Unexpected Dyno Results: Flex Fuel E46 M3 Loses Power? The Full Story

Dive into the world of BMW tuning with our latest adventure on the dyno. After equipping our E46 M3 with a flex fuel kit, alongside modifications like a new exhaust section 1 and heavier wheels, we still expected a boost in performance. However, the results took us by surprise. This video breaks down the dyno test, the modifications we made, and the science behind the unexpected loss in power and torque.
We explore how each modification impacts performance, providing valuable insights for fellow enthusiasts and tuners. Whether you're considering a flex fuel conversion or curious about the intricacies of automotive tuning, join us for a detailed analysis and learnings from our experience.
🔧 Featured Modifications:
Flex Fuel Kit Installation
CPI Exhaust Section 1 Update
Heavier Wheel Set
📊 What You'll Learn:
The impact of flex fuel on performance
How exhaust modifications can affect power
The role of wheel weight in vehicle dynamics
💬 Join the Discussion:
Have you experienced surprises in your tuning journey? Share your story in the comments below!
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#E46M3 #FlexFuel #DynoTest #BMWMods #PerformanceTuning #CarModification #EthanolFuel #AutomotiveEngineering #DIYAutoRepair #CarEnthusiast #BimmerLife #M3Mods #PerformanceCars #EngineTuning #AutoDIY

[@JTAloft]

Your drop in power below 3200rpm is due to your cpi section one. There should be no H pipe or x pipe in section 1. Both headers should not be merged until section 2.

[@tractioncontroldelete]

Wow. Very unexpected. Thanks for sharing

[@MunichVenom]

Thought we were going to see power from the mod but turned out not to be the case. We did have a suspicion that this was the case before doing the dyno since we have two M3s with the kit installed and both cars didn't see a noticeable power increase

[@tyreemakesbeats]

can you provide links to the exhaust set up, thank you brother!

[@MunichVenom]

I don’t have specific links but this is my setup:
CPI section 1, rogue engineering x-pipe and supersprint race muffler

[@Scarlif3x]

This is the first time I hear about a e46 m3 not making power on E85

[@MunichVenom]

A lot of people that tested these flex fuel modules were somehow associated with the companies or selling the product. We can get some power out of the car if we did a dedicated e85 tune on it

[@Undercover_FE]

Hey mate, well I’m glad I listened to my tuner. I was advised to steer away from Flex Fuel since you have a static tune without optimization for variable mix. Your best bet is to go dedicated maps and switch when needed. Also, did you do any fuel hardware improvements?

[@MunichVenom]

I never really use flex fuel mixtures if I’m going to the track or driving hard to protect the engine but I mainly use it to clean the engine every now and then. I didn’t upgrade injectors since I wasn’t planning on going full e85 so I’ll run a e40 mix max

[@PaleD]

Was this a complete retune with the original tuner HTE?

[@MunichVenom]

This was not a complete retune. It was a flex fuel module that was plugged in

[@_Chev_Chelios]

Nice video!
What ai did you use to write the script?

[@AcTzGlitcher]

That low rpm drop already shows something is wrong with the tune possibly.
E85 should give power across the whole RPM, not lose it.

[@MunichVenom]

That’s what was expected but the flex fuel module won’t work as well as an actual e85 tuned car.