View Single Post
      03-22-2012, 09:55 AM   #2
eric@helix's Avatar

Drives: 01 M Coupe, 08 135i, '12 328i
Join Date: Jul 2007
Location: Philadelphia

iTrader: (0)

Core Design

Prior to this stepped core design you had the option to either go Taller or thicker with the cores. In my design process I measured the captive areas in the front of the bumper in both depth and height and went about designing an intercooler that took up all of this area, yet still retained the all important seal to the back of the fan shroud so the radiator fan could still draw ambient air through the core. The end result is an intercooler with 56% more frontal area as well as core volume. now about the core I was not constrained to an off the shelf core in regards to ambient and internal fin count as we custom spec'd the core to this application the core in the helix FMIC is a single unit stacked up to our specifications in regards to ambient and charge row height and internal and external fin count. since our core has more volume I could increase the internal fin count to remove more temperature and still meet the targeted air flow and pressure drop for this application. as you see by the AIT data logs the intercooler works amazingly well

Another Design feature to our core is the use of half round header bars on the ambient face and in the charge side of the core. These half round bars help to direct airflow with less restriction though the core to the radiator and less pressure drop as the charge air does not have to find its direction into the core nor fight flat surfaces!

Endtank Design
All endtanks are not created equal. Air likes to flow in a smooth curved radius and as you can see the Helix FMIC has rounded endtanks that are cast. Another thing you will notice is we opted not to utilize the factory O-ring connectors even though we could have easily implemented them into our design. Our reasoning was simple; the factory connectors are THE flow restriction in the charge side as they shrink down to less than 2 inches in diameter at the inlet and outlet.

STOCK: 2-4 gear

Helix Intercooler: 2-4 gear

Independant AIT test through 2nd-4th gears-Incredible AIT control!

Independent testing and comments on the Helix FMIC:

I've been testing the Helix FMIC and it keeps IATs within a couple degrees of ambient. Pretty ridiculous. In a good way, of course. And it doesn't block too much of the radiator either. That would be my recommendation.

I've tested 3 different aftermarket FMICs in my car and the Helix unit performed the best in terms of cooling efficiency and pressure loss. I don't see things getting much better than that to be honest.

I will attest that this intercooler will help your cars. I have had it on since early winter/last fall and have seen little to no decrease in power with the warmer weather or after repeated hard runs that would have heatsoaked the tiny stock intercooler in no time.

Helix FMIC Install Video:

Fits in stock location- YES
Requires NO cutting,removal and/or permanent modification- Yes on 335i, No on 135i
**On 135i about 1.5 square inches must be trimmed**
Can it be installed without removing front Bumper- YES
Utilizes factory mounting points- Yes

***Late model N54 and N55 require a custom Helix Charge Pipe to replace the drivers side lower charge pipe***

More core volume than stock- Yes 56%
More Ambient face than stock- Yes 56%
More charge rows than stock(8)- Yes 13
Bar and Plate construction- Yes
Removes restrictive stock O ring connectors- Yes
Seals to factory radiator fan shroud so air is drawn through when car is not in motion- Yes

Helix intercooler at 13.5psi 63 degree ambient temps:
372whp +22whp
turbo outlet temperature 228 degrees F(estimated using a 63 degree ambient and 65% compressor efficiency at 13.5 psi)
AIT temp- 75 degrees F - 54 degree drop over stock
pre and post intercooler temp drop- 153 degrees F
Intercooler efficiency- 93% - 33% improvement in efficiency over stock
Core pressure drop spec is .5psi at 450hp(600cfm) airflow