Lost Torque but Gained HP

[welding rod]

I am running 225 ml per minute on a 2.0 liter Ford Focus at 10 pounds of boost. I am using 25% methanol / 75% distilled water. Using Aquamist 1S and triggering at 7.5 PSI. My open loop AFR is 12:1.

On back to back dyno runs with and without water, no other changes, I lost about 25 + foot pounds of torque below 4K RPM, no change at 4K, and then a consistant gain of 3-5 HP above 4K to redline. My intake air temperature sensor is after the water jet so my timing is advancing slightly with the decreased temps.

Since then I have added a pound of boost and advanced high load timing 2 degrees across the RPM range, but I still have a very obvious lull in the power at 3-4 K that I would like to tune out.

I have full control over the OEM computer with my SCT Pro Racer tuning software.

Any suggestions?

[Charged Performance]

You are experiencing the problem with static flow systems.

With the exception of the reduction in pressure across the jet (water line pressure against rising boost pressure) you are essentially flowing the same amount of water no matter how much air and fuel the engine is using.

So at low rpms and loads you are flowing a lot of water into the cylinder relative to the amount of air and fuel coming in. Your engine is bogging on the excess water (don't worry not so much you will lock the motor but enough to hurt combustion).

The real solution is to upgrade to a 2d which will meter water at a better approximation relative to the amount of air and fuel being inducted into the cylinder so that you can run an approximately constant ratio of water to fuel.

However, in the short term your options are to decrease your water flow by using a smaller jet (be careful above 4k you will also be running less water per cylinder stroke than before - you will be reducing the knock suppression of the prior water injection) or set your trigger to be at a boost above the point where it is bogging down.

[welding rod]

Thanks, that is what I figured, too much water at lower airflows.

What I was wondering though is if I can effectively tune the power drop out by trying to take advantage of the extra water and going more aggressive with the tuning.

I was wondering in perhaps leaning out the AFR in that range may prove beneficial? Of course I can try adding more timing too. Or maybe using a higher % of methanol?

I will check out the 2D as well.

[TurboGTi]

Hey i was thinking the same thing .... at low RPM where there is additional water being injected. could i increase timing at that point to aid in combustion, then retard timing to a more suuitable degree when the RPM reaches a higher level?

This should be interesting..... currently i'm running 12:1 AFR on full boost with water spraying.

I would love to tune out this 12:1 to a more efficient 13:1 ...i am taking into consideration that the water affects the lambda sensor so an indicated 13:1 AFR is actually 12:1 or there abouts.

look at my dyno sheet you can see where i need some fuel adjustments with the AFR
also you can see the smoooooooth curves.

[dc96819]

Maybe a 2 stage system would help

[alpina]

Hey all,

Could it also be that the manifold was not in full heat-soaked stage yet? Hence water wasn't that *ready* to evaporate?

[welding rod]

My manifold is plastic and never really gets too hot. In any case even out on the road flogging the hell out of it the torque loss below 4K is very obvious. I can turn the water off and the car is much more responsive and crisp below 4K.

My turbo spools quickly and I reach full boost around 3200. The point at which I have the spray turn on (7.5) is probably reached before 3K. I don't want to raise the spray point though for two reasons. First it will have negligeable effect on the trouble area at 3-4K, and second I want (need) to provide a little lead time (small fractions of a second) for the water to get going for protection during high RPM transient conditions.

[Charged Performance]

You could advance timing some at that point - but keep in mind that tuning during boost transition (while spooling up from vacuum to boost) is already touchy at best. Some tuners like to retard there to get some combustion in the manifold to spool up the turbo.

I see the options as:

variable flow system
2-stage (used multiple stages a lot before variable systems were around - one low flow early and the second stage over it later)
set for later water injection turn on
lean fuel in the area a little more if det is not present (which it shouldn't be)

[Sato]

Originally Posted by welding rod

I am running 225 ml per minute on a 2.0 liter Ford Focus at 10 pounds of boost. I am using 25% methanol / 75% distilled water. Using Aquamist 1S and triggering at 7.5 PSI. My open loop AFR is 12:1.

On back to back dyno runs with and without water, no other changes, I lost about 25 + foot pounds of torque below 4K RPM, no change at 4K, and then a consistant gain of 3-5 HP above 4K to redline. My intake air temperature sensor is after the water jet so my timing is advancing slightly with the decreased temps.

Since then I have added a pound of boost and advanced high load timing 2 degrees across the RPM range, but I still have a very obvious lull in the power at 3-4 K that I would like to tune out.

I have full control over the OEM computer with my SCT Pro Racer tuning software.

Any suggestions?

I am NO expert for sure . The jet may be too big for your application and or sprayed sooner than needed. Maybe a smaller jet at the same trigger point will work better.
I run a 1s and use a 1mm jet. I was getting a detonation signal and found out I was trigering it too late[too high psi boost] and I never bog. No two engines are the same of course but try to figure out what the 1s is lacking first by tuning it in the best you can before going to a much more complex system. In the end for me at the moment I am very happy with the 1s system,,for now. My car goes like stink in any weather with no detonation.