Background:
This post was made in a Mk8 discussion group, and it generated some debate on the merits and shortcomings of a bicooler intercooler setup.
I was encouraged to see that the original post contained a link to one of the comparisons I had made between a bicooler and other intercooler arrangements. Having test results available to reference should help the discussion move past wild speculation and center on evidence, at least in concept… real life on social media has a habit of devolving into a circus.
In this post, I will examine some of the more amusing comments people made in the discussion about bicoolers.
Note: As of the date of this post, I have installed a baker’s dozen different bicooler combinations on my Mk7 GTI and logged their real-world performance.
Participant Comments:
Out of the gate, we have Felix pooh-poohing the bicooler as something that “real racers” don’t use. The plausibility that Felix knows what all “real racers” use for an intercooler arrangement is doubtful, but irrelevant to a discussion about a passenger car.
Felix’s following comment torpedoes his credibility when he incorrectly states, “Pressure loss is an issue causing spool lag...”
Bicoolers reduce pressure losses across the intercoolers, which does not cause spool lag.
Felix also states that they are a “waste of time on inline 4’s with a single turbo setup.” This is a subjective judgment, but objectively, a bicooler improves cooling performance and reduces pressure loss compared to a stock GTI IC.
The next comment Felix makes illustrates why racing for a few decades doesn’t mean you understand how a bicooler changes the cooling performance on a Mk7.
Later on, when someone tries to point out to Felix that the results on the Mk7 are positive, he turns to ridiculing that person, not a good look when you’re wrong Felix.
Unfortunately, the facts Felix offers are either irrelevant or incorrect.
This is cringeworthy, being such an ass when you don’t know how a bicooler performs on a Mk8/Mk7.
Next Commentator:
The next participant seemingly didn’t bother to look at the post that the OP provided the link to.
If he had, he might have seen that, as a practical matter, any “lag” is inconsequential to the operator.
This highlights a problem with using a “model-based” argument; the model must accurately capture all factors to produce an accurate result.
Juan states that the “air will flow through the least restrictive intercooler“; air will flow through both intercoolers. It’s unclear whether Juan believes that air will flow through only the least restrictive intercooler; hopefully not, otherwise he should contact the school and request a refund.
“It will only flow through the least restrictive one.” Yikes, time to get that refund.
Next:
There’s sooo much wrong here that I’m going to skip addressing it all. One thing to point out is that there is not “more volume the air has to fill“. Air is always contained within the intercoolers; a larger volume of air is being compressed with the bicooler.
Next:
WTF? Why don’t people take the time to look at test results comparing these products?
No, there isn’t a “pressure loss issue“. I even went through the trouble of making a picture to try to simplify the concept in the post the OP provided.
Followed by an actual flow test of the two configurations:
Hint: Higher airflow is correlated with a lower pressure loss.
The next response illustrates what happens when someone who doesn’t understand how the system functions attempts to provide a technical explanation. Dunning-Kruger ring a bell?
“Increasing the volume increases the amount of pressure required for the most efficient flow.” So far off, not worth trying to correct, just ignore.
“Causes turbo lag on smaller turbo setups.” Previously debunked, while valid in concept, in practice, the lag is indistinguishable from measurement noise. Also shown in the linked post, jeez, think of how much misinformation could have been avoided.
Ignorance tell, quoting manufacturers’ advertising as if it is authoritative – “ARM even advertises their bicooler hoses as contributing to pressure drops on stock turbo Mk7s“. ARM is indeed confused about how pressure drop is caused and advertises this false information. I’ve tried to get them to correct the advertisement without success.
Best of the Rest:
“most likely just going to hurt response and cause an increase in lag” – Notice the trend? Ironically, Ken says the horse has been beaten from the MK5/MK6 days with the Forge product, but I tested the Forge Twintercooler and it has a lower pressure drop than the stock IC.
Sebastian says that it’s arguable if it’s an improvement vs a stock location brand name when factoring in pressure drop and IAT. While the point can be debated, there’s evidence to compare the two. The bicooler holds its own against Wagner and APR.
Conclusions:
Despite an easily accessible source of test data for a bicooler intercooler configuration being presented along with a question about the products, a large portion of consumers debated the product value with misinformation.
Given that the objective information about the bicooler performance was made public four years ago, owners of the Mk8 GTI will likely waste a significant amount of time exchanging incorrect information about bicoolers and other aftermarket performance parts.