what's the deal with automatic transmissions?
 

I'm just wondering why automatic transmissions make cars slower than manuals. For the 4th gens, i think the autos run about a second slower than manuals (0-60). How does it rob so much performance out of the car? I think the auto puts down less fwhp than the manuals, but again i'd like to know why.

With regard to don's vb mod, does it make the automatic "feel" like a manual? With the stock auto transmission when i press the accelerator, along with the long pause during shifts, the car accelerates between shifts a bit lazily compared to a manual. Is this because of the gears in the auto? Does the vb mod improve the feel? As you can see i am very sore about my transmission...
but i still love my maxima :)

The reason why the auto makes less fwhp than manual is because of gearing ratio. The manual makes more fwhp is because it has a ratio very close to 1:1. The auto has one gear less, so it needs to have a gear shorter than 1:1, so therefore it has less hp.

Re: what's the deal with automatic transmissions?
 

'95 Maxima's ran 0-60 in 7.3-7.6, so in that regard 1 second at the worst. But yes CONSIDERABLY slower.

For one its heavier, two it shifts VIA fluid and the manual actually u are shifting with a rod. Don't worry Jeffrey or smart-@ss sprinty or someone will clear this up for you

A bit lazy ? It feels like fockin' whipped cream. It's weaksauce! Yes Don's VB will kick you into gear similer to a 5spd. But if you wanna pay 1/10th of the price and no downtime buy a trans-go kit. Not quite as good but much more convienient.

Automatic transmissions use fluid coupling via a torque converter which is less efficient, and they are also heavier which makes them less efficient.

Manual transmissions use a direct mechanical coupling via a clutch which is more efficient and they are also lighter which makes them more efficient as well.

Auto tranny's typically lose about 25% of the engine's power in the process of transmitting it to the wheels. Manual transmissions are much more efficient at only a 15% loss or so.

Thanks for the lecture mr professor......

:confused:


SteVTEC, very well put. You basically dressed my words up, but still good summary. :D

whoops. sorry

I hit reply after Telus.net's first reply so i never saw yours :D

He plagerized you?

:laugh: It's more like I got the luck of the draw and got my post posted first. Although I'm glad he posted his cause his was well written.

You both did a good job! :cool:

the difference between auto and manual is that auto sux!

:laugh: True.

Craig - I kept getting server timeout messages. Dammit. You beat me. At least we beat "the bot" though :D

Yea he's actually off! Can you believe it ! :eek: :eek:

Little sprinty must have had some bad encounters with some civics lately cuzz he's been a cranky little bugger. On another note MedicSonic has been a rare find nowadays too. :(

Unless you get a fully build Level Ten transmission, the auto tranny just suck. As far as doing a 5spd swap, sure it's possible. However, it's not an easy process. Finding all the right parts and then find someone to do the swap for you is a PITA. So, in my case, I might go with a Stage I Level Ten rebuild because I'm sure my tranny is on it's last leg.

Re: what's the deal with automatic transmissions?
 

automatics rule! dont let nobody tell u different!

Actually, a guy at AccordV6.com just got done with a custom turbo and a full Level-10 tranny build up. He's had absolutely nothing but trouble with the tranny. It keeps on slipping and he has to keep on taking it back. Fortunately he lives close by so he can get the car to Level-10 pretty easily. The car is in the shop more than it's on the road. He apparently knows a bunch of other people that have had similar problems with Level 10 also, and they're actally being sued right now.

cool, thanks for all the info guys. knowing what the actual weaknesses of the autotragic actually makes me feel enlightened. maybe i'll eventually get a vb mod when i can afford it :D

...one more question, if the hydraulic torque converter in the auto robs power between the engine to the wheels, is it possible to swap the tc with a "stronger" one? i know of the high stall speed tc's, but does anyone make a tc that transmits the power better without increasing stall speed?

does anybody know the time benefits of a trans go kit, don's kit, and the level 10 kit? im talking 1/4 here. Also, whats the downtime for don's vb mod?

down time should be as long as it takes to get your vb installed. i believe how they were doing it was he sends you his "modded" and you get it installed then send your old one down to him. as for times, dunno, but i'd like to find out. my guess is that it goes something like this:

Level 10 ($~700): drop about .5 - .8
Don's VB ($450 + core swap): drop about .4 - .6
TransGo($ i have no clue): .2-.4

mind you, these times are for a 4th gen

so theoretically, it wont be as good as a Level 10, at its best, be as good as Don's kit at its worst.

if i'm wrong, please smack me over the head and correct me.

Level-10 and Protorque both have aftermarket performance torque converters available, and I think they're both the same thing and Protorque actually supplies them to Level-10.

With an aftermarket torque converter you can specify a higher stall speed which will let you launch at a higher RPM than stock and help avoid that "auto bog" when you launch in 1st gear and you're out of the power band. I think they're also a little more efficient as well and allow you to get some nominal power gains - probably less than 10 fwhp or so.

One of our Accord V6'ers got just the Level-10 torque converter installed on his car and he gained about 0.2-0.3s at the track and reported that it did seem to pull a little stronger in each gear. I don't think he ever dyno'ed though - just went to the track. Gains might be similar for the Maxima. But if you combine Don's VB mod with an aftermarket torque converter I think you could nearly equal to a 5spd Maxima.