waterspray data.

[jimnielsen]

I used my waterspray for the intercooler for the first time, last weekend at Winton. I have always wondered if they actually worked. Attached is a spreadsheet view of some run data that shows that they do!

What the data shows is that the car developed the most power when it was run from 'cool' and the least power when it was run when already hot with no intercooler spray. The spray was ONLY used in run 3. The difference is approx 15hp.

The Y axis is power (at the wheels) in hp. The X axis is lap number.

.. also attached is a picture from the same runs of absolute inlet manifold temp (in degrees C) for lap four of each of the same runs. You can see that the lowest temp was run1 (car was cooler - yellow line) the highest was run2 (no intercooler spray - black line) and run3 the last run with the spray on is between the other two (red line)

[Steve Webb]

Interesting to see the differences in inlet temps and power. I did some temp tests when I first fitted a water spray (the Autospeed kit) and the difference was pretty impressive.


How much water were you getting through per lap?

[jimnielsen]

The spray uses a litre of water every 2.5 mins.

[Steve Webb]

Thats not too bad considering it'll be on boost for pretty much the whole of the 2.5mins

[Evodelta]

If I am reading this right then the difference with the water spray is between 4 and 6 Bhp?

[jimnielsen]

Its just data, so its open to interpretation, but from my reading of it, its between 4 and 15 hp. I am going to implement another identical sensor to record the ambient temp as well so I can add that to the mix.

jim ~

[1NRO]

Interesting how well the engine did before heat soaked, lost a lot once up to temp. The power looks to me to benifit to the tune of about 15 bhp off the data you put up there. Only 4% ish loss over the cool engine compared to 7.5% ish loss without spray , superb.

[arjunior45]

I'm a little confused.
You made 3 runs with 5 laps each run?
What do you mean with 'cool engine'-1st run? Any data with engine temperatures for each lap, and each run?

[jimnielsen]

Nick - yes, i made three runs of at least five laps each..and the first five laps of each of those runs are included in the data. Yes, I do have engine temp data for each run as well..but it looks pretty messy if you try to put it all on the one graph.

jim~

[ecl]

guess i should finally consider putting in that relay then.. Cause thats all thats missing right?

[arjunior45]

guess i should finally consider putting in that relay then.. Cause thats all thats missing right?

If you have the original waterspray system keep in mind that it sprays only above 0,7 bar of boost. Not before.

In any case, go buy the relay missing.

[arjunior45]

but it looks pretty messy if you try to put it all on the one graph.

jim~

yes, you are probably right.
Just for curiosity, do you think there is something else to do to keep engine cooler?

[Steve Webb]

yes, you are probably right.
Just for curiosity, do you think there is something else to do to keep engine cooler?

Additional chargecooler maybe?

[Evodelta]

Its just data, so its open to interpretation, but from my reading of it, its between 4 and 15 hp. I am going to implement another identical sensor to record the ambient temp as well so I can add that to the mix.

jim ~

The cold engine run as a direct comparison it is a red herring. The only comparable results are those with the same factors apart from water spray or no water spray.

Do you race the car seriously (as opposed to what we call 'Trackdays)? And if so how many laps would you do without stopping?

What happens further on when more laps are done on this test?

It is quite interesting and refreshing to see testing of components like this.

[arjunior45]

Additional chargecooler maybe?

I think he already has a FMIC. I was thinking for double radiator fan. HPE HF type maybe? Bigger oil radiator?
Something extra like this?

[1NRO]

yes, you are probably right.
Just for curiosity, do you think there is something else to do to keep engine cooler?

An area to address is radient heat from the likes of the hot hot turbo / manifold / downpipe. Shields, coatings, wraps, jackets etc (there's others I'd not share too freely), the possibilities are there if you fancy the work. Like Jim already does, run E85, the temps are easier to manage just by using that. I've never tested it as it'd be expensive to do but a change of oil brand can change the temps. A wise man once told me that a fair % of race engine building was temperature managment, I'm inclined to believe that advice.

Nik

[Trazor]

If you have the original waterspray system keep in mind that it sprays only above 0,7 bar of boost. Not before.

In any case, go buy the relay missing.

When you buy the relay, what specs should it have? (Amps, volts etc) Dont know much about relays, so the question might be silly to most of you.

[Jan]

jim,

did you measure g-force from your data logger?
which datalogger are you using?

[Jan]

jim, did you measure g-force from your data logger? which datalogger are you using?

[#84]

Jim,

This is really intresting. Not so much the waterspary itself as the physical correlations. Like + 3 deg C in average give -4,5 % hp in average. It is scarrying to see how much the power drops after each lap you run and it is also scarrying to see that the intecooler + waterspray has no chance to keep up with the performance of a cool engine.

I have a few questions (Probably you have posted this info several times..):
- How is your air filter mounted? (Risk for suction of hot air?)
- What kind of IC do you use? (Size, location)

Nik (1NRO)has a good point with the temperature management and the question if the IC is too small, if the under hood temperature heats the air after the IC or if it is the inlet air that is too hot when the car runs?

[Jan]

Sorry guys, found it myself

[jimnielsen]

#84, the bottom line is that in normal running the pre inlet air temp gets to 118 degrees and the inlet manifold air temp gets to 60 degrees.

here are two new examples of this taken from the cars last two runs this year at phillip Island and Sandown. You can see that even when the car is pushed to 230 kph and 1.35 bar boost, the temps still sit at about that level.

the intercooler is certainly not big, it HAS to fit within the normal body work of the car for my purposes.

the real problem is lack of comparable data, in reality very few people actually bother to install the sensors and collect the data - so there is little to compare my data to.

[SteveNZ]

I wonder how much is just heat soak from the engine bay.

[#84]

Ok, your IC is not very big, but it is approximately twice as big as the original one and it has much better air flow on it. Ok, it screws up some ogf the flow to the radiator, but anyway the overall gain is positive

I took a look at your plots and it is never good when the inlet temperature contnues to rise at higher speed sinced the IC has more cooling aior flow at its service. The available cooling is more or less linear in relation to vehicle speed until the IC core is choked. And I suppose it doesn't cholke already at 170 kph. Or?

But, the pre-IC temp increase with speed and by doing so the IC have a tougher task at higher speed. What i find particulary interesting is two things:

1. There is some heat soak effect when you go on throttle/boost during the first seconds. ?ou cansee that the IC and the pipings absorbs some of the temperature increase from the pre-IC. temp.

2. When you go ff boost/throttle the temperature continoues to rise for some seconds. That is strange since the compressor always is cooler than the highjest air outlet temperature. The temp must come from somewhere else. Either it is the inlet air from the engine bay or it is heat from the engine bay that goes through the pipings and heats it more when the mass flow is lower. Delta T = (Heat input)/massflow
What do you think. Maybe the asnwer to that question is the ansswer to the entire problem?

[jimnielsen]

#84, the engine air intake is low down and at the absolute front of the car, certainly I think that the increase in temp over a few laps is due to heat soak - I am not sure that much can be done about that, as the engine does warm up over time. Myself, (in the absence of data to the contrary) I do not believe that there is a problem with the intake temp, at least for the narrow purposes that I use the car for. I have included some data that shows the coolant temp as well over a few fast laps..

What do you see as a practical target for inlet temp?

jim.