Typhoon 1/4 miles

[Scruffman]

I still dont see any evidence for your claim that manuals are faster. Is there anyone out there with a manual T that has a fast time under 14s?

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A mate I work with here has a stock standard XR6T Manual.

He run a 13.9 somthing on it at WSID I can get a copy of the time sheet and post it if you want.

My mate is a drag racer with other cars as well and actually knows how to drive his car to go fast.

I always have a little chuckle to myself when I see people with phase 1 and it aint crackign 13's yet. The car probably can do it its jsut the driver holding it back.

Oh well that's my $0.02 worth.

Scruffman

[Turbo6man]

2. Issue a challenge for someone to explain how, in theory, a Manual transmission, all other things being equal, is expected to have quicker performance times in a turbocharged car with the power/torque levels of F6 and other modified cars compared to a decent Auto transmission.

Keep the Auto v Manual driver enjoyment debate out of this, just strictly link it to performance times, because IMHO, everything I know about turbocharging tells me that the F6 would have better performance times in a decently capable Auto transmission.

I chose NOT to do number 1 because I did not want to risk insulting anyone's intelligence or subjecting them to stuff most people know, so that just leaves number 2.  If anyone is up to that challenge, feel free to enlighten us.   

Safe and happy driving...Dr Z. 

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The theory is really very simple. It all comes down to driveline losses. That's it, no more no less. It doesn't matter whether it's a turbo motor or not. Torque is torque regardless of how the engine is designed to produce it. You said all things being equal - so this is it. All things being equal a torque convertor has greater losses than a clutch. An auto has greater losses than a manual. I not going to itemise or document each and every reason why as it is already done and is unarguable fact. So there it is in a nutshell. The theory that is. But you already knew that Dr. so why are you teasing us?

Now the real issue is what is happening in practice. In practice you have this much variable item which overrides the "all things being equal" basis. It's called the driver.

Furthermore, there is another major influence on the "all things being equal" comparison. The fact is that they aren't because one of the major determining factors of a car's performance is it's gearing. For optimum efficiency gearing has to be matched to the engine's torque. So, if you assume that Ford has chosen the perfect ratios for each of the manual and the auto then "all things are equal". But if one set of ratios is better suited to the engine's torque characteristics then all the comparisions go out the window. The difference can be as much as the difference in driving technique.

[ktford]

most of the top ls1's are all manual

auto will always be faster but manual isnt that far behind if driven correctly

I don't know what he's drinking but I'll have 1/2. Clown

Scotty

[Geeseman]

Torque converters multiply the engines crankshaft torque, they dont reduce it.

It would be interesting to compare torque figures for manuals and autos to see which has the greater.

[ktford]

Oh and Auto drivers are lazy and slow :lol:

Hey mal, stick it up your Willy three times hard.

Scotty

[Guest jteale]

Oh and Auto drivers are lazy and slow :lol:

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Hey mal, stick it up your Willy three times hard.

Scotty

<{POST_SNAPBACK}>

I agree, I'll see you in my mirrors :lol:

Cheers, Jason.

[Turbo6man]

Torque converters multiply the engines crankshaft torque, they dont reduce it.

It would be interesting to compare torque figures for manuals and autos to see which has the greater.

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That's true Steve. Well, the bit where you say "torque convertors multiply the engines torque" is. You HAVE been reading my posts after all. I have stated that several times on the forum when this auto/manual debate comes up. However it does it by slipping, much as you might slip a clutch on take-off. If you are slipping the clutch, or the torque convertor, then not all the available torque is being fed through the system. Therefore there is a loss and as I have said the loss is greater with a torque convertor than a clutch. That is an indisputable fact that is able to be proved mathematically.

The maximum multiplier effect the torque convertor can produce is theoretically 2x (or 100%) in most instances. That is achieved when maximum load is coincidently placed on the engine at the revs where the torque convertor stalls ie reaches the point of maximum slip. In practice 100% is never achieved. Now, at all other times the multiplier effect is far less and is usually only around 8% to 10%. And reaches zero when the convertor locks.

OK, given that the "normal" amount of torque multiplication is in the order of say 8%-10% and to do that there is a heat loss of about 10%-15% over and above what a clutch produces you see the torque convertor actually loses out.

[Blown BA]

Oh and Auto drivers are lazy and slow :lol:

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Hey mal, stick it up your Willy three times hard.

Scotty

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I agree, I'll see you in my mirrors :lol:

Cheers, Jason.

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[Dr Z]

Turbo6man, what you write regarding transmissions we all know to be true, and thank you for your explanations, but my point is that we can not dismiss the fact that the torque delivery from a turbocharged vehicle comes directly from the gases supplied by the accelerator. We know with an automatic transmission that is a continuous supply, whereas with a manual transmission it is discontinunous. Thus, we cannot ignore that we are comparing a turbocharged car when making this transmission comparison.

It is this part of the point that I hope someone could elaborate on to explain how a discontinuous supply of gases running through a turbocharged vehicle in a manual transmission can, in theory, all other things being equal, without any wacky gearing etc, lead to better acceleration performance times than a capable automatic transmission which delivers a continuous supply.

Thanks in advance.

Safe and happy driving...Dr Z.

[Turbo6man]

OK, I see where you're at. You are basically referring to turbo lag or spool time.

It is true that the turbo lag is not as damaging to the continual torque delivery with the auto. Now I have to admit to not having any scientific proof of exactly how much difference there is. A dyno could measure it but the problem is you'd have to use the same engine in the test. This is going to be a fairly difficult thing to achieve for us, although I'm sure that vehicle manufacturers would do it. They would have to know these things in order to select the best gear ratios for the cars, both auto and manual.

However, my own experience with turbo cars over several years, in fact going back to 1978, leads me to believe that with modern turbo technology the amount of lag has been significantly reduced. So any benefit the auto may have in this regard would in my opinion be negated by the extra horsepower it drains from the engine. It seems that the rear wheel horsepower difference of manaul to auto can be as much as 10%. This is taken from stats provided on this site by people like APS who should know. Now I doubt very much if that 10% can be compensated for by the auto not dropping boost at gear changes. I reckon in fact it would be a very line-ball call and this is why we see times very close for both types. I still maintain driver input is the most determining factor in the manual's performance.