Turbo Boost Level
Discussion
Last year I got the car remapped to around 410bhp and that included the turbos being turned up from 0.7 to 0.9 bar. The guage has always appeared to be accurate. I then had issues with both wearing out and had to refurb them. Now they're back on the car I've noticed the max boost I get is 0.6, falling to 0.5/0.55.
This might seem like a daft question but is it possible the new turbos are running at 0.55 bar and giving me the same power as before, given that the old turbos were seriously worn out? What controls the boost? ECU, some other electrical device or is it simply mechanical?
This might seem like a daft question but is it possible the new turbos are running at 0.55 bar and giving me the same power as before, given that the old turbos were seriously worn out? What controls the boost? ECU, some other electrical device or is it simply mechanical?
So, given that the new turbos hopefully are in slightly better condition than they were, is it possible the ECU is making an intelligent decision to limit the turbos to 0.55 bar because that's the boost it thinks it needs to satisfy the required power output? Or is not that intelligent?
I'm just wondering if I've actually lost any power - I don't think I've lost much (if any) but it's hard to tell - or if the new turbos are putting out the same power as before, just at the lower boost. The turbos were apparently in a seriously bad condition before the refurb.
I'm just wondering if I've actually lost any power - I don't think I've lost much (if any) but it's hard to tell - or if the new turbos are putting out the same power as before, just at the lower boost. The turbos were apparently in a seriously bad condition before the refurb.
Adrian W said:
Not a big fan of coincidences, if you disconnect the boost solenoid completely you will still get 0. 5 bar of boost , you may want to check your connections and vacuum pipes.
Hmmm, I did have that thought too. I've gone over and over the vaccum pipes but can't find any obvious areas for concern. Like you say, 0.5 is the magic number isn't it. Maybe the solenoid is just knackered.Edited by NobleGuy on Friday 10th July 09:52
Intelligent 
It's an MBE ! The Boost map is set to a required number (ie 0.95 bar at whatever revs) and the soleniod does it's best to hold the boost at that figure, given that all the other variables such as temps etc etc are within the normal scope of operation.
As Adrian suggested, with the solenoid disconnected and standard wastegate capsules fitted, it should run about 0.5 bar so maybe that's your first place to look.
Steve
It's an MBE ! The Boost map is set to a required number (ie 0.95 bar at whatever revs) and the soleniod does it's best to hold the boost at that figure, given that all the other variables such as temps etc etc are within the normal scope of operation. As Adrian suggested, with the solenoid disconnected and standard wastegate capsules fitted, it should run about 0.5 bar so maybe that's your first place to look.
Steve
Adrian W said:
Not a big fan of coincidences, if you disconnect the boost solenoid completely you will still get 0. 5 bar of boost , you may want to check your connections and vacuum pipes.
Played with the one connecting directly to the actuator and it seemed awfully happy just to slide off with a little help. Secured it with a tie and I'm now making 0.75 reducing to 5.5/6.0 in all gears except 5th, which appears to hold 0.8 consistently.
TuxMan said:
when you got the turbos back did they refitt your actuators or fit new ones ?? could they be set at a lower level ??
I did wonder this too, but I went through the settings with the refurb company at the time and they confirmed that on same-type swaps or rebuilds they just set them to whatever it was set to on the item they received. They also told me they'd set each one to the figure I was expecting without prompting them so I think they were on the right track.
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