[DLSJ5]

Originally Posted by Lemans_Blue_M

Meth/H20 injection is not a necessity to make big power or a safe tune...

Meth/H20 injection is the 'easy' band-aid approach to fix poorly tuned FI performance upgrades, increase the rwhp numbers, or to overcome some hardware engineering defect in the kit. (such as high IAT's)

A poorly engineered hardware design will lead to a number of performance related issues.

The last thing the tuner wants to see...is a poorly designed and engineered hardware package.

Why?

Because that means he's going to have his work cut out for him, in order to tune that car properly.

In other words, he'll have TUNE AROUND the bad or ill-conceived hardware design. (in order to get the kit working properly)

This will be necessary to prevent detonation and overheating issues from cropping up.

Methanol is not good for your engine (long term), so if you CAN avoid using this toxic chemical to tune your car, you should certainly do that...

All you need is one hiccup and bye-bye engine. It's too risky in my book if your kit REQUIRES the use of Meth/Water to function properly. The less elaborate you can make the tuning, the better. Pump fuel only is a far safer route to take, unless you have a spare 25k to replace your existing 4.0 V8 engine.

50/50 isn't terrible, but the hardcore guys that are using 90%-100% Meth are completely nuts. When you tune an engine using methanol injection, you have to adjust the tuning parameters accordingly. Methanol has a low stoich AFR of (6.4), and it has a very high latent heat value compared to unleaded gasoline.

Keep in mind that OEM 02 sensors are designed for production cars that use Unleaded gasoline ONLY.

Meth/Water injection is just another potential failure point with the FI kit, which decreases the overall reliability.

If someone wants a 'free' power bump (without having the ECU re-tuned) for their FI M3, just throw in some 100-octane unleaded race gas instead.

The M3's factory ECU is sophisticated enough to adapt the tuning, so that it can take advantage of the better fuel grade in a boosted application. (even more than it can when the engine was still naturally aspirated)

You can realistically gain 30rwhp or more by going that route.

It's also completely safe for the engine, and there are no hardware or software concerns to worry about.

Just my .02...

That it is certainly one way to look at it and absolutely true in some cases, you make some great points. You're right it's not needed or essential either I would say, unless you want to run more than 7psi on 91 octane.

However, there's another way to look at it. As we all know, the S65 was never intended to run FI. I think the main goal when you design the hardware for this setup is to keep IAT's in check, WM is a GREAT safety feature in this regard. It will also help with the poor quality of 91 octane gas, especially with the CR on the S65. So it's a win win if you run it that way.

As you correctly pointed out, if you tune for the WM and it relies on it for appropriate AFR's, to higher timing, etc., then no doubt your points are even more valid, because if the WM fails the the motor may as well. There are safety features for this though. However running it on a FI S65, if you choose, I think is a good idea at least they where with my FI experiences on the S54, that being near 40K (not all of it on WM) with as much as 11psi in it's latter stages.

BTW, a member on M3forum, is having ESS tune his VT3 E46 M3 for water meth, so I don't think AJ hates it that much.