[Tato]

Pardon me if I'm not well-versed in tuning knowledge, but I see that BM3 has a stage 2+ OTS for 91 octane, and was curious why MHD doesn't provide a similar offering. According to the PTF website, their stage 2+ on 91 offers 13% more horsepower and 30% more torque over stock compared to their stage 2 tune. If this is possible, why wouldn't MHD be able to map something similar to take advantage of a stronger HPFP? In another thread it's mentioned it is because at 91 you're octane limited as opposed to flow limited, but why is that not an issue for the BM3 map? I thought the gen 2 b58 could make more power on 91 than the gen 1 b58 because the HPFP was the limiting factor, but it seems I'm wrong. Anyone with the technical knowledge able to explain it? I was hoping I could get more power out of my TU pump until I get a flexfuel kit for my car.

[G.Newt]

Okay a couple of things:
1. You live in California. You have the worst gas in the country, along with Arizona and Nevada. You were never going to make more power on any of the 91 maps. They make specific maps for your state (ACN).
2. You can run the Stage 2+ E30 map to take advantage of your TU pump. You don't need a flex fuel kit. Target E35 since you're mixing with crappy Cali 91 and take a log to verify. Should be much faster and you'll enjoy the newfound power.

For the technical tuning stuff, that I don't know. 91 does limit how much timing you can run. BM3 may be increasing boost by a decent amount to make up for it, and more boost = more air, more air = more fuel. The more fuel part is related to fuel capacity, where the TU pump would come into play. Again, just a guess.

[Tato]

Originally Posted by G.Newt

Okay a couple of things:
1. You live in California. You have the worst gas in the country, along with Arizona and Nevada. You were never going to make more power on any of the 91 maps. They make specific maps for your state (ACN).
2. You can run the Stage 2+ E30 map to take advantage of your TU pump. You don't need a flex fuel kit. Target E35 since you're mixing with crappy Cali 91 and take a log to verify. Should be much faster and you'll enjoy the newfound power.

For the technical tuning stuff, that I don't know. 91 does limit how much timing you can run. BM3 may be increasing boost by a decent amount to make up for it, and more boost = more air, more air = more fuel. The more fuel part is related to fuel capacity, where the TU pump would come into play. Again, just a guess.

You're right, our gas is very crappy. I checked my stage 2 log and there's already a good amount of timing corrections during the pull. I'm going to drop down to stage 1 for the time being just to keep the engine in a safer margin. I'd like to try mixing e30 myself, but I'm not confident I'll be able to keep it at the correct level just calculating it myself. The flexfuel sensor is mostly for peace of mind I have the ethanol content at the right place.

[Ivilla035]

Originally Posted by Tato

Pardon me if I'm not well-versed in tuning knowledge, but I see that BM3 has a stage 2+ OTS for 91 octane, and was curious why MHD doesn't provide a similar offering. According to the PTF website, their stage 2+ on 91 offers 13% more horsepower and 30% more torque over stock compared to their stage 2 tune. If this is possible, why wouldn't MHD be able to map something similar to take advantage of a stronger HPFP? In another thread it's mentioned it is because at 91 you're octane limited as opposed to flow limited, but why is that not an issue for the BM3 map? I thought the gen 2 b58 could make more power on 91 than the gen 1 b58 because the HPFP was the limiting factor, but it seems I'm wrong. Anyone with the technical knowledge able to explain it? I was hoping I could get more power out of my TU pump until I get a flexfuel kit for my car.

So essentially, I went through this with BM3 back and fourth, and they eventually added a 91 map for stg 2+ multimap. I use the flex fuel kit with bm3 and run the multimap, which added 91 octane when I contacted them. Just solely because I live in different 91 octane states, and I don't want to keep reflashing over and over from stg 2 multimap to stg 2+. Highly recommend the flex fuel kit. I run my FBO 340i in san Diego, and usually always have some kind of e85 in the tank. Sometimes i'll just run 91 for solely gas mileage purposes. https://f30.bimmerpost.com/forums/sh....php?t=2000829

[G.Newt]

Originally Posted by Tato

You're right, our gas is very crappy. I checked my stage 2 log and there's already a good amount of timing corrections during the pull. I'm going to drop down to stage 1 for the time being just to keep the engine in a safer margin. I'd like to try mixing e30 myself, but I'm not confident I'll be able to keep it at the correct level just calculating it myself. The flexfuel sensor is mostly for peace of mind I have the ethanol content at the right place.

Getting an E mix right is super easy. Just get an ethanol tester from Amazon or fuel-it. There are tons of apps and online E85 calcs to ensure you get the right mixture. Just overshoot a bit, like E35 since you're mixing with Cali 91. Once you go E, it's hard to go back.

[DreamerJoe]

Originally Posted by G.Newt

Getting an E mix right is super easy. Just get an ethanol tester from Amazon or fuel-it. There are tons of apps and online E85 calcs to ensure you get the right mixture. Just overshoot a bit, like E35 since you're mixing with Cali 91. Once you go E, it's hard to go back.

Its even easier if you just mix it 50/50, I run the e40 tune and always go half and half, always better to error on the side of more e85 and I got tired of using the e85 calculator. Also considering how really shitty our gas is in Cali I would still always go more when “trying” to actually do the e40

[lens]

Originally Posted by Tato

Pardon me if I'm not well-versed in tuning knowledge, but I see that BM3 has a stage 2+ OTS for 91 octane, and was curious why MHD doesn't provide a similar offering. According to the PTF website, their stage 2+ on 91 offers 13% more horsepower and 30% more torque over stock compared to their stage 2 tune. If this is possible, why wouldn't MHD be able to map something similar to take advantage of a stronger HPFP? In another thread it's mentioned it is because at 91 you're octane limited as opposed to flow limited, but why is that not an issue for the BM3 map? I thought the gen 2 b58 could make more power on 91 than the gen 1 b58 because the HPFP was the limiting factor, but it seems I'm wrong. Anyone with the technical knowledge able to explain it? I was hoping I could get more power out of my TU pump until I get a flexfuel kit for my car.

MHD tunes are based off EU fuel, which is why their maps require good quality fuel to minimize timing corrections.

BM3 is based out of Toronto/Canada, so their OTS maps are based on NA fuel.

I currently run their Stage 2+ 91 MM OTS, and i put it on the dyno and it made 433AWHP/521AWTQ, it ran 11.49@119mph on dragy as well.

This was using NS piss 91 oct (our fuel is literally in competition worst than california,nevada,arizona gas quality)

[B58]

Originally Posted by lens

This was using NS piss 91 oct (our fuel is literally in competition worst than california,nevada,arizona gas quality)

Oh trust me our fuel isn't any better in Cali. I can put a few gallons of E and get the entire gas station to piss inside my tank until it fills up and have better octane than what they give us at the pump. They're so concerned about emissions, but give us garbage that doesn't burn clean.