Arithmetic

iTrader: (9)

^^^ somebody explain this, i know it doesnt mean that auto have the upper against stick turbos, but is this statement true?

TURBOit

iTrader: (26)

well sort of, in the caseof the lancer it is better to have a 5speed unless the automatic has done a transmission upgrade

but in regards to that statement (im not sure what is in reference too, it may not even be in reference to a lancer... what they mean is that the auto shifts so quick that by the time it shifts the turbo is nearly at max spool up already, whereas with the manual you let off, turbo slows down, you shift, then hit the gas, all that time in ebetwen for the turbo to drop spool

basically

Arithmetic

iTrader: (9)

would a tuned/upgrade auto trans with a turbo be better than a stick with a turbo?

P.S. i believe the thread was about a turbo auto civic.

imapunkclaimer

iTrader: (29)

when you change gears you may lose some RPMs depending on how fast you shift, I dont believe that statement at all because you can shift faster than an automatic, if youre good unless, like turboit said, you get a transmission upgrade (i hear airshift is great), but i mean it would be cheaper and faster to just go manual.

pickleknock

well, the auto does a better job of keeping the motor in the powerband range, though it has a higher powertrain loss. im not quite sure what would happen if two identicle lancers, accept for the tranny, raced at say 7psi. with that much power, the auto trannies loss would be much less noticable, which is why i disagree that drive train loss should be a % value, it should rather be a hp loss value. and i think that the auto tranny would make up for its drive train loss in the fact that the turbo doesnt take quite as long to spool up, doesnt have compressor surge between gears, and it has the intake manifold under constant boost being that the throttle body is always wide open. another point to consider, in a manual tranny, you acceleration stops for a short period of a time in between gears. say it takes you .2 seconds to shift, and you shift 3 times when you get to 4th gear, thats .6 seconds you arent accelerating, which could be as much as a .3 second head start in a race. when the manual tranny is in 4th gear, it is likely the auto will still be in its 3rd gear, which tops out around 105mph. so at that time, its only shifted twice, and it doesnt loose 100% of its acceleration in between gears. in conclusion, my theory, the more boost both lancers are pushing, the closer the race. throwing in an upgraded tq converter would bring it even closer.

this should be cleaned up and made a sticky.

bahamut

only powerful auto TC are Supra (proven a few auto are faster than their manual counterparts) and Scooby. Everyone will torched theirs in the long run.

IILANCERII02

iTrader: (1)

there is a company in IL who made a 500whp evo, or something close to that, and they changed it over to an automatic for the reson it would be faster.

In sense - if you upgrade your automatic transmission to be able to withstand the pressure of 8psi or 9psi even and get like a upgradded transmission, u can potentially be faster than a manual car.

Thats why most drag cars are automatic. Rally cars are manual, but thats for a whole differnt reason.

HobieKopek

iTrader: (8)

You cannot shift faster than a modern automatic transmission.

edit: And we already have too many stickies (generally speaking). There's no conclusive technical info in here anyway.

Guru_Del

iTrader: (5)

I believe that statement is in reference to a CVT transmission where the car is always in the Powerband as there are no gears to shift, just constantly changing pullies and bands. The only down fall with the Continuously Variable Transmission is few companies have one that can handle seious power.

As for being able to shift faster than an auto, frankly you are in dream land. An auto can shift in the range of .005-.01 seconds. Even the best of drivers can't shift much faster than .1 seconds.

Also a tranny upgrade is looking around $2000. (with new torque converter, bands, plates, clutches, etc.. and install). A conversion to manual would run you near $4000. I say a built auto would be cheaper.

As for the reason most drag cars are auto, it is to reduce driver error and for consitency. Dial in times are based off of what you think you can do, tossing in a manual tranny opens the door for missed shifts and a whole gang of other errors.

I have an auto, and when in boost I never go out of it untill I let off the gas, even when I shift gears. 1-2-3-4 shifts all done and I never fall out of boost, I do loose some boost during the shift but it is usually less than 1psi.

I would love to see what the same PSI lancer auto vs manual would do.

bahamut

As for the reason most drag cars are auto, it is to reduce driver error and for consitency. Dial in times are based off of what you think you can do, tossing in a manual tranny opens the door for missed shifts and a whole gang of other errors.

====================

I totally agree. When sponsorship money is on the line, torching a NHRA topfuel dragster from a misshift hurts insanely.

uranium9v

iTrader: (3)

Something I hate about the auto tranny - It will shift when you dont want it to, leaving you at low rpm sometimes. Manual will have better ratios because it has 5 of them, where the auto has 4.

Graeme

They say the auto transmission is better under boost is because when you shift in an auto, your turbo stays spooled, there's no wait time. If you get a stutterbox, you can do pretty much the same thing. Autos have fewer gears, which means a different (IMO worse) gear ratio. Most Drag autos have two gears, and usually the first one is used for about .5~1 sec and then the second gear is shifted in. Autos can shift faster than manuals, but depending on who programmed it, not as reliably. Even the new manumatic transmissions shift automatically when you hit redline, or will shift down when you stay at a high RPM too long. It's very very annoying to say the least. The Ferrari and BMW clutchless manuals are different, and are actually manual transmissions with computer actuated clutch and shift linkage.

I have driven the manumatic transmissions, and they are alright. However, if you expect the control and responsiveness of a Manual, think again. Mitsubishi, Honduh, Audi/VW are the manumatics I've driven. All shift when I didn't want to--although the Audi (New A4 1.8T/Old 2.8) one, and Eclipse Manumatic let you control it a little better, but they still shifted before I wanted them to.

IILANCERII02

iTrader: (1)

ya - i will agree with that Vince - and good job explaining why dragers use auto's, makes sense.

I too would also lik to see a graph or chart of an auto turbo vs. manual turbo and where the PSI is at gear shifts and all that stuff.

uranium9v

iTrader: (3)

I test drove a Mazda 3 manumatic a while ago...I was able to red line it and it and keep it at high rpm's and it never auto shifted for me....was kinda cool, freaked out the sales guy though.

imapunkclaimer

iTrader: (29)

Race shifting, if you dont let your foot off the gas at all you will not drop in rpms.

I find some automatic transmissions to shift slow for some reason and in my friends cars i catch it when its not evem in a gear and it just jolts. whats up with that?