IamSMC

Excellent

IamSMC

Is the EVC tuning and/or coding in there "anywhere"?

Taj

No EVC don't do the tuning, they provide hardware and software for the tuning industry. There will be a protection or encryption code or decoding program on one of the small chips, this is the one that was corrupt, hence the tuned map was ok as its on the other small chip.. As someone said earlier in the thread, we think one small chip is the decoder and the other holds the map...pretty clever and elegant.

cheers

Taj

I've got the ecu back, and took a look inside...and as part of the process they have put an additional socket onto the board for the large chip that was next to the piggy back assembly. Maybe for diagnostics purposes. Anyway, plugging it into the car, and the car starts! which is progress. I now need to get the VDO Vision boost gauge fitted which has also arrived and then I will be in a position to get a feel for what this chipped ecu actually does...

I got the VDO boost/Vacuum gauge( -30 to +25PSI) from a US supplier, WWW.AutoElectricService.net, brilliant good ole american service...Jimmy was brilliant and to be fair, EVC and Frank have also been brilliant. I reckon EVC would be the place for ECU repairs as they go to component level.

Will feedback once the snow disappears and I get a chance to work on the car.. hopefully in the next 2 weeks.

cheers Taj

Taj

Hi All,
Spent the weekend fitting the VDO Vision gauge into the airvent. As it was from the states, it has a 1/8 NPT fitting which had to be converted to a 1/8 BSP fitting and finally to 6mm push fit nylon pipe which I ran into the engine bay.

I ran it along the centre console and then really struggled to get it under the carpet into the corner where the loom enters the engine bay. The carpet and sound deadening material was pretty hard to get under.

I managed to get there in the end, hook it up and go for my first drive. The gauge is really good quality, nice damped movement, matches the OEM equipement really well and is very bright.

So on testing the ECU from Roock?? I found the following behaviour. In temps of approx 6 degrees celcius, I found that under full throttle the boost hit 11PSI quickly and held there to the red line....very quick :-) there is no pulling of boost as the revs rise. Initially I even saw a peak momentarily of 13psi which was pulled to 11 and then it stayed at a peak of 11PSI. This could be the ECU adapting on its first run.

The porsche 450 ecu peaked at 10psi and then pulled boost to 8PSI...I need to test it more as I was limited on time.

My primary reason to do all this was to make sure I do not damage my turbos from over spinning which was a potential danger with an ECU which was mapped for K24's, and to ensure that I know what the ECU's are doing in terms of boost. Clearly at boost levels of 13 PSI to 11PSI I am completely within the range of the K16's

Will be interesting to see what happens in the summer when more boost will be needed to provide the same power, but as I suspected, cold air temps and the K16's are fine, even with the factory 450 ECU. Maybe Porsche switched to the K24's to deal with those extreme situations where altitude, temp and load result in higher boost levels of 1bar to 1.1bar.... to still get to 450.

I am looking forward to testing the 408, 450, and Roock?? ecu's alongside each other..to see what boost pressures they request as this data in nowhere I could find on rennlist..and will report back as and when I get time.

Taj.

IamSMC

Very nice, Taj

Keep us posted

Felix

Is it just me or would it be a good idea to monitor the air/fuel ratio as well to ensure the fueling is correct?

Taj

Hi Phelix,
Could do....don't have any gadgets to do so though, unless it could be done by logging OBD data from the O2 sensors which could be logged. Again, I don't have the kit to do so.

What was your thinking?

Taj.

JBL930

I'm with Phelix, take the car to a dyno and check, you can try both ECU's then. You don't know whether the fuel pressure regulator is the right one for the ECU, stock is around 3.7bar i think, and most tuners up this to a 5.0bar unit. This will really screw up your fueling if you have the wrong one for the map. I'll be going to a dyno in a week or two when my new gearbox is in, maybe we can go together as you're local

Taj

Ok Jon, you're on...

If the fuelling is incorrect, that would result in a lean/rich condition. I thought these ecu's adapted to achieve optimal lambda. So if it runs over lean, boost is pulled, timing is adapted, injector opening duration etc.. is all adjusted to achieve optimal lambda??

So I would not get the best from the map, but there's little chance of damage right?

Taj.

JBL930

I will no doubt be corrected here as i am certainly NO expert.
But if the ECU map is expecting 5.0bar at the fuel rail the whole thing will be out of whack with only 3.7bar as the ECU will expect more fuel to come out of the injector each time. The ECU will try to compensate as the exhaust gas sensors will know the mixture is lean. If the ECU still can't get enough fuel in to reach it's targets i would assume an engine check light would show and it may even go into limp mode which will limit boost to 0.5bar, as that is what the wastegate actuators are set at, basically the ECU will have the N75 valve open all the time so max boost will be 0.5bar.
If the ECU is somehow being fooled, and is still allowing full boost even though the mixture is lean, then you will get knock (detonation), and then the ECU will definitely pull ignition and boost. But knock is bad news mate, pre ignition/knock/detonation, call it what you like, is going to cause damage is very short order, broken rings, hot spots form on the piston etc... Not good!

As soon as my car is ready we'll get a dyno session booked, i need to do this before VMax anyway so it would be cool to go together. I have a spare fuel pressure regulator which has been played with and gives 4.7bar at the fuel rail, i'll bring it along with me just in case you need it, they are a doddle to fit. I just bought a new 5.0bar one as a precaution.

Until then Taj just run whichever ECU you know is safe, the weather is crap at the moment so it's not like you're out driving like a loon anyway...

Basal Skull

jbl930/phelix +1

did the porsche 450 ecu use a 5 Bar regulator? I know the 5 bar regulator I have is a porsche part but do not know what vehicle/porsche tune uses it.

Felix

The oxygen sensors only fine tune the mixture - they can't correct for significant rich/lean running. And on many cars (not sure about the 993tt) the oxygen sensors are ignored at Wide Open Throttle.

Best would be a wideband sensor like http://www.innovatemotorsports.com/products/lc1.php and then the output is either logged or displayed.