AT Turbo Spooling

[Acroth]

First of all, I know, I know... Turbo on an Automatic sucks... (but my supra will still waste most Honda/Acura posers out there) Anyways...

Does anyone know if there is a kit or modification for an Automatic Transmission to have the turbo spool up while in nuetral?

(i'm sick of people pullin up next to me and blasting their BOV and I can't do anything but sit there and smile when the last thing they see is the rear end of my car..)

~Acroth

[HellKnight]

Originally posted by Acroth
First of all, I know, I know... Turbo on an Automatic sucks... (but my supra will still waste most Honda/Acura posers out there) Anyways...

Does anyone know if there is a kit or modification for an Automatic Transmission to have the turbo spool up while in nuetral?

(i'm sick of people pullin up next to me and blasting their BOV and I can't do anything but sit there and smile when the last thing they see is the rear end of my car..)

~Acroth

Yes, there is a modification you are able to do so that you get a good launch from idle or rest. The term is called the "Turbo Launch" check it out at http://www.geocities.com/turbo6p/

Pretty much just tells you how to modify you ignition etc., heres a quote from the page:
"The Turbo Launch is a secondary rev limiter built for the MKIV Supra that limits the engine speed to a preset RPM . It does this by interrupting the ignition signal going to the ECU. This allows the engine to build turbo boost with the car at rest. This is great for a car that needs a harder and more consistant launch. The system is engaged with a switch just before the launch and disengaged just after. "

Details on how to modify your car to have a turbo launch can be read here: http://www.geocities.com/turbo6p/TLinstructions.html

P.S - I have a friend already running the Turbo Launch in his MKIV, he needs a lot of traction when launching so I suggest you do major traction modifications when you do this or you will loose time instead of gain any.

[PNG]

First of all, you don't know jack. Turbos and automatics are a perfect match because you CAN spool the turbo and build boost on the line, unlike a manual turbo car where all you can do is get the BOV to go "wheee!!!"

Second of all, you shouldn't be in neutral, ever. Slamming an AT from neutral to drive will destroy it very, very quickly.

Do a search on "automatic" and "turbo" to read what's already been said on this before. Since I'm in a charitable mood, I'll help you out by giving you a quick primer on how to launch a turbo automatic.

Step one:

Install a transmission cooler ($50 and about 1-2 hours of your time, depending on how stuffed with crap your engine bay is)

Step two:

Put transmission in "Drive" (not overdrive or 4th, since this generally reduces line pressure in the transmission, which is bad)


Step three:

Stand on the brake pedal with your left foot

Step four:

Press the accelerator pedal with your right foot to bring the engine speed up against the resistance from the torque converter

Step five:

When the RPM won't climb any higher, that's called the "stall speed" of the torque converter. Some cars won't let you rev that high - the engine will "push through" the brakes and the car will start to creep forward.

Step six:

When it's time to leave, sidestep the brake to release it, and stomp on the gas.

Note: Try not to brake-torque the engine against the TC for more than about 5-8 seconds at a time, since doing this puts a ton of heat into the transmission. That's why a cooler is MANDATORY for racing a car with an automatic transmission.

Using this technique, I can get my WRX to spool up to 15psi on the line and cut a 2.00 60' time on the crappy stock tires, with no mods other than a transmission cooler, K&N filter, and a manual boost controller.

[Acroth]

HellKnight: Thanks a lot, I'll look into that...

PNG: I've actually done that before but was worried about toasting my brakes.. (once I get my slotted/drilled rotors and new pads I'll test it out) *Acroth searches online for a tranny cooler*... thanks for all the info and going easy on me!

~Acroth

P.S. WRX's kick ass :)

[PNG]

Originally posted by Acroth
HellKnight: Thanks a lot, I'll look into that...

PNG: I've actually done that before but was worried about toasting my brakes.. (once I get my slotted/drilled rotors and new pads I'll test it out) *Acroth searches online for a tranny cooler*... thanks for all the info and going easy on me!

~Acroth

P.S. WRX's kick ass :)

It won't hurt your brakes one bit. If you're launching from a standstill, all the brakes have to do is hold you in place - nothing should be turning. Most stock brake systems on RWD cars don't put enough line pressure to the back end to keep the engine from overpowering the brakes (at least on V8 cars - this may not be the case for cars like the 240SX) so they'll slowly churn the back tires if you brake-torque them too hard. FWD cars generally don't have enough torque to "push through" the front brakes, since the proportioning valve sends the majority of the pedal pressure there.

On the WRX, I end up taking advantage of that "push" to perfect my staging technique. I'll light the prestage bulb, then push the brake to the floor and start running the engine up against it. As the boost builds, the car will start to creep forward a little bit, lighting the stage bulb. I have to increase the pressure on the brake to hold it there, and the engine will rev to about 3200 rpm at 15psi. When the third yellow comes on, I just sidestep the brake and mash the throttle.

Like I said before, the only thing that will be potentially harmful doing starts like that is holding it for a long time, or doing it without a cooler for the transmission. It's actually easier on the drivetrain than a maximum-effort launch in a manual transmission car would be, because everything's slowly preloaded instead of getting hit with the torque in one big bang.

[Acroth]

PNG, Thank you so much for all your help...

I'm definitelly going to work on this, I just have one more question..
Do you have any recommendations on Tranny coolers? I was looking around online and i'm not exactly sure if I need a specific cooler built specifically for my vehicle or if any of them will work as long as I can find room to stuff it in there..

Thx again!

[PNG]

Pretty much anything that will fit will work. I prefer "multiflow" ones like those sold by Fluidyne, or "stacked plate" designs (available from a variety of manufacturers) over the regular "round tube and fin" kind, because the first two types tend to be more efficient, resistant to damage, and less likely to suffer a fatal clog than the last one.

Multiflow:
http://www.fluidyne.com/images/hpcooler3.gif

Stacked-Plate:
http://www.fluidyne.com/images/hpcooler1.gif

Round tube and fin:
http://store.summitracing.com/global/images/prod/large/FLX-3818.jpg

[MistaFosta]

Thank you Paul. I really didn't want to write all that... LOL. But, if you didn't someone would have had to..

[PNG]

Damn, I must be losing it. I almost missed a chance to pimp my website... (http://www.techweasel.com) Time to fix that little mistake!

Here's the stacked-plate cooler I'm gonna be running on my Sy:
http://www.techweasel.com/images/P6200292.JPG

[HellKnight]

No problems Acroth, thats what people come on here for, to learn stuff. Listen to PNG when he speaks, he is one of the three wise men.

If you need further help with your car give me a PM, would be glad to help you out further, got some experience working on MKIV/MKIII's.

[Acroth]

Thank you all, especially PNG..

This is the best forum i've found, think i'll stick around :)

[Acroth]

I'm sure that any of the stacked or multiflow coolers out there would work just fine...

I am looking at the B&M supercooler (stacked)..
I know it will work fine, just thought i'd ask if anyone had any opinions on brands for good tranny coolers?

PNG: i've bugged you enough, you need not reply if you even slightly dont want to :P

[PNG]

B&M's fine. So is Perma-Cool, or Earl's (they're kinda spendy, though). I like the Fluidyne multiflows because I used to get them for free, since I worked for the company that distributed them. Well, I also got to see how they were built, so that helped too.

[Acroth]

Ok thanks :)

*Acroth orders tranny cooler*

[Qx4Beebs]

My truck came with a stacked tranny cooler, but I have noticed severe losses in 60' times and r/t if I brake torque past 1.5k rpm... I would like to think that once the tranny gets hot, it doesn't lock up as quickly or with as much force so it kinda slips. So would another tranny cooler along with the original help solve this problems? I am also thinking of flushing the tranny with synthetic ATF since I only drained and filled it with synthetic instead of completely flushing.

[PNG]

Originally posted by Qx4Beebs
My truck came with a stacked tranny cooler, but I have noticed severe losses in 60' times and r/t if I brake torque past 1.5k rpm... I would like to think that once the tranny gets hot, it doesn't lock up as quickly or with as much force so it kinda slips. So would another tranny cooler along with the original help solve this problems? I am also thinking of flushing the tranny with synthetic ATF since I only drained and filled it with synthetic instead of completely flushing.

Was the tranny cooler part of a towing or severe duty package? If not, I'd guess that it's probably marginal for racing... Might be worthwhile to invest in a transmission temperature gauge to see what's really going on, or find a friend with an infrared thermometer and see how hot the cooler's getting.

[Qx4Beebs]

Well, since its an 4x4 its probably for low range crawling situations, so I don't think it is that great... Would a new one help me get a quicker 60' time?

[PNG]

Originally posted by Qx4Beebs
Well, since its an 4x4 its probably for low range crawling situations, so I don't think it is that great... Would a new one help me get a quicker 60' time?

Well, it can't hurt, that's for certain. If your tranny is slipping because the fluid is cooked, it will definitely help.