ScionDad

Here is the ZPI solution - ESK and Valve body upgrades -
https://www.scionlife.com/forums/vie...349651#1349651


So far, I have searched alot of information for the automatic for much stronger shifting. Most auto companies have gone to electronic control with some positive and negative. Shift kit control might be as simple as an ECU change. Here is a good start to understanding. I am looking at several different options that are plug and play.

With the advent of the move to (TOTAL) electronically controlled automatic transmissions Toyota/Lexus decided to take advantage of the additional capability to add several new "features".

1. Extend the fuel economy by significantly lowering vehicle "drag" from engine compression braking. Anytime the throttle is fully closed the transmission is automatically upshifted to lower engine compression braking.

2. Significantly reduce the danger of loss of control of FWD, or front torque biased AWD, on slippery roadbed surfaces by reducing engine compression braking.

3. Significantly extend the useful life of the transmission by reducing its "workload" from engine compression braking. Many of these vehicles were shipped from the factory with a transmission fluid life expectency of that of the vehicle itself.

Keep in mind that by the year 2000 the analog, fluid based, "computers" previously used to control automatic transmissions were virtually PERFECT in their overall control operation.

Toyota's electronically controlled transmissions represented a totally new, clean sheet, design.

So, the transmission ECU firmware, software, detects that the vehicle is in a "coastdown" mode, throttle fully closed, and accordingly begins an "upshift" gear change sequence (and/or an unlocking of the torque converter) to reduce engine compression braking.

But what happens if the driver suddenly decides that he/she wants to accelerate at just about the same time the transmission begins the upshift sequence?

The only "feedback" the transmission ECU has to "know" that the previously commanded gear shifting has completed (other than elapsed time)is via a comparison of the transmission input shaft rotational speed and the output shaft rotational speed.

Up until the 2004 model year these transmissions would react correctly to this sudden change of input, quick change from coastdown to acceleration, but by now Toyota had discovered an anomally in the design.

In some instances you couldn't just change the commanded gear selection right in the middle, or during, a previously commanded gear change without compromising the operation of the transmission. The transmission momentarily being in two gear ratios simultaneously, for instance.

So, the 2001 AWD RX300 required no transmission fluid replenishing or replacement for the life of the vehicle, according to the owners manual. But then a significant number of these transmissions began to fail prematurely. The dealers have now been told to advise owners of these vehicles that a 15,000 mile transmission flush and replenishment is recommended.

So, as of 2004 the firmware was rewritten and an e-throttle was added. With an e-throttle the engine can be prevented from developing torque until the transmission can complete the upshift it started at coastdown, and then be downshifted into the proper lower gear for acceleration once the e-throttle is given the GO signal.

A 1 to 2 second delay in acceleration wouldn't be all that unusual in this circumstance.

MysTiKchRis

nice find

ZPIracing

RICAR....quit making excuses for your daughter as to why you can't turn the boost up in her car.

ScionDad

Who me? Na, I'm just trying to increase my post count.

killerxromances

^ ^

LOL! Your daughters car is nice i suppose. I really don't care for the hood lights and all of the neon crap. (no offense) But i must say, for a girl car, its not that bad. I've seen much, my god, MUCH worse. lol

Cya

mattssi

On the lex - I had purchased a unit from turboeast that they made for the IS300, basically had a connection for power, load, rpm, and line pressure. It worked like a s-afc for the trans. Basically took a signal, and output a different one to increase line pressure under load/heavy throttle.

This DID help a lot while NA, but when I went from the stock (170 rwhp) to 320 rwhp it didn't help for the 1-2 shift (but this could be a Lex problem since the 2nd gear is an overdrive gear)

mattssi

I eventually got a valve body upgrade which was sweet. 2-3 chrip and even 3-4 sometimes.
Suuuuuuuure blame the hankooks

ScionDad

Nice - I wonder if either is an option here.

bubblemyster

and your conclusion is...

ScionDad

My conclusion is the tranny will hold up to a stage one with it's internals....however, we need to assume control of the transmission from the stock ECU.

ScionDad

I emailed turboeast to see if their upgrades are adjustable for the Scion TC. That would be EXACTLY what is needed.

Thanks for the heads up.

JustAnotherAsian

yay for the automatics! interesting indeed.

ScionDad

Well thanks...i suppose. No offense taken. They are not for everyone. It's her car and she likes them, so that's what counts.

She does alot of car shows and most of the time, lights always helps set the cars apart....esp at a night show. If all the car has is lights, then yea...seems like a cheap mod. But a car that is heavily modded with performance parts and lights added as well....fits right in to a car show every time.

ScionDad

Well, thanks to mattssi, we have our solution. turboeast apprears to have the solution and at last word, Kenny at ZPI is going to work with them to iron out the details for the kits.

The true automatic will soon be released. There is nothing like 2nd and 3rd gear scratch from an auto shift kit.

AZURETCTONY

Great find and thinking guys! Nice to hear some performance mods that will benifit the AUTO TC's since we are starting at a disadvantage at the line. I will def be upgrading my TC when an auto shift kit is complete and refined.

ScionDad

Yup, def at a launch disadvantage.....and after that.......the advantage will "SHIFT" back to us.

ScionDad

Just a bump for this thread on progress.

Here is the latest email I received from them. They said it will work and are lookinig to test. Kenny at ZPI said the IS300 wiring is the same on our TC. Hopefully by next week...we will have one to test with.

<SNIP>

-----Original Message-----
From: TurboEast Sales [mailto:sales@turboeast.com]
Sent: Friday, October 28, 2005 1:47 PM
To: EJK
Subject: Re: Valve Body Upgrade or Electronic Shift Kit Upgrade

Yes, our E.S.K. module should work with the Scion, however I do not have a wiring diagram for the Scion. So, any of our E.S.K. modules are going to be for in-house installation only, besides Lexus cars. In the future we should have our E.S.K. module available for ship out on various Toyota cars, including the Scion. As far as the valve-body, it is a fairly simple upgrade, yet very delicate. I don't believe we have ever done a valve-body on a Scion, but we may be willing to give it a shot.
I will forward this email to Jeff (the owner), and see what he has to
say.
Thanks,
Sam Windsor
sam@turboeast.com
301-829-4902

-----Original Message-----
From: TurboEast Sales [mailto:sales@turboeast.com]
Sent: Monday, October 31, 2005 2:08 PM
To: EJK
Subject: RE: Valve Body Upgrade or Electronic Shift Kit Upgrade

I spoke with Jeff, he said if you guys would like to try one out to see if it works we can work with you. If you guys possibly want to setup some kind of group-buy, we can work on pricing and things of that nature. Let me know what you would like to do, and I will work with you as best as possible. Thankyou-Sam

<END SNIP>

AZURETCTONY

Hey Auto TC guys.... lets get some support for ZPI to get working on a E.S.K What would the install consist of? Group buy would be a great start to get things developed and rolling.

MysTiKchRis

Yes great idea. I really want this E.S.K. and for a good price.

David616

iTrader: (1)

Count me in.

Do we know of a price range yet for an E.S.K. for the tC?