Boost logs- some advice please

[martziniuk]

Hi all,
I fitted an FMIC recently to my Octavia Vrs with the AUQ engine (same as the cupra). I had this before fitting but the actual does not meet up to the requested boost. The N75 is in no way maxed out as the graphs show, so why doesn't the N75 compensate for the difference? Any advice appreciated.
Thanks

Boost

N75 duty cycle, sorry i started @3000rpm

 

[Damoegan]

Did you actualy do a power run (foot flat to the floor from 2.5k to redline)?

 

[martziniuk]

yes i did

 

[Damoegan]

Well duty cycle is all over the place. Looks like a boost leak to me.

 

[martziniuk]

Wouldn't the n75 compensate if it were a leak though, the max it reads is 75. I would have thought it would read 95 if it were a leak??

 

[Damoegan]

Not realy, depends on where and how big the leak is.

 

[martziniuk]

I don't think the duty cycle is too bad, just maybe the graph makes it look bad.
Here are the figures i used for it

Thanks for your help, I think i will buy a boost leak tester and go from there.

 

[ibizacupra]

what map?

 

[martziniuk]

It's a DNA Tuning generic map. Don't get me wrong, there is nothing wrong with the way it drives or the power its just strange not to hit requested boost.

 

[DPJ]

Have you logged 115 and 003?

 

[martziniuk]

115 is the top graph. I haven't done 003 yet, is there anything else i need to log?

 

[martziniuk]

Ok just done some more logs

and 032

Thanks

 

[DPJ]

Your car is running a little lean - possibly a maf past its sell-by date? Actual meets requested fine all the way to over 5k rpm and then starts to fall away a bit. Whilst the turbo does run out of puff, you should be able to achieve a bit more high rpm boost than it actually does. I note you have an N75J - was it mapped for that? Try putting your original N75 on and see what it does?

 

[martziniuk]

Yeah i agree about it dropping off at the top end. My sig is a bit old, i had to take the J valve off after it went into limp and kept doing it after the scn RR day@ RS Tuning back in may last yr. So these logs are from the F valve. AFAIK the MAF is the original after 115k so this may be the problem.
Another question would the FMIC make it run a little leaner?
Thanks for the reply

 

[DPJ]

.............would the FMIC make it run a little leaner?
........

No, it won't.

It might be worth trying to borrow an N75 to try - to see if it performs differently to yours.

 

[martziniuk]

No, it won't.

It might be worth trying to borrow an N75 to try - to see if it performs differently to yours.

Thanks again for the reply.
I have got and tried a new one but interestingly it gave slightly worse results, the high mileage one gave the best results.
It just seems strange that the N75 will barely adjust to compensate the lack of boost. I did previous logs before the FMIC and they were better but still not right. I also went back to standard airbox and performance panel filter and did logs tonight but no difference
Can you tell me how you know it's running lean too please?

 

[martziniuk]

Just done an AFR run on block 031, looks to be quite good to me. Interestingly where the boost drops off in the rev range AFR suddenly gets a lot richer, as in 11:1. Could the mixture being too rich have an effect on the boost dropping off????. Comments please.......