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So my understanding is that water/meth (and E85) is primarily used in turbo applications to reduce the detonation threshold allowing to turn up the boost while injecting water/meth (cools the cylinders and creates an overall higher octane). But you can always turn down the boost and not need to run water/meth/E85. So its a flexible system that can be turned on and off along with boost levels...
In NA applications this would mean you would only be able to see gains through greatly increased compression ratio's... but you would also need to run water/meth 24/7 in this application, since there is no real way to "turn down" the compression ratio (since the engine has been built this way) and its going to detonate if you arent running water/meth all the time. Its static an unable to be changed.
Seems like water/meth just isnt a great application for N/A unless its for full race or drag applications and secondly, not going to provide large HP gains as it would with a turbocharged system, since you are only seeing gains through CR increases (small) and not through boost (large)... This goes for E85 as well - great for turbo applications but the gains for NA just arent substantial enough to be worth it, considering the small gains and the elaborate system needed to implement E85 (completely new/upgraded fuel lines, E85 sensor, reservoir, etc). And again, what do you do when you cant find E85??
Not worth it for the small gains you would see in an NA application, and not feasible for real world situations. Great tools for turbocharged applications though...
One thing you havent mentioned (but may be assumed) is converting the car to standalone engine management, especially to a speed density setup, where there have been fairly good gains due to the removal of the AFM and full control over fuel and timing. I would say your money is better spent here than chasing water/meth or E85.
Just my 2c
Last edited by walfreyydo; 08-08-2023 at 02:43 PM.
I'll post this as a point of reference. I began racing with a 9442V which was inexpensive and reliable. Power was okay, but once going 4V I never looked back. Here's a 2.5L 4V engine on carbs. I'm happy to provide build detail if there's any interest.
Car was with Wössner Pistons 10.5:1(?), sleeved 944 block, with removed Balanceshafts. Custom cam, custom intake with Jenvey TB.
Car had exhaust manifold (nothing too exotic). Tatech engine management. Most of the gains we got was from cams that were not yet super aggressive but semi.
Started building the Supercharger route but lost the interest and time, sold it 2022, now car was back on track and it had 300hp without proper tune.