Need help with shift points: Colonel, Anyone
Thread Starter
Joined: Jan 2003
Posts: 1,455
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From: Fort Worth, TX
Need help with shift points: Colonel, Anyone Background: I have a 2000 SS A4 SI(bolt-on) with a TCI 3500. My shift points are at 1-2(6000), 2-3(6000), 3-4(6000). I did a search and went through the info it found about shift pionts and here is what I came up with. Do a dyno first to see where you make the most power. Then adjust shift points just as the curve starts to go back down. The problem is my curve is pretty much flat from 6000 to 6700 where the graph ends. Where should I set my shift to get the most out of it?
Thanks,
Richard
Thanks,
Richard
Problem? Sounds more like a damn nice curve to me.
You want the upshift RPMs to keep the engine safe
(valve gear up to that kind of frequent abuse?) and
off the rev limiter by a couple of hundred RPM, for
"windage" to cover the AT shift lag. Might need more
slack on the 1-2 as you run up faster there. You also
want the MPH to be about the same effective point.
I would set the RPMs first, to maybe max-300,
max-200, max-200 for the 1-2, 2-3, 3-4 where max
is whatever you are sure won't put the hurt on the
motor long-term and then start creeping the MPH
shiftpoints up from where they are, until the logs
(not the tach) show you're shifting at the point you
picked. The amount of RPM "lead" needed to stay off
the rev limiter will depend a lot on how you have the
AT shift adaptation time and pressure set up, any
hydraulic mods to the tranny (shift kit or builder prep)
etc. Just cut-and-try here, start from the safe side and
find where the limit of sanity is.
You want the upshift RPMs to keep the engine safe
(valve gear up to that kind of frequent abuse?) and
off the rev limiter by a couple of hundred RPM, for
"windage" to cover the AT shift lag. Might need more
slack on the 1-2 as you run up faster there. You also
want the MPH to be about the same effective point.
I would set the RPMs first, to maybe max-300,
max-200, max-200 for the 1-2, 2-3, 3-4 where max
is whatever you are sure won't put the hurt on the
motor long-term and then start creeping the MPH
shiftpoints up from where they are, until the logs
(not the tach) show you're shifting at the point you
picked. The amount of RPM "lead" needed to stay off
the rev limiter will depend a lot on how you have the
AT shift adaptation time and pressure set up, any
hydraulic mods to the tranny (shift kit or builder prep)
etc. Just cut-and-try here, start from the safe side and
find where the limit of sanity is.
TECH Fanatic
Joined: Jun 2003
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From: Further South than Hell
Originally Posted by BAIN
Thanks for your help I will try that. 
How high can you rev a stock internal car safely?
How high can you rev a stock internal car safely?6200 for longevity, 6500 for kicks but if you have stock valvetrain you'll run into possible valve float.
Assuming you have the stock cam. anything above 6000 is a waste as the stock cam peaks around 5800.
Basicaly check your peak torque curve, when you upshift you want to land the closest to that, usualy 6200 gets you pretty close in the average stock motor.
Did you lock the converter on the dyno? If you are not certain, you are seeing the effect of a high stall and its skewing of the rpm scale. Its hard to beleive that you did not hit a rev limiter at 6400 or 6500 rpm.
A stock cam car with LS6 intake, headers, a good exhaust and a high stall converter is probably best shifted around 6200 rpm. Its pretty safe on the valvetrain and gets 99% of the performance from the car.
A stock cam car with LS6 intake, headers, a good exhaust and a high stall converter is probably best shifted around 6200 rpm. Its pretty safe on the valvetrain and gets 99% of the performance from the car.
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Stock cam for best ETs? Try about 6300-6400 ACTUAL shift point. I don't mean to set it at that. I mean to set it to where that's the highest RPM seen on the shift (your programmed shift point will likely be lower.)
A shift point higher than 6000 will be faster than 6000 despite the HP peak being 5800. The HP peak absolutely IS NOT the optimum shift point. The optimum shift point will always be higher than the HP peak (sometimes ALOT higher with cams who's power drops off slowly after the HP peak.) For example, my HP peak is 5900 with my Stealth II cam but my best shift point is about 6700-6800 best I can tell. With the wide LSA the power drops off very slowly after the HP peak. (The stock cam has a very wide LSA too.)
A shift point higher than 6000 will be faster than 6000 despite the HP peak being 5800. The HP peak absolutely IS NOT the optimum shift point. The optimum shift point will always be higher than the HP peak (sometimes ALOT higher with cams who's power drops off slowly after the HP peak.) For example, my HP peak is 5900 with my Stealth II cam but my best shift point is about 6700-6800 best I can tell. With the wide LSA the power drops off very slowly after the HP peak. (The stock cam has a very wide LSA too.)
