Understanding AFR: Medium Boost/High Boost
Watch This Course
$89 USD $44.50 USD
-OR-
Or
8 easy payments of only $5.56
Instant access. Easy checkout. No fees.
Medium Boost/High Boost
01.28
| 00:00 | If we are dealing with an engine running forced induction, applying full throttle will have the engine move into positive boost. |
| 00:06 | The amount of boost pressure the engine runs will be a function of the turbo or supercharger installation, and its important to understand how this can impact your target AFR. |
| 00:18 | As we increase the boost pressure, the amount of load on the engine increases. |
| 00:23 | We have more air and fuel moving through the engine and hence the combustion pressure and temperature rises. |
| 00:31 | This means as boost increases we need to adapt our target AFR to move richer also. |
| 00:38 | I have taken two arbitrary points in this map to illustrate how the AFR changes with boost, however the actual boost levels you choose to run may vary. |
| 00:49 | At a boost level of around 1 bar or 14.5 psi, I will start with a target AFR of 0.80-0.82. |
| 00:59 | As we move higher in the boost, the AFR moves richer and at 2 bar boost I would start by targeting 0.78-0.80. |
| 01:08 | I have proven these targets to be a safe place to start tuning, and they will result in good power while controlling combustion temperature. |
| 01:17 | There are some instances where we may want to modify these starting AFR targets and we will look at these a little later in this section of the course. |
