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-   -   Real world data from Pre Turbo WI (http://www.aquamist.co.uk/forum2/vbulletin/showthread.php?t=3200)

redvictor 20-01-2020 09:32 PM

Real world data from Pre Turbo WI
 
Just thought i'd post up here after speaking to Richard today. We have been long time (14 years) turbo proponents, particularly street legal drag racing.
We did use WI with nitrous way back in the day, but ever since then we haven't dabbled with it.
We decided to give it another go having talked with our USA tuner, and a super stock tractor puller in the UK. Basically we were seeing 360f inlet temps, and meth injection (through fuel injectors) wasn't making that much of a difference.
I spoke to Richard last year to get a couple of his biggest nozzles to do a simple pre turbo system, as i didn't want to spend a fortune on a system if it didn't make a difference.
So we had a 1 litre bottle made, pressurised from the turbo inlet, used a Turbosmart solenoid to feed the 1.2+mm Aquamist nozzles and gave it a go. I tested the cone before hand at 60psi to see how far away from the turbo wheel they should be placed, and made up a holder to sit right in front of the nut.
The upshot is that the system on at 60psi for less than 4 seconds kept the inlet temps at 170f instead of 360f. We did 4 full 1/4 mile runs to test this system and the data was the same on each run. This used .8 litre per pass with the 2 nozzles. This was water only. No methanol in the WI. Car runs on methanol at the track.

It's hard to quantify performance as we changed a few things from the last set of runs we did, but the inlet temps were astounding in comparison to the previous temps.

This is a 4350hp std bore space Big Block Chevy with twin 102mm turbos, and twin MoTeC M800's. 1/4mile time is 5.87 @ 263.7mph, and 1/8 mile is 3.96 @ 208mph. Car weighs 3050lbs, which is 70 lbs heavier than when it drives on the street.

Just thought folk would be interested in a bit of real world data, rather than a debate on "will it work or won't it?".

RICE RACING 21-01-2020 06:51 AM

Re: Real world data from Pre Turbo WI
 
^ Been doing this for decades.

Full methanol engines in racing cars and everyone asked us 'why use water injection' and make disparaging remarks.

We just laugh at the cunts as these cars keep running and are faster and more durable than anything they ever put forward.

RICE RACING 21-01-2020 04:50 PM

Re: Real world data from Pre Turbo WI
 
So had to guess allot of things here LOL
But a boat anchor engine will put out about specific power of 95bhp/lt/bar
ASSuming 9lt capacity and your map level of 5.1bar gives a water to fuel ratio of about 15%

https://i.imgur.com/guYqAjE.jpg

You can maybe correct us on finer specifics :)

redvictor 21-01-2020 10:08 PM

Re: Real world data from Pre Turbo WI
 
Thanks for the reply. I agree that the engine felt and sounded much happier with WI than without. We did think about it before, but never broached it until we spoke with Shane T(Our tuner) and the tractor guy. Both had real world experience of pre turbo WI.

So, some figures so you can be a little more accurate. I worked it out to about 5% when i used a much lesser chart than yours.

RPM 8900 through the traps. 1-2 shift 8350rpm, 2-3 shift 9000 rpm
Lambda .64
Fuel Injector sizes Primary 220 lbs Seimens x 8. Billet atomizers 700lbs x 8
Fuel pressure 105psi base.
Fuel pump Waterman 35 gallons per minute belt driven
Engine size 521ci.
Air temp outside 25c
Primary injectors 100% duty cycle. Secondary 65% duty cycle.

Give those a go...

RICE RACING 22-01-2020 12:26 AM

Re: Real world data from Pre Turbo WI
 
Hi Mate,

So just to describe the basic *important parts*
Your power 4350bhp
Specific power est 8500rpm for peak power is ~100bhp/lt/bar this is about right for that engine type being run the way it is
Water consumption rate ~800ml say for 6 seconds (one run and a bit of a skid)
Works out to around 11% water to fuel by mass

The specifics of new delta head pressure across injector and dead times and your voltage of your system you run I dont know but that is not important here (it will only have effect on the reported duty cycle is all, be it equally balanced or shared in some ratio as yours is etc). The only thing is the air mass required (to make your power), and how much water you are consuming and well known specific power parameters for this engine type. Assuming the lambda sensors are calibrated that is the only thing than can stuff up this guess really. All other things are inferred and compounded, only real way would be when the thing is on engine dyno to put the fuel tank on a precision scale and measure the mass consumed seems ghetto but works well without spending a shit load on calibrated fuel flow sensor/s.

All the rest is real easy to work out.

I just put down std inj duty for common variables converting the listed lb/hr into cc/min for methanol.

FYI the AIT is if you used some of my donmega thermocouples http://www.syvecs.co.uk/forum/viewto...8b18c&start=10 and placed them behind the interface of the inlet manifold flange to the engine block to a give a true reading of what goes into the engine. Its why the specific power on methanol is always greater than that of other fuels for the most part, the actual air inlet temp or ACT is much lower due to the latent heat of vaporization and the sheer qty of the shit you have to put into the engine! the motors are cooled by the fuel in great part. You have about 80 deg C now in the plenum I am guessing, then you have the methanol cooling further in the short run to the back of the inlet valves, time transfer is low but estimated 40 deg C? dunno till you measure it honestly but again specific power is your guide here. It's a really powerful and elegant in its simplicity to quickly define a package.

https://i.imgur.com/BzKNNg9.jpg

redvictor 22-01-2020 08:46 PM

Re: Real world data from Pre Turbo WI
 
That is cool, and a lot of info to take in! Thanks for taking the time to do it.

Is there a percentage of water to fuel that is optimal? I can change the flow easily by putting co2 to the top of the water and flow more with more pressure than 60psi if we need more.

6 seconds would be about right. Water doesn't flow at all till 15psi, so a bit in the burnout, and nothing till about 1 second into the run.

RICE RACING 23-01-2020 04:56 AM

Re: Real world data from Pre Turbo WI
 
Quote:

Originally Posted by redvictor (Post 25040)
Is there a percentage of water to fuel that is optimal?

Great question, I am not smart enough to answer it.


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