Jump to content
SAU Community

Shift Kits Auto Box

Chids34
 Share

Recommended Posts

Chids34 Explorer

Chids34

Posted
Posted

Hi, I have recently bought a stage 3 shift kit for my auto r34, I will probably get a medium stall converter. Is there anything else I am going to need besides a rebuild to the box also how will a shift kit affect gear changes and the way the car drives, stage 3 is the firmest you can get I think and I've heard that they can be pretty wild, as its going in a street car would it be to much, can I still just put the car into 'D' and go grab some Thai noodles on a Friday? WILL IT STILL BE STREETABLE?

Thanks J

Link to comment
https://www.sau.com.au/forums/topic/447296-shift-kits-auto-box/
Share on other sites
LTHLRB Grand Master

LTHLRB

Posted
Posted

Shift kits are just kits that put higher amounts of pressure through your valve body making the vehicle shift more "positive" so to speak. The shifting will be harsh when cruising, kind of like a kick in the pants and it might even let off a little churp. Your stall converter size should be coming in when your power comes in, so lets say your cars power band is from 3 - 7500. Your converter would need to be 2800 - 3200 or thereabouts.

It would still be streetable, but will chew more juice because of a stall converter. You are still able to drive the car in D unless you have a semi manualised or a fully manualised valve body, then you'll need to manually shift from 1 2 3 D or whatever pattern your car has.

As Ben stated, a decent sized trans cooler is a MUST when it comes to stall converters and stuff.

Chids34 Explorer

Chids34

Posted
  • Author
Posted

Hmm thanks, as to bens comment Ive worked with auto boxes before so Im building it myself, but mainly 727 torqueflytes and 904 boxes out of valiants and dodges so old school. Just out of curiosity what happens if I don't upgrade the converter, say because I wanted to use less fuel. As a street car I'm not going to be stalling it up, so is it necessary. Also the shift kit goes into the existing valvebody if I'm right, so If I have a normal valvebody (the r34 has the triptronic or whatever its called where it has the sideline so you can choose gears semi manually) it should be able to be used in the same way? Ill definately be adding a trans cooler anyhow.

Ben C34 Grand Master

Ben C34

Posted
Posted

Also as the factory trans computer is staying in place shifts are still reasonably nice at light throttle due to the trans computer reducing line pressure. It's only when you go full manual and run full pressure the whole time that shifts become very harsh all the time.

Kinkstaah Grand Master

Kinkstaah

Posted
Posted

Is there any info anywhere as to how much the standard computer modulates line pressure? Does it go for "X" PSI or does changing the valve body result in it working in a "percentage?"

eg, at 'low' load does it go for "50%" of line pressure, or a set PSI?. I am kind of assuming it does a percentage, otherwise upgrading a valve body would do literally nothing if the standard computer would control exactly how much pressure to shift with :P

What you want though, is an aftermarket TCM for your transmission. Hopefully I will be able to see what the difference is running a big shift kit on the standard computer to one with a tuned TCM.

In all aspects though, a big shift kit is usually just fine for the driver, passengers may complain, though. This is the case with almost any modified car mind you..

  • Like 1
Ben C34 Grand Master

Ben C34

Posted
Posted (edited)

From what I understand it does it by pulsing a solenoid to bleed off pressure.

It doesn't monitor what the actual pressure is, so its just a set duty cycle thing.

You can add add larger resistor into the solenoid wiring so it bleeds less pressure off by not allowing the solenoid to open fully. At full throttle it's full line pressure so it just adds pressure for part throttle stuff. I did it as I run an rb2530 so make more torque with less throttle openings than the stock trans ecu would be expecting.

Edited by Ben C34

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      33 GTR Broken front wheel knuckle

      By GTSBoy · Posted

      There's plenty of OEM steering arms that are bolted on. Not in the same fashion/orientation as that one, to be sure, but still. Examples of what I'm thinking of would use holes like the ones that have the downward facing studs on the GTR uprights (down the bottom end, under the driveshaft opening, near the lower balljoint) and bolt a steering arm on using only 2 bolts that would be somewhat similarly in shear as these you're complainig about. I reckon old Holdens did that, and I've never seen a broken one of those.
    • MBS206
      33 GTR Broken front wheel knuckle

      By MBS206 · Posted

      Let's be honest, most of the people designing parts like the above, aren't engineers. Sometimes they come from disciplines that gives them more qualitative feel for design than quantitive, however, plenty of them have just picked up a license to Fusion and started making things. And that's the honest part about the majority of these guys making parts like that, they don't have huge R&D teams and heaps of time or experience working out the numbers on it. Shit, most smaller teams that do have real engineers still roll with "yeah, it should be okay, and does the job, let's make them and just see"...   The smaller guys like KiwiCNC, aren't the likes of Bosch etc with proper engineering procedures, and oversights, and sign off. As such, it's why they can produce a product to market a lot quicker, but it always comes back to, question it all.   I'm still not a fan of that bolt on piece. Why not just machine it all in one go? With the right design it's possible. The only reason I can see is if they want different heights/length for the tie rod to bolt to. And if they have the cncs themselves,they can easily offer that exact feature, and just machine it all in one go. 
    • Bennym35
      New guy

      By Bennym35 · Posted

      The roof is wrapped
    • Duncan
      R34 GT-T cycling ABS pump

      By Duncan · Posted

      This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • GTSBoy
      33 GTR Broken front wheel knuckle

      By GTSBoy · Posted

      Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
×
×
  • Create New...