Automatic ka-t..???

Post by **rn240sx** » Tue Jul 27, 2004 2:38 pm

Has anyone on this board or know someone that has done an automatic ka-t...?? Or should we stick to a 5 speed ka-t..??

ThanksRobert

Post by **GEO** » Tue Jul 27, 2004 2:38 pm

automatic KA-T's are awesome. You stay in boost during shifts and the turbo's SPOOOL faster.

Post by **Structure240sx** » Tue Jul 27, 2004 2:38 pm

theres actually more lag with an auto mainly off the line. when shifting with a 5spd your back in boost as soon as you get back on the gas. the benefit to the auto kat is consitency like any car.

i did have an auto kat for about a month. it was pretty decent. for drag racing purposes i would defeintly take the auto. i just liek drving a manual, its more fun excpet when you miss a gear racing

Post by **AZhitman** » Tue Jul 27, 2004 2:38 pm

If mine goes KA-T, it'll be an auto.

Actually, if I go SR, it'll be an auto too.

Post by **GEO** » Tue Jul 27, 2004 2:38 pm

dman.. I hard the auto's spool faster..

Post by **Structure240sx** » Tue Jul 27, 2004 2:38 pm

why woudl they? think about it everyone wants a 5spd because they say they are faster. this is because less power is lost through the drivetrain of a 5spd. the more power you get out the faster the revs get up then the faster the turbo spools up. really the difference isnt that much. only time the auto is behind would be off the line or coming out of a turn

Post by **ftrs13** » Tue Jul 27, 2004 2:38 pm

maybe the auto tranny puts more of a load on the engine causing the turbo to spool faster

Post by **s14det** » Tue Jul 27, 2004 2:38 pm

Off the line they would really suck, unless you change the stall speed of the tq converter to like 2k or something....after that it would be faster then a 5-speed I bet.

Post by **98s14inaz** » Tue Jul 27, 2004 2:38 pm

It spools faster because you are always under boost. when an auto's throttle body is open it stays open until you let your foot off the gas. You don't loose boost every time you shift.

I will let you know in septemeber when my kit goes on. Just waiting on a couple of parts and new oil pan. kat auto Mwhahaha

Post by **Ubernoober** » Tue Jul 27, 2004 2:38 pm

Quote »It spools faster because you are always under boost[/quote]

Umm, ya. Maybe you are not fully cognizant of the definition of "spooling up". :rolleyes

Post by **s14det** » Tue Jul 27, 2004 2:38 pm

The correct thing to say is that you do not need a BOV because the Throttle body never closes.

Post by **98s14inaz** » Tue Jul 27, 2004 2:38 pm

WellIi was in a hurry when I typed that and it was half a thought.

You need a bov anyway for when the throttle body slams shut. What I meant to say about an auto boosting is that once you have "spooled up" you don't lose boost between shifts because the throttle body never closes unlike the clutch, gas, shift, gas sequence in a manual. Probably some lag of the line but the quick shifts and no loss of boost pressure between them should make up for that. Sorry about the misinformation.

Post by **WDRacing** » Tue Jul 27, 2004 2:38 pm

Auto's are almost always quicker off the line then manuals. If I'm sitting at the lights with boost already sitting at 1 bar and your simply sitting at 4500 rpm, who's gonna have the better 60' time. Here's a hint...me. Not only is the auto more consistent, it can build boost sitting still. Your only problem would be if you were running a turbo to large to build boost, in which case all you need is a better stall converter.

Greg's car is going to be an animal when I'm done with it, unless he decides to go SR. Then he's on his own.

WD

Post by **jtsarnak** » Tue Jul 27, 2004 2:38 pm

Quote »If I'm sitting at the lights with boost already sitting at 1 bar and your simply sitting at 4500 rpm, who's gonna have the better 60' time.[/quote]

Are you saying that you can sit and build boost assuming you have a different stall on your torque converter? Or are we talking stock?

Also, since i don't know a whole lot about automatic trannies, is a higher stall converter one that allows no transmission of power until that RPM is reached, and then suddenly starts pushing power? For example, if I have a converter with a stall of 2000 rpm, does that mean I can rev anywhere between 0 and 2000 and the car just sits there, and then once I get above 2000, the car takes off as if the clutch in a manual tranny was just dropped at that same rpm?

If that is the case, what does that do to regular driveability. Does that mean that when I let off the brake in the auto car with a 2000 stall that it doesn't creep forward like normal, because it only idles around 750 rpm? What about in parking lots where small adjustments or low speed turns are needed? Does the car not respond until 2000 rpm making driving at low speeds in tight quarters really erratic and scary?

Post by **sxseguy** » Tue Jul 27, 2004 2:38 pm

That's not quite how it works. The stall speed is just the point at which the converter reaches maximum coupling efficiency. Below that point, it WILL transmit power, but with slippage between the stator and impeller, reducing the amount of power reaching the rear end. So, you may see something like 50% coupling at 1000 RPM, but 98% coupling at stall speed.

Post by **WDRacing** » Tue Jul 27, 2004 2:38 pm

YES, what he said...

Post by **jtsarnak** » Tue Jul 27, 2004 2:38 pm

So if some amount of power is being transmitted below stall speed, how does one build boost at a standstill, by also stepping on the brakes while building revs?

Post by **Ubernoober** » Tue Jul 27, 2004 2:38 pm

Yup, exactly that.

Post by **rtsol** » Tue Jul 27, 2004 2:38 pm

hows the longevity of the auto when making 300+ HP?

Post by **WDRacing** » Tue Jul 27, 2004 2:38 pm

The 240 has the same tranny as the GTS-t Skyline, so I know for a fact it can take the abuse. I was neutral dropping mine for about a year when I installed a turbo far to large for an automatic 2.0. She just grinned and kept on ticking.

I'd install a nice tranny cooler though, keeping the slush box cool is the key to longevity.

Post by **D Money** » Tue Jul 27, 2004 2:38 pm

Screw auto, power shift

Post by **98s14inaz** » Tue Jul 27, 2004 2:38 pm

Which tranny cooler works the best? I have seen two kinds... One looks like a mini radiator and the other is an aluminum tube with heat sinks going down the entire length of the tube. just curious? Jegs carries both if you want to see what they look like.

Post by **WDRacing** » Tue Jul 27, 2004 2:38 pm

The radiator type works best...and Summit has better shipping then Jegs.

Post by **98s14inaz** » Tue Jul 27, 2004 2:38 pm

Thanks

Post by **rn240sx** » Tue Jul 27, 2004 2:38 pm

HEY 98s14inaz:

I found this picture on your web page (car domain) and I was curious to know what the color code was for it..??I know your is DN1, but which is this green S14..??

http://memimage.cardomain.com/...9.jpg

ThanksRobert

Post by **98s14inaz** » Tue Jul 27, 2004 2:38 pm

same color, same car. It kinda color shifts depending on lighting conditions.

Post by **onosqv** » Tue Jul 27, 2004 2:38 pm

darn it. And I thought I was gonna be the only one building an auto ka-t.

Auto cuz I can barely drive manual. And auto because that's what I got.

SHIFT_AUTOMATIC :-D

Post by **Structure240sx** » Tue Jul 27, 2004 2:38 pm

this time last year i was putting my turbo kit on my auto s14. there were plenty before who have fully built auto kat's

Post by **rn240sx** » Tue Jul 27, 2004 2:38 pm

I just wana speak to someone that had or still runs an automatic ka turbo...I dont wana go out and buy an auto S14, turbo it, hate it, and then have to deal with swapping it back to 5 speed.

Post by **Structure240sx** » Tue Jul 27, 2004 2:38 pm

you can IM me at structure240sx if u want to talk

Automatic ka-t..???

Automatic ka-t..???

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