gearing and convertor question......
gearing and convertor question...... just looking for some advice about this. for a turbocharged A4 car, 200r4 trans, what would be an optimum gear ration? 3.42's i thought was a good start, but i have 3.23's stock. so that isn't much of a change, so i was thinking of going with 3.73's. but would that be too much for a stock motored car with the turbo? spinning too high at the traps? i have 28" tall tires now though, they came with rims i got.
now i'm asking this so i can get a better launch. so that being the case, should i just go with the 3.42's but when i get the custom convertor for the trans, should i go with a higher STR to get out of the hole quicker, but keep the revs down?
Chris
ps-i know my stock rear's gonna last about one pass, so this is just a general question. <img src="images/icons/smile.gif" border="0">
now i'm asking this so i can get a better launch. so that being the case, should i just go with the 3.42's but when i get the custom convertor for the trans, should i go with a higher STR to get out of the hole quicker, but keep the revs down?
Chris
ps-i know my stock rear's gonna last about one pass, so this is just a general question. <img src="images/icons/smile.gif" border="0">
Re: gearing and convertor question...... A turbo car makes its power much lower in the register...more like 5000 rpms. The stock 3.23 gears should be ideal.
As far as converter is concerned, I would recommend being a little on the conservative side. A low STR will make it easy to slip the turbo motor into a favorable power-band, but it won't do a good job of "lugging" down the motor after each shift (too much shift extension). A converter with a very high STR will not allow the motor to spool up as easily and once it does, it will blow away the tires.
You probably want to keep your stall around 3300-3500 (as rated for a turbo motor) and STR of around 2.0. A Yank 3000 would work very well in this case (stall about 3400 in a turbo car) or a tightened up version of the Pro Yank 3400 Extreme (to stall 3400 behind a turbo motor). These recommendations are based on a lot of turbo experience Yank has had buiding converters for Turbo Buicks and Twin Turbo C5s for Lingenfelter. Take it for what it's worth.
As far as converter is concerned, I would recommend being a little on the conservative side. A low STR will make it easy to slip the turbo motor into a favorable power-band, but it won't do a good job of "lugging" down the motor after each shift (too much shift extension). A converter with a very high STR will not allow the motor to spool up as easily and once it does, it will blow away the tires.
You probably want to keep your stall around 3300-3500 (as rated for a turbo motor) and STR of around 2.0. A Yank 3000 would work very well in this case (stall about 3400 in a turbo car) or a tightened up version of the Pro Yank 3400 Extreme (to stall 3400 behind a turbo motor). These recommendations are based on a lot of turbo experience Yank has had buiding converters for Turbo Buicks and Twin Turbo C5s for Lingenfelter. Take it for what it's worth.
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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.
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Custom LSX tuning in person or via email press here.
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
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Re: gearing and convertor question...... thanks man, i got a vig3200 now, and the stock trans is staying in for a bit. how well would that convertor work? like i said, a 200r4 may be going in so maybe that PYE3400 would work good. cani have that down stalled to like a PYE3000 or something?
Chris
Chris
Re: gearing and convertor question...... Your Vig 3200 is probably going to stall too high behind a turbo motor. If you want to stay with a Vig, I would restall it to a 2800. However, I agree with Patrick that you need a converter that won't stretch too much under a heavy torque load like the PYE 3400.
As far as gears go; like you said the 10 bolt isn't going to last so you might as well blow up the stock gears. When you go with a new rear, I would look at 3.42s / 3.55s / 3.73s. A 28" tire's larger size reduces your effective gearing and you'll need to keep that in mind.
Also what are the details of your set-up? A stage 1 kit needs a different converter/gear set-up than a car with S2 and H&C. Do you anticipate hitting 120 mph or 130 mph in the 1/4? This will effect your gear selection.
As far as gears go; like you said the 10 bolt isn't going to last so you might as well blow up the stock gears. When you go with a new rear, I would look at 3.42s / 3.55s / 3.73s. A 28" tire's larger size reduces your effective gearing and you'll need to keep that in mind.
Also what are the details of your set-up? A stage 1 kit needs a different converter/gear set-up than a car with S2 and H&C. Do you anticipate hitting 120 mph or 130 mph in the 1/4? This will effect your gear selection.
