Back To Back Testing Of P98 Vs P98+water Injection Vs P98 Vs Water Meth Injection

[JGB1600]

Gday guys,

Thought Id throw a post up about my experiment with water and water/meth injection and the results.

First off, the test bed for this little experiment was my FJ20T powered Datsun 1600. The engine mods are as follows,

* Engine rebuilt back in 2007 by Stewart Wilkins. Nothing fancy, just forged pistons and a clean up of the inlet and exhaust ports

* Garrett GT3071r turbo with a twin scroll .78 rear housing

* Custom split pulse manifold with twin v44 tial waste gates

* 3 exhaust system with plumb back waste gates

* Autronic SM4 ecu and CDI 500r

* FMIC

* 750cc injectors

In 2011, I stumble across water injection while surfing the net. After 6 month of further research, which involve speaking with several mechanical engineers, I decided to set up a water injection system on my car. Through my research, I found that the key to a successful system that works and works well is precise control of the injection rate and correct atomisation of the fluid being injected. With this in mind, I decided to go with the Aquamist HFS3 water injection system. This unit was, and still is head and shoulders above the competition with regards to build quality, performance and price. Aquamist systems are the only systems that use constant pump pressure (160 psi) and pulse width modulation to control injection. Other systems use progressive pump speed to control injection. This creates very poor atomisation at less then 50% duty cycle and a delay in the starting and stopping of injection.

For precise control, utilising a constant pressure pump coupled with a fast acting solenoid valve critically allow correct atomisation of the fluid. Through the use of water/methanol I wanted to pull as much heat out of my system. When a liquid is atomised it becomes easier to vaporise. Simplistically, heat is absorbed when the atomised liquid changes state to vapour. Cooling your air temp increases its density allowing for more fuel and more bang. As the final part of this state change occurs during compression, a torque advantage was also welcomed.

The HFS3 unit was installed using a single, 1mm injection nozzle, located in the inlet pipe just after the intercooler. When the car was tuned with this setup, it made 280rwkw @ 26psi with water injection and 258kw @ 23 psi without water injection. Pump 98 was the base fuel and the ambient air temp was about 30 degrees on the day of testing.

A few weeks ago, I decided to upgrade my set up to the latest Aquamist HFS4 water injection system. As I wanted to push the water injection system as far as possible this time, as well as experiment with 50:50 water meth mix, I decided to use a total of 6 injection nozzles. 110cc nozzles were installed in each intake runner. These nozzles incorporate a built in check valve to prevent water been sucked out under vacuum. The original 110 cc nozzle was left in place in the inlet piping just after the intercooler and an additional 50cc nozzle was installed in the intake before the turbo. Aquamist recommends jetting your system for 1-1.5cc/1hp. I was aiming for around 400hp, I went with 1.5 cc/1hp, which required 600cc.

The install was completed in a day and the car was tuned last Thursday by Yavus at Unigroup engineering. Again, base fuel was pump 98. Air temp was a cool 18 degrees Celsius. The results are as follows:

· 267kw @ 22 psi on pump 98

· 291kw @ 25 psi on pump 98 + 100% water injection

· 312kw @ 30 psi on pump 98 + 50:50 water/meth

NB: water/methanol is mixed on a mass basis.

These results were obtained during the same dyno session. No changes to ambient were observed during the testing. It is also interesting to note that a maximum figure of 302 kW was achieved on pump 98 + 100% water injection; however detonation was observed when back to back run were completed. As a result, timing was reduced for protection as we realised we were right on the limit. In this case, the limiting factor was the flow rate of water. We had simply reached the limit where there wasnt sufficient cooling. We had the option to increase the mass water flow by upsizing the post intercooler nozzle however, this would have required recalibrating the failsafes and was decided against due to the time constraints.

There is a lot of misinformation circling the internet and club meetings about water injection. I hope this test has demonstrated that when a quality system is set up correctly, it works extremely well. This set up me cost around $2500 to purchase, install and tune and netted a 9% and 17% power gain for water and water/methanol respectively over typical pump 98. When comparing capital and operating expenditure, a water injection system will stack up favourably to be one of the cheapest $/kW power upgrades available to the boosted aftermarket. With my system sitting at approximately $56/kW (water/meth), I think most would agree its an absolute bargain and in my opinion is an option well worth considering for those looking for a healthy performance gain from their boosted rides. Looking forward to see the journey of others who choose to experiment down this path

Please feel free to post any questions you make have and Ill do my best to answer them.

Cheers.

http://i1122.photobucket.com/albums/l535/Theboostshack/20150610_214703_zpsdihqh4zk.jpg

http://i1122.photobucket.com/albums/l535/Theboostshack/Mobile%20Uploads/IMG-20150615-WA0023_zpsaoqnx1t5.jpg

http://i1122.photobucket.com/albums/l535/Theboostshack/Mobile%20Uploads/Screenshot_2015-06-19-06-04-35-1_zpsyqyku8je.png

http://i1122.photobucket.com/albums/l535/Theboostshack/Mobile%20Uploads/Screenshot_2015-06-19-06-04-25-1_zpslatoyunk.png

http://i1122.photobucket.com/albums/l535/Theboostshack/Mobile%20Uploads/20150623_010748_zpslsaao29o.jpg

[JGB1600]

[JGB1600]

[GTSBoy]

It's a good result.

Sounds like an advert. You're not the local dealer?

[JGB1600]

No I'm not. I invested a lot of time researching and conducting this experiment so I thought I'd do it some justice and do a decent write up.

[JGB1600]

Would have liked to have done an e85 comparison at the same time but as I stated earlier, the cost of an e85 set up, especially just for an experiment, couldn't be justified

Edited June 29, 2015 by JGB1600

[GTRPSI]

I had a old engineer mate who around 25 years ago fitted a supercharger to his Datsun 1600 after bringing in 2 supercharges from the US for fun.

He ended up rigging up a direct water injection setup to help control Det, it simply consisted of a wiper bottle and its pump, a home made jet, relay and a switch hooked onto work from the accelerator linkage when near full throttle, tubing was solid copper to the manifold and plastic to the bottle to allow for movement..

This is back in the day of carbs and distributors with points, took him a bit of playing to find the right jet through experimentation, it ended up running for years on 1 Bar, last time we spoke on the phone about 2 years ago, he still had it, engine was fine just the shell had started to rust on him.

[MagicMikeZ32]

How much difference in timing at max load between 98 only, water only and 50-50?

Any adjustments to fuel maps?

[JGB1600]

I can't remember what the difference in timing was so I'll have to double check. Fuel was reduced for the water meth injection tuning.

[JGB1600]

Acceleration testing

[KiwiRS4T]

Thanks for posting up the back to back comparisons. So often people end up comparing apples with oranges etc.

That must be a quick little Datsun!

[BlackBox]

Was the 22kw gain from the hfs3 system just on water or 50:50 water meth?

[JGB1600]

Just water. That was as much as we could push it with the single 450cc nozzle. I should have experienced a little more with that set up but I broke the rb20 gearbox not long after that upgrade. While converting to a rb25 turbo box things kinda spiralled out of control and here we are!

In response to the previous post, the car is quite a handful now. The acceleration is phenomenal! I posted a link to a quick vid of acceleration testing.

Edited June 30, 2015 by JGB1600

[mutex]

Could you post what the average timing went up by from standard tune to 100% water tune, then water-meth combo.

I like the idea of pure water injection versus e85 if nets good power increase and saves lugging e85 to far away track days!

[JGB1600]

My car is on a transporter at the moment on the way to Cairns. I'll retrieve the requested data once it arrives in a few weeks.

Water injection could very well be the alternative you are looking for and we'll worth considering.

[tridentt150v]

What triggers did you use? ie commence at 10psi and all in by 20psi and/or commence at 50% DC and all in by 75%

And what switch - vacuum, injector cycle or both?

[JGB1600]

The control unit can be configured to be triggered by either injector duty cycle, boost pressure or a mixture of both. The website below explains it in more detail.

http://howertonengineering.com/hfs-4-injection-mapping/

I use only injector duty cycle as I couldnt tap into the internal Autronics map sensor. There was the option to set up an external map sensor but time constraints prevented this from happening. It will be captured in the next upgrade.

The IDC trigger is set at factory set to begin at 40%, with a linear ramp rate. The control unit has a 0-5v output from the flow sensor which can be connected to an ECU input for data logging. I will have this function operating on my car in the near future and post a log of the injection cycle.

Cheers

[tridentt150v]

Yeah, 40% is probably a bit low IMO. But if you aren't running with the boost option as well then it could be OK - I honestly don't know.

I have the snow performance stage III unit and run with 60% and all in at 85% and also vacuum 9psi and all in at 14.

Your pump is an advantage in a perfect world, but you won't see it on the road because you start low [boost and IDC] and end high plus you are already boosting and driving and revving before your system cuts in.

If it was such an advantage wouldn't you think that other companies would offer it as an option???

I did look at the various kits when I was buying and compared but for street use didn't see any clear advanatge so settled for kit completeness and cost. I nearly did buy an Aquamist but it lost out somewhere I guess [can't remember, price I think?].

Had mine for 4-5 years now and when you can't get E85 or do interstate trips WMI is the way to go.

http://www.sau.com.au/forums/topic/306109-my-wmi-install/

I like the comparison BTW thanks for doing that.

[JGB1600]

I will more than likely add the boost injection set point and there is definitely room to optimise injection set points for max torque and power requirements. So far I'm happy with the default injection settings with the linear ramp rate. Optimisation may be the next experiment, but gains may not be worth the time & dollars spent on the dyno testing.

IMO, you will feel tangible difference on the street with a constant pressure pump (if that's what you were alluding to). Being able to control your atomisation precisely at low rpm/throttle position means I can increase my mass flow through the engine earlier without the risk of damage from poor atomisation. Creating more mass flow has the added effect of building boost earlier in the rev range.

You also want the best atomisation possible for pre turbo injection to limit any potential compressor wear over time if you are an aggressive user.

Im guessing others don't do it so they can price there systems accordingly. There is definitely a market there for those that are on a budget and/or don't require a system with all the functionality that the Aquamist units offer.

Cheers

[STATUS]

Water meth is awesome! BUT only if you have sufficient fall back measures literally one pull without the WMI working will turn the engine inside out.

Its UBER important to make sure the ecu can pull timing or shut down the minute the WMI system falters or runs dry.