shift extension question
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From: Bethesda, MD
Re: shift extension question A little higher shift extension would be ok so long as you don't trade efficency above the shift extension to get it. Even with 5400, you should be getting good torque multiplication.
4200 flash would be fine. You want to enter peak torque as soon as you start to move.
FWIW, I've tried to measure flash and even at the track it is tough because the car will start to move as soon as you release the brake. Here is a the data from a log where I only log rpm & mph:
rpm...speed
2531...0 (foot stall)
2779...1
3310...2
3857...6
4228...8
4408...11
4560...13
4714...16
Knowing the converter is 4200 you can look and say it is starting to catch and hold at that point, but the problem is the output shaft is moving so maybe it is only 4000/4100 in my car.
Point being is that you can probably guess +/- 200 rpm w/o a transbrake or starting in 3rd gear.
4200 flash would be fine. You want to enter peak torque as soon as you start to move.
FWIW, I've tried to measure flash and even at the track it is tough because the car will start to move as soon as you release the brake. Here is a the data from a log where I only log rpm & mph:
rpm...speed
2531...0 (foot stall)
2779...1
3310...2
3857...6
4228...8
4408...11
4560...13
4714...16
Knowing the converter is 4200 you can look and say it is starting to catch and hold at that point, but the problem is the output shaft is moving so maybe it is only 4000/4100 in my car.
Point being is that you can probably guess +/- 200 rpm w/o a transbrake or starting in 3rd gear.
Re: shift extension question Rag so what your saying is I should have a verter with a higher shift extension but stay with the 4200 to 4400 stall?
My Yank flashed to 4400 and only dropped to 5600 MAX.I think thats what I need?
My Yank flashed to 4400 and only dropped to 5600 MAX.I think thats what I need?
shift extension question Say u make peak hp at 6500 and peak tq at 4500.
Now shifting at 6700 what would u like to see the rpm to drop off at? 5600,5700?
I'm dropping to 5300,5400 and I think this is too low.
Now on autotap it looks like I'm only flashing to 4200?Is this alittle low for my 4500 Tq peak,6500 Hp peak?
JS
Now shifting at 6700 what would u like to see the rpm to drop off at? 5600,5700?
I'm dropping to 5300,5400 and I think this is too low.
Now on autotap it looks like I'm only flashing to 4200?Is this alittle low for my 4500 Tq peak,6500 Hp peak?
JS
Thread Starter
TECH Senior Member
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From: Bethesda, MD
Re: shift extension question </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JS:
<strong>
My Yank flashed to 4400 and only dropped to 5600 MAX.I think thats what I need?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That should work pretty well, why don't you stick it back in and try it.
Personally, I would not want flash above max torque unless the torque curve is very flat, say 98% of max torque for a 1000 rpm or so.
<strong>
My Yank flashed to 4400 and only dropped to 5600 MAX.I think thats what I need?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That should work pretty well, why don't you stick it back in and try it.
Personally, I would not want flash above max torque unless the torque curve is very flat, say 98% of max torque for a 1000 rpm or so.
Re: shift extension question Rag my tq really doesnt drop off that much.I'd say its 400 RWTQ at 4450 to 385RWTQ to 5100rpm.
I wanna go to the track one more time and try hitting the converter off idle or maybe right at 1500.Then I will autotap to see if this helps.If not, it looks like either I need about 2 to 300 more rpm on my shift extension and I need to try and lu the verter at 6100 instead of 5300.I think locking the verter that low hurt me last week.
I'm still playing with the car and it looks like the tq multiplacation is higher than 5300?Patrick G told me I'm hurting myself locking at that low of an rpm.He said try it around 5900 to 6200 and see what happens.
I have the feree stall so why not take advantage of it.I can always go TP4500 if I dont get the results I' looking for outta the VIG.
JS
I wanna go to the track one more time and try hitting the converter off idle or maybe right at 1500.Then I will autotap to see if this helps.If not, it looks like either I need about 2 to 300 more rpm on my shift extension and I need to try and lu the verter at 6100 instead of 5300.I think locking the verter that low hurt me last week.
I'm still playing with the car and it looks like the tq multiplacation is higher than 5300?Patrick G told me I'm hurting myself locking at that low of an rpm.He said try it around 5900 to 6200 and see what happens.
I have the feree stall so why not take advantage of it.I can always go TP4500 if I dont get the results I' looking for outta the VIG.
JS
Re: shift extension question JS,
Be carefull about the free stall change. All they'll do at PI is change the pump or the pump blade angles to raise or lower your stall. They use the same 082 stator in everything and it's not going to give you the high shift extension without totally losing your top-end efficiency.
That's why it's a FREE stall change. You're getting what you paying for.
Be carefull about the free stall change. All they'll do at PI is change the pump or the pump blade angles to raise or lower your stall. They use the same 082 stator in everything and it's not going to give you the high shift extension without totally losing your top-end efficiency.
That's why it's a FREE stall change. You're getting what you paying for.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
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2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Re: shift extension question My stock converter shifts into 2nd and it is at 4000 RPM when it starts 2nd. My friend's PI converter that flashes to 3300 also starts 2nd at 4000 RPM. Is that right? Plus my shift points are off right now and I'm shifting at 5700 RPM and he is shifting at 6000 RPM, so after I fix that would my second gear start higher then his? Would a Pro Thruster also start 2nd at 4000RPM? Other then initial launch I don't see any benefit to my friends PI converter. It's not a vigilantee btw.
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Thread Starter
TECH Senior Member
iTrader: (7)
Joined: Nov 2001
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From: Bethesda, MD
Re: shift extension question </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Dom:
<strong>
My stock converter shifts into 2nd and it is at 4000 RPM when it starts 2nd. My friend's PI converter that flashes to 3300 also starts 2nd at 4000 RPM...Would a Pro Thruster also start 2nd at 4000RPM? Other then initial launch I don't see any benefit to my friends PI converter. It's not a vigilantee btw.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">A good converter will hold 4200 or higher rpms on the upshift depending on the stall. A YTP 4400 will hold about 5200 rpms on a near stock motor and about 5500 on a H&C motor. That shift extension provides a lot of extra torque for faster 1/8 mile times and for racing from a roll.
<strong>
My stock converter shifts into 2nd and it is at 4000 RPM when it starts 2nd. My friend's PI converter that flashes to 3300 also starts 2nd at 4000 RPM...Would a Pro Thruster also start 2nd at 4000RPM? Other then initial launch I don't see any benefit to my friends PI converter. It's not a vigilantee btw.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">A good converter will hold 4200 or higher rpms on the upshift depending on the stall. A YTP 4400 will hold about 5200 rpms on a near stock motor and about 5500 on a H&C motor. That shift extension provides a lot of extra torque for faster 1/8 mile times and for racing from a roll.
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Brett Foote Thread Starter
TECH Senior Member
iTrader: (7)
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From: Bethesda, MD
Re: shift extension question </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JS:
<strong>
I'm still playing with the car and it looks like the tq multiplacation is higher than 5300? Patrick G told me I'm hurting myself locking at that low of an rpm.He said try it around 5900 to 6200 and see what happens.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I agree with Patrick. When you lock up just coming out of the shift extension it knocks you down in rpms. So if you hit the switch at 5500, you'll drop to 5000 - 5200 rpm. That's too far from your max HP. If you wait until 6000 - 6200 rpm you are much closer to max HP and will stay longer in that range.
<strong>
I'm still playing with the car and it looks like the tq multiplacation is higher than 5300? Patrick G told me I'm hurting myself locking at that low of an rpm.He said try it around 5900 to 6200 and see what happens.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I agree with Patrick. When you lock up just coming out of the shift extension it knocks you down in rpms. So if you hit the switch at 5500, you'll drop to 5000 - 5200 rpm. That's too far from your max HP. If you wait until 6000 - 6200 rpm you are much closer to max HP and will stay longer in that range.
