Auto vs. 6spd E.T. Comparison
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From: Jupiter, Fl. USA
Auto vs. 6spd E.T. Comparison
Does anyone out there have a direct comparison as to how much advantage a properly set up auto trans is worth in the Qtr. Mi.?
I'm talking about a 6spd. with the right gears and tires vs.an auto trans with the right stall speed converter, and gears. As anyone out there converted to auto and gone quicker? How much?
I'm blown away by some of the Automatic's 60ft. times I see on here, even by stock motor cars.
I'm talking about a 6spd. with the right gears and tires vs.an auto trans with the right stall speed converter, and gears. As anyone out there converted to auto and gone quicker? How much?
I'm blown away by some of the Automatic's 60ft. times I see on here, even by stock motor cars.
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Re: Auto vs. 6spd E.T. Comparison (mvabob)
Eric and Bill Fischer converted an LT4 into an automatic. Article and photos here http://www.corvettechallenge.info/billfischer.shtml
With the right stall speed and gear stock for stock will be about the same.
As you get deeper into ET the A4 will start to see an advantage.
With the right stall speed and gear stock for stock will be about the same.
As you get deeper into ET the A4 will start to see an advantage.
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From: Somers NY
Re: Auto vs. 6spd E.T. Comparison (REDGAR)
I think an Auto will run a better 60' almost 100% of the time all things being = I know with my 2800 converter, & good air & track I'd 60' in 1.6x and thats with a STOCK motor (1.6 RR)
I think a well set up "auto" will have about a .15 advantage in the 60' This can vary .. but as for consistence I've made 6-7 runs in one day and my 60' NEVER varied more than .012 I'd bet my house a stick car would never be that consistent.
[Modified by Red96Coupe, 7:39 PM 11/19/2002]
I think a well set up "auto" will have about a .15 advantage in the 60' This can vary .. but as for consistence I've made 6-7 runs in one day and my 60' NEVER varied more than .012 I'd bet my house a stick car would never be that consistent.
[Modified by Red96Coupe, 7:39 PM 11/19/2002]
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Re: Auto vs. 6spd E.T. Comparison (Red96Coupe)
I think an Auto will run a better 60' almost 100% of the time all things being = I know with my 2800 converter, & good air & track I'd 60' in 1.6x and thats with a STOCK moter (1.6 RR)
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Re: Auto vs. 6spd E.T. Comparison (mackeyred96)
Having raced both, here's my take on it.
My '95 sixspeed with 3.45 gears stock ran a best of 12.97@106mph
My '93 automatic with a 2800 TC and 3.45 gears has run a best of 12.996@102mph.
The six speed ran a best 60' of 1.95, the automatic has gone 1.73.
For some reason, the automatic is dying at the top end. I don't manually shift it and the shift points are approximately at 5300-5500 rpm, where in the six speed car I'm shifting at well over 5800 rpm.
Also for some reason, I am more consistent in my six speed car than with the auto.
If you want to see most of my times, there are two links in my sig. I haven't logged in all my current '93 times yet, but my entire season from my 1995 in the year 2000 are there.
My '95 sixspeed with 3.45 gears stock ran a best of 12.97@106mph
My '93 automatic with a 2800 TC and 3.45 gears has run a best of 12.996@102mph.
The six speed ran a best 60' of 1.95, the automatic has gone 1.73.
For some reason, the automatic is dying at the top end. I don't manually shift it and the shift points are approximately at 5300-5500 rpm, where in the six speed car I'm shifting at well over 5800 rpm.
Also for some reason, I am more consistent in my six speed car than with the auto.
If you want to see most of my times, there are two links in my sig. I haven't logged in all my current '93 times yet, but my entire season from my 1995 in the year 2000 are there.
Melting Slicks
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From: Freehold, NJ
Re: Auto vs. 6spd E.T. Comparison (mvabob)
I guess I am qualified to answer this question since we did exactly what you are asking...
See my sig for the best results of each configuration. Honestly I was expecting the A4 to be a little quicker than the 6M. But it seems as though that what the A4 gains in 60' it gives it back at the big end because of the inefficiency of the converter and trans. The 60' has picked up appreciably with the A4 but trap speeds are down about 2 MPH.
However, the all time best figures below don't present the full picture. The A4 is consistently quicker on average than the 6M. In analyzing the top 20 runs, 16 of the quickest runs were performed with the A4. The M6 holds the 1st, 2nd, 5th and 8th spots.
There might still be more in it, especially considering how well Panuzzo's car has run on a nice cold night, but at a slightly lower trap speed than my Dad's car.
Bottom line is that the car is one heckuva bracket car now, and is much easier to drive consistently...
See my sig for the best results of each configuration. Honestly I was expecting the A4 to be a little quicker than the 6M. But it seems as though that what the A4 gains in 60' it gives it back at the big end because of the inefficiency of the converter and trans. The 60' has picked up appreciably with the A4 but trap speeds are down about 2 MPH.
However, the all time best figures below don't present the full picture. The A4 is consistently quicker on average than the 6M. In analyzing the top 20 runs, 16 of the quickest runs were performed with the A4. The M6 holds the 1st, 2nd, 5th and 8th spots.
There might still be more in it, especially considering how well Panuzzo's car has run on a nice cold night, but at a slightly lower trap speed than my Dad's car.
Bottom line is that the car is one heckuva bracket car now, and is much easier to drive consistently...
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From: Rehoboth MA
Re: Auto vs. 6spd E.T. Comparison (mvabob)
I believe an automatic will do better short times than a stick for this reason: Most of the time an autonatic is launched by pre-loading the torque converter. So this means tension is built up on the driveline and the suspension. When the car is launched this tension is released all at once. With a stick; there is no torque converter, pressure is not built up on the driveline before launch; all of the energy comes very-sudden or very gradual depending on the driver. But it seems to me the a stick will make it up, up-top, as opposed to an automatic which sometimes will peter-out up top.
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From: Jupiter, Fl. USA
Re: Auto vs. 6spd E.T. Comparison (mvabob)
Thanks for the feedback, guys. It's no surprise that the A4 generally gets more consistent, and quicker, 60ft. times. But I wasn't aware that it might give up a little at the other end. BTW, you guys have some pretty strong LT1-LT4's up in the N.E. We're finally getting some of your cool air down here. I'm going to finally get my ZF6 back in the car and try for the elevens. :yesnod:
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Melting Slicks
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From: Freehold, NJ
Re: Auto vs. 6spd E.T. Comparison (KyleBst264)
I believe an automatic will do better short times than a stick for this reason: Most of the time an autonatic is launched by pre-loading the torque converter. So this means tension is built up on the driveline and the suspension. When the car is launched this tension is released all at once. With a stick; there is no torque converter, pressure is not built up on the driveline before launch; all of the energy comes very-sudden or very gradual depending on the driver. But it seems to me the a stick will make it up, up-top, as opposed to an automatic which sometimes will peter-out up top.
Now this scenario doesn't apply to all cars. In the 5.0 Mustang it's the exact opposite. The 5 speed has a high (numerically) first gear (3.35) and the automatic has a 2.46. A stock 13 second Mustang will on slicks will cut a 1.7x short time on slicks while the automatic will cut a 2.0x if you're lucky.
And BTW, with the A4 in my dad's car, it makes very little difference in 60' if we launch off an idle or at 2000 RPM against the brake. Most guys I have talked have had the same experience, but launch off the brake anyway cause it tends to help their reaction times.
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From: Rehoboth MA
Re: Auto vs. 6spd E.T. Comparison (Eric Fischer)
The 6 speed also give you one more gear. (1-4 Racing, 5-6, Overdrive) The A4 has 3 regular gears and the overdrive. So on the track an A4 will have 3 gears and an M6 will usually use 4. My point; tighter ratios when racing the M6.
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Re: Auto vs. 6spd E.T. Comparison (KyleBst264)
I believe an automatic will do better short times than a stick for this reason: Most of the time an autonatic is launched by pre-loading the torque converter. So this means tension is built up on the driveline and the suspension. When the car is launched this tension is released all at once. With a stick; there is no torque converter, pressure is not built up on the driveline before launch; all of the energy comes very-sudden or very gradual depending on the driver. But it seems to me the a stick will make it up, up-top, as opposed to an automatic which sometimes will peter-out up top.
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From: WilkesBarre PA
Re: Auto vs. 6spd E.T. Comparison (mackeyred96)
My short times are decent for a M6 with DRs, but no where close to the auto cars. The auto cars usually have the advantage in bracket racing.
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From: Alexandria VA
Re: Auto vs. 6spd E.T. Comparison (RichS)
From what I have read in this post, it seems most have not done their research on converters and how they are superior over the manual in getting a certain ET.
In a manual, sure you can launch at any given rpm you chose, BUT when you let the clutch up, rpm's drop and must build up again to accelerate. So as you are going down the track, your rpms drop to 4000 then have to build back up to 6000 in each gear.
In an auto, you may launch at idle but the converter will flash to 5000rpm, where the motor makes peak power, and stay there, multiplying torque and maintaining 300hp at ALL TIMES as you go down the track, regardless of what gear your in.
Lastly, not all converters work better if you preload them. The PI Vig. series like to be flashed whereas the Yank's prefer to be loaded up. Also, if you have a 3000 stall converter, that does NOT mean that you can hold the brake and rev up to 3000rpm.
Hope this helps clear the air.
Mike
In a manual, sure you can launch at any given rpm you chose, BUT when you let the clutch up, rpm's drop and must build up again to accelerate. So as you are going down the track, your rpms drop to 4000 then have to build back up to 6000 in each gear.
In an auto, you may launch at idle but the converter will flash to 5000rpm, where the motor makes peak power, and stay there, multiplying torque and maintaining 300hp at ALL TIMES as you go down the track, regardless of what gear your in.
Lastly, not all converters work better if you preload them. The PI Vig. series like to be flashed whereas the Yank's prefer to be loaded up. Also, if you have a 3000 stall converter, that does NOT mean that you can hold the brake and rev up to 3000rpm.
Hope this helps clear the air.
Mike
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From: Lancaster CA
Re: Auto vs. 6spd E.T. Comparison (KyleBst264)
I believe an automatic will do better short times than a stick for this reason: Most of the time an autonatic is launched by pre-loading the torque converter. So this means tension is built up on the driveline and the suspension. When the car is launched this tension is released all at once. With a stick; there is no torque converter, pressure is not built up on the driveline before launch; all of the energy comes very-sudden or very gradual depending on the driver. But it seems to me the a stick will make it up, up-top, as opposed to an automatic which sometimes will peter-out up top.
I agree on the way power will come on in the stick. That's why when I stage, once both lights are set I let up a little on the clutch with the breaks on, at an idle until I see the tach dip a little. By doing this I hope to pull out any slack that may be in the drive train. Does it really work? Probably not but, it's kind of become a "good luck" thing like rubbing budda's belly. :D
But I really do enjoy it when the manual starts out pulling the A4's on the top end. :jester
:cheers:
[Modified by scool93535, 10:13 PM 12/2/2002]
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From: rehboth mas
Re: Auto vs. 6spd E.T. Comparison (KyleBst264)
i go with kyleb264 . i run a stick in my camaro with 31.00x18.50.tire and some them .auto is a lot more constion then a stick plus there a lot more can brake with a stick :chevy
