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Hello guys,
I went with my Q4 to make a Dyno Test.
The car is Almost Std, i've just replaced the original Exhaust Line with a 3" Decat.
What Do you think of..? the turbo reach a peak of just 0.7 Bar.
I'm considering 33% loss, almost 199Hp at the engine.
Cheers,
http://img513.imageshack.us/img513/1...no155q4bar.jpg
http://img406.imageshack.us/img406/9676/dyno155q4.jpg
it should boost up to 1 bar , so i think the Hp`s are OK.
Bruno, no sabia que eras vos !!
saludos!
Juan
looks about what I'd expect with 0.7 bar. If you can get it to 1.0 bar it will make significantly more power... is there a leaking turbo hose? AFR's look good.
jimn~
Looks OK, but why they didn't do a descendant for calculating looses?
I would try to make AFR more constant.
1.1bar boost is not at peak power, it will only affect peak tq value (and power at that range).
Thanx Guys for your answers!
When making the test, we realized that the air hose was broken, a little bit, but broken anyway.
Could That have affected the turbo performane..?
How many more HP can expect with the turbo with all the pressure?
Thanx again.
Pronto subir? fotos de la Q4 Juan!
Sl2.
Hi Bruno,Quote:
Originally Posted by BrunoQ4
There is no reason why you should not see 190hp or more. Which hose was broken? If it was the main pipe in to the inlet then it will have a big effect on the power.
If it is one of the small bore pipes then you would still loose power and have a bad idle and it will probably run rich!
Hi Jack,
In fact is the main one into the inlet...
I covered with tape in the meanwhile i get a new one.
Can the 0.7 bar could be a reason for that hose?
Or should i think about the turbo is getting old?
Or the Wastegate connection..?
Thanx!
It is the most likely culprit. See how it goes when that pipe is fixed. As it is under pressure, any leakage is bad. 0.7 is the base boost allowed by the ecu and if all of the sensor readings are ok it will allow 1.1 bar at a certain point in the revs when you put your foot down.
Well, trying to understand how the ecu works I’d like to ask about the 1,1 bar overboost function, with throttle full open {foot to the ground}.
Does anyone has a graphic {from a dyno test maybe} where it is possible to see this 1,1 bar pressure? Does this 1,1 bar last for a certain period of time regardless the rpm {is it time related}? Or is it rpm related only?
And if you do not kick down the throttle {if you press the gas gradually} what happens? Boost goes only to 0,9 bar?
Sorry for being off topic but I’m very curious about this function.
Nick,
iirc there's a boost map, depending in RPM and TPS. There's set the duty cycle for overboost.
I know the 'wastegate duty-cycle' map, depending on 4 throttle body positions and the rpm, but it is not what I meant.
Many people say {and I believe Alfa claimed that too - not so sure about the Q4 though} that "with gas pedal kicked down to the floor {going to full throttle suddenly}, there is an EXTRA 0,2 bar boost for almost 30 seconds {or something near to those secs}".
As far as I understood, the highest bar boost 'normally' should be about 0,9 bars. But if someone press the gas pedal suddenly and down to the floor, bar boost goes to 1,1 bar {0,9 + 0,2} for 20 - 30 secs.
I do not know if this 'function' really exists in the ecu map. But if there is, I'd like very much to find the hex address for this function.
hi
with the oem ecu and the engine in very good condition and the turbo of course
i never so 1.0bar in my blitz
the bigger i saw is 0.8 for a very sort
the 0.7 is the usually
with the squadra chip i see 1.2 in the dyno and the track day
and in the road the1.1 is the usually
i thing that 0.7 is the oem over boost and in this press you get about 192hp
the power that alfa romeo gives for that car is 190hp and this power is at 0.6 press
this is written to the q4 manual
this is my dyno test with the squadra
Thanx for your answers :)
So, 150Whp + 33% of loss gives 199 hp at the engine, am i too optimistic?
Cheers,
Quote:
Originally Posted by na15575
are you greek too?
yes of course and im from greece :smile:
Thessalon?ki is only in Greece :cool:
im writing to alfisti as seitanis
I have two comments:
High rpm boost - With uprated exhaust system (with std 2xcatalysts) and better air filter I normally saw 0,8-0,85 bar @ 6000 rpm with just below 0,8 bar at red limit.
The AFR is amazingly high at low rpm. You should definitely not have more than 14.7 at wide open throttle. Maximum power is normally achieved at AFR 12.7. By that said it runs too rich at high speed. At 0.7 bar boost it would do fine with AFR 12, not less. At low rpm it is normally better at around 13.5, and by going a little lower it might help turbo spool up if the ignition timing and pressure balance is right. The pressure balance is definitely gained by your new exhaust system.