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Old 10-31-06, 07:44 PM
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skjohnson
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Default auto to manual

Do you guys think it would be stupid for me to change from automatic to manual?

and i dunno where but i heard that actually sometimes automatic with turbo would be faster that manual with turbo, Is that true??
and i also heard that a 4 cyl manual would be technically faster than a 6 cyl auto...Have no clue if this true either...

Thanks...srry for 3 q's at once
Old 10-31-06, 07:52 PM
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sliva001
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I was also wondering about the same thing. I searched and found out that there are a lot of parts involved in swapping to manual and its very expensive. The ecu also controls the auto trans it will be very complicated and expensive swap. Worth it? maybe if you really like to shift.
Old 11-01-06, 07:58 AM
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lfrers
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I did auto to V160 6 speed.
Old 11-01-06, 03:56 PM
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Built autos are faster in the quarter mile... that's why people go and upgrade to the th400 transmissions.

The ECU without an auto will just throw a CEL code.
Old 11-01-06, 05:53 PM
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skjohnson
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i have a sc300....how did they build it to be faster in automatic?
Old 11-01-06, 07:05 PM
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0l33l
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Originally Posted by skjohnson
i have a sc300....how did they build it to be faster in automatic?
https://www.clublexus.com/forums/sho...d.php?t=246262
Old 11-01-06, 09:30 PM
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stokdd
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Not to sound harsh, but you obviously know nothing about this subject (that's why you're here!).

Two vehicles (stock for stock) of the same spec (one manual/one auto), the manual transmission will generally be faster because the automatic transmission (aka slushbox) A. is slow shifting and B. uses fluids and many clutch packs/plates and a torque converter instead of actual gears, which equates to lost power.

The above is true unless, the automatic in question is the new DSG-style (found in new Audi, VW, and now in more and more manufacturers). This style transmission uses conventional gears and two clutch assembies instead of the plates and whatnot found ir regular automatics. The DSG functions the same as a manually-shifted tranmission, minus the fact that it is computer controlled (ie no clutch pedal). How it works is at rest (stopped, like at a light) both clutches are disengaged. When one pushes on the gas pedal, the first clutch assy. engages, just as it would in a normal manual transmission, albeit computer-controlled. When it's time to shift, the first clutch disengages while the transmission slides out of gear, selects the next gear, and the second clutch engages. This entire process can take as little as 0.2 seconds! This particular transmission is much faster than a conventional automatic, but OEM applications have not been pushed very deep into power/torque figures. For example, the new VW GTI is rated at 7.1 seconds 0-60mph with a conventional 6-speed manual transmission. The DSG-equipped GTI is rated 6.8 seconds 0-60mph: a full three-tenths faster!

Now we get into the realm of big power numbers and low quarter-mile ETs. At some point, a vehicle begins to make too much power and torque to smoothly and accuratly shift manually to make full use of the available power and torque. I won't even get into launching! Let's say you have a built Supra capable of 8-second quarter mile times. With the OEM 6-speed manual transmission, you'll have to shift as many as 5 times in those 8 seconds (depending on your rear gears) - that's a lot of shifting in a short amount of time! You're bound to screw something up - miss a shift, let the clutch out too fast causing excessive wheelspin or even breaking something! You must accomplish all of this while trying to keep your beast headed in the right direction!

Let's take that same Supra and equip it with a good automatic transmission (TH400 for example). Set your stall and when those green devils illuminate, let her rip. No focus on choosing the correct gear and accurate clutch engagement, just hang on for dear life! In some cases you'll have move a lever for the automatic to switch gears, but that's as simple as pulling back on a stick.

If you were able to follow all of this, you should have at least some idea of why automatics are easier and better to use in high-horsepower drag application

As far as a manually-shifter 4cyl being 'faster' than an automatic 6cyl, the varies HEAVILY on the car(s)! A stock automatic TT Supra slower than a stock manually-shifter Civic? Maybe with the weight difference, but that has nothing to do with the transmissions!

-Evan

Last edited by stokdd; 11-01-06 at 09:33 PM.
Old 11-03-06, 09:10 AM
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nasc300
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Originally Posted by skjohnson
Do you guys think it would be stupid for me to change from automatic to manual?
Yes it would be stupid to if you intend to keep the engine stock. It will still be slow.
It may still be stupid, even if you to make more power. A stock auto in good condition will handle 300whp OKish. The W58 WILL break between 300 to 450whp depending on driving style.
If you plan on making between 500 to 600 whp or just want a reliable tranny it would be cheaper to go with a built auto vs a R154 or 6sp swap.
Old 11-03-06, 11:02 AM
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np20412
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Originally Posted by nasc300
Yes it would be stupid to if you intend to keep the engine stock. It will still be slow.
It may still be stupid, even if you to make more power. A stock auto in good condition will handle 300whp OKish. The W58 WILL break between 300 to 450whp depending on driving style.
If you plan on making between 500 to 600 whp or just want a reliable tranny it would be cheaper to go with a built auto vs a R154 or 6sp swap.
Not stupid if you have an automatic, maybe becuase you couldnt find a 5 speed, then find a W58 for sale and swap it up because you really want to drive a 5 speed because you find that it is 100x more enjoyable than driving an automatic. Granted the car would still be slow, it would be more fun to drive.

Or if your auto happens to ***** a brick, then swapping in a 5 speed wouldn't be a bad idea compared to having a tranny rebuild or bringing in a new auto transmission...
Old 11-03-06, 01:18 PM
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PsiQo1
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talk to jspec3 -- he has done the auto to 5spd swap..ive seen it and he did a pretty damn good job ... he could chime in on this subject
Old 11-03-06, 06:15 PM
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ThomsonCharm
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Originally Posted by skjohnson
Do you guys think it would be stupid for me to change from automatic to manual?

and i dunno where but i heard that actually sometimes automatic with turbo would be faster that manual with turbo, Is that true??
and i also heard that a 4 cyl manual would be technically faster than a 6 cyl auto...Have no clue if this true either...

Thanks...srry for 3 q's at once
I wouldnt necessarily call it "stupid" if someone decided to go from an auto to manual as that is all relative and up to the owner. In reality for an average Joe going from auto to manual isnt really the best of ideas. It is quite a bit of work to make the conversion and there are plenty of things you have to take into consideration that you probably just are better off not even bothering with in the long run.

Automatics with turbos can infact be faster as they are able to build boost off the line with larger stalls and various other goodies you can get with the transmission *transbrake,* this allows the turbo to already be spooling up before the car even launches because there is already a load on the motor. So instead of having no boost when you launch you have 5 pounds of boost. Not only that but wheel spin and 60 foot times again to the average Joe are lower with an automatic transmission then with a manual. This is based completely off of 1/4 mile and drag strip racing, if you plan on competing in any other type of racing manual is better as you need as much control of the car as you can possibly get.

But this is ALL relative to the type of transmission being used, the stall on the automatic transmission, the gearing in the transmission and rear end, the motor connected to the transmission. In other words its not something you can just indefinately answer without knowing the specifics between the two comparisons.
Old 11-03-06, 09:14 PM
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skjohnson
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thanks for the answers n ur help!

what could i do to make my automatic transmission better? without actually swapping it or something too difficult...
and what is a "transbreak"

thanks agian in advance...srry for noobish questions...
Old 11-04-06, 05:53 AM
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np20412
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By transbrake I think he means "powerbrake" where you step on the brakes and gas at the same time to rev up the motor before you actually launch.

As for improving your tranny, you could upgrade the torque converter and add a transmission cooler, flush your tranny fluid etc.
Old 11-04-06, 06:14 PM
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A trans brake is installed in the transmission. It effectively pits 1st &
reverse against each other. By doing so the trans is locked in place.
This allows the driver to fully preload the suspension & hold the pedal
to a desired rpm (build boost) for take off. With the push of a button
reverse is removed & your gone.

In a nut shell auto's are good for going straight fast. Sticks are good
for going in & out of turns fast. It's up to you, what do you want the
car to do & what is its purpose. Mine was to drive fast on back roads
w/ lots of turns & to push your eye ***** to the back of your head on
the straights.

Lastly, before you look @ the bmw/audi "electronic" clutch trans w/
padel shifting. Drop 15G on a hollinger sequential. You use the clutch
to leave, then just shift from there, no clutch. It's fully syncronized,
up is up & back is down + it will hold big HP. Nice piece, but ya gotta
pay if you want to play.
Old 11-05-06, 08:13 AM
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JspecSC3
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I dont like four cylinders. But I changed over from automatic to 5speed manual. Total cost at the most would probably be around $1000. I spent way less than that. Did most of the work myself too. The Supra 6speed will cost you thousands only because there are more work and parts involved. Id rather have a manual with my turbo. Some people like having built TH300/400 automatic transmissions with their 2JZs but the majority of people that have those automatics do lots of drag racing. Im an all around type of guy so I keep my manual.
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