ECOTEC never came with a 3T40.
So i'm still right.
Well, not really. OD IS a different gear. 4th gear is your overdrive with a 4 speed auto trans and would still be there even if you didn't have a lockup converter.
Chris wrote:SHOoff wrote:Chris wrote:SHOoff wrote:Uhm.... OD is not a different gear. It is simply the torque converter locking in 4th gear.
Unless he has the 3T40 transmission, this is incorrect. The 4Txxx transmissions all have 4 forward gears
This is true, but the ECOTEC never came with a 3T40.
So i'm still right.
Well, not really. OD IS a different gear. 4th gear is your overdrive with a 4 speed auto trans and would still be there even if you didn't have a lockup converter.
Yeah, but when you converter doesn't lock up and you have a gear ratio >1:1 then it's not overdrive.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
SHOoff wrote:Yeah, but when you converter doesn't lock up and you have a gear ratio >1:1 then it's not overdrive.
Still wrong. 4th gear is approximately 0.70/1 gear ratio in most overdrive transmissions. It has nothing to do with the converter locking up. The converter clutch locks up to eliminate the slippage in the converter, nothing else.
So should I expect decent pulls with around 260fwhp and a j-body gutted with only two front seats and a dashboard?
"Vroom."
"Yo I wouldn't race him, there's not even an interior in his car man."
"Vrooooooom PSSSSHHH!"
"Oh sh*t. F*ck that, dude..."
SLEEPINECO wrote:So should I expect decent pulls with around 260fwhp and a j-body gutted with only two front seats and a dashboard?
There are too many variables to say, but if your transaxle is geared right and you're in your powerband when you're pulling 4th gear, then yes it should be decent.
um no...
4th gear may be overdrive but our converters go even further than that and lock up AFTERWARDS.
technically its 'like' having a 5th gear, actually.
how the hell else do you think these cars get 30+ mpg? it certainly isnt gm's awesome engine design.
Trailer Queen corvette wanna-be with 40 coats of wax and powdercoating that soaks in.
Chris wrote:SLEEPINECO wrote:So should I expect decent pulls with around 260fwhp and a j-body gutted with only two front seats and a dashboard?
There are too many variables to say, but if your transaxle is geared right and you're in your powerband when you're pulling 4th gear, then yes it should be decent.
Well seeing as I've got a stock 4T40E and I know little about that trans, I have no idea as far as gearing. Powerband-wise once out of 3rd and into 4th at WOT I'm sittin around 3,8000rpms so I should move along well at that point. (Ran on the Dyno in PHX at 143mph @ 5,100rpms roughly in 4th/OD)
"Vroom."
"Yo I wouldn't race him, there's not even an interior in his car man."
"Vrooooooom PSSSSHHH!"
"Oh sh*t. F*ck that, dude..."
SLEEPINECO wrote:Chris wrote:SLEEPINECO wrote:So should I expect decent pulls with around 260fwhp and a j-body gutted with only two front seats and a dashboard?
There are too many variables to say, but if your transaxle is geared right and you're in your powerband when you're pulling 4th gear, then yes it should be decent.
Well seeing as I've got a stock 4T40E and I know little about that trans, I have no idea as far as gearing. Powerband-wise once out of 3rd and into 4th at WOT I'm sittin around 3,8000rpms so I should move along well at that point. (Ran on the Dyno in PHX at 143mph @ 5,100rpms roughly in 4th/OD)
Just ran a few calculations and it looks like you have the 3.73 final drive ratio which is the highest numerical gear you can have (best for acceleration). Just an FYI.
