Previously I looked at results published by Integrated Engineering for their direct replacement intercooler for the Mk7 GTI/R and tried to estimate what the results might translate to if they were presented in more typical fashion, as flow rate at a specified pressure drop.
The estimates I came up with were:
- R: 201 CFM @ 28″ of H2O
- IE: 232 CFM @ 28″ of H2O
I also included results from several other intercoolers that have been flow tested to judge how accurate the estimate by analysis may be. The other measured flow results were:
- Mazdaspeed MX-5: 165 CFM @ 28″ of H2O
- Porsche GT2RS: 225 CFM @ 28″ of H2O
- Audi B5 RS4: 245 CFM @ 28″ of H2O
For this analysis I am looking into another intercooler that is available for the Mk7 GTI, this a front mounted unit based around the Vibrant Performance model 12810 core.
The FMIC for the Mk7 GTI is sold under the name Baun Performance.
Baun Performance has not published any flow results of their own with the intercooler but they do reference flow numbers quoted by a vendor selling the product. The stated flow performance is 725 CFM at 1.5 psi. Or in the more common measurement of a flow bench, 725 CFM @ 41.5″ of H2O.
The comparison measurements available are based on a pressure drop of 28″ of H2O therefore it is necessary to adjust the Vibrant core measurement to a common 28″ reading from the 41.5″ that it was reported at. Adjusting airflow to a new pressure drop is straight forward and the result is the Vibrant core should flow 595 CFM @ 28″ of H2O.
A comparison of the three GTI/R intercoolers is shown below:
Clearly the Baun Performance/Vibrant core appears to significantly outflow the other intercoolers.
With the Baun Performance/Vibrant core out-flowing the Integrated Engineering core and R core by a little more than two and one half times looking more closely at the results is in order.
The other series of intercoolers that have been flow tested provide a good collection to compare with the GTI/R products. The flow results from the collection of intercoolers is shown below:
Based upon these results I am skeptical of the claimed flow performance of the Baun/Vibrant core.
Looking at the comparison cores for which I have known flow data the Porsche GT2RS is close in size to the Baun/Vibrant core.
- Baun/Vibrant: 22″ x 9″ x 3.25″
- Porsche GT2RS: 14″ x 9″ x 3.5″
The Porsche core has charge air passages that are not as long as the Baun/Vibrant, which should improve pressure drop as there is not as much length for surface friction to resist the air flow. As the chart above illustrates, the Baun/Vibrant core should more than double the airflow of the similarly sized Porsche core if the published values are correct, something that seems improbable.
The advertised flow numbers for the Baun/Vibrant intercooler core of 725 CFM at 1.5 psi of pressure drop are very questionable.
Notably Vibrant Performance does not advertise these flow numbers for their intercooler core, it is a reseller of the product that advertises them. Baun Performance has not performed a flow test on the FMIC product, they only reference the reseller’s advertised flow numbers and thus are dependent upon the accuracy reported by the Vibrant core vendor.
Update: The Vibrant 12810 core was obtained and flow tested.