Drag racing automatics, what gets done?

[BLSTIC]

I'm talking strictly 1/4 mile stormer here.

What do you guys do to make your automatics last under any kind of power? I'm guessing I should start with an SVX or TwinTurbo gearbox as a base (both are more powerful things that start with EJ bolt patterns), but that's about where my knowledge ends...

Any contributions are welcome, just note that I have no interest in dog boxes or button clutches, the key to drag racing is consistancy...

[Guest keltik]

High stall torque converter, performance clutches and strengthened bands, modified valve body (IPT make one for the 4EAT) and stronger axles. I think thats about it.

Check out the IPT website. http://www.importperformancetrans.com/subaruindex.shtml . I think a fully worked 4 speed cost around 6k last time i looked.

[BLSTIC]

Not nearly as much as a dog-box and button clutch.

So why don't I see any auto wrx's on the street?

[Guest keltik]

The high stall torque converters make them pretty impossible to drive on the street. Also the gearchanges are brutal. At least thats my experience from being in a modded auto.

[BLSTIC]

Therin lies the joy of an electronically controlled auto... I know with commodores you can re-program them to suit just about anything. Has no-one done this to the subaru gearboxes yet?

[Guest keltik]

Someones figured out how to 'hack' the 4AT control system and make the shifts super firm, but because drag racing is a mostly american thing - and americans are scared of japanese treachery - not many people put the time and effort into subaru stuff over there.

[Shale]

 keltik said:

Someones figured out how to 'hack' the 4AT control system and make the shifts super firm, but because drag racing is a mostly american thing - and americans are scared of japanese treachery - not many people put the time and effort into subaru stuff over there.

Added to that, most of us put our rally-inspired Jap-rockets through corners

[BLSTIC]

Hmm well I'm not too interested in corners. They come with their own compromises. You can still drive a drag car on the streets without a bone-jarring ride. Oh, and no-one in their right mind would expect something that appears to be a GX impreza leave a vapour trail off the start line.

If I do go get another subaru, I'll have to start from the bottom though. A 1500 auto awd impreza should do as a base (basically because it has the right pedals already, and an automatic computer). I think a 250T engine can be made to handle the grunt (with secret block strengthening methods), and I'll see if I can adapt a BD/BG GT gearbox to suit.

However all of those will set me back nearly $6000 for what is really a slightly quick wrx in a plain wrapper... It won't launch hard if I use a big turbo though. But if I build the engine right I can just turn up the wick when I get the cash for the gearbox.

[Guest boostcut]

Hmm well I'm not too interested in corners. They come with their own compromises. You can still drive a drag car on the streets without a bone-jarring ride. Oh, and no-one in their right mind would expect something that appears to be a GX impreza leave a vapour trail off the start line.

If I do go get another subaru, I'll have to start from the bottom though. A 1500 auto awd impreza should do as a base (basically because it has the right pedals already, and an automatic computer). I think a 250T engine can be made to handle the grunt (with secret block strengthening methods), and I'll see if I can adapt a BD/BG GT gearbox to suit.

However all of those will set me back nearly $6000 for what is really a slightly quick wrx in a plain wrapper... It won't launch hard if I use a big turbo though. But if I build the engine right I can just turn up the wick when I get the cash for the gearbox

how do you figure that? you can make anything launch hard with any turbo. maybe talk to a pro about drag racing and find out the facts and cost.. because if you want to even see a 250t engine handle the jandle. 60k will be you budget. not 6

[BLSTIC]

Not with a standard torque converter you can't. It doesn't matter how long you stall it, if the turbo is too big it won't get on boost. Not without nitrous or anti-lag anyway.

And how do you figure it would cost $60,000? I'm not aiming for a 7-flat down the quarter, I'm aiming for a fast car that can still be street driven. A fast street car is anything in the 12 second range.

BTW, the problem with the 250T engine is the fact that the top of the bock isn't supported. That isn't a major engineering task to fix...

[Guest boostcut]

im not sure i said anything about a standard converter. and neither did you...

[Guest keltik]

Build a blown EG33 for it. At least then you can get some good times down the strip.

[Guest boostcut]

12 second? you dont set your goals very high. you could do a 12 in a standard wrx freeboosting a vf22 and some sticky tyres.

[BLSTIC]

No, but I did imply using a standard gearbox before I get the cash for a big one. Meaning a standard torque converter as well. Anyway that's not the point.

EG33? Too rare. EZ30R, now *THAT* would be awesome. But both are expensive.

6 cylinder noise FTW thoguh

[BLSTIC]

Not with any kind of reliability. I know manual wrx gearboxes really hate launching...

[Guest keltik]

EZ30R is more rare and more expensive. EG33 is a shitload easier to build as its all EJ22 parts. Do some research.

Also with a standard box, you can wire up a system of push buttons for each gear which will give you an instant shift at full line pressure. Cant remember where i read up on it - but its not that hard to do.

Also Id hook up a switch to the duty C solenoid so you can lock the center fully for launches

[BLSTIC]

I'm aware of electronically controlled gearboxes. Two solenoids control the shifting, a third controls the line pressure, a 4th controls the torque converter. Two others help with shifting smoothly, and the last does the 4wd system.

Depending on how bad it slips I can modify the signal to the line pressure solenoid to make the shifts firmer, or I can have one switch that disables the auto computer and another two for shifting.

If I use a later model gearbox (ie B4 era), don't they have constant 4wd, and the clutch just locks them? I know the early boxes are FWD with computer controlled rear drive though...

[Guest keltik]

Correct, You'l be wanting a Lancaster VDC auto or certain forester models with the good center diff. Or just swap the tail housing off one of them onto whatever box you use. On the forester owners forum they have a real good thread about the swap to the VTD center diff instead of the MPT one. The guys 60ft and 200ft time improved immensely.

[BLSTIC]

Well all of these useful things add up...

I should be able to get a single wreck with most of the good bits in it, you would think. But then again, if I move back to dunedin I know a few people who do subies regularly, so I might not have to put up with two cars in my yard.

That's enough plotting for tonight though. Proper research tomorrow, then I'll decide

[Guest boostin]

This thing is auto...

http://members.iinet.net.au/~zrinski/wags1125.wmv

[BLSTIC]

http://www.autospeed.com/cms/A_1801/article.html

so is this. The inspiration for this thread...

[Guest boostin]

 BLSTIC said:

http://www.autospeed.com/cms/A_1801/article.html

so is this. The inspiration for this thread...

Holy s**t!!

Here's a vid of the same wagon. After a few runs it starts to spin the rears while sitting on the start line.

[Guest keltik]

Im in love

[Old Skool Subbie]

 keltik said:

EZ30R is more rare and more expensive. EG33 is a ****load easier to build as its all EJ22 parts. Do some research.

Not Quite... EG33 is lossely based on the EJ22 but most things are different.. for a start the pistons are different to EJ22 pistons..

Only thing that I can think of the top of my head that is the same is Conrods.

Infact theres bearly any thing you can use off a EJ22..

To build one its really big money.

You will also run into cooling problems...

They are a good engine tho

I plan to do a major build sometime down the track on my EG33.

Theres guys still trying to sort out problems with there builds...

Im just waiting on some more fixes to go ahead and see how they prove them selves.