Audi RS2

[AVP]

Update:

trigger errors are now eliminated and cold start is slightly better for the 630cc siemens deka injectors.
I am getting better fuel economy on 1.06-1.09 lamda so i am leaving it as it is for now.

Boost control is very good and what would be nice is some kind of safety mechanism to allow VEMS to understand when there is a boost leak( ie an rpm threshold where boost should come in in revs or kpa or both, which when not reached an error might appear)

After recent problems with idle again following a wash!! of the car, i took apart the idle valve and TB assembly, cleaned all surfaces and reconnected everything up. This allowed for the use of 34% DC on the idle speed IAC in order to have the 950rpm idle that i like. Idle is not as good as it can be and im happy with it.

I will be changing some stuff on the makeshift heat shield i have for the air filter and adding on the lava mat which will give it a better look.

[AVP]

a bit of bling?

[amd is the best]

Great project!  I have a 91 200 20v running VEMS and a GT30r myself.  I've got a few quick questions:

1: How did you get the speed sensor wired in?  Or was this a plug and play from EFI Express?

2: How did you resolve your trigger errors?  I am currently getting them usually in 2nd gear, WOT at around 6500rpms and the car seems to misfire right at the point of the TR E.

[AVP]

Hi

if your car misfires, then the trigger error may be correct(true). I didnt have any misfires, and i was getting trigger errors. But then i used for min/max window the numbers 1-359 and that cured it.
as you see i use LS2 ignition modules, and those have solved all misfires.

The speed sensor is not supplied. Its the one on the car already. VEMS still has trouble getting a stable signal from it, and therefore i do not use it at the moment. However i would like to see if future firmwares improve things.

[amd is the best]

Hi

if your car misfires, then the trigger error may be correct(true). I didnt have any misfires, and i was getting trigger errors. But then i used for min/max window the numbers 1-359 and that cured it.
as you see i use LS2 ignition modules, and those have solved all misfires.

The speed sensor is not supplied. Its the one on the car already. VEMS still has trouble getting a stable signal from it, and therefore i do not use it at the moment. However i would like to see if future firmwares improve things.

How does having a trigger error negatively affect things if there is no misfire?  I'll have to try putting those numbers in and see if that helps a bit.  How did you come up with them?  I am also using the LS2 coils in my setup, might just need a bit more dwell..?

I figured it would use the factory speed sensor but I was curious if the signal was already supplied to the ECU through the factory harness and/or if you had to do any internal modifications to the VEMS ECU to use the speed input.  If it's still unstable then I am not too concerned with getting it up and working yet but I'd love to at some point.

[AVP]

wheel speed is VERY unstable and untunable at the moment, which is why i dropped it. i use 1.1.81 firmware and i dont know how the 1.1.88 reacts to it, as there are some different features there. Speed reading jumps around everytime you accelerate. There is no linearity to it and sometimes it doesnt even reach the maximum speed you are at.

The trigger errors, sometimes happen without misfire when you have a problem with the crank sensor having too much noise. They may turn up on vemstune, but you are not feeling the car jerking or having any problems on the run.
That is what i was getting. So as soon as i fixed the window min/max, then i didnt get any trigger error signals again.

I assume that if i was having misfires, i would be still be getting errors of some sort.

[AVP]

1.1.88 firmware is on and working.

i havent managed to try the new settings yet, but it seems stable enough.

I wanted to point out, that as far as the idle is concerned, it is near to impossible to tune the idle without the use of the ignition timing holding things closer and tighter and the reason is that if ignition timing is turned off, then the only things that interfere with idle are: VE,lamda, MAT and IAC through its PID.

So if i try to tune the PID without the ignition timing is ON, at idle speed even with the VE nicely tuned and stable, lamda will not be 100% stable enough to have an accurate PID testing and tuning. So when i tried this, any PID settings would not work 100%. When i turned the ignition timing on, then idle was much more stable, even with very slight timing fluctuations, but this gave me the opportunity to get the PID setup as much as i could when electrical load was high, which is the most important bit to tune with PID i believe.

anyway, with the new firmware, on high electrical load, i still get the idle dipping when returning to the idle speed area, but it doesnt stall. This was done with a stationary car and accelerator pedal getting pressed lightly to while changing PID numbers.

[AVP]

I have been having some issues with my crankcase ventilation system. Apparently my drain to sump was unsuccesfull in means of my sump getting some pressure during boost, thus likely pushing oil towards the tank,and as the tank's outlet was returning to the turbo/airfilter as OEM configuration made the turbo and inlet lines oily.

Im not sure how much oil has been brought up this way, but after a few runs which i realised what was going on, i disengaged the oil drain to sump and used an open to atmoshpere filter as  a temporary solution.

The result is that its a bit better now. BUT here is my problem:

When i originaly had put the GT30R in, i was able to hold 2+bar overboost and keep it close to 1.95-2bar to the redline.
Now, my boost holds till 5000-5500rpm to 2.1bar then drops rapidly to 1.7 on the redline.

I can see from the logs that the N75valve tries to keep the boost high by increasing the DC, but there is no way.

Im wondering if this is down to increased backpressure of some sort. What kind of damage could the crankcase system have caused to the engine to not allow it to sustain this high boost anymore?

There is no turbo play(as in, normal for the BB turbos), and other than the fact that the N75 valve and lines were oily, but cleaned, i cannot see any other apparent issue with the turbo itself. Obviously i havent taken it off.

There is no white smoke coming off the turbo itself either.
Could this be down to damaged piston rings, causing excessive sump pressurization and loss of boost on higher revs? If that, shouldnt i be seeing higher oil consumption(which i dont).?

Ill try and see if i can run a compression test after easter as well.

any ideas?

thanks

[Jamo]

1.1.88 firmware is on and working.

i havent managed to try the new settings yet, but it seems stable enough.

I wanted to point out, that as far as the idle is concerned, it is near to impossible to tune the idle without the use of the ignition timing holding things closer and tighter and the reason is that if ignition timing is turned off, then the only things that interfere with idle are: VE,lamda, MAT and IAC through its PID.

So if i try to tune the PID without the ignition timing is ON, at idle speed even with the VE nicely tuned and stable, lamda will not be 100% stable enough to have an accurate PID testing and tuning. So when i tried this, any PID settings would not work 100%. When i turned the ignition timing on, then idle was much more stable, even with very slight timing fluctuations, but this gave me the opportunity to get the PID setup as much as i could when electrical load was high, which is the most important bit to tune with PID i believe.

anyway, with the new firmware, on high electrical load, i still get the idle dipping when returning to the idle speed area, but it doesnt stall. This was done with a stationary car and accelerator pedal getting pressed lightly to while changing PID numbers.

This is interesting what are you using for idle timing? I have the reverse on my car I have to turn it off as it cause terrible fluttering and vibrations if I turn on idle ignition control so I a purely PID based

[AVP]

I have 12deg on idle area. No problems with fluttering, but idle could be better with wc14 objectors I guess. However, still better than motronic

[boostd audi]

i have been looking for a coupe for years in the states... i finally found one that is rusted or beat to hell.

very nice car 

[AVP]

recently on a trip i was having idle issues again as it was dropping due to the use of headlights, wipers, heater at the same time. So i followed mattias advice and recalculated the DC to even higher spec to keep the idle from dropping off when putting it into neutral and now its even better! Thanks Mattias!

The car will be having an engine/head rebuilt in the following months as it seems to be down on power and the PCV system which wasnt sorted may have caused a few things to go wrong. I know however the turbo is ok and checked, i now have a dual catch tank setup, so thats ok as well, and also i am retrofitting a vaccum brake servo and getting rid of the hydraulic one, which has caused me a heavy load of money and no success in making it work properly. So in turn, im going back to the trusted vaccum servo which although S2/RS2 cars are not built with it, it appears that it is shown in the ETKA files!

anyway, vemswise, i am at 1.1.88.

Can someone verify if the speed sensor is working better on 1.1.88 and what values are needed on the dividers in order to get an accurate reading? I am keen on using gear depended boost control but if the speed sensor is not working properly, then its a no go...

[AVP]

Update:

a lot of things have been done.
Engine was stripped to investigate the loss of compression and indeed, all cylinders were worn and pressure was lost that way. So another block was sourced in order to keep the pistons,but that wasnt possible. Eventually i bought 2nd step oversize pistons 81.50 and got everything together again.

A modified 7A cyl.head is now on, with larger valves, OEM springs, all checked for their spring rates, some porting has also been done, and compression ratio somewhere around stock (9-9.3:1) by head skimming. Cams are still ADU and the engine has been run in nicely. The turbo is still a 3076R, now with 0.63AR instead of the 0.82 and it also has a similar size billet wheel.

I have managed to get it to 1.4bar on a safe tune, still fiddling around with settings, but its likely i may be heading on a dyno for some more elaborate tuning. Not sure yet due to hectic work timetable...

car runs nice by the way!

[AVP]

after a tuning session that i had on a dyno to check my timing and knock(all was ok) i couldnt get the boost to not oscilate on spool on the runs. After not wanting to spend too much time  on the dyno, i decided to fix it on the road. However i was unsuccesful, until i realised that my newly rebuilt wastegate was sticking open as the valve was scoring on the guide!

A secondhand wastegate later, and i was back in business.

On the dyno with the oscillations and 1.68bar on the redline it made 368.7whp (dyno dynamics)

on my virtual dyno excel sheet i managed about 374whp on 1.87overboost and 1.68 at the redline.

here is a dyno chart (comparison) vs an RS2 with K27/26 tuned to 2.2bar overboost and gradual reduction on a newly rebuilt engine and ported head.



I must say i am not impressed with the way vems logs the rpm. On 2 out of 3 runs during the mid range 4800-5300rpm the rpms almost flattened out, when the boost was 300kpa! I am not sure if that was happening because the VE table had 300kpa as the top bin, and for some reason there was a problem of the log.

Then on the final run, which was a slight downhill, the rpm log was ok, and virtual dyno measured 429whp, which i cannot take as true!

for anyone wanting to see a log with the flatspot on the revrange i can email the log if you give me the email address.(uploading the log on a server is much to time consuming).

I have now dealt with the PID settings on the boost and left it to 1.9bar overboost and 1.8 till 6000rpm and 1.7bar at 6500 tailing off at 7300.

Car has a beautifull midrange and it gives almost around 470-480hp crank which is brilliant!

[mattias]

for anyone wanting to see a log with the flatspot on the revrange i can email the log if you give me the email address.(uploading the log on a server is much to time consuming).

The built-in report tool in VemsTune takes no time at all, just give us a link to the report when you're done.