Another "Stroker" Project

[Billman]

i think i dont want more than 16. I think that the 16 with the HX35 hotside will be a very good compromise for the stroker.

[rash]

Boost setting is max 2.3bar Above that boost the backpressure gets too high / AR too small.

What ist the ratio of boost vs backpressure at the point the backpressure gets to high?? What backpressure ist "to high?"

[quattro84]

Over 300mbar is 'too high'. But watch for the temperature rise as well!

[rash]

Over 300mbar is 'too high'. But watch for the temperature rise as well!

300mbar?? Thats not much.

In the back of the Turbine??

In the front of the Turbine?

300mbar absolut oder 300mbar above boost pressure??

For example 2bar boost pressure --> max 2,3 bar backpressure in Front of the Turbine??

[quattro84]

After turbine. You will know when your turbine starts to choke. Temperature will rise very quick, power does not rise anymore. Those are clear signals.
You can't predict what the 'turbine in' pressure will because of the ignition angle, etc.
You can see the performance decline when backpressures are higher than 350mbar. Which means your exhaust system is becoming a restriction.

Just some rough guidelines...

[Audi_CQ]

After turbine. You will know when your turbine starts to choke. Temperature will rise very quick, power does not rise anymore. Those are clear signals.
You can't predict what the 'turbine in' pressure will because of the ignition angle, etc.
You can see the performance decline when backpressures are higher than 350mbar. Which means your exhaust system is becoming a restriction.

Just some rough guidelines...

Exhaust system restriction yes, but question was turbo restriction wasn't it?

Backpressure lower then boost pressure is what you want to avoid overlap problems.

[Billman]

Small Help please to sum the parts up:

I am thinking of using the 7a pump but with the adu belt and tensioner. Would it fit?

[Audi_CQ]

Small Help please to sum the parts up:

I am thinking of using the 7a pump but with the adu belt and tensioner. Would it fit?

On a tall block use 7A/3B pump, ADU belt, but NOT ADU tensioner. Use waterpump for tensioner. If using ADU type tensioner you need longer belt.

[rash]

After turbine. You will know when your turbine starts to choke. Temperature will rise very quick, power does not rise anymore. Those are clear signals.
You can't predict what the 'turbine in' pressure will because of the ignition angle, etc.
You can see the performance decline when backpressures are higher than 350mbar. Which means your exhaust system is becoming a restriction.

Just some rough guidelines...

We measured exhaust backpressure and the result is between 400-600 mbar fluttering - after turbine... mhh... I need to use a glycerin filled gauge

measuring the 7A cams is in progress... they have overlap at 0mm lift - when the inlet valve begins to open, the exhaust valve seems to be still 0.3-0.4mm open... ...so the have no overlap at 1mm lift... but i've not finished this work because of some issues with measuring the correct degrees... so the results are under reserve

[Billman]

please post these results as soon as you can because i am about to install the cams and i really dont know yet what to choose between ADU, AAN or 7A or combinations of them!

[Bram]

Which cams you use is dependant on what turbo you use. Garretts for example prefer the stock ABY / AAN cams and surge on the ADU

Start with the AAN cams especially if you have to map in the turbo.

Isn't this all depending on cam wheel adjustments? Or will you be using OEM cam gears?

[A80Avant]

billman has the ADU cam wheel.Dont know if that makes a difference or not.

Also for all i know,he is not using adjustables anywhere atm

[AndyP]

Not 100 % correct, I'm using the full ADU setup, of ABY / RS2 oilpump, and ADU water pump & tensioner and ABY cambelt so it can be done quite easily.

AndyP is using your setup Audi_CQ except I believe he's using an ABY belt as the ADU one didn't fit, would have to check his project thread.

To the original question if you use Audi_CQ setup use the 3B oilpump wouldn't trust a 7A one don't think they are the same flow.

Correct, I had both ABY and ADU belts and the ABY is the one I used, could get the ADU on. I'm using 3B water pump and relay roller on oil pump.

[rash]

...and surge on the ADU

what is the reason for this behaviour??

[Audi_CQ]

Not 100 % correct, I'm using the full ADU setup, of ABY / RS2 oilpump, and ADU water pump & tensioner and ABY cambelt so it can be done quite easily.

AndyP is using your setup Audi_CQ except I believe he's using an ABY belt as the ADU one didn't fit, would have to check his project thread.

Does the tensioner stay in another angle then stock? Normaly you would need ~30mm longer bekt to compansate for the extra 16mm of deck height.

ADU belt in my setup was a tight fit, but worked for me.