3800 3.29 Gearing Question

CoolGTX

let sleeping dogs lie
Nov 17, 2008
3,241
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Hotel 4 Dogs
Real Name
J/O
Originally posted by syP@Nov 28 2004, 04:39 PM
mine still shifts at ~50mph and ~91mph

which is what it shifted at before i got my "3.29 gearing" 

I also have a standard DHP if that means anything.
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yup, you need gears programmed, or one of the other ways to use the 3.29 gears.

ive got the stock gearing in pcm, reluctor wheel in tranny-3.29 gears, and speed recalibrator.

or, just have pcm done to accept 3.29s, instead of stock gearing.


ive been told it was ok to do the pcm.

but the tranny shop told me it would work better with reluctor, and src...hope they werent pulling my leg.

time will tell


my first re-build used the pcm with NO problems
No-problems with reluctor way so far.
 

rob

TCG Elite Member
Dec 28, 2008
1,237
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Im interested in this aswell. I would like to verify RPMS/SPEED. So could someone with a stock gear and wheels give me a baseline after the TCC is locked up. Say 50-60mph...How many RPMs are you running at....Please. I atleat want to verify that was installed. It feels like it. Thanks
 

Mike K

TCG Elite Member
Apr 11, 2008
13,214
2,586
Originally posted by syP@Nov 28 2004, 08:09 PM
mike... he obviously didnt if im shifting at 50mph.. right?

It appears you're still shifting at the stock shift points, or at least what the PCM thinks are the stock shiftpoints. Your actual MPH is probably higher at both shift points. You need either the reluctor wheel, mini-SRC, or a Tuner. The right way to do it is the tuner, but the other two will work also.
 

Mike K

TCG Elite Member
Apr 11, 2008
13,214
2,586
Originally posted by syP@Nov 28 2004, 11:04 PM
well it shoulda been done when i got the gearing... why would it not be dont by the shop?

A shop that's not accustomed to doing this wouldn't think twice about it. It's custom work for anyone other than a W Body vendor. If they put the gears in your car ask them what car they're from and what kind of machining they had to do to get them to fit. Assuming you didn't buy a kit, it's odd that they would know to machine the gears down but not know to add compensation for the different speed being picked up.

It's putting undue wear on your transmission if it's not being compensated for. It's not going to destroy the transmission since the difference is minimal (3% or so) but you're not shifting where you should be and that's not ideal for 1/4 mile times and not ideal for the transmission.
 

CoolGTX

let sleeping dogs lie
Nov 17, 2008
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Hotel 4 Dogs
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Originally posted by Mike K+Nov 28 2004, 11:19 PM-->
<!--QuoteBegin-syP
@Nov 28 2004, 11:04 PM
well it shoulda been done when i got the gearing... why would it not be dont by the shop?

It's not going to destroy the transmission since the difference is minimal (3% or so) but you're not shifting where you should be and that's not ideal for 1/4 mile times and not ideal for the transmission.
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youve got to be kidding, right?

bad advise...ask lp3800 what happens when you dont do what YOU are Told.

you have to pay to get it rebuilt AGAIN!!!!!!!!!!!!!!

dont drive it to long like this ;)
 

superchargedgp

TCG Elite Member
Nov 11, 2008
2,253
0
Originally posted by Mike K+Nov 29 2004, 12:19 AM-->
<!--QuoteBegin-syP
@Nov 28 2004, 11:04 PM
well it shoulda been done when i got the gearing... why would it not be dont by the shop?

A shop that's not accustomed to doing this wouldn't think twice about it. It's custom work for anyone other than a W Body vendor. If they put the gears in your car ask them what car they're from and what kind of machining they had to do to get them to fit. Assuming you didn't buy a kit, it's odd that they would know to machine the gears down but not know to add compensation for the different speed being picked up.

It's putting undue wear on your transmission if it's not being compensated for. It's not going to destroy the transmission since the difference is minimal (3% or so) but you're not shifting where you should be and that's not ideal for 1/4 mile times and not ideal for the transmission.
[snapback]61592[/snapback]​
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from intense


How Steeper Gearing Will Affect Your Car

Generally speaking, steeper gear ratios will improve your acceleration and E.T., while reducing your fuel economy and trap speeds. In round numbers, each gear step (from 2.93:1 to 3.29:1 for example) will reduce your quarter mile E.T. by about a tenth of a second and your trap speed by about 1.0 MPH. Your engine speed (RPM) will increase by about 13% at any given vehicle speed and your gas mileage will be reduced by about 5%. Changing from 2.93:1 to 3.69:1 gears will approximately double all the effects listed in this paragraph.


With steeper gears, your PCM will incorrectly interpret your vehicle speed, and command shifts the wrong engine RPM. At WOT, the shifts may not occur at all, since the required Vehicle Speed can no longer be achieved with your steeper gears.



get thats shit fixed! or you will see them again
 

LPSPEED2

TCG Elite Member
Nov 10, 2008
1,447
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Addison
also, one more thing, we have done a few of these "racing" transmissions for the GTP, and so far they are all still running, and still running strong, so don't scare this kid into thinking he is gunna blow up if he drives it. Our longest going trans has been over a year and a half now, and it is a daily driver and track car running in the low 12's. So far so good, knock on wood, it is a race car and things can happen, but they are all running well to the best of my knowledge to date.
 
I

imported_GraFFix

Guest
I know that a rebuilt trans with steeper gears needs either the reluctor wheel or PCM changes to get the shifts back on track. I drove my car about a week after miker did my trans with 3.29's and when it shifted it really slammed into gear at a low RPM. which of course I dont think is good for the trans. once charles reflashed my PCM for the gears its been fine ever since. I know most people with the intense trans have the reluctor wheel thing to correct their shift points.

I wouldnt drive it that hard untill you get it fixed right.

JMO
 
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