okay i know its stupid but i raced my friends ls1 powerd camaro in my 3.1 bird. i've never lost so bad before, and in a way it was fun. that car hauls.

 

Well you have an automatic transmission, that is one reason why you lost so badly. The 3.1L V6 with the auto was a real dog. I have a 3.1L V6 with a 5-Speed, and I can easily keep up with 305s. Im not saying that I can beat LS1s, I know I would get owned by them, but you wouldn't of had so many bus lengths between you and him if you had stick

 

Yes, you probably wouldn't of lost by 13 buslengths, just 12 and 7/8s if you had a manual. Seriously, the difference in speed with manual vs. auto in a 3.1 is negligible. Especially when you are talking about racing a car that probably has three times the power.

 

its true, i have a rachet shifter in my car, its not as good as a manual but its almost the same. by the way it was only ten buslengths

 

Redarrow have you ever driven a v6 auto and a v6 manual?

 

theres not much difference. if you want ill run you to show you

 

Manuals weigh less. Not a whole bunch less, but with the 3.1, any little bit helps some. Plus, parasitic power loss is less in a manual and manuals have the option of better rear gear ratio's, right? Also, aren't the gear ratio's in the manual different then the automatic? Not sure how much different, and it it's even a favorable difference. First gear in a 700R4 is nice and steep, but the jump to second is pretty big in terms of ratio. Auto's have the potential to be more consistent, it removes the operator from the equation. Have a bad day with a stick, and you're done. It's kind of hard to screw up mashing the gas pedal and letting the tranny do the work for you, unless you put it in '1' and try to upshift it manually - you can screw that part up, if you shift it too late or something.

I can see how a good driver that has his foot work down could do better then an automatic, though. Not too much, but I can see it happening.

 

In a straight line (assuming both cars have identical RWHP/TQ numbers and weigh the same) the auto will ALWAYS 100% of the time WIN, due to the fact that even the fastest shifter in the world can't shift as fast as an auto.

The reason that stock vs. stock a manual is capable of beating an auto is because you can hold shifts (unless you're manually shifting the auto), the parasitic loss is around 4% compared to about 12-14%, and it usually weighs slightly less. But that's ONLY stock vs stock, and in a straight line, on identically optioned cars.

Sorry had to throw that in there.

I doubt an 8% reduction in drivetrain loss would have helped him. A few extra feet maybe. The LS1 just outclasses him in every way.

 

thats probably the most correct statment on this thread. i got out classed. but i knew that was going to happen. this race wasnt about winning.

 

Yup, outclassed. Sorry if I got a bit long-winded - I tend to do that a lot.

 

Maybe an auto with a shift kit or an properly built race tranny but not many stock auto trannys shift as fast as a properly powershifted manual. Most manual trannys are around 18% or so on the parastic loss and an auto is 20%+. The manuals have better gearing and are about 70lbs lighter. The difference in low power cars is not as drastic as it is with higher power ones. That is why you don't see much difference between the A4 and T5 V6 cars in terms of ET's. When you get into monster power numbers nothing beats a properly built auto. Until you get there though a manual will out perform it in every way. One of the best ways to make your car faster is to reduce drivetrain losses. Most cars see better improvements at the track with that than with simple bolt ons.

 

What are the internal gear ratio's for the stock T5 that comes in the stick cars?

 

A race automatic with a properly matched converter would probobly beat a manual most of the time.Stock vs stock is another thing.The stock automatic will have a tight converter and "slushbox"shifts compared to the manual that can be launched at any desired RPM and can be shifted as fast as the driver is capable of.A manual also generally gets more HP to the rear wheels.

 

I am not sure what they were for V6 T5's but they are listed on the main page FAQ.

 

well unless the 3.1 manual is car lengths a head of a 3.1 automatic you not gonna keep up with many 305 maybe the early lg4 but not anything after 86 and auto are faster from a take off!

 

My transmission is no where near that kind of parasitic loss. My car put down 260 RWHP in it's stock form. That's less than 14% loss if I estimate flywheel HP at 300, which is what these cars really had, as opposed to the factory number. Figure the numbers for yourself if you use the under-rating of 275 FWHP. And I'm A4.

Yes you're right, the difference is much more seen in high horsepower applications, but I'll stand by my statement that a properly built (shift-kit, converter, etc.) auto will outshift a manual any day of the week. And if you pick the right parts, you can really minimize parasitic loss through a 'slushbox.'

Even my tranny (stock form) with just me hitting the 'performance' button made it shift very fast, faster than I've ever been with someone powershifting. Without the button on though, with lower line pressures it does shift slower. but it's still quick.

 

Your motor makes more than 300hp then. You need to estimate higher . The LT1 engines were almost as underrated as the LS1 was. The 4L60E is around 20% with the T56 near 18%. There are hundreds of dyno charts out there to come up with these figures. Any automotive company would kill for a gear box that only sucked up 14% or so of the power. I couldn't agree more that a properly built auto can shift faster than a manual. We are talking about mili seconds though. These are not triptronic trannies which basically get rid of any shift lag. You can do certain things to reduce parastic losses in an auto but the inherent design of it yeilds much greater losses than a manual. For one there is far more viscous friction than in a manual. Its whole design focuses on the movement of fluid in the converter. Tight clutch packs also increase losses. Typically you don't even step up to a super built auto unless you have enough power to negate some of the losses. Beefy rears and turbo trannys's eat up all kinda of power. That is fine though because they are backed with monster motors that would shred a manual. If you were to put a turbo 350 or 400 with a moser rear in your car your 260rwhp would drop another 10% or more.

99.99% of all T56 4th gens are faster than their 4L60E siblings. If you were to swap a T56 in your car, your ET's would drop.

 

there's no way that auto tranny is faster than stick unless driver behind stick lacks skill then it's a different issue. Manual transmission gives better power to the wheels.

 

It still doesnt give the car that much more hp it doesnt make a big as a difference as some people make it out to be.......

 

True but with smaller motors like 3.1 trust me your better off with a stick than auto.

 

Yes it does. On a 135hp car you are partially right. The percent losses do not go as far on a motor that makes so little power. Therefore the times you see are vary close. Auto trannys eat up power. Planetary gear systems are hungry for friction and have lots of moving parts. The viscous losses at high RPM's are huge in an auto. If you don't think there is a difference just go watch all the A4 and T56 cars at the track. Also, look at dyno numbers where the T56 guys are putting down 310 at the wheels and the A4 guys are at 285. There is a huge difference.

 

ok..ok... your right The 6 speed do have alot on a4...but i stilll not gonna buy that a 3.1 5speed is hellva fast... but on cars with high hp your are right ....

 

I'll assume you mean faster. You are right. With only 135 hp you are talking about a 3 hp difference between peak values. With a 350 hp car you are talking about 15+.

 

My buddy did an auto to manual swap in his weekend toy. And when he took it to the track he had a better ET and MPH. Nothing else was changed. And the auto was built for his car.

 

Exactly! More proof of what I am trying to say.

 

Oh yeah, I believe the T56 would make my ET's drop, until I start hitting 11.9s, then I would prolly want my auto back lol. Simply because I'm not a good shifter. Although a bolt-on LT1 DID just hit 11.9.. crazy.

And with the 20% loss theory, I'm making 312 FWHP stock.

Yeah I agree with you shifty, on stock and near stock applications anyway. I know if I was building a 10 second drag car I would want an auto all the way.

I was actually originally looking for an LT1 with a 6-speed but couldn't find one.

 

No, no, no, no, no, no..
A lot of LS1 cars that have broken very low 1/4 times have an A4 trans. Most of the time, when your 1/4 times get to around that time, the time it takes to shift just doesn't justify the "lower drivetrain loss." Of course there are a lot of M6s breaking 12s and such, but NOT "99.9%"

 

Consistency = Auto
Fun = Manual
From a dig = Auto
From a roll = Manual

 

The V6 Auto had 3.23 gears
The V6 Manual had 3.42 gears

Auto has 4 gears
Manual has 5 gears

If you know how to drive a stick, manual will win from a roll, or from a dig, either or.

 

We were talking pretty much stock applications.

As you get lower in times and higher in HP, an auto becomes more desirable.

 

Yea I know A4 cars are fast too. I was trying to exaggerate the point. Perhaps I should have said the majority instead of my grotesquely overachieving figure . This is really for stock cars and cars that are in the 12's. Once you get into the 11's a properly built auto is the way to go. I couldn;t agrre more in that regard.

 

this is funny.....an ls1 walked car lengths on my not stock 305

 

a mini van tried to walk lenghts on you and faild........tragicly. damn soccer moms.

 

Let's just sum this whole post up.

5 or 6 speed = fun to drive

Auto = easier to drive

that is all.

 

go do a dyno on ur car quit basing ur numbers off of other peoples lt1 cars

 

#1, he has an LT1, not an L98
#2, he's been to a dyno and says he has 260rwhp.

He was guessing at 300 flywheel HP which would equate to 14% loss, but drivetrain loss is greater than that, and he is making more power than he guessed at the flywheel. As mentioned, probably somewhere around 315. That's not hard for an LT1 to make with intake/exhaust stuff (I'm talking flywheel numbers). I've heard gains of up to 20-25HP just from changing the stock LT1 cat-back to an SLP 3" setup.