Halon

iTrader: (6)

I am still in the process of trying to buy an SC300. At first I was strictly looking at 5-speed models, but have recently decided to research a bit on building an Auto setup, before I completely limit myself to a manual.

I'm still what I consider a noobie to these vehicles. I'm coming from a Mitsubishi background (DSM's), where Auto's are starting to become a little more popular, especially when it comes to drag racing. So figured I'd see what the scoop is on these vehicles, and see if it's popular or not.

Some of my thoughts are, whatever I choose (manual or auto) I will eventually need to address the tranny as they both have their limits. I was running a BW 62mm turbo on my Talon, loved it and plan to use almost an identical turbo on an SC300 once I get one. So at those power levels, the tranny needs to be addressed either way so that's kind of a wash in my eyes.

I'm assuming an Auto is going to have a lot more "stuff" involved though. Lines running around for a tranny cooler, maybe some solenoids, etc in the engine bay. Is this true, and if so does anyone have pictures of what kind of mess the Auto Tranny creates in the engine bay? Just wondering how much that will be a factor, like if certain turbo setups won't fit as well because of all the extra crap in there due to it being an auto.

Anyhow, if anyone has some constructive feedback on building an Auto setup, please share anything you can with me, as I want to consider this as an option before I 100% tell myself I only want a manual setup.

Thanks in advance!

Halon

iTrader: (6)

http://www.clubna-t.com/forums/showthread.php?t=4145

Found some good info in there for anyone else reading this.

I guess what I'm understanding at this point is a I there's a couple options to keep this as simple as possible. The stock N/A tranny can't hold too much. It can be built, but even built won't support anything more than the stock TT Auto, so that's pretty much pointless. So here's the simplest options I see, the way I understand it at the moment:

1) Use a 1JZ tranny. It should, for the most part, bolt right in. Should be as strong as the 2JZ TT Auto tranny, and should be able to be built in the future to handle a lot of power.

2) Use a TT Tranny, do some internal parts swapping. Use the TT tq converter, SC400 driveshaft, and be on your way. Should support decent power, but can be upgraded in the future to handle lots of power if need be.


One thing I haven't figured out yet is how to do From Roll racing. Everyone suggests that you shouldn't shift these manually due to too much timing being ran if you shift it manually. So if you are getting ready to do a From Roll, I guess I don't see how to get into the ideal gear with the car automatically shifting to a higher gear, which you won't want to be in if you're about to do a pull.

SChema

iTrader: (2)

It really depends on what you want to do with the car. If you want to strictly race the car and run a time, autos are the way to go of course.

If you want to have fun on the street and track, a manual gearbox is better in my opinion. I love to have fun driving my car, so my build is including a manual gearbox.

turbodremz

iTrader: (18)

^^^ Halon nailed it.

The stock auto isnt worth much over 325hp, and even shimmed I wouldnt push more than 350 with it. And to be all honest I have been playing with matches and gasoline with my stock auto @ 9psi with stock compression..not to mention I shift it manually (2 yrs now with no issues)

While the TT auto trans is a bit stronger, it still holds a fairly low breaking point, but again shimmed accumulators and a cooler will raise this a bit, and IIRC with the cooler and shims is only good to just over 400hp, not to mention you need to either go standalone or swap to a GTE ECU, which can be used on the GE engine, but no confirmation on trans control just yet.


The ideal auto would be the TH400 if you have the pockets for it. The trans itself can be had for just a couple hundred bucks, but the BH adapter and flexplate adapter are where it adds up, not to mention the custom DS, and cross member.

The upside of an auto, is 100% positive boost pressure though the gears. Only downside is lack of total power support.

1siksc

iTrader: (8)

trust me just go with a manual even if you do drag racing, unless if you want single digits all day long. I went with a th350 3 Speed Auto and I have a 5spd VR6 Jetta for a DD and when comparing the two i wish i would of gone manual. To be able to control the car that much more is awesome, determining when the bov should go off or if your passing someone you know and want to show off by putting the clutch in and giving it a rev.

Halon

iTrader: (6)

The plans for the car are to basically build it to a similar level my Talon was. 600ish levels, 62mm turbo. Fun toy car to tool around in, with probably 3 trips/year to the track. Break into the 10's. I loved my Talon, loves it's power, but hated the lag of a 2.0 and the cheap feeling of it. Basically just looking to build the same thing, but on a more mature platform like an SC300.

I feel I can have fun in an auto. No more worrying about mis-shifts, easier to launch (in my opinion). I think an auto could be plenty of fun. I do agree a manual would be a little more fun, but I can still have fun in an auto. Plus, finding a decent condition older SC300 in Auto form, for a decent asking price, is about 90x easier than finding a manual.

I'm also trying to keep it as simple as possible, meaning I don't want to run a standalone. Will probably go the FIC route. So no GM trannies for me. From what I gather, a stock SC300 ecu should still be able to control a TT tranny, as long as I swap out the electronically controlled line pressure setup and put in the stock SC300 manual line pressure setup. Is that a true assumption?