A/T vs M/T

Thread Tools
 
Search this Thread
 
  #1  
Old 09-25-2008, 01:56 AM
Sam Misled's Avatar
Member
Thread Starter
Join Date: Mar 2008
Location: Oklahoma City, OK
Posts: 300
A/T vs M/T

I purchased an A/T last year and I am now wanting more power, and obviously speed. Why are manuals faster than automatics? Is there anything that can be done to make the A/T just as fast, if not faster, than an m/t?
 
  #2  
Old 09-25-2008, 07:45 AM
binaryh4x's Avatar
Member
5 Year Member
iTrader: (1)
Join Date: May 2007
Location: Fairfax, VA
Posts: 269
Drop some weight out of the car. Auto's are usually heavier than their manual counterpart.
 
  #3  
Old 09-25-2008, 07:58 AM
feddup's Avatar
Member
iTrader: (1)
Join Date: Sep 2007
Location: Kansas City
Posts: 1,155
control

The engine is the same. An auto "slips" some to make the transitions smoother. MTs, in general, will always be faster and get better MPG. The time to ponder this issue, MT VS AT, is prior to the purchase!
 
  #4  
Old 09-25-2008, 09:00 AM
Padraic's Avatar
Member
5 Year Member
iTrader: (21)
Join Date: Sep 2007
Location: St.Louis
Posts: 742
Slushbox.

A/Ts have more drivetrain loss through the use of a torque converter. That, coupled with more weight means the car has less power with which to move the higher weight.

Even with the paddle shifters, the Fit is nowhere near as fun to drive as a M/T equipped version.
 
  #5  
Old 09-25-2008, 02:11 PM
TOOL's Avatar
Retired Moderator
iTrader: (4)
Join Date: Jun 2007
Location: San Ramon, CA
Posts: 9,487
The Mini Cooper S AT, is faster then the Mini Cooper S MT.

Anyway, as for the Fit thats not the case.
I say get intake, and full exhaust. That will help the power. Also headers may give you some gains too.
 
  #6  
Old 09-25-2008, 02:18 PM
Sam Misled's Avatar
Member
Thread Starter
Join Date: Mar 2008
Location: Oklahoma City, OK
Posts: 300
would a catback exhaust give me more gains than a header?
 
  #7  
Old 09-25-2008, 03:18 PM
TurboManGT's Avatar
Member
iTrader: (4)
Join Date: Apr 2008
Location: Twin Cities
Posts: 1,421
1. Sell your AT
2. Get a MT
3. ????
4. Profit

 
  #8  
Old 09-25-2008, 03:19 PM
Fa1's Avatar
Fa1
Fa1 is offline
Member
iTrader: (1)
Join Date: Jul 2008
Location: San Francisco, CA
Posts: 710
AT Fit is slow. MT fit is less slow.
 
  #9  
Old 09-26-2008, 12:10 AM
polaski's Avatar
Member
Join Date: Jul 2008
Location: USA
Posts: 548
In a manual-equipped fit, the losses are as follows:
-inertia of roughly 18 lb flywheel and the clutch, which is much lighter than the flywheel
-bearings, which is almost negligible
-five gearsets, and whichever one is selected gives the most friction of the 5
-differential ring gear on countershaft, and its bearings.

In an automatic, the losses are as follows:
-inertia of flexplate and torque converter, similar to flywheel-clutch assembly
-inertia of transmission fluid in torque converter (if similar to civic, 3 quarts), roughly 10-12 lb concentrated at the outermost ring of the converter
-bearings
-fluid pump that maintains transmission fluid pressure, shouldering the work of holding the clutches
-planetary gearset
-differential and its bearings.

The two MAIN losses in the automatic are the fluid mass of the torque converter and the fluid pump. In a manual, it's all just friction of moving parts and that's it. If you wanted to mimic an automatic, you could just double or even triple the flywheel weight and you could be close performancewise.

Now about all those who claim it's the slipping of the converter, well sorry that's not it. That is actually the only saving grace of the automatic. The torque multiplication that it gives when not in lockup before stall speed is where all the grunt off the line comes from. Think about it-- ever floor a manual fit from idle? It takes a while before it decides to move on down the road, but the automatic gets with the program.

But, you can rev the manual and slip the clutch to get the same effect, so...
 
  #10  
Old 09-26-2008, 05:05 PM
grtpumpkin's Avatar
Member
iTrader: (6)
Join Date: Jun 2008
Location: inwood WV
Posts: 1,616
^^^What he said. As well as this: The auto tranny in the Fit was never meant to enhance performance, but instead to make the car easier to drive for folks who can't handle three pedal driving. The Fit is, after all, an ECONOMY car (thats fuel economy) The auto also won't hold gears as long in auto mode or continuously bounce off the rev limiter like you can in a manual, although the power advantages of bouncing off the fuel cut are very limited. Road and Track did manage to shave a few tenths off their 0-60 time by shifting with the paddles in sport mode. To make the auto faster than a manual you'll want to get a T1R turbo and then put the car on a serious diet, that oughta do it!
 
  #11  
Old 09-26-2008, 07:23 PM
TurboManGT's Avatar
Member
iTrader: (4)
Join Date: Apr 2008
Location: Twin Cities
Posts: 1,421
Even the boosted ATs look just as slow as my stock MT lol
 
  #12  
Old 09-26-2008, 08:25 PM
dank24's Avatar
Member
5 Year Member
iTrader: (-2)
Join Date: Apr 2007
Location: NEPA
Posts: 1,189
You bought the wrong car if you want power.
 
  #13  
Old 09-27-2008, 12:46 AM
solbrothers's Avatar
Member
5 Year Member
iTrader: (2)
Join Date: Aug 2007
Location: Vallejo, Ca
Posts: 7,343
Originally Posted by feddup
The engine is the same. An auto "slips" some to make the transitions smoother. MTs, in general, will always be faster and get better MPG. The time to ponder this issue, MT VS AT, is prior to the purchase!
yep. also, in the fit, the auto has taller gearing.
 
  #14  
Old 09-27-2008, 01:22 AM
TFB Designs's Avatar
Merchant / Group Buy Organizer ( non-certified )
iTrader: (4)
Join Date: Jan 2008
Location: Morgan Hill, CA
Posts: 452
Neither the A/T or M/T Fit is going to be fast unless you go FI. The Fit just wasn't designed to be a sports car. You can make the car a little faster and more enjoyable to drive with a few mods though.
 
  #15  
Old 09-27-2008, 01:26 AM
BlackUp's Avatar
Member
5 Year Member
iTrader: (1)
Join Date: Aug 2008
Location: You Ess and A
Posts: 348
Originally Posted by Fa1
AT Fit is slow. MT fit is less slow.
well said.
 
  #16  
Old 09-30-2008, 11:50 PM
Neebs's Avatar
Member
5 Year Member
Join Date: Sep 2008
Location: Tucson, Az
Posts: 359
AT throttle response no bueno.
 
  #17  
Old 10-01-2008, 12:01 AM
cojaro's Avatar
Member
5 Year Member
Join Date: Jul 2007
Location: Memphis, TN
Posts: 1,584
At has different gearing and eats more power from the engine.
I think an AT will, depending on make and model, sap 15-20% of the total crank output, whereas a MT will sap only about 15-10%.
 
  #18  
Old 10-01-2008, 03:02 PM
kenchan's Avatar
Official Fit Blogger of FitFreak
5 Year Member
iTrader: (4)
Join Date: Dec 2007
Location: OG Club
Posts: 20,289
at least on the MT you can force the car to chirp or even spin the tires
if you need to pull off line real quick. but the AT can catch up to you
between your 1-2 shift if you're not fast.
 
  #19  
Old 10-01-2008, 09:18 PM
eldaino's Avatar
Member
5 Year Member
iTrader: (1)
Join Date: May 2007
Location: North Carolina
Posts: 2,705
you can bounce off the rev limiter when in sport mode with the a/t



the only a/t boosted video that exists is leonies, and he has a m/t kwsc installed on an a/t.

not exactly the best indicator of performance imo.

i'm sure that a kwsc or tr1 turboed fit will easily beat an even moderatley modded m/t.
 
  #20  
Old 10-01-2008, 10:14 PM
TurboManGT's Avatar
Member
iTrader: (4)
Join Date: Apr 2008
Location: Twin Cities
Posts: 1,421
Its still supercharged?!? I'm not sure what is involved with making a KWSC fit the AT, but I can't see it making it less powerful
 


Quick Reply: A/T vs M/T



All times are GMT -4. The time now is 11:16 PM.