Summary

IAT or intake air temperature, if it climbs to say 60 degrees centigrade, we can't keep the same advance. I've set up minus one for 40, minus two for 50, and minus three for 60, but it's guess work, how do I safely tune this? Really good question there Mike. So the first thing to understand here is actually as our intake air temperature climbs, our air density, the density of the charge inside the cylinder becomes lower.

00:00 - Mike has asked, IAT or intake air temperature, if it climbs to say 60 degrees centigrade, we can't keep the same advance.
00:06 I've set up minus one for 40, minus two for 50, and minus three for 60, but it's guess work, how do I safely tune this? Really good question there Mike.
00:14 So the first thing to understand here is actually as our intake air temperature climbs, our air density, the density of the charge inside the cylinder becomes lower.
00:26 And all things being equal, what this actually means is that we may end up needing a little bit more ignition advance as our air temperature climbs.
00:35 So you've mentioned there that you're removing timing and that isn't a bad idea, I'm gonna get to that in a short second here, but it is worth mentioning there that as our air density drops, just like we saw that as the load is reduced, we actually tend to need a little bit more advance.
00:52 That's only one aspect, of course as our intake air temperature climbs, we're also likely to find that our engine is more prone or more sensitive to knock or detonation and this is where what Mike's done comes in.
01:03 It's totally sensible what Mike's done there is retarded the timing to help safeguard that and prevent the chances of detonation occurring.
01:10 Alright so with that out of the way, how do we actually go about tuning this? Well really what we wanna do is artificially raise the intake air temperature so that we can see how the engine responds as we get to those areas.
01:23 There are a few ways of doing this.
01:24 Often we're going to see our higher intake air temperatures on a turbocharged car so a really good way that I do this is get my tune dialled in under normal conditions with the dyno fan blowing onto the intercooler, and then once I'm happy with everything, what I can do is artificially raise the intake air temperature by performing two or maybe three runs with something like a piece of cardboard blocking the intercooler.
01:46 And this is going to raise our air temperature so we can see what happens up at 50 or 60 degrees instead of maybe 30 degrees that we're normally seeing.
01:54 So that's what I'd suggest there.
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