Telltale signs that S4 has been remapped

[AndrewW]

hi,

As mentioned in another thread (https://www.audi-sport.net/xf/threads/bhp-from-maf-reading.396102/) I have a suspicion that my S4 isn’t standard, is there anything I can do to check if it’s been remapped? I’m reasonably sure it has standard SC pulley but it’s hard to tell with the belt on so would probably only be stage 1 if anything.

I.e would max boost pressure be different to standard? Anything else I could measure? I have VCDS and some other diag equipment.

It would just be good to know what my tuning options are going forward.

Cheers!

 

[Tobe]

Log ignition timing which is one of the main things tuned on stage 1, should be more advanced. and also log SC bypass valve, stage 1 it should not really be bypassing any boost so look for 0% up it high rpms, whereas stock the bypass duty maybe around 20% in high rpms. At redline boost would be almost double without any bypass so around 12-13psi compared to 6-7psi stock.

 

[AndrewW]

Excellent thanks! I understand the valve and pressure but If I got my logs for timing would it be obvious it wasn’t standard? I will have a play when I get home from work

 

[Tobe]

No worries, The boost is probably more obvious at a glance.

 

[Dippy]

If you have VCDS then you can just check the ECU flash status.

 

[AndrewW]

I didn’t realise that was a thing! I’ll see what I can find thank you

 

[AndrewW]

Ok, I tried boost pressure on my way home using my normal WiFi obd2 and an iPhone app, it peaked at 26psi for “boost pressure A” which was the only boost pressure one to give a reading...

I’ll try with VCDS later because that doesn’t sound right to me...

 

[Tobe]

That will include atmospheric at 1000mbar just over 14psi anyway. So actual about right at 12ish psi. Unfortunately peak is not to different between the 2, vcds will tell what it is at high rpm which is when stage 1 will let it keep building.

 

[AndrewW]

Right, got you! I’ll plot boost and rpm and go for a spin later on. Thanks for your help, I’m very new to this.

 

[AndrewW]

Right, I've done a few runs to see if I can spot what's going on, here's a run in 2nd and 3rd:

It looks like the bypass starts to close high in the revs but I've no reference point to know if this is less than standard or not, any input would be great

Bypass % is quite difficult to see on the graph being such a low value so raw data below:


EDIT: Just re-read the thread - looks standard to me? (if so, great news!)

 

[Tobe]

stock i reckon, unless its a poor stage 1 and its not making use of the max boost you can get. Either that or it has got a pulley upgrade and is not tuned for it so is bleeding boost when it hits requested level, buts that pretty unlikely.

 

[AndrewW]

stock i reckon, unless its a poor stage 1 and its not making use of the max boost you can get. Either that or it has got a pulley upgrade and is not tuned for it so is bleeding boost when it hits requested level, buts that pretty unlikely.

Well either way sounds like I need to get it booked into someone for a decent stage 1! Thanks

 

[RyanJonS4]

Well either way sounds like I need to get it booked into someone for a decent stage 1! Thanks

U won’t regret it! Only thing I regret with mine is not getting it done sooner!

 

[AndrewW]

stock i reckon, unless its a poor stage 1 and its not making use of the max boost you can get. Either that or it has got a pulley upgrade and is not tuned for it so is bleeding boost when it hits requested level, buts that pretty unlikely.

Do you happen to know what the total timing ("ignition angle: actual") should be reading?

I think you may be right it's a not very good example of a stage 1, i'm seeing some readings that suggest it's more than stock but not quite what you'd expect from a decent stage 1.

 

[Dippy]

Didn't you check the ECU flash status then?

 

[AndrewW]

Didn't you check the ECU flash status then?

Sorry totally forgot about that, yes i did but it showed no date and attempts 0/0/1 (i think), but from what I've read this may not be 100% accurate?

 

[Tobe]

Some tools bypass flash counters, another way only relevant if it has been tuned using alientech tools is to do an Id on the ECU and it will give you an unlocked or locked on the end. If it's unlocked highly likely it's tuned. But also not 100% as pretty much all others tools now can flash these via obd without the ECU being unlocked first.

 

[Dippy]

I wish I'd checked mine before I went to MRC. But afterwards it showed 3/3/1 and flash date 00.00.00.

 

[AndrewW]

Some tools bypass flash counters, another way only relevant if it has been tuned using alientech tools is to do an Id on the ECU and it will give you an unlocked or locked on the end. If it's unlocked highly likely it's tuned. But also not 100% as pretty much all others tools now can flash these via obd without the ECU being unlocked first.

Well I hooked it up to a KESS V2 today and it’s already unlocked so that’s pretty definitive! So looks like it’s a less-than-optimal Stage 1