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Jenno007

Boost Issue

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Hi All,

About a year ago I got my car tuned by a garage specialising in Link ECUs. The car is a 2002 Audi S3 and it made 460whp at 28psi on e85.

Problem is, the car was dyno'd in 5th gear and driving around the street in second and third I don't get close to 28psi. So I have been playing around with "Boost Gear Wastegate Trim".

The figures are set quite high and I'm still only getting around 22psi in second gear and I haven't had a chance to test 3rd gear to red line.

The ecu knows what gear the car it is in I have already checked to make sure this isn't the problem.

Do these figures seem a little high and potentially point to another problem, or should I just keep increasing them until I get 28psi?

Thanks

Screenshot (4).png

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I will send a copy of the calibration tonight - The spring pressure is around 15psi, but the car has made 30psi on the dyno without problem, so the boost controller doesn't have a problem bleeding off air.

I haven't got any logs but will try get some when we get some dry weather.

My main concern is whether it is unusual to be setting those wastegate duty trims so high?

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Here is the ecu file.

Turbo GTX3071r

Wastegate 39mm

The picture shows how it is plumbed. Top goes to boost controller, bottom goes to charge pipe.

I really don't want you to waste your time going too in depth, more just a simple yes or no whether its unreasonable to have such high values as I have to achieve the boost. I've checked for boost leaks with a smoke leak detector so I know that's not the issue.

Really appreciate it,

Thanks

ecu26092017.pclr

20170926_212751.jpg

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had a look at the calibration.  

The wastegate duty tables are rather low for trying to hit 28-30 psi.

This will need tuning to sort this out.  Not just gear trim adjustment.

There is also a digital input that I'm assuming is supposed to be an ethanol content sensor but is only configured as gp input.  This input is switching between 2 wg duty tables.

But the values in both tables are rather low for a 15psi spring trying to hit 28-30 psi.

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had a look at the calibration.  

The wastegate duty tables are rather low for trying to hit 28-30 psi.

This will need tuning to sort this out.  Not just gear trim adjustment.

There is also a digital input that I'm assuming is supposed to be an ethanol content sensor but is only configured as gp input.  This input is switching between 2 wg duty tables.

But the values in both tables are rather low for a 15psi spring trying to hit 28-30 psi.

Thanks for the reply,

The car does make 28psi in 5th gear with the current wastegate duty as seen from the attached dyno sheet.

Only problem is the boost is quite a lot lower in 2nd gear and 3rd gear.

Really I'm just wondering if 32% is too high of a figure in the gear trim.

I will probably take the car to the dyno again for a health check to make sure all AFRs etc are okay.

FB_IMG_1506472544074.jpg

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the values in you gear based trim are not out of this world

you have to keep in mind that this a percentage applied to the wg duty table, not 32% added.

example:

With this set to 10%, and the base duty cycle is currently 50%, the effective base duty cycle will be 55% (50 + 50 * 10%).

 

Also my concern is that the car last saw a dyno a year ago according to your original post.  A lot can change in a year on a high horsepower car.

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the values in you gear based trim are not out of this world

you have to keep in mind that this a percentage applied to the wg duty table, not 32% added.

example:

With this set to 10%, and the base duty cycle is currently 50%, the effective base duty cycle will be 55% (50 + 50 * 10%).

 

Also my concern is that the car last saw a dyno a year ago according to your original post.  A lot can change in a year on a high horsepower car.

The car has only seen approx 1000km in this time, but I do intend on doing a health check. I will call and book it in today. Thanks for all your help!

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