Why not use water/methanol injection?
Do people know how to tune for it? There are situations where the car will cut fuel instead of timing, and if it's spraying meth when that happens you'll get a bad lean knock.Why not use water/methanol injection?
Methanol's main function is to lower IAT, some have increased the volume to also increase octane of the fuel but I think that requires a lot more volume and multiple injectors. If the only goal is to reduce IAT (to lower likelihood of knock on pump gas) the volume of methanol needed is actually not that much in my experience. Some kits actually just use the washer fluid tank as the methanol reservoir.Do people know how to tune for it? There are situations where the car will cut fuel instead of timing, and if it's spraying meth when that happens you'll get a bad lean knock.
In theory yes it's possible but I've never seen it happen to an s550. Lund recommend I don't tune for it and just use it for the extra octane/ cooling but I know they tuned another local members gt with good success. If i remember correctly for @Chris Barnes Lund had him relocate his iat sensor to the number 8 cylinder to monitor iat2. The computer adds timing with the meth but let's stft handle adding or removing fuel. If the meth flow stops it just pulls the timing back to prevent issues. Maybe he can chime in in case I'm missing something but I think that was the jist of it.Do people know how to tune for it? There are situations where the car will cut fuel instead of timing, and if it's spraying meth when that happens you'll get a bad lean knock.
100% correct. The Alky system allowed me to run up to 19 deg timing cap on shitty AZ 91 octane. The tune did not remove any fuel, but just let the wide bands do their job and remove fuel. Ran this setup for years even in the AZ Summers without issue. It simply worked and never missed a beat. Im actually getting ready to do the same setup on my 2021 GT500.In theory yes it's possible but I've never seen it happen to an s550. Lund recommend I don't tune for it and just use it for the extra octane/ cooling but I know they tuned another local members gt with good success. If i remember correctly for @Chris Barnes Lund had him relocate his iat sensor to the number 8 cylinder to monitor iat2. The computer adds timing with the meth but let's stft handle adding or removing fuel. If the meth flow stops it just pulls the timing back to prevent issues. Maybe he can chime in in case I'm missing something but I think that was the jist of it.
But yes adding meth is a cheap easy way to have a safety net with high compression and boost.
Meth enriches lambdaThe issue isn't tuning around the additional fuel or adding octane. That stuff is easy.
The issue is if meth is spraying and the car cuts fuel. Fuel cut is one of the fast path torque reduction methods in the pcm. If the car suddenly fuel cuts as a method of fast path torque reduction under load, the meth probably won't shut off quick enough. This can lead to a mega lean detonation event.
Unless you can be 100% sure the car will never cut fuel as a means of torque reduction, I don't think meth is a good idea.
Obviously you don't get it. I don't know how else to explain it. Normally fuel cut at WOT is fine because all fuel is cut, there's nothing to combust and cause a lean event. But if you're spraying meth and the car goes into fuel cut, now that meth is the ONLY fuel there (and not very much of it) So it can still combust which would cause a mega lean event.Meth enriches lambda
The water/meth kit can stop and start as fast as the solenoid opens and closes. Never had or heard of anyone having this problem. Not saying that it can’t happen but what are the chancesObviously you don't get it. I don't know how else to explain it. Normally fuel cut at WOT is fine because all fuel is cut, there's nothing to combust and cause a lean event. But if you're spraying meth and the car goes into fuel cut, now that meth is the ONLY fuel there (and not very much of it) So it can still combust which would cause a mega lean event.
There are no safeguards to stop the meth fast enough in this scenario. and logs have shown the PCM going to fuel cut instead of spark cut. So as I keep saying, I wouldn't run meth unless you can be 100% sure the PCM won't cut fuel.
My water/meth is progressive so it doesn’t have to be dead on at 6psi so even if it needs 1/4 of a second it’s fine. Also I have zero torque reduction anywhere that w/m is on in a race tuneIf it's triggered on by boost or maf voltage, I don't think it would react quick enough. There's nothing stopping it immediately with the fuel cut.
If it were triggered by IDC which certain AEM controllers can do, then maybe it could.
I haven't heard of it happening on an S550 (haven't really looked) but I've definitely seen this situation grenade engines on other platforms - various meth set ups and split second controlled port injection. Since I don't have a concrete answer of why/when the car decides to use fuel cut as fast path for torque reduction, so idk how likely it is. That isn't how the PCM usually deals with torque reduction but it can, someone has posted a log of it somewhere. To me that seems like a big risk.