Meet my Polo!

[Guy_H]

The flow charts are the most important, as you can see the stock one flows more than the unit in question, and the APR one flows, well you can see how it flows.

The dyno plots are three different cars, but the ones to look at are the blue & the red lines.

These are two K04 cars, both running downpipes (one with a catback), both running standard airboxes & the exact same software.

The big difference is one runs the APR intercooler (BLUE) It could make 24PSI & hold a good boost curve.

The Red line has the Forge intercooler & could only make 22psi, but the curve dropped off hard as you can see.

The green line is a well worked K03 car that goes well.

We have data logging from both the Blue car & the red car & it shows exactly the same, with the Forge intercooler on board, it can not make its requested boost, nor can it maintain a solid curve through a power run.

James is trying to find the dyno's of the red car once the intercooler was swapped and how now the boost curve is the same as the red car.

[noone]

The flow charts are the most important, as you can see the stock one flows more than the unit in question, and the APR one flows, well you can see how it flows.

So what does it mean? What is the unit of measurement? I googled it, but could not find other flow testing or comparisons with PSI / Bar.

I guess what I need to understand is what makes this example accurate for the Polo vs preferable for your product? If you tested at 25 Psi, then it's not really relevant as we don't make that much boost.

[gjuu]

and another question is...
Does this mean that you think better flow but higher intake temperatures (std vs forge) are more desirable than cooler intake temps and less airflow.
(were the tests done after a good fang around the block to get that heat soak happening?)

[Guy_H]

What it boils down to is power loss, which ever the way you look at it, due to inefficient intercooling & poor flow. As I mentioned earlier, the tests were on behalf of some customers that had the exact same issue.

Going back several years (years before the Forge unit was on the market), we need an intercooler for our Tarmac Rally Polo 9N, we approached Richard at ARE ARE Cooling (Aluminium Radiators & Engineering P/L) - their reputation is second to none. Anyway, we had 2 choices, build a completely new core or modify the existing APR 1.8T specific intercooler to suit. Richard carried out flow testing & analysis on the APR core & it was deemed "More than adequate" - we also have APR's pressure drop figures through the core (air supply to the radiator) so there was zero danger of overheating. Anyway, it was expensive, but they worked.

Don't take my word for it, feel free to have a stock vs any after-market version rested by any intercooler manufacturer with a flow bench - the results speak for themselves, as does the data logs & the dyno wheel readings & PSI drop.

[Tim]

you can see just by looking at the designs why the forge unit wouldnt flow as well. Doesnt look like they have put a lot of thought into it beyond getting as much cooling as possible.

[Guy_H]

Actually Julian Edgar who is now a forum member (resides mostly in the Skoda section) may be able to comment further - he is a writer for Autospeed. A while ago (2003) they did a test on JDM intercooler (lots of them) using flow bench & volumetric measurements (mass also). Might be good for Autospeed to test several units side by side?

AUTOSPEED LINK

AUTOSPEED LINK

Anyway, you should be able to gain a lot of information from those sites, as well as ARE's.

[Guy_H]

Just had a couple of beers with an Auto engineer friend of mine - we were discussing this thread. He also mentioned a well known fact that for every 5 PSI extra a turbo has to make, it will increase heat by 13 - 17 degrees C.

4. Its worth noting here that the MAP sensor is POST intercooler on the Polo - so any loss of boost pressure will be taken into account by the ECU; it will work the turbo harder to get the programmed boost. This will result in more overall air. I would have thought a tuner would understand that fact.

So working the turbo harder will create more heat, the purpose of intercooling is to reduce intake heat & hopefully not working the turbocharger harder.

[kaanage]

You've taken that quote out of it's original context. Xtturbo was saying that the boost fell because of the superior cooling provided by his IC (while the mass of air flowed stayed constant) so by running the turbo harder to get the same level of boost, you would end up with a greater mass of air flowed to the cylinders => more power.

Now I'm not saying the Forge is better (or worse, for that matter) but the way you have cherry picked the quote makes it seem like xtturbo is just saying that the turbo will just force more air through to counteract the restriction of the IC

[Guy_H]

Sorry Kaanage, I disagree, I could comment on the other sentences as well, but there is plenty of information here already.

Fact is if the ECU is requesting X amount of boost, it will hold the wastegate accordingly to try to reach that requested amount of boost - hence a pressure drop WILL work the turbo harder & produce more heat.

You can check this by logging block 115 (actual & requested boost) and block 118 for N75 duty cycle. You can compare these values.

http://www.ross-tech.com/vag-com/m_blocks/110-119.html

There is a good article somewhere on WG duty cycle - I just have to find it.

[RoSonic]

I honestly think that this discussion could be split/moved into a thread of its own.
Since it's not about Plauto's car... and this is his build thread.