Twin turbos

[Robertio]

Originally posted by maximtaylor
I\'m glad you ended up having a semi productive day Robbie. Any idea\'s why you seem unable to get more secondary boost?

Regards

Max

No real idea at the moment  looking back at the logs boost drops off and knock values go strange, it doesn\'t get to 20 during the rest of the run then- 26,47,23,21,19,17,25,75,26,18,18,75,43,15 - you get the idea.  Could it be ignition break up (logs show ignition is correct though) combined with the PFCs unique version of boost control?

It is around this point that the air temp reaches 60 degrees for the first time (high twenties at the start of the run), could be pulling boost back because of temperature?

Water temp stays at a constant 83 through the run, but does creep up afterwards.

Is at the same point as oil temp gets over 90 degrees? (again temp issue?)

Injectors once touch 88%, but that is the highest they get, so nothing wrong there.

The ever useful wastegate % column seems normal - 150-200% gradually increase when on secondary (sits at 243 when on the primary).


Unless anyone has any other ideas I\'ll go along with the fitting the other bits and seeing if that fixes the holding of secondary boost (which seems fine when set to 0.7) issue.

[maximtaylor]

mmmm....

Put the front mount on and see how it goes. The turbo should be good for more boost, as shown by Johns logs.

Are you changing your wastegate duty cycles when you are upping the boost?

Out of interest, what numbers are you running on this screen?

Regards

Max

[Carl]

Hi Robbie,
Have a play with your wastegate duty cyles as Max said.I think that is where your problem is.
You should be able to run 1 bar with the stock injectors and right map.Then you will see some real power.
Kind regards
Carl

[Robertio]

Thanks both

I didn\'t do much with the wastegate duty when I put the boost up, small change - IIRC to 44 and 54, but I\'ll have to nip out and read the map off the car before I can confirm - and it\'s raining at the moment so I\'m staying where it\'s dry.  I think the rest of the values on this screen are still from the map you gave me Max (that I have beeen gradually destroying )

I should have the profec on soon, and will have to set it up to do the boost control anyway.

Ultimately I couldn\'t spend much time on it as there were 20 of us having runs, about another 20 watching and I probably spent the most time on the rollers as it was :o  Not helped by the operator enjoying blipping the throttle at low revs to get lots of pops and bangs :rollin

[Carl]

Hi Robbie,
It is not good to run too rich with popping and banging in the exhaust,it will destroy the packing.
10.6A/F is way too rich outside of boost and also as the boost decreases top end it is too rich.
Kind regards
Carl

[20B_boy]

What A/F\'s ARE you going to shoot for Robbie?

Feeling a bit more positive today hopefully

[Robertio]

When we set it up a few weeks back (wideband stuck on the end of the backbox) on the road we had set it for 11:1 to 6k then leaning it out to 11.5:1 as it headed for the red line.  It just seems to be whatever is affecting the boost was also stuffing up the top end AFRs (could have done with watching them on the first run to see if they were better with the original boost settings, but I was too busy keeping an eye on temps).
Haven\'t been able to sort out the low end values - my wideband hasn\'t gone on yet due to the extra time spent fighting with the intercooler - we spent our time trying to get the cruise and boost values confirmed as OK when I had Marcs wideband on the car.  Once I get the wideband on the bottom end will be sorted out as it has been driving me bonkers - as long as it is above 2.5 it is fine, but before that on a light throttle it is too rich (had taken a guess and removed a little which helped, so it (mostly) only does it with cold ambients now).  

Carl, have to confess I never noticed the AFRs at the bottom end off-boost, the 10:6 was what it dropped to top end at 8.1k having started to tail off around 7k.
As a side note the exhaust was classified as at least as noisy as a 200SX with 3" all the way exhaust (which along with the GTi-R was the loudest there).  I\'m going to have to put a sticker on the back of the car saying \'This is the quiet exhaust, so stop asking me when it is going on\'

Rich, a bit, guess that\'s what a bit of friendly rivalry over bhp figures does

[Robertio]

Having checked the secondary wastegate % was still 56, so have hacked that back to 52, wont be able to find out for a while if it has had the desired effect.  Thanks all