Audi S2 project

[Jamo]

I've been knocking about a bit thought I'd put a project page up

Car is an Audi S2 Avant current basics specs

Stroker engine, diesel block, petrol head taking cc from 2226 to 2526
750cc injectors
Garrett 3076r Turbo
3" tip to tail exhaust system
Est BHP is between 500-600 range

Running vems on audi trigger at present, tuning was done on 1.1.27 ( ecu was ship on 1.1.63 but had a config issue ) and then ecu taken to 1.1.65
Currently running 1.1.70 with 0 issues and planning to update to 1.1.74 or 1.1.75 when the new vems tune is released.

Had issues with smoothness but recently re-ordered the rpm bin points to focus better on midrange and I'm very happy with the results.

Current issues are regarding acceleration enrichment, I really can't find anything that helps you tune or describes what the values mean as i'm getting rich and lean on off throttle.

I'm going to attempt to use Mattias settings and see if they translate better.

[th.b.w.]

Hy Jamo,

i have the Stroker parts for 6 month ago, but no time to build it up....


I run VEMS 1.1.64 with 2,2l and 3071 und will upgrade to 1.1.70 next time.

Can you say that the 1.1.70 is stabile or is there some bugs


Thomas

[Jamo]

I haven't had any issues, I upgraded to 1.1.74 a couple of days ago I had issues upgrading using the latest version of vemstune 2010-04-28- which kept crashing midway through the firmware upload of 1.1.74 and leaving the ecu in boot loader mode.

Had to use megatune to go the 1.1.27 and then used vemstune version 2010-03-08 to upgrade to 1.1.74

Maybe useful information to anyone who's going to 1.1.74 if they have the same problem

[Jamo]

Recently upgraded to 1.1.81 and i'm looking forward to playing with the injector angles.

Also my VEMS is going back for some tweaks I want put in not least I want to change from PTC to NTC IAT.

Currently trying to find details about the speed sensor and how to integrate it and looking at water injection.

[Jamo]

I haven't really been keeping this project page up to date but think I will start using it a bit more

Following on from a post http://www.vemssupport.com/forum/index.php/topic,1664.0/topicseen.html I altered my VE table to have a lower value of 600 and it's helped my idle no end, I wish more stuff like this was documented from the off.

One thing which is very very annoying is why does the vemstune remap option not let you change to lower and higher value on the boundaries? I had to use megalogviewer to get values into the new lower rpm bin.

I am having a terrible time with boost control, I cannot get boost to smooth hold at a boost target, it kangaroo hops at the target, there are no boost leaks and my wastegate is fine as I have checked these, I'm getting really annoyed with it I've treid changing to an N75 valve and whilst that is smoother the same issue occurs

I do have an aftermarket boost controller and I think it will be installed soon to eliminate the boost holding problems

[mattias]

Following on from a post http://www.vemssupport.com/forum/index.php/topic,1664.0/topicseen.html I altered my VE table to have a lower value of 600 and it's helped my idle no end, I wish more stuff like this was documented from the off.

Describing how to properly tune and the relationship between ignition timing, fueling and idle control mechanisms requires understanding the engine too. Should the documentation describe how the software or the engine works?
At what level should the documentation be written? For the novice, new to engines, or experienced tuner with in-depth knowledge of engines?
If you understand how the engine works, the software is kind of self-explanatory. It's a gray area.

One thing which is very very annoying is why does the vemstune remap option not let you change to lower and higher value on the boundaries? I had to use megalogviewer to get values into the new lower rpm bin.

You can change those bins before you do the remap, I've stumbled upon that a few times too.
I added that to the wishlist : http://www.vems.hu/wiki/index.php?page=VemsTune%2FWishList

I am having a terrible time with boost control, I cannot get boost to smooth hold at a boost target, it kangaroo hops at the target, there are no boost leaks and my wastegate is fine as I have checked these, I'm getting really annoyed with it I've treid changing to an N75 valve and whilst that is smoother the same issue occurs

Good thread with PDF document at motec.com :
http://www.motec.com/forum/viewtopic.php?f=11&t=210

I do have an aftermarket boost controller and I think it will be installed soon to eliminate the boost holding problems

Shouldn't be necessary with proper testing and setup.  You might even be having problems with the control of the valve, maybe another PWM frequency and/or flyback diode helps to get more exact control?

[tweak]

I cant really see the advantages of using an electronic boost valve which require tuning and setup. In a petrolengine with a big turbo you usually just need to limit the max boost, which can be done with a manual controlvalve.

[PeepPaadam]

Actually there is a point in using electronic boost control as you can set up so that boost comes earlier plus to have gear-dependant boost.

[Jamo]

My boost problems have been down to the wastegate which is due to be replaced, at the moment I running on spring boost with gives me 1.2 bar until my new turbosmart one is fitted.

On a separate note I experiencing triggering errors which show as misfires, in the logs it comes up with trigger error, too many secondary triggers

Can anybody shed any light on what that means?

[rob@vems.co.uk]

Check the condition of the sensors and the wires going to the ECU, triggering errors are a very bad sign.

[tweak]

Actually there is a point in using electronic boost control as you can set up so that boost comes earlier plus to have gear-dependant boost.

With a big turbo you don't get any early enough boost anyway
OK for gear dependant i could agree, but it's always possible to use the gaspedal...

I'm not going to waste time, fuel, and engine on PID tuning the boost valve. I'm running a XS dual stage valve with street and race setup, controlled by a switch. Good enough for me, but one thing that could be done is to set it up together with a separate map that again control the dual valve switch electronically. And if it was possible, some kind of emergency mode state in VEMS that would limit the valve automatically to street mode if problems like lean condition etc. was detected.

[stecka]

Sometimes you have to take away boost on low rpms because to much torque for clutch, gearbox, that you cant  do with a manual boost control 

[Jamo]

Today I found out my friend and VEMS supplier and advisor Peter Nanassy passed away on wednesday gone

RIP Peter you will be missed

It was only last week we had planned for my ecu return for the 1.1.96 update and some future tuning, I can't believe such a talented man is no longer with us

[Ignitec]

Very sad news. 
RIP Peter