Does anyone know anything about the different software versions in the TCU? I am fairly certain there is different software in the '01 tiptronics and the '04/'05 tiptronics.

I believe the latest part number for a 996 TCU is 99661818004.

I guess I could check it against my TCU, but its hard to get to with the roll bar in place.

I am really trying to determine if its worth it for people with 2001 tiptronics to upgrade to a newer TCU. Anyone done that through the dealership and notice a change?

Any help would be appreciated! I would call the dealership, but the chance of getting a hold of someone who knows about TCUs is small.

TIA

 

Drop Ken a mail

ken.napier@nineexcellence.com

www.nineexcellence.com

Ken had to upgrade his TCU when one of his got fried, and there were some differences, noticable the quicker gear change times for the newer version.

I will let him know this thread is running.

Good luck

Regards

Gary

 

Thank you...I e-mailed him.

 

Ben,

I thought I would answer your question email here since it then is shared knowledge for others.

The TCU in the 2001 car only had 5 programs. The TCU in 2002+ has 250 programs. That was the upgrade that was done to the car along with new valve body (which controls shifting pressures) on the tiptronic box.

I have through our partner MKB, the MKB performance upgrade. This has upgraded clutches, the very latest valve body, and the TCU tq limits changed from the standard 700nm to 1300nm. In fact the box is rated to 1500nm tq but for longevity it is restricted to 1300nm tq. No other changes were made to the TCU. We do not do TCU changes for speed. In our opinion, and in real world testing, it has not been necessary. Our test car changes in 0.2 seconds - that is measured not in terms of shift itself, but from the time that boost is dropped during the shift to the time that boost is regained.

In our first tests, I had an 01 TCU. It was shifting at around 0.3. Changing to the latest TCU and then reapplying the tq limits reduced the shifting to 0.2.

The latest TCU is 996.618.180.04 as you stated. It is the only one you can get now.

You should also know that there are tricks with the TCU to get it into its highest shifting mode. When you first turn the car on, it is in a comfort mode. To get it into quickest shift, put the pedal twice in short succession to kick down mode. Now it will be in its quickest setting.

In terms of TCU programming it is not something that I have felt necessary. You always must have the DME at least 200rpm higher than the shift point in the TCU. It would be best to change the DME to 300rpm higher to ensure that the shifting at 7000rpm.

However, maybe you are not aware, but the tiptronic box is very clever - it has adaption values. It even looks at things like whether you are on incline or decline, it looks at PSM values and so on. This is why many times people wonder why it does not shift at 6750 or 7000. Personally if I wanting to be on it, then I will double shift the kick down, and then it is ready. Switching PSM off for racing starts of course.

Hope that answers some of your points.

Ken

 

thank you for the reply...I did not realize you were the same person I was e-mailing

what do you mean by latest valve body? Do you have a part number? Are you using blue top solenoids?

why is all of this info not published anywhere? i wish it was lol

1 nm = .737 ft lb so 700 nm * .737 = ~516 ft lb

The tcu has torque limits that low?

Is that in every gear?

My understanding was that the 996 tcu had a very high torque limit and the 997 had a low torque limit in gears 1 and 2.

If i bought a new TCU, how do you get it coded to your car? I am wondering if I can just buy one from a dismantler or junkyard.



Thanks!

 

Hey,

The valve body is known by Porsche as "switch unit" 722.270.020.6 - there might be a later version than that - I would need to check our parts system to see. This is the one I recall.
It contains switch unit, solenoid valve and pressure regulator. The solonoid valves need to be the blue ones as you mentioned.

The torque limit is 700nm tq, but rememeber you can exceed that without tripping the emergency mode (EM). The emergency mode is trip when a number of codes within the TCU are issued due to power - so for example, if the car struggled to shift because of implausible shift speed between say 3 and 4th gear, it would note the code, but no EM. However, if you continued to shift between 3 & 4th so that the ATF heated up, then you would find even more slippage and eventually you end up with 10 codes and EM. EM can be tripped by single code of course depending on whether it is warning or actual fault.

The main problem in the tiptronic box is the housing and clutch packs for gear 3. It is the smallest housing in the box, and contains therefore the smallest number of clutch packs. Crazy when you consider that 3rd gear is probably one of the best gears for using. It is the most common problem 3 to 4th gear shift.

To give you some idea, when I ran my set up as before on std box with 20g full install, y-pipe etc, at only 1.1 bar, the gearbox was toast in just 20 miles.

Also remember that peak torque is not when you shift @ 6750rpm etc. It is this more than anything else that causes the problem in the gearbox. The inability to shift gear because of too much torque at the point of shifting. So you can have more tq at 3000rpm which is not a problem.

Coming back to your issue, if your TCU has been code to 7000rpm I would check whether that is for all gears. My DME is set so that 1-2, 2-3 is still 6,750 and 3-4, 4-5 is 7300rpm. I don't have the EVOMS TCU upgrade, but it might be worth you checking with them as to what the limits are in the TCU for each gear. As I said it must be at LEAST 200rpm higher in the DME always.

Let me know how you get on.

I come back to you re the code for the valve body.

Ken

 

My car puts out about 650 wtq at under 4,000 RPM at 1.6 bar and goes to ~575whp. My tranny lasted longer than i thought.

I had my tranny built, but they only rebuilt the valve body. They changed out the springs, changed up the maze a bit and added the blue top pressure solenoids (changed 2 of the 4).

I had softronic confirm (several times) that my ECU is set to 7,200 RPM. I had the same program that vividracingtx (blackhorseturbo) used, but he had a 2004.

Evo set my TCU to 7,000.

I am fairly certain the tune I got from Evo did nothing because the 2001 TCU is different.

No one mentioned the redline at specific shifts. Do you specify the shift point of each gear in both the ECU and TCU?

sounds to me like I need to buy a new TCU. They are like $1,500 so hopefully I can find a used one. Can they be reset to work on a new car?

Thanks!

 

When you get your new TCU, it needs to be coded to the car. Anyone with a PIWIS can do this. Then it will work. But then of course you will need to get the reprogramming done again on the TCU.

Re the shift points, yes that can be done in both DME and TCU. So you really need to find out more about what has been done. But yes, you can set different shift RPM in the low gears and increase in high gears.

 

did you ever measure the shifting without "tuning" the TCU?

I am still a bit confused as to the torque limits because I have not had any issue yet with that (to my knowledge).

Also, do the programs really matter if you drive in M mode?

I just ordered a TCU ending in .04 from porsche dismantlers...i am planning on first just putting it in the car without tuning (obviously get it coded to my car) and seeing how it runs...

What boost controller do you run?

Thanks again Ken! Sorry for all the posts and the e-mails, but you have the fastest 996 tiptronic (by a long shot) and seem to know more about than anyone else.

 

hey, where did you order the TCU from, and how much was it? my 996tt didnt have the 3701 TSB performed and makes that grinding noise which is fairly disconcerting.
Btw, how much bad is it for it to be in the wrong mode? will it damage the transmission over time? Is there a way to work around it without shelling out $16-1800?

Thanks