So the auto is just 1 second slower than the manual driven by a decent driver (whos no doubt pretty handy with his heel/toe action keeping the engine/power down maximised in the manual) despite a little longer gearing!

I can certainly live with that!
I dare say the average driver may not find any difference in lap times?
And even if they are pretty handy behind the wheel is such a small difference noticeable in real world driving? I may track mine once or twice for a laugh but that's all it'd be for.. A laugh.. not trying to break laptime records.

The loss on the FR-S auto has got to be pretty minimal given the big improvement in gas mileage it produces over the manual. It's the gearing that gives it the slower acceleration - the ratio differences in the upper end are very big. There is probably 1/2 second lost at the start due to the non-locked 1st gear as well, can't generate the wheelspin. Be interesting to see the rolling times, 5-60 or 40-70.

:word:

Like I said, less than the old days.

A dyno comparo would be nice to see what (if any) the difference is. The manual has shown that it is quite efficient at putting power down. But no auto dyno so far that I am aware of.

Yup there is still the weight penalty, but I still refuse to believe that the parasitic losses are significant. By dry clutch automatic I was referring to any automatic that uses only a computer controlled clutch to transfer power, so that include DSG, DCTs, etc. I think that there would be far more incentive to use these transmissions if parasitic losses under lockup were a problem.

they cost too much. that's why the TC auto still lives.

and exactly what do you mean by significant? having to turn the heavy TC filled with fluid will sap some power. exactly how much? we wont know until the dynos come out.

I think I forgot that even DCTs use hydraulics to control the clutches anyways lol... so all automatics have parasitic loss there. Long live the manual transmission? :D

What do I mean by significant? I am not sure how much power the hydraulic pump costs but it does not take much power to move some clutches and stuff around so in a setting where you're actually giving the engine 100% load at high rpm, I think it's safe to say the hydraulic pump itself is not doing much to hurt power output. As for the torque converter, I suppose it is still churning the ATF, but the turbine speed and impeller speed are matched under locked conditions, and the losses would be rpm dependent. If say 7000rpm vs 3000rpm is a 10 fold difference in this loss (kinda just cubing the difference), and the torque converter was costing say 10hp, then at 3000 it costs you ~1hp, which for rolling around town/on the highway is a MASSIVE parasitic load and highly unlikely, or we'd be seeing much worse fuel economy numbers. Of course I'm making some very strong assumptions but I would be very surprised if the locked converter were losing more than a few hp.

well.
given the same tires and FD ratio:

3rd gear
1.541 vs 1.404 is around 10% more torque
4th gear
1.213 vs. 1.0 is around 21 % more torque

Whatever the engine is putting out, the gears multiplying it determine the torque where the "rubber hits the road."

Since the MT will more ofter be at a lower gear ratio it is putting down higher torque more of the time. So the quote above is somewhat true (just exaggerates a bit). Even with a super fast AT shift (less time at zero torque), the MT will deliver higher torque wile in gear.

And for more anecdotal evidence. The Toyota/Lexus 2GRs are putting down WAY less power with their (locking) ATs than those swapped into MR2s with MT (and Fidanza FW).

^ I said "with equal gear and final drive ratios". The differences you are talking about are all due to different gear ratios, they are not the result of a differential in the inherent inefficiencies of the 2 transmissions.

That's not necessarily true... In mileage tests modern autos can often outperform their manual counterparts, due partly to their ability to keep the engine operating in it peak efficient specific fuel consumption range. I'm with you though I want to see dyno results and rolling times...

It's almost definitely due to poorer gearing (and maybe a little bit due to the weight penalty), unless not all of the nannies were switched off.

The drivetrain losses should be essentially equivalent on a dyno pull. Hopefully someone will confirm (or refute) this with data soon.

Pity it isn't a 7 speed so the ratios could have been made closer (that's how they did it on the Z!).

Hopefully with tuning, shift speed can be increased (on modern trans like this, no need to change valve body -- line pressure is controlled electronically) and with additional power ups, the difference will shrink.

Anyway, I definitely owe someone on here a beer -- I had thought the AT might be marginally faster than the MT, but that would have only held true if the gearing were closer.

So I stand corrected... I don't mind being proven wrong, but it sucks that I had to be wrong on this issue in particular...

Oh well.

It kind of shows the parts-bin vs ground-up nature of the car. Off the shelf transmissions. Sounds like they tried their best with what they were given but there are limits.

Just looking at peak torque to the wheels comparisons, 1-3 are reasonably close, but 4-6 not so much. I'll try to compare with rpm drop over a dyno graph later...

It's more like this, an automatic transmission can be programmed to shift up as many gears as possible, and when you stab the gas it hopefully automatically drops down a gear or two. With a manual transmission, you can shift the gears in a similar way yourself...but very few people bother to do this. The EPA test, unfortunately, shifts a lot like most manual transmission drivers.

The difference is amplified then, because the EPA test has fixed acceleration as well as an inefficient shift schedule, so MT cars end up sitting in low gears chugging along with barely any load, while ATs will shift up early. In the real world, drivers will typically use a more reasonable level of engine load for acceleration and so they get better fuel economy. Thus the EPA city mileage in particular for a manual transmission can be thought of almost as a "worst case scenario" of sorts. Of course, if you get too happy with the gas and end up hitting the brakes a lot you can do worse.

But yea, I agree with Dimman, it seems that the mostly parts bin transmissions were one of the places where they needed to cut costs :/