Automatic and Standard difference

[mr_man]

<blockquote>quote:</font><hr>Originally posted by DYNAMIKO:
Does my location have anything to do with my 1/4 mile times? It is always hot and dry here in El Paso, Texas. Is that why my best time is a 16.2 stock.<hr></blockquote>

The dryness is good, but the heat is bad. How warm was it when you ran? I'm not sure where El Paso is, but i think most of Texas is close to sea level(not sure there) which is also good. Do you have the 3.08's?

[DYNAMIKO]

El paso is at the southern tip of the Rocky Mountains and 4,000 feet above sea level.

[Dominic]

M5 - 3.23 no question about it. You CAN'T order it with any other gearing at all.

And yes, the M5 pulls harder gear after gear and there is no slushbox torque converter losses.

Im very consistant with my manual but its all in how you drive. I drive pretty well and so I do pretty well. An automatic is *easier* but not necessarily *more fun* to drive fast down the track.

[99Camaro99]

<blockquote>quote:</font><hr>Originally posted by Dominic:
M5 - 3.23 no question about it. You CAN'T order it with any other gearing at all.

And yes, the M5 pulls harder gear after gear and there is no slushbox torque converter losses.

Im very consistant with my manual but its all in how you drive. I drive pretty well and so I do pretty well. An automatic is *easier* but not necessarily *more fun* to drive fast down the track.<hr></blockquote>

Yes the M5 will pull stronger. See his best time is a 15.22@91 to my 15.21@88.80mph. Can we say I might get passed if the race continued! [img]tongue.gif[/img]

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by Dominic:
An automatic is *easier* but not necessarily *more fun* to drive fast down the track.<hr></blockquote>
Yeah, cause with the manual there is always teh miss a shift and blow up element ;)

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by Bliggida:
Going from the slush box to bang mode is a performance improvement almost always in any vehicle platform. But especially in ours.<hr></blockquote>

The performance hierarchy (in terms of ET) is 3.08 auto &lt; 3.23 manual &lt; 3.42auto

I dunno what your door code says, but GM says they never made a 3.08 geared manual.

When you speak of evening things out, you forgot about the torque multiplication effect of the torque converter. You cannot launch a manual as hard as an auto. That is why the auto's always pull a better 60'. It's been my experience that the manuals are playing catch up all the way to then end of the 1/4.

[ April 30, 2003: Message edited by: HAZ-Matt ]</p>

[Bliggida]

tellin' ya, my door code says GU4, and its quite clear I have a manual transmission.

You figure it out.

Even so, if the automatic has 3.08, and the manual has 3.23's that just goes to further the point that the manual will pull even harder than I suggested, and at that point it was already a clear winner. With a manual car you should be in the low 15's. 15.5 at worst.

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by Bliggida:
tellin' ya, my door code says GU4, and its quite clear I have a manual transmission.

You figure it out. <hr></blockquote>

Your car was hit in the side, and the door was replaced with one from an auto.

[Bliggida]

<blockquote>quote:</font><hr>Originally posted by HAZ-Matt:
When you speak of evening things out, you forgot about the torque multiplication effect of the torque converter. You cannot launch a manual as hard as an auto. That is why the auto's always pull a better 60'. It's been my experience that the manuals are playing catch up all the way to then end of the 1/4.<hr></blockquote>
The torque multiplication effect of the torque converter is nothing in the face of being able to engage the clutch at any RPM you wish. So no, an automatic won't launch harder. And they do not get better 60 foot times. Your experiance may be that the manual loses. Your experiance could also entail a person not knowing how to drive one. In the V6 F-body the manual outpowers the automatic hands down.

-It weighs less
-uses up less horsepower
-and is geared better, both in each individual gear and in final drive ratio.

The manual has the clear performance edge.
And even if they were exactly even in terms of weight, powerloss, and the exact same gearing, a manual would still win because they have the ability to launch at any RPM, and feather the clutch. They put power to the ground more efficiently.

3.08 A4 vs. 3.23 T5
excluding the torque multiplication of the torque converter (will show later) The T5 has a gearing advantage equivalent of:
(HP * GR * FDR)
1884.96 vs 2422.5
57 horsepower in first gear
997.92 vs. 1414.74
83 horsepower in second gear
616 vs. 910.86
96 horsepower in third gear

Now if you can agree that under extreme conditions a torque converter will yeild between 2:1 to 2.5:1 (probably be a performance converter..meaning...not stock a stock converter will probably yeild about 1.85:1 torque multiplication ratio.

So I plug in those allowances and I get:
(HP * GR * FDR * TMR (Torque Multiplication Ratio)
@ 3.06 = 3487.176
T5 needs 88 more horsepower in first
@ 1.62 = 1846.152
T5 needs 61 more horsepower in second
@ 1:1 = 1139.6
T5 needs 50 more horsepower in third

So now I go back and subtract the differences from the two equations:
T5 had 57 HP advantage minus 88 HP advantage for the TMR of the TC and that means the T5 is down by 31 horses in first gear.
83hp - 61hp = 22HP advantage for the T5 in 2nd gear.
And 96HP - 50HP = 46HP advantage for the T5 in 3rd gear.

So at this point it still looks as if the automatic pulls harder in first gear, and then the manual plays catch up and storms by later on down the track. (as one person mentioned) BUT! we forgot to figure that yes the torque converter multiplies torque - but is also robs you with inefficiency.

So assuming you have a 2200 stall for the stock converter. And you can only run it to around 1800 to keep the tires from smoking. Then that figures to about 81% inefficiency.
So the 31 horsepower advantage it had without figuring efficiency is now down to 24.8 horsepower advantage.
Since the torque converter is above stall speed in the rest of the gears I'll spare you the math on those - especially when the T5 has the advantage.

So now, we are almost done but you forgot to consider the 5% difference in drivetrain loss between the automatic and the manual.
So that 24.8 HP advantage of the A4 drops down to 23.56 HP. And although it would be relavent, the loss would transfer into the other gears as well, making the T5 advantage already larger.

And finally we come to who is launching with more horsepower than the other. Being that the T5 has a clutch, it clearly is spinning more torque and horsepower than the automatic. 1,800 RPM compared to 2,500 RPM. I personally don't know exactly how much torque and horsepower are available at both 1800 and 2,500 on a stock L36. However, I can tell you that obviously in our engines there is more at 2,500 than 1,800. So you figure for example the automatic is making about 100 horsepower to the ground at 1,800 RPM, and the T5 at 2,500 is putting down about 120 horsepower. Give or take - this is all relative without a dyno report handy. Just speculating with an educated guess.

So then that 23.56 HP lead the A4 has on the T5, drops down to 3.56 HP advantage - negligable.

Then you figure in that the manual will reach redline and shift consistantly there, while the stock automatic will be foreced to shift down lower between 4,800 and 5,300.

In the end by math alone you can see that off the line they are just about dead even, but as soon as the light goes green - or yellow the equality stops, and the T5 has the advantage all the way down the track.

[Dominic]

Blig - you have some errors in that post.

When you do gearing calculations you calculate torque, not horsepower.

I.E. Its fine to say 225 * 3.23 * 1.41 = 1024ftlbs.

You cannot do this calc for horsepower... its false.

Also I think you mean TC EFFICIENCY, not IN-EFFICIENCY.

And, torque converters only have torque multiplication before launch... i.e. when stalled up. After they launch and the car rolls a bit the multiplication is gone.

[Bliggida]

To be correct yes you use torque. Most people don't understand torque only horsepower. Since horsepower is only a mathmatical equation of torque, its some what relevant - for these intended purposes.

I'm not about to go back and refirgure for 225 ft-lbs. That took me over an hour to use 200 horsepower.

TC efficiency yes, but technically if it's not at 100% its not efficient. Anything less than 100% is inefficient, but you are correct.

If the torque multiplication is gone after launch - because all other gears are above stall - which they are, and I mentioned that already. It just goes to prove further the T5 has that much more an advantage!

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by Dominic:
And, torque converters only have torque multiplication before launch... i.e. when stalled up. After they launch and the car rolls a bit the multiplication is gone.<hr></blockquote>

No the multiplication drops after launch. Technically the torque multiplication starts to drop as the converter begins to couple. With the stock one, this happens fairly quicky. Without aftermarket, you won't see it in 2nd or 3rd :(

<blockquote>quote:</font><hr>Originally posted by Bliggida
The torque multiplication effect of the torque converter is nothing in the face of being able to engage the clutch at any RPM you wish. So no, an automatic won't launch harder. And they do not get better 60 foot times. Your experiance may be that the manual loses. Your experiance could also entail a person not knowing how to drive one. In the V6 F-body the manual outpowers the automatic hands down.<hr></blockquote>
There is enough torque to spin the wheels in either transmission configuration...therefore, all this big gearing advantage you have in first is wasted in spinning the tires, or reducing the throttle, or feathering the clutch. In any case, you are reducing your acceleration. Your "fuzzy math" calculations are all well and good, but it is obvious that you haven't seen very many of these cars run at the track. Manual v auto with similar times, the auto is ahead at the 60' mark all the way until the 8th mile.


1. A slipping clutch and a torque converter don't do the same thing for you, which is what you have implied.
2. Hmmm and auto won't launch harder... again see torque converter.
3. They don't get better 60's? Now that is just plain ignorant. http://timeslips.firebirdv6.com/
4. My experience is that a lighter manual car with an experienced driver and similar mods loses in ET, but finishes with higher mph
5. My experience is that when a manual driver doesn't know how to drive, ET's are reduced by a significant margin, not 0.1s
6. In the whole world in which a car is offered with and auto and a manual, and the manual has higher efficiency, the manual will outpower the auto. This doesn't necessarily translate into quicker ET's.

<blockquote>quote:</font><hr>In the end by math alone you can see that off the line they are just about dead even, but as soon as the light goes green - or yellow the equality stops, and the T5 has the advantage all the way down the track.<hr></blockquote>
Yes, and in the end when the model doesn't fit the experimental data, it is the model that has to be reworked. Yours is oversimplified and contains errors that need to be redressed.

[ April 30, 2003: Message edited by: HAZ-Matt ]</p>

[Arctc Wolf]

alright, back in the old days, manuals ruled the street, drag, and auto x stuff. today, manuals only rule auto x. yes, manuals are geared higher, but they don't have torque multiplication of a torque converter. yes, auto's lose more power thru the tranny cuz of heavier parts and are also lower geared. There are race-prepped auto's out there that weigh just as much as manuals do, so the only bad thing about auto's is the gearing, but now, we have 5-speed and 6-speed auto's out there. But, just for our cars, we have manuals w/ better gearing, and auto's w/ worse gearing. This is made up tho w/ the TC's str, so we have the edge on the launch, and u guys gotta make up for it on top-end gearing. drag racing, auto's have it. auto x, manuals have it, cuz u can hold a higher gear on a road course better w/ a manual than an auto.

[Bliggida]

Sorry to say this timeslip page isn't the Bible. And I see these cars at the strip and what you are claiming is true - I am not seeing. Don't call me ignorant because I've seen things you haven't.

Stock for stock you look at ET's - Manuals are clearly winning, and this in nothing new - known since the 60's.

Why is it that the automatic cars I have run against, having been treated to substantial aftermarket modification only stay with me. Shouldn't they be pulling on me?

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by Bliggida:
Why is it that the automatic cars I have run against, having been treated to substantial aftermarket modification only stay with me. Shouldn't they be pulling on me?<hr></blockquote>

Driver error.