what are the pros and cons of automatic and manual transmissions?

Posted by RedEyeBanDiT, Dec 7, 2006
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

  1. RedEyeBanDiT

    RedEyeBanDiT Proven Member

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    Rowley, Massachusetts
    hey im new to these cars and want to learn more before i decide to buy one.

    i was wondering what is better for drag racing, an automatic or manual?

    which would be faster/quicker with simple mods (intake exhause bov uppipe) ?

    what launches better for dragging? which is worse on the car the auto or manual launch?

    whats known to break more, the autos or standards ?

    thanks im a newb!
    #1
  2. Eclipse45150

    Eclipse45150 Proven Member

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    Well I cant say much for the turbo cars but from my experience on a nt, the auto breaks usually atleast once a year LOL, I had mune rebuilt twice and the first time then went throught five gear boxes if that tells ya anything. Since I swapped the tranny to a manual I havent had a problem, as for racing Im hardcore that you can race an auto and with proper mods keep up but go with the manual, my opinion, the belts in a auto wont stand the strain from shifting that quick for long, and besides with a manual you can control when you shift instead of a computer, hoping that the computer will shift at the right time and never mess up. My opinion though
    #2
  3. absolute_DSM

    absolute_DSM Proven Member

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    Boise, Idaho
    Thats all how you drive it. That depends on the driver.

    5 speed. Well it depends on the driver too.


    I think most people on the board will agree the Auto is the way to go for draggin nowadays.

    5 speed would be my way for road racing.
    #3
  4. AndrewD5418

    AndrewD5418 Supporting Member

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    West Bend, Wisconsin
    I think you mean autoxing..?
    #4
  5. absolute_DSM

    absolute_DSM Proven Member

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    Boise, Idaho
    No I meant road racing. But 5 sp is great for parking lot AutoX too.

    Road Racing
    [​IMG]

    AutoX
    [​IMG]

    I would never promote Street Racing - its retarded.

    Back on topic.......
    #5
  6. wvturbo2

    wvturbo2 Proven Member

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    Auto would be the way for drag racing, but obviously if your car is built you auto tranny will have to be built as well. Standard will be more fun to drive and give you better control of the car if you were to do something besides go in a straight line. Auto's are good if you want you mom, grandma, gf to drive LOL. I'd say manuals are given more respect regardless of what type of racing it is. I don't think auto's are really good for anything besides a straight line. Gl with finding a dsm.
    #6
  7. brandonclum

    brandonclum Proven Member

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    just wondering im putting my auto tranny back in my 1g awd tsi and was wondering what are the up and downs to going with the auto for drag racing???
    #7
  8. knochgoon24

    knochgoon24 DSM Wiseman

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    Rochester Hills, Michigan
    Pros:
    Brake boosting
    Preloads drivetrain (less snapped axles)
    Faster shifts
    Never misses a shift

    Cons:
    Absorbs some power (10-15% is a common figure)
    #8
  9. 2g eclipse kid

    2g eclipse kid Probationary Member

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    Candiac, Quebec_Canada
    Depending on your set up , over heating can be an issue as well.:notgood:
    #9
  10. 420a-t

    420a-t Proven Member

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    Idaho Falls, Idaho
    Heavier. But I'd stay with the auto for drag.
    #10
  11. TSIMonsteR

    TSIMonsteR Proven Member

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    HP, North_Carolina
    To add to this list (some of these don't apply to drag racing):

    Pros:
    -Boost between shifts
    -Consistent
    -Typically much stronger than M/T counterparts
    -Around town driving
    -Your mom or wife or grandma can move your car
    -As easy to rebuild as M/T

    Cons:
    -Not as fun to drive at times (slamming through the gears can be rewarding)
    -Heavy sumbeaches
    -Launching takes more practice and patience
    -Not good for Auto-x/Road Course without some sort of shift control
    #11
  12. cyclonekid77

    cyclonekid77 Proven Member

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    Bellevue, Ohio
    As long as your not repeatedly launching overheating shouldnt be too much of an issue. Nice coolers are available at reasonable prices too. The auto is a power absorber, but you will gain alot of consistancy. They arent as fragile as the 5 speed trannys either. Its really just personal preferance.
    #12
  13. Thumper32k

    Thumper32k Probationary Member

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    Kirkland, Washington
    I'd say go with the 5 speed. Automatic transmissions take a lot of the fun out of drag racing and as far as I've looked more expensive to upgrade then a manual trans.
    #13
  14. slickers111

    slickers111 Proven Member

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    Took the words right out of my mouth.
    #14
  15. gettingwop

    gettingwop Proven Member

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    If drag racing is going to be your fix for going fast. An auto trans is the trans for you. All the above mentioned pros will certainly make it worth it's weight in gold..no pun intended. If you plan on making serious awd horse power you'll be much much better off with the AT. For as long as I can remember 7-10 second cars have been using auto transmissions to eliminate the mistakes, inconsistencies, and in our cases is a great way to cut down on drive train demolition.

    I am dying to find a cheap 1g awd auto.
    #15
  16. IndyTsi95

    IndyTsi95 Probationary Member

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    I agree 100% that A/T takes somewhat of the fun out of driving but as long as your still turbo and AWD for that matter then its still quite a bit of fun to drive.
    #16
  17. EagleTalonTim

    EagleTalonTim Supporting Vendor

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    Brighton, Tennessee
    I would stay auto! I have owned 3 1g DSM's and all the manual versions were always down for repairs. I've gone through 5 transmissions in the manual cars. I now own an auto DSM and love it! If you are wanting to make an auto fun to drive, try using a shift box. You control each shift just like a manual but you don't have to let off the gas meaning you stay in full boost all the way down the track. As for reliability.... I drive the crap out of my car and have only destroyed one auto tranny because a bolt in the strut was the wrong size which let the hub move on a launch and the axle broke punching a huge hole in the case of the tranny. That sucked! All in all, it is your choice on what you want to drive :)
    #17
  18. knochgoon24

    knochgoon24 DSM Wiseman

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    I had my car at the track last weekend for the local 1/8th mile street legal drags. I out launched every car there because of the combination of brake-boosting and AWD. Sadly, the T25 (R.I.P.) didn't have any top end and most people caught up. It finally died that day.
    #18
  19. brandonclum

    brandonclum Proven Member

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    spokane, Washington
    great thanx guys. im also thinking about a trans break but dont know where to get one any ideas?
    #19
  20. knochgoon24

    knochgoon24 DSM Wiseman

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    Rochester Hills, Michigan
    I haven't heard of a trans brake or manual valve body being made for our cars.
    #20
  21. TunaTalon

    TunaTalon Proven Member

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    While its true that an auto drive train loses some 10% to 15% power to the wheels at WOT that's only important near or past peak horsepower RPM. While the converter is slipping the engine is at a higher RPM than for a manual car and is making more power. With my high stall TC the engine goes immediately to 4000 RPM at WOT and I don't mind the lower efficiency.

    One more thing: A manual may be more fun for canyon carving while it has your full attention, but the fuzzy logic on the auto is always paying attention and trying to keep the right gear selected. This can keep you alive if you're past your teens and no longer immortal.

    In 1997 when the TSI was brand new I was driving my new baby in the right lane of a four lane divided when a pickup came through a red, across his merging lane, and tried suicide by Talon. ABS was not enough but an emergency lane change onto the empty merging lane worked. When I released the ABS the Talon had made a two gear down shift and was in second gear with RPMs up, boost up and ready to go. While passing the pickup at WOT and 7000 RPM the transmission took third with a bang. By the end of the merging lane I was clear of the pickup, back on the highway and lifted the throttle. The Talon held third gear for a long time seeming to ask if I really wanted to use overdrive, or wouldn't I prefer to go back down on the throttle.
    Last edited by a moderator: Jun 5, 2014
    #21
  22. AWD_Hybrid

    AWD_Hybrid Proven Member

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    If you save the pic, the missing lines will apear. Stupid photobucket.
    I made this 1G Auto vs VR4 Man overlayed graph to compare revs vs mph
    for yous dudes up there using mph ;) kph down here in Australia ;)
    A VR4 has a 2.846 1st & your 1g/2g man has a 3.083 1st, so the pink man
    1st gear is a bit more generous in a VR4 man overlay.
    [​IMG]
    If you draw horizontal lines over this graph, you will see your revs per
    gear change. eg: Auto 1st @ 7k gives you 4k changing to 2nd. etc etc.
    Notice the Auto 2nd gear legs. Don't give an auto a rolling start drag ;]
    Cheers !
    #22
  23. TunaTalon

    TunaTalon Proven Member

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    Dittmer, Missouri
    Aldo,
    That graph shows a linear relationship between RPM and speed. For an auto with a slipping torque converter that is not true. As noted in post 15 above my Talon may be at 4000RPM at 15 MPH in first gear and when the wheels catch up at the 7000RPM shift point the car is only doing about 40 MPH. The torque converter is like having more gears. The high stall TC comes off the line as if the Talon is running a jeep granny gear.
    #23
  24. AWD_Hybrid

    AWD_Hybrid Proven Member

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    Hi matey. Yeah I understand what you are saying about your high stall
    convertor making the graph incorrect bellow your 4k. So long as you
    are still using the same large dia convertor, it will be efficient from 5k
    onwards. That's why your 40mph at 7k in 1st matches the graph. The
    smaller dia high stalls are more inefficient up top. I use a 3.2k stall
    so I still have decent engine braking. If you are right into autos & are
    interested in using a switchable transfer on your auto, well as you know
    you need the centre diff welded for starters. You use the auto front tc
    section. You get 4.5mm (around 7/32") machined off the back of the
    front auto section. (I ground the top level on the man switchable mid
    section) Mark the new straight intersection & only remove the 7/32"
    from that line downwards. This makes it a snug joint like dowling.
    Now the 2 gears will mesh properly. I didn't need the shim. But check
    your shaft turning tollerance. If tight, use your std shim.
    If you are going on a long cruise, switch it to fwd. Saves mega gas.
    Cheers !
    PS: The manual section needs the top bracket ground back a bit.
    No bolt to line that up with on the auto box.
    #24
  25. Bud92gsx

    Bud92gsx Supporting Member

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    Your moms house, BC_Canada
    Exactly,everyone is saying autotrans for drag..Will someone delete that rebuilding is a pain on Knochgoon's post..I have only rebuilt one auto and one manual tranny in my life, and I must say that with the proper tools, the auto was MUCH easier to rebuild..There are alot of upgrades out there for auto trans as well..Man valve bodies, shift kits, better shift solonoids, tranny coolers,..EagleTalonTim sell those wonderful auto shift boxes, if you feel the need to shift.. point is there are tons of stuff for performance in an auto tranny..
    #25

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