6 Speed versus auto trans.
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From: Hinckley Ohio
Re: 6 Speed versus auto trans. (Jim Holbrook)
Regarding the C4's, the performance difference is mostly related to the gearing. The std auto with 2.59 gears has poor performance compared to auto with 3.07 gears. The auto with 3.07 is almost identical to 6 speed performance and I am sure in my case the auto would be better due to speed shifting capability. Based on reports in the forum I believe a C4 auto with torque converter & 3.73 gears would out perform a 6 speed, with all else being equal.
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From: Pinellas Florida Misfit
Cruise-In III Veteran
Re: 6 Speed versus auto trans. (LT4BUD)
I don't think the auto with the 3.07 is equal to the 6spd... Drivetrain loss comes to mind, 15% for the 6spd compared to 18-20% for the auto. Also... most of the faster stock LT1's on this forum are 6spd cars. I don't think MrMojo's 93 auto with convertor and 3.45's has beat his 95- 6 spd times yet... and the 95 is stock.
Of course it is easier to race the auto on a more consistant basis I'd imagine.
Of course it is easier to race the auto on a more consistant basis I'd imagine.
Burning Brakes
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Re: 6 Speed versus auto trans. (LT4BUD)
I remember a Motor Trend Article in the late eighties compared an auto vs. manual for Vettes, F bodies, Mustang and 300ZX. This was before the 6 speed. As I recall, the auto tran cars came ahead.
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: 6 Speed versus auto trans. (Jim Holbrook)
An automatic loses more power due to frictional losses in the transmission compared to a manual.
However, at high HP levels, the manuals get harder and harder to launch without spinning the tires, so the automatic beats it because it can shift by itself better than the driver can (usually).
This is why drag cars are almost always automatics.
However, at high HP levels, the manuals get harder and harder to launch without spinning the tires, so the automatic beats it because it can shift by itself better than the driver can (usually).
This is why drag cars are almost always automatics.
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Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: (Jim Holbrook)
The frictional losses in the 4L60E have been improved, its a higher HP engine so the launch comes into play some. The Tremec T56 is not the greatest manual transmission either, certainly not as good as the ZF6.
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From: Hinckley Ohio
Re: 6 Speed versus auto trans. (Springer's LT4)
I just looked @Mr Mojo's signature and see 13.071@108 for 6-speed & 13.02 @103 for the auto with 3.45 rear end. Pretty close! I bet 3.73 would put the auto in the 12's and faster than the 6 speed even with Mojo driving, EVERYTHING ELSE BEING EQUAL. Don't have all the facts so I am just quessing.
I need to find the article comparing various vettes but I am certain the 6 speed went 14.0, the auto 3.07 went 14.1, and auto 2.59 went 14.8.
I am guessing that if the C5 auto is faster, it is partially because of its improved very flat torque curve.
I need to find the article comparing various vettes but I am certain the 6 speed went 14.0, the auto 3.07 went 14.1, and auto 2.59 went 14.8.
I am guessing that if the C5 auto is faster, it is partially because of its improved very flat torque curve.
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From: Pinellas Florida Misfit
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Re: 6 Speed versus auto trans. (LT4BUD)
If I'm not mistaken the auto Frank has (Mr Mojo) also has a set of weld wheels setup for drag racing (skinnies up front, etc)
I missed the "in a C5 part" of the original post... and I must agree with Scorp... Bone stock FRC C5's will run 12s with the 6spd, but I haven't heard of any autos running a 12. It is very easy to get them there thou.
Using magazine articles to compare times is like blowing in the wind... most drivers in those comparisions aren't very good, don't know the cars they are driving, using poor ways of measuring the performance, etc.
At the cruise in this year, I raced My 95's 1995 6spd vette with my 1995 auto equipped car with the 3.07 rear. This was both our 1st time down the track with these cars, my best time was a 14.0 @ 100 to his 13.59 @ 106... same track, same weather, both never raced the cars on the track and we even had the same tires type of street tires!
[Modified by Springer's LT4, 1:19 PM 11/5/2002]
I missed the "in a C5 part" of the original post... and I must agree with Scorp... Bone stock FRC C5's will run 12s with the 6spd, but I haven't heard of any autos running a 12. It is very easy to get them there thou.
Using magazine articles to compare times is like blowing in the wind... most drivers in those comparisions aren't very good, don't know the cars they are driving, using poor ways of measuring the performance, etc.
At the cruise in this year, I raced My 95's 1995 6spd vette with my 1995 auto equipped car with the 3.07 rear. This was both our 1st time down the track with these cars, my best time was a 14.0 @ 100 to his 13.59 @ 106... same track, same weather, both never raced the cars on the track and we even had the same tires type of street tires!
[Modified by Springer's LT4, 1:19 PM 11/5/2002]
