Please note that the data shown below has been generated by factoring up the results from a 26.42cm² sample of foam material, actual flow rates may differ
CFM figures quoted at 1.5 inches of H2O
Our eight trumpet filter will perform better than two four trumpet filters in a hockenheim 405 V8 air box as there is no centre line shrouding.
Product Image | Part Number | Description | Size (mm) | Filter surface area (cm²) | CFM |
 | R01SE6166 | ITG Foam filter for use in Zolder 112 Air boxes | 420 long x 130 wide x 70 deep | 909 | 1285 |
 | R01SE6173 | ITG Foam filter (low Height) for use in Hockenheim 422 and Interlagos 425 air boxes | 410 long x 120 wide x 105 deep | 1149 | 1630 |
 | R01SE6172 | ITG Foam filter (increased Height) for use in Hockenheim 422 air boxes | 410 long x 120 wide x 160 deep | 1794 | 2645 |
| R01SE6178 | ITG Foam filter (Four trumpet dome) for use in Hockenheim 405 V6 / V8 airboxes | 390 long x 120 wide x 105 deep | 1127 | 1590 |
 | R01SE6183 | ITG Foam filter (Eight trumpet dome) for use in Hockenheim 405 V6 / V8 airboxes | 390 long x 250 wide x 105 deep | 2171 | 3200 |
Guide for selecting snorkel sizes when fitting a snorkel to one of the air boxes compatible with these filters
An inlet that is too small will cause a pressure drop inside the air box restricting performance. The Snorkel sizing guide shows the minimum recommended inlet and ducting snorkel size for a power output category. The larger the power output of an engine the more air it will require to run at peak efficiency, therefore a larger snorkel is needed as power increases. Multiple smaller snorkels can be used to achieve the same open inlet area as a larger snorkel for example if a larger snorkel won’t fit on the air box multiple smaller snorkels or oval exit snorkels could be used to create a comparable open area. High flow alloy straight trumpets can also be used as intake snorkels.
| BHP Category | Open Area (cm²) | Snorkel Diameter (mm) |
| 1 - 150 | 44.18 | 75.0 |
| 150 - 205 | 56.75 | 85.0 |
| 205 - 265 | 78.54 | 100.0 |
| 265 - 325 | 127.68 | 127.5 |
| 325 + | 181.46 | 152.0 |
On typical engines 150CFM is required for each 100BHP
On high performance engines 130CFM is required for each 100 BHP
The formula below shows the formula for required airflow to the engine in cubic feet per minute.
CFM = Engine Capacity (Cubic Inches) / 3464 * Max RPM
1L = 61.0237in³
For example a 5.7 litre engine requires 703CFM of air at 7000rpm :
703 CFM = 347.84CI / 3464 * 7000RPM
Or if supercharged...
CFM = (CI * RPM / 3456) * (boost [psi] / 14.7 + 1)
ReVerie Limited & its product range are not connected with Lotus Cars Limited or Lotus Sports
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