2.0 TDI Sportline - Dyno Results

[mikinoz]

So here is a comparison graph with the Modshack R32 intake on the TDI.

It was on a DynoDynamics dyno, however it was a 4WD version and a different location so figures are not 100% accurate.

Interesting the difference in the smoothness of the curves.



and for comparison the old chart.

[Jaymz]

What's interesting, all things aside, is that its actually making more torque at a lower speed and peaks for longer. This would suggest that its actually boosting earlier and staying on full boost for longer, excellent work!

[Greg Roles]

Suprisingly, Jaymz is onto something here.

It follows that a smoother, more freely flowing inlet would both allow the turbo to spool faster, and the ingress of air would be smoother.

I remember reading an article when the Gen 3 V8 Holden motor came out, and they raved about the torque increases from a smooth walled inlet tract over previous typical "accordian" style ones. I'd expect a pod, over the twisty turny stock inlet would account for a lot of what you see on the dyno, and feel with the bummometer.

Good work my friend, and I can add to your great airbox mod that earlier this week i drove my car through absolutley torrential rain up around Nambour when it was flooding, drove through a LOT of water, and was a little worried about the pod, but had absolutely zero problems. Not even a single stumble!
I've decided to drill a 10mm hole in the bottom of mine, just in case.

I did make an effort not to put that side of the car into huge puddles though!

[mikinoz]

My worry is all of the airborne dirt in the spray following vehicles clogging the filter prematurely.

[Greg Roles]

AND unlike stock, you can wash it as much as you want! Just think how clogged the stock aircleaner is before it gets changed whenever it does, probably 30-50k's?

Part of the extra power and airflow bonus, is increased dirt to deal with!

[gldgti]

Suprisingly, Jaymz is onto something here.

It follows that a smoother, more freely flowing inlet would both allow the turbo to spool faster, and the ingress of air would be smoother.

im not convinced.... the reason is because its turbo'd.

in a n/a car, anything you can do to the inlet to smooth things out is beneficial, because it will ultimately help flow into the engine.

when you have a turbo which is governed by your ECU which takes a manifold pressure reading, then there is only one scenario in which you could increase your engines output - that would be if the turbo was already running at maximum capacity (say all vanes undilated on your VNT's).

if your ECU is asking for full boost (on its pressure map) and telling your vane actuator to fully close, then your turbo needs all the help it can get to make up the difference - sure. but i very much doubt that the turbo is running at maximum capacity unless your at quite low revs, when the volumetric throughput is small.

anyway, thats a theory.... discussion?

[Greg Roles]

Off boost, the turbo is obviously the biggest restriction - we call it turbo lag.

On boost, the turbo is a pump, and drawing in air beyond atmospheric pressure. From even 0.001 psi onwards, you basically want nothing in front of the turbo for maximum effect - the speed at which it can spool up. You are spot on that if you drive like Miss Daisy, a less restrictive inlet pre turbo will do sweet F all. If, like you and me, you are looking for greater performance, you want minimum restriction, thus maximum air available to the inlet impeller. Most important with NA as you rely on the atmosphere to fill the cylinder, but still an aspect to consider with a turbo.

In the end the age old rule still applies: Air in, Exhaust out. Only we got a pump to assist!

[gldgti]

mmmmm pump......

[POLARBEAR666]

Dont worry about the dyno haters OP. They just don't get that modern dyno's are very accurate.

I have dyno'd the same car on a dyno with no change in mods 1 year later and got within 3hp with slightly different curves on both charts.

The measurement at the wheels is generally very accurate, however the calculation of drivetrain loss does vary.

But arguing about whether he got ~103.4kw at wheels is pointless because he DID. Read the chart. Also that figure seems appropriate given the engine and the mods.