dom

Ok, we know that the MT is quicker than the AT in acceleration mainly because of its superior gear ratio's and I guess the added gear. But, what would happen on a rolll from say 40 or 50 on the highway when the advantages of the tranny don't come into play as much and the weight difference isn't as prominent? Can the AT hang? or could it be even quicker?

Here are the gear ratios again in case anyone forgot. I have no clue what they mean and how they effect each car so I'm hoping someone can clarify how they affect highway situations.


Gear Ratios

TSX Automatic

1st - 2.652

2nd - 1.517

3rd - 1.082

4th - 0.773

5th - 0.566

FD - 4.440


TSX Manual

1st - 3.267

2nd - 1.880

3rd - 1.355

4th - 1.028

5th - 0.825

6th - 0.659

FD - 4.760


I only bring this up because I rarely take my AT TSX on the highway. I had a chance to this morning and IMO its a completely different beast once rolling. I'm thinking that when the designer of the TSX's K24 said he was most proud of this engine he was specifically reffering to its performace already at speed. Its damn impressive.

BTW - my cars turns at 3400RPM while in 5th @ 160km/hr (100 MPH)

Dan Martin

The AT is a great choice for people cruising on the highway because the lower gearing lends to a much more relaxed environment. The 6MT will have stronger passing power at the expense of more engine noise. As I remember in 6th gear it will pull away from a TL purely because of gearing.

dom

So if we're both rolling at 50 side by side and punch it the MT will still walk?

Dan, we'll have to test this after we install the intakes.

Check out this thread from Tinky. I timed his runs at under 8 sec. Can you give it a try?

http://www.acura-tsx.com/forums/showthread.php?t=10896

Dan Martin

My work box doesn't like his video for some reason. I'll have to watch it at home.

If you left your car in 5th and I had mine in 6th and we punched it from say 100 km/h I'm pretty sure the 6mt would walk away. The 5at should have a higher maximum speed (I don't think we'll test that) but the 6mt will have better acceleration. I welcome the challenge though!

MarkPinTx

Man it walks and talks. Even in 6th.

I had an auto Aurora with a 4.0 liter DOHC V8 spitting out 250hp and 285fp @4000. Thing was in top ten (in its day) 50-70 passing times. TSX just as good if not better.

jlukja

The advantage of the AT, though, is that if you're at speed and then punch it, it will drop down a gear or two (unless you're cruising in SS).

ClutchPerformer

Are we shifting here, or just top gear acceleration? Either way the MT should win, but it wins more when you downshift a couple gears.

rb1

Yes, if both cars just punch it, the AT will smoke the MT because of the downshift.

However, if the MT driver downshifts to the appropriate gear prior to the punch, it will smoke the AT no matter what gear the AT chooses.

provench

I think we are talking like top gear passing here ... I always really didn't understand that though. Put me in the camp where 6th is an overdrive gear with zero power. Are we really that lazy where we can shift? That's what the 5AT is for

ClutchPerformer

THANK YOU! At least I'm not the only one...

ClutchPerformer

Or if the AT owner is in SS 5th, it won't shift (I think...), and MT beats AT. And all is right with the world.

dom

Hmmm, what your all saying should be right, but I'd like to test things out.

MT whores.

Dan Martin

Ok domn it's on!

provench

man domn ... you have 9 greenie bars ... you rep whore

provench

.... I'm just jealous :P

dom

Its on. Lest see if we can fdl to do some video. I think its a service to the site afterall.

dom

And it should be on the cover of next months PW Monthy

Dan Martin vs domn, MT vs AT, NooB vs Mod

TinkySD

I think my little unscientific video has given domn too much faith in his AT .... I mean AT powa' all the way!

dom

I know I'm gonna lose, but I wanna see how badly. I don't think the gap is all that much once both are at speed.

And was'nt it Kurt Bradley who said (or maybe it was someone else who works at a dealer) that claimed the AT caught up and passed a MT at higher speeds? Anyone remember this?

Either way though it will give us some great info. Its research really.

Now we have to figure out where Dan?



domn, who feels MT TSX drivers think their all that Kinda like Gilbo in a BMW

ClutchPerformer

Prepare to be 0wn3d... (assuming Dan can drive)

dom

I'm gonna buy some NOS and OWN all you damn MT snobs

bigwilliestyle

Sorry, domn, I don't think you got a chance. Even if the gear ratios matched, the fact that you control the shifts will get ya'.

bigwilliestyle

How 'bout some bets on the side?

I'm thinking Dan is a 5 to 1 favorite out of the gates. :bubbarubb

Dan Martin

Ok so who's going to be the bookie so we can place our bets?

I'll tell you what domn, fdl can ride in my back seat to video tape the event because I wouldn't want the weight penalty to slow you down... :P

Dan Martin

Drive? The only thing i have to do is keep it between the lines and have my foot to the floor! I think I should be able to handle that...

toddstuh

The AT weighs almost 100 lbs more than the MT...40KG...or 88lbs more.
That's quite a bit ?!

Dan Martin

Don't worry about the weight. I probably weigh 88lbs more than domn anyways

rb1

The main point of having 6-speeds is so that you can close up the ratios of the gears 1-5 and get better overall performance. Sure, I would expect 6th gear on a 6 speed to generally be a little taller than 5th gear on 5-speed.

It's largely pointless (IMHO) to just add a 6th gear while leaving the other ratios alone.

On a related note, I only have a 5-speed, and my overall final drive (including wheel size) is slightly shorter than the TSX -- it turns 3100 RPM @ 70 mph. One benefit of having a not-so-tall top gear in combination with drive-by-wire is razor-accurate cruise control, even on fair-sized hills. Make your 6th gear too tall and you'd have to downshift to climb grades.

ClutchPerformer

Not pointless from a gas mileage standpoint.

Not a problem. What kind of serious grades do you have on the highway anyway?

sauceman

You are absolutely right about this.

Guys, there is a track in Blainville just north of Montreal that Transport Canada uses to test cars and various things as well. This track will accept speeds of well over 250kph. If I tried to arrange to get access to the track, would anyone be willing to come out and test their cars?

rb1

I pretty much think it is. What's the difference in highway mileage between the AT and the MT? 2 mpg? Now look at the difference in the overall final drive, it's HUGE -- the MT turns 25% more rev's on the highway than the AT, but burns only 6% more gas (using the EPA estimates)? :sqnteek:

Let's say for argument sake we split the difference and shorten the MT by 12% or so, bringing down the RPM at 70 mph from say 3000ish (I don't have one, this is an educated guess) down to 2650 or so. If you extrapolate the numbers this might add a wee bit over 1 mpg to your EPA rating, but the car would be much less responsive and sensitive to loads (extra passengers, luggage, A/C). No thanks.

(Note also the torque converter lockup eliminate most of the efficiency disadvantage of the AT when cruising, just in case someone was going to say the MT would do significantly better on the highway mileage-wise with the same gearing)

Historical note: The first generation Integra turned 3750 RPM @ 70 mph in top gear, or almost 3000 RPM @ 55 mph