Can I run OTS Race Fuel tune w/ 93oct+meth

[methkingM2C]

Hey so subject says it all. Running a good amount of 100% meth in Jpipe with 93oct.

Bootmod3 Stage 2 93oct tune doesn't like it. I'm Dyno tuning next week but curious if I can just run the Race Fuel map meanwhile, safely.

Posting on M3/4 forum cuz M2 forum weak sauce lol

[TopJimmy]

The RaceGas maps expect 100 octane for timing reasons. If you try to spray enough Meth to boost your octane to 100 you'll likely have way too much fuel volume in the cylinders. I would never try this without a custom tune made for it.

Without a custom Meth tune you should only run a light WMI spray for cooling only. I've been told a single #3 nozzle is the maximum in the J.

[methkingM2C]

Originally Posted by TopJimmy

The RaceGas maps expect 100 octane for timing reasons. If you try to spray enough Meth to boost your octane to 100 you'll likely have way too much fuel volume in the cylinders. I would never try this without a custom tune made for it.

Without a custom Meth tune you should only run a light WMI spray for cooling only. I've been told a single #3 nozzle is the maximum in the J.

Well said. Yeah JordanTuned suggest #6 in the Jpipe actually. It's quite a lot of fuel but hey I'm not complaining. I ran #4 in my n55 back in day for a few years

[slaughter.mode]

You can also explore adding E85 to your fill to bring the overall octane rating up. I ran a 93 S2+ OTS map for a long time by adding a few gallons of E85 to every fill. My ethanol content was in the 22-25% range which converted (I believe) to about 94 octane. Ran great. I trust it more than meth spray, especially if it's not in the charge pipes. J pipe meth spray from what I've seen is very uneven.

[methkingM2C]

Originally Posted by nv_f82

You can also explore adding E85 to your fill to bring the overall octane rating up. I ran a 93 S2+ OTS map for a long time by adding a few gallons of E85 to every fill. My ethanol content was in the 22-25% range which converted (I believe) to about 94 octane. Ran great. I trust it more than meth spray, especially if it's not in the charge pipes. J pipe meth spray from what I've seen is very uneven.

JordanTuned told me there is no evidence on the uneven spray. Also installing on the chargepipes can flood the intercooler with unevaporated or sitting puddles. This can lead to bigger issues than minor cylinder distribution issues which the timing and tune will detect and correct if needed.

Also, I ran e40+meth on my last car for years and the ethanol was annoying. Even with local stations. Meth will be more set and forget, plus insane cooling with 120oct supplemental fuel at WOT. Installed right, it's the move. Been down the ethanol road and I'd do full e85+meth for shits and giggles but can't daily it. 93 runs out fast enough.

[slaughter.mode]

Originally Posted by methkingM2C

JordanTuned told me there is no evidence on the uneven spray. Also installing on the chargepipes can flood the intercooler with unevaporated or sitting puddles. This can lead to bigger issues than minor cylinder distribution issues which the timing and tune will detect and correct if needed.

Also, I ran e40+meth on my last car for years and the ethanol was annoying. Even with local stations. Meth will be more set and forget, plus insane cooling with 120oct supplemental fuel at WOT. Installed right, it's the move. Been down the ethanol road and I'd do fill e85+meth for shit and giggles but can't daily it. 93 runs out fast enough.

I've seen it at the shops locally and many tuners tell me the same. The evidence is in the logging with what's happening in the cylinders. JordanTuned (not Jordan but a rep who represented their business) even told me that when I was choosing a Flex tuner and running different scenarios by them. They said charge pipes give a better mix and distribution while hitting the J will focus more on the center cylinders. There's a thread on it here and I know some of these folks personally who told me the same. Tapping the intake manifold is very doable too, there's a pic on that thread somewhere.

[methkingM2C]

Originally Posted by nv_f82

I've seen it at the shops locally and many tuners tell me the same. The evidence is in the logging with what's happening in the cylinders. JordanTuned (not Jordan but a rep who represented their business) even told me that when I was choosing a Flex tuner and running different scenarios by them. They said charge pipes give a better mix and distribution while hitting the J will focus more on the center cylinders. There's a thread on it here and I know some of these folks personally who told me the same. Tapping the intake manifold is very doable too, there's a pic on that thread somewhere.

Yeah I've read that post, it's theoretical. My n55 ran meth starting at last cylinder, much worse entry point, and timing ran fine. I ran that car till 100k miles like that too…

It's not like I'm using it to fuel the car. Just a supplement and for cooling. It's gonna be a stage 2+ that's consistent. I get this POV but my cars have shown me it doesn't really matter as long as it's tuned appropriately with intention.