Auto rebuild and strengthen, looong and piccish.

the stally i have is a 3k stally with the lockup still in there ... ?

 

ok cool . maybe things have changed since my auto days .

you dont seem to have any porbelms with yours, so i guess the auto thing has changed , back in the day you could not be on stall because it would get so hot that it would blow the auto box up . .

i have a manual so i guess i should stick to what i know yes ? lol

all good . you shit auto people

 

mines still in a box i havnt fitted mine yet itll happen when i pull the engine for the big mods, hanging for it though :zlove:

 

good good ,, when tho . summer is coming ,, build thread ?

 

not rushing into it wont be this year, i want to completly finish the inside and outside of the car first. car is/has been running mint with relativly nice power so ill just leave it like this untill ive completed all the interior and outside of the car.

sorry for the hijak mickw u can blame alex on that lol

 

As for a safe power figure for a stock transmission? Adam at ATS Automatics who did my build kept telling me to stop spending
money on unnecessary bits. He felt that the stock set up with a shift kit would easily handle the high 12's I am chasing, no
need to go silly with bigger this and better that.

I used the Superior Transmissions Shift kit in my stock Auto and it held high 11's with out issue , I have only heard good things about MV's version and i can only imagine it would equal or better.

As for High Stalls , They are a subject on there own . A well made non lock up Converter can have reasonable maners and won't eat up your Auto with heat , I recently fitted a Trimatic with a 4K TCE converter to my car it happily sits 3-3200rpm @100klms . While they are a lot looser than a stock converter it's a myth that they won't operate below there Advertised Stall speeds , A good Quality Converter builder such as "Converter Shop" or TCE , Dominator Will match the Converter to your engine/cars requirments and will be as tight as possible while matching your stall speed requirments and have minimal slip up top.

P.S Good write up Mick W "Automagics FTW"

 

ofcorse how could i forget, you did many many drag runs with the stock auto box with a shift kit in it at least 50runs if i remember correctly and never had a problem correct me if im wrong ? also how much power where/are you running with the box. have you still got it in the car or have you converted to man now ? if u still have the auto box in the car are you running more power , and with the stock box with shift kit and stally or have you added anything to the box ?

 

Great write up Mick

 

this has to be one of the most professional installs presented on this Forum .. top stuff.

 

Aaaargh, you ignorant pinhead!!!

( another private joke peeps, cheers and many thanks for your help Kingy )

 

Mick, congratulations on this thread and your attention to (expensive) detail. It has been an eye opener.

It has however raised a query in my mind. My Zed has a lockup clutch problem where it locks, then unlocks, then locks again, etc, etc, and that adds a lot of harshness to the drive, but only at 2100rpm. Lower than that it doesn't lock, and higher than that, it locks once and stays locked just as it should. So if I am travelling less than say 80kmh, I use the button to stop those clutches working at all.

I have always thought my torque converter was the problem, and I have not yet dealt with it while I decided what else to do. If the box has to come off, do I overhaul it, beef it up, replace it with a better one, etc? Even Coz has TT autos brand new for US$3,300 which looks a bargain. Maybe they are now available locally for around that price too.

But it was the following comments of yours about the A/T ECU that made me stop and think (my emphasis added):

Could my problems be A/T ECU related and not the torque converter at all? Do you think that is possible? I would appreciate any thoughts. Anyone got a spare known good one?

 

What size con have you got I'n Barry ?

 

Rather than show my ignorance and try and guess what a "con" is, let me say that this particular Zed is absolutely stock except for the pod filter.

 

if only I cared about autos as much as you do or more than I do about manuals

great write up, was an awesome read, maybe my 2nd Z can be an auto
keep up the awesomeness
:zlove:

 

angrybear, have I got this right -

even when your throttle is steady and engine load is consistent, the lockup clutch cuts in and out at the 2100 rpm range?
When you say 2100 rpm, I take that to mean before the clutch engages.

I can't recall if you have an ECUtalk display. If you do, have you tried watching your TPS voltage while the lockup clutch is misbehaving?
Does the voltage fluctuate even a little? ( maybe try it with cruise control )

Lockup happens for me as low as 63 kph in overdrive, obviously at very low throttle. Pexzed posted ages ago that his transmission would lockup at 62 kph.
Page AT-32 of the service manual seems to show this is correct for a TT? Or am I reading it wrong?



( And NO, I don't advocate driving along at 63 kph in OD and lockup. Just saying that it's possible )

 

Sorry no ECUTalk.

Yep, this all happens at 62/63 kmh, at very light throttle, and the engagement of the lockup clutches drops the rpm by about 100rpm. When it disengages it goes back up 100rpm. It is this continual +/- 100 rpm that gives the harsh ride. Like there was a big miss in the engine.

Looking at those diagrams, I never previously realised lockup also happens in 3rd gear. Something new every day.

 

100 rpm change at 2100 rpm, that's worth noting. I've asked other auto owners in the past how many revs they drop when lockup happens
on their transmission, never got a consensus figure. It's only now that I understand, that the amount of rpm drop will depend
on how far away you are from the stall point -

Consider a stock 2500 rpm converter ticking over at 2100 rpm, it would be getting close to good efficiency of fluid coupling.
Activate the lockup clutch so the engine is now directly coupled to the transmission's input shaft.
Revs will drop by X amount, let's say 100 rpm.

Now imagine a 3000 rpm converter running at 2100 rpm, or 900 rpm below the stall point. Engage the lockup clutch. It would be more
noticeable because this converter was slipping a lot more than the 2500 rpm one. (I get a drop of 4 - 500 rpm)
So in simplistic terms, instead of taking up 400 rpm of slack the lockup clutch is now taking up 900 rpm of slack.

Anyone care to add their rpm drops?


Guys and gurus, feel free to pull me up if I'm getting it wrong. The whole point of the post is to get some discussions going for
the benefit of all auto owners. Much of the auto's workings are still a mystery to me, I'm here to learn too

 

Happy to be corrected, but I have seen high stall torque converters advertised claiming to be rated at 2500 rpm, making me think the stock converter has a stall point somewhere lower than that.

That aside, everything in your post makes perfect sense to me, as much as a Zed can make perfect sense.

 

Converters