Aggressive remap and timing ******

[Gavin Cooper]

Hi guys,

Reading an excellent resource on VAG.com stuff, the TTweakers Guide v0.6 (PM me if you want a copy) I noticed that aggressive remaps display timing ****** across the cylinders.

I had a play with VAG and saw that mine hardly shows any timing ******, even up to 6000rpm. I was surprised as it was remapped by MRC after a BT upgrade (GT2860).

Does anyone know if this is normal or is my mapping screwed?

Cheers,
GC

 

[voorhees]

Gavin, 190% that looks unhealthy

 

[Gavin Cooper]

hmmmm...thanks voorhees in what respect? Can you elaborate any further?

Why would the engine not be retarding the timing?

 

[voorhees]

To override a safety measure cannot be healthy can it ?
Who remapped it ?
timing ****** is to stop it going BANG I thought.

 

[Gavin Cooper]

MRC - one of the best! It has since gone BANG. Cyl 1 cracked and cracked the gasket in 8 places. £2k repairs and a new turbo...really dont want it to happen again.

thanks for the help

 

[voorhees]

Ouchy!
Go to MRC and ask why this happened,its a bit naughty and at a far shot negligent

 

[Broken Byzan]

Are you sure those are the right blocks for ******? It states idle stabalisation?

Oh and whats this TT Tweakers guide thingumy?

Bad luck on the blow up, its possible that too much timing contributed to it.

 

[Gavin Cooper]

I believe they are the right blocks for timing ******, or at least that what it states in the TT Mk1 tweakers guide.

PM me your email address that accepts attachments and I'll gladly send you a copy. If you think it worthy you can put it up as a sticky.

Cheers,

 

[badger5]

its not pulling a lot of timing and its MRC's fault it went wrong?

If it has been pulling a load of timing then this statement would make more sense.
It look conservative timing to me with such little or no timing pull.

this on a gt28rs? looks very laggy if so from the log of boost
did you log block 031?

 

[Broken Byzan]

I wonder if the fuel pump wasnt changed at time of upgrade and its running lean etc

 

[Gavin Cooper]

Yes it is a GT28rs, which had to be replaced by my g/f's father when I was away traveling after it blew. He did say he replaced it with the same turbo. You've got me thinking now it may not be.

Out of interest Badger what boost should I expect to see at what RPM from that turbo?

Here is Block 031 from another run.

 

[jcb]

what spec turbo? A/R?

 

[badger5]

guessing from airlfow your at the 1.3 bar boost levels.. that log looks lean to me and erratic

you should see 3000-3500rpm full boost to >1bar on a 0.62ar gt28rs sized turbo

 

[Gavin Cooper]

Thanks for the replies.

Jcb - A/R? 0.8AR it says in my spec. If this is not it, I'm not sure what you mean. I only know it's a GT2860RS Garrett turbo.

Badger - How can you tell i'm running lean? I thought a Lambda value greater than 1.0 indicates that you have a surplus of air and the engine is running lean. If Lambda is less than 1.0, then I thought there is a surplus of fuel and the engine is running rich. Additionally max power is made between 0.85 and 0.95 Lambda (12.5 to 14.0 A/F with isooctane) which it seems I'm getting at 5880RPM.

Help! What should I do next guys? Head back to MRC for some checks? Head down to my local injection specialist to test the injectors/fuel pump? Or is there some more logging that will help to identify my problem. If I'm running lean and I know I'm getting multiple misfires across cylinders, should i be driving the car?

G

 

[Gavin Cooper]

Ok. Looking at another log for the lambda value across the Rev range (multiplicative) I can see some positive and errative values which suggest more evidence it is running lean.

-TT Tweakers Guide-
"You can check your current state of trim by using VAG-COM or equivalent to look in Group 032 in your engine measuring blocks. The first two fields will have percentages. The first field tells the fuel trim at idle (Additive). The second field tells the fuel trim at elevated engine speeds (Multiplicative). Negative values indicate that the engine is running too rich and oxygen sensor control is therefore making it leaner by reducing the amount of time that the injectors are open. Positive values indicate that the engine is running too lean and oxygen sensor control is therefore making it richer by increasing the amount of time that the injectors are open."

 

[badger5]

there is insufficient data in your posted logs

you do not want to be seeing 0.9 lambda under boost - too lean
exhaust valves will be getting mighty hot, as will piston crowns..

extreme case, burnt valves, melted pistons

 

[Gavin Cooper]

Thanks for the comment Badger5.

Here is another log showing a WOT run in 3rd gear.

From what I can see the mixture is riching up under boost. No 0.9's at all, all 0.8's apart from the reading at 6200RPM. In your opinion, do you think the readings suggest anything is suspect?

Cheers,
Gav

 

[badger5]

that looks better, aside from as you say over 6krpm...
wondering if your fuel pumps keeping up

have you done a log, showing injector duty cycles.. might find they're 100%..
lean at top end but the rest looks ok

 

[Gavin Cooper]

Thanks for the reply.

I'm still using a standard fuel pump and injectors. Maybe these need upgrading based on what you've said?? I havn't done that log yet but I will now you've mentioned it.

I ran block 120 to see what torque I was getting and was shocked by the results. Based on a £7k engine upgrade just over one year old. Spec below. I'm getting 270 bhp and 252 lbft after a knackered turbo, melted cylinder head and blown HG. Hmmmmmmm money well spent???!! May as well have spent £500 on REVO mapping.

GT2860RS Turbo (Part Number: 739548-5001) Comp Housing: .60 AR Turbine Housing:.86
Custom cast manifold
Stainless steel charge, inlet and 3" down pipe
4 bar fuel pressure regulator
Standard Injectors
Forge front mounted intercooler
Uprated flywheel and clutch (sachs stage 3)
Supersprint exhaust system
Hi-flow sport Cat
Haldex Performance 4x4 controller

 

[freegeek]

My 1.8T timing pull looks like this on 95 ron fuel but flatlines on 98 ron.

The tweakers guide indicates that flatline is the ideal.

 

[Gavin Cooper]

ok cheers freegeek. at least that's something.