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View Full Version : Pre Turbo Injection Recorded Temps 2


Gelf
09-11-2004, 09:29 PM
Results from last weekend.

Things to consider, i have used a combination of one and two jets this time, placed about 14" furher back from the turbo.

Boost trigger point was lowered to about 10 or 11 psi.

The equipment will only record temps every 15 seconds :evil:

The engine bay was heat saturated at the start, (because i lost input from one of the sensors and had to start again :evil:) which is why the manifold temps are so high from the start point.

Temperature was 11 degrees C and there was some light rain during the session, should explain why some temps at the air filter dropped to zero :?

I started out with no WI and progressed to 0.4, 0.5, 0.4+0.5, 0.6, 0.5+0.6, 0.7, 0.6+0.7, 0.7+0.7, 0.8, 0.8+0.8, 0.9, 0.9+0.9 (i dont have pairs of 0.4,0.5 and 0.6 at present).

http://www.imagehdd.com/d1y2004/2027wi_off.jpg
http://www.imagehdd.com/d1y2004/98440.4.jpg
http://www.imagehdd.com/d1y2004/91100.5.jpg
http://www.imagehdd.com/d1y2004/91620.6.jpg
http://www.imagehdd.com/d1y2004/3380.7.jpg
http://www.imagehdd.com/d1y2004/52720.8.jpg
http://www.imagehdd.com/d1y2004/1090.9.jpg
http://www.imagehdd.com/d1y2004/56600.4_and_0.5.jpg
http://www.imagehdd.com/d1y2004/78190.5_and_0.6.jpg
http://www.imagehdd.com/d1y2004/5770.6_and_0.7.jpg
http://www.imagehdd.com/d1y2004/399twin_0.7.jpg
http://www.imagehdd.com/d1y2004/9684twin_0.8.jpg
http://www.imagehdd.com/d1y2004/9182twin_0.9.jpg

PuntoRex
10-11-2004, 02:17 AM
Sorry, I supposed you placed jet(s) all before the turbo? (as topic?)
Then, " 14" furher back from the turbo " means the jet(s) are just before the compressor?
I got a little confused here. :oops:

I got confused about the charts too.
Averagely, it seemed the more water, the cooler the results (pre-thottle), but not so linear.

The phenomenun of "the cooler the compressor outlet, the hotter the IC outlet" still exists. But the pre-throttle temp also dropped. I guess among those bigger jet(s), there's still some water in liquid form after the compressor, even after the IC. So it kept on cooling the air down the track.


Did you sortout the WOT shrink problem?
What did you feel about these combinations?

JohnA
10-11-2004, 10:40 AM
Let's see what we've got here... :D

Best temps at turbo exit were with 0.6 + 0.9

Best temps at intercooler exit were without WI. Less offensive was the 0.4mm jet. Hmmm....

Best temps at throttle were with 0.9, twin 0.8 or twin 0.9 (lots of water then)

Another interesting figure is the temp difference between throttle and ambient - shows the overall cooling effect, after the reduced i/c efficiency is factored in:

WI off..........20-40C
0.4...............5-30C
0.5...............0-30C
0.6...............0-30C
0.7...............0-20C
0.8...............0-10C
0.9...............0-5C
0.4+0.5........0-15C
0.5 + 0.6......0-20C
0.6 + 0.7......0-15C
0.7 x2..........0-15C
0.8 x2..........less than 0-10C
0.9 x2..........less than 0-10C

So there is a distinct improvement everywhere by at least 10C.
The pattern is not clear though, being best at 0.9 and 0.9x2 but not in between. :?

Clearly this is not a comprehensive test, since it was only done at 10psi and not 13-14psi where it might have been a different story.

We also have no clue as to the total effect on power, since the extra water going in the cylinders will play a major role in lowering in-cylinder temps, perhaps even lowering EGTs to levels unacceptably low.
In an ideal world we would have these runs on a RR, where we could see the power tailing off due to excess water (and adjust accordingly)

...but for DIY datalogging it's excellent!
well done mate! :D

Gelf
10-11-2004, 09:43 PM
Sorry, I supposed you placed jet(s) all before the turbo? (as topic?)
Then, " 14" furher back from the turbo " means the jet(s) are just before the compressor?
I got a little confused here. :oops:

I got confused about the charts too.
Averagely, it seemed the more water, the cooler the results (pre-thottle), but not so linear.

The phenomenun of "the cooler the compressor outlet, the hotter the IC outlet" still exists. But the pre-throttle temp also dropped. I guess among those bigger jet(s), there's still some water in liquid form after the compressor, even after the IC. So it kept on cooling the air down the track.


Did you sortout the WOT shrink problem?
What did you feel about these combinations?


Origonal jet position
http://www.imagehdd.com/d1y2004/3066IM001193_1.jpg


New jet positions
http://www.imagehdd.com/d1y2004/7334IM001199.jpg

Have not sorted out WOT problem, i am going to try ad check IDC this weekend.

Gelf
11-11-2004, 12:28 AM
After further study of all the graphs, i am 99% certain the temps at the air filter and throttle body must be back to front, human error :oops:.

Ive noticed where ever theres is a spike or trough in the turbo exit temp, it is mirrored with a smaller peak and troughs in the IC exit temp, but also the air filter inlet temp, but not at the throttle temp:? Cant be right :!:

The graphs would make much more sense if they were reversed.

I did have a problem on the first attempt and may have mixed up the sesors on the recording equipment, it was dark :oops:

I will remove graphs and update, if every one agrees

marck_c
11-11-2004, 05:11 AM
After further study of all the graphs, i am 99% certain the temps at the air filter and throttle body must be back to front, human error





If this is so then how do you explain an air filter temperature of as high as 60C on a day when the ambient is 11C :shock:

Gelf
11-11-2004, 11:03 AM
After further study of all the graphs, i am 99% certain the temps at the air filter and throttle body must be back to front, human error





If this is so then how do you explain an air filter temperature of as high as 60C on a day when the ambient is 11C :shock:

Heat saturation in the enbine bay, the car had been sat for 15 mins after my first run at recdording temps (35 minutes of boost runs), which i had to abandon because i lost input from one of the thermocouples.

The temp continues to decline until it settles at near ambient at the end of the session.

Also in my previous recording session the manifold temps were for the majority of the time lower than ambient. I know ive moved the jet location, but ive injected at lower boost - more water and used two jets - more water, which should see the manifold temps even lower.

SaabTuner
11-11-2004, 12:00 PM
Interesting to note that the coolest temperatures after the intercooler occurred with the WI off, and that was despite some of the highest turbo exit temps.

Methinks according to this that pre-turbo WI takes away from intercooler efficiency a lot more than one would otherwise think.

Adrian~

Gelf
11-11-2004, 01:23 PM
Interesting to note that the coolest temperatures after the intercooler occurred with the WI off, and that was despite some of the highest turbo exit temps.

Methinks according to this that pre-turbo WI takes away from intercooler efficiency a lot more than one would otherwise think.

Adrian~

Could it be that the inner surface of the IC gets soaked with some of the unevaporarted water, reducing it efficiency to conduct heat to the external ambient temp air, compounding the reduced efficiency effects of lower turbo exit temps ?

More evidence to support removing the IC completely with pre turbo WI

JohnA
11-11-2004, 05:25 PM
If I had to pick one line to represent ambient (well, airbox!) for all of these graphs, it would have to be the blue one.
Not perfect, but looks less weird than the others.
Except if the mixup happened halfway through the tests. Could that happen?

By the way, that 90degree bend on the high pressure line, is it sold from Aquamist?
Not that I don't find it a bit harsh, I always favour smooth, open turns.

Gelf
11-11-2004, 06:14 PM
If I had to pick one line to represent ambient (well, airbox!) for all of these graphs, it would have to be the blue one.
Not perfect, but looks less weird than the others.
Except if the mixup happened halfway through the tests. Could that happen?

By the way, that 90degree bend on the high pressure line, is it sold from Aquamist?
Not that I don't find it a bit harsh, I always favour smooth, open turns.

Recorded temps were continuous. Sorry which blue (light or dark)?

Yes, 90dgree bend came from aquamist via interex :smile:

JohnA
11-11-2004, 06:51 PM
.
Recorded temps were continuous. Sorry which blue (light or dark)?

Dark blue I'd think

In the "WI off" graph it couldn't be the light blue line, could it?

Gelf
11-11-2004, 09:11 PM
After i drove back into town, the temps still being recorded, i stopped for a take away.

Still using all the same format as the above graphs (i havnt swapped the air filter and throttle graph lines over yet).

http://www.imagehdd.com/d1y2004/8952Slide1.jpg

The steepest temp rise is shown at the air filter, where theres no direct heat source, cant be right can it?, steepest rise should be at the throttle, from the heat transferred from the block through the inlet manifold :?

And then when driving away, the throttle temp drops to ambient within several minutes :?

The reason the IC rises so high is that the transfer pipe where the thermocouple was positioned sits directly above the turbo itself.

JohnA
11-11-2004, 09:21 PM
...The steepest temp rise is shown at the air filter, where theres no direct heat source, cant be right can it?, ...
airbox temp would go up, as it will absorb heat radiated from all that hot metal.
There is no air through the bay to cool it down, neither is there airflow through the airbox (which also cools it down)

it's not as bad as the intercooler, because it isn't metal.

TurboGTi
11-11-2004, 09:28 PM
Just curious ....are you sure those thermocouples aren't measuring the intercooler pipes also... as the pipes temperature could also rise due to heat soak under the bonnet.

This would clearly give a error in your graphs.

I dunnno just ccurious. :?

Gelf
12-11-2004, 10:50 AM
Cracked the problem with the 15 second sample rate now, the equipment samples iniatially at 40 times per second, counts a 1000 samples, then drops to 20 x a second, another 1000 samples and halves again etc etc.

Amazing what you can find out when you read the instruction manual :lol:

If its not raining i will attempt the experiment one more time, this time resseting and recording each jet size on its own.

Recording sessions lasting less than 13 minutes, will give samples at 1.25 per second, and put to bed the doubts of the previous experiment :D

JohnA
12-11-2004, 11:49 AM
Gelf, why don't you try a run or two with the WI starting at higher boost pressure.

What is the max boost of your engine right now?

You see, the WI will be much more effective if it starts when the intercooler is overwhelmed.
It becomes counter-productive when it's activated during the intercooler's sweet spot

You've got the std Z20LET intercooler, right?

Gelf
12-11-2004, 03:00 PM
Gelf, why don't you try a run or two with the WI starting at higher boost pressure.

What is the max boost of your engine right now?

You see, the WI will be much more effective if it starts when the intercooler is overwhelmed.
It becomes counter-productive when it's activated during the intercooler's sweet spot

You've got the std Z20LET intercooler, right?

I can hold 15 psi at 3/4 throttle upto about 4.5k rpm, about 11 psi at WOT and over boost of 19 psi between 2.5k and 3.5k rpm

I could trigger one jet at 10 psi and the other at 13psi, but for this experiment i will trigger at 13 psi.

I have an larger after market IC, been thinkin about swapping it for the stock one, less pressure loss - better for top end breathing, if WI is keeping the temps down.

PuntoRex
12-11-2004, 03:34 PM
It's funny that I always think larger IC produce less restriction thus less pressure drop.

Gelf
12-11-2004, 03:57 PM
It's funny that I always think larger IC produce less restriction thus less pressure drop.

The pressure loss of the stock and larger IC have been measured, the stock has a lower pressure drop, but the larger has better temperature drop.

The design of the end tanks of IC's has a lot to do with pressure drops.

The stock IC has better designed end tanks which flow better, but a small surface area core.

JohnA
12-11-2004, 07:34 PM
Holding 1 bar with uprated FMIC is not really W.I. territory in my opinion.
You're not getting ridiculous charge temps after the IC, so the cooling function of the water is limited.

Now if you were holding 20+psi, I understand...

I wouldn't trigger the WI before 14psi, as it would bog the engine down, especially now in the winter.

Gelf
12-11-2004, 10:37 PM
Holding 1 bar with uprated FMIC is not really W.I. territory in my opinion.
You're not getting ridiculous charge temps after the IC, so the cooling function of the water is limited.

Now if you were holding 20+psi, I understand...

I wouldn't trigger the WI before 14psi, as it would bog the engine down, especially now in the winter.

It would appear that i left it a bit late in the year to set up :sad:

Should be fine for next summer, part of my plan was to get WI installed before i get the software RR remapped, i going to try and persaude the tuner to increase the boost map to take into account of the WI. Have to put failsafes in place to disable boost if water is low or WI switched off.

Not sure how to do that with the zlet though. Any ideas :?: Seen the circuitry on this forum, but im not sure how to disable boost electronically.

JohnA
13-11-2004, 09:24 AM
..Not sure how to do that with the zlet though. Any ideas :?: Seen the circuitry on this forum, but im not sure how to disable boost electronically.
I would expect the idle state of the amal valve to be directing all boost to the actuator (easy to check if you undo the pipes and blow air through it)
So if you interrupt the electric signal to the valve, that should bring it down to 'idle', giving boost as low as possible (electronically)

Gelf
13-11-2004, 01:14 PM
..Not sure how to do that with the zlet though. Any ideas :?: Seen the circuitry on this forum, but im not sure how to disable boost electronically.
I would expect the idle state of the amal valve to be directing all boost to the actuator (easy to check if you undo the pipes and blow air through it)
So if you interrupt the electric signal to the valve, that should bring it down to 'idle', giving boost as low as possible (electronically)

Thanks i'll see if i can do that

Got some results last night, ambient temps were down to 7 C though, but recorded data at 2 samples per second. Post them on Monday

Holding 1 bar with uprated FMIC is not really W.I. territory in my opinion.
You're not getting ridiculous charge temps after the IC, so the cooling function of the water is limited.

Now if you were holding 20+psi, I understand...

I wouldn't trigger the WI before 14psi, as it would bog the engine down, especially now in the winter.

I agree, I think the results show that my intercooler is doing a pretty good job on its own, typically drops of 60 degrees C. Injecting before the turbo with the IC in place just reduces the IC eficiency substancially.

Several options available

Increase boost/remove precat - planning to

Switch off WI for the winter months - if i cant increase boost

Remove the IC and record temps at the turbo exit and throttle with WI only - improved turbo efficiency and less pressure losses

Position jet directly after IC and as far back from the throttle as possible - Oh isnt that where aquamist say to position the jet :lol:

Gelf
13-11-2004, 01:21 PM
Presently my Astras putting out 230 bhp, pretty tame compared to some of these zlet engines

http://www.zlet.co.uk/zlet%20rr%202.htm

Gelf
16-11-2004, 09:20 PM
What do peeps think of this graph.

Considerably lower Turbo exit temps, similar IC exit and lower throttle temps than without water injection :D

Without considerable compromise of the IC efficiency :D


Mystery set up
http://www.imagehdd.com/d1y2004/2449Slide1.jpg

Journey Out
http://www.imagehdd.com/d1y2004/4439Slide1.jpg

Sampled at 2 x second

Have more graphs to post, but this one gave an interesting result. I will reveal all, but would be interested to see what set up everyone thinks gave this result

Richard L
16-11-2004, 11:51 PM
The logged charts are fascinating to read great work, keep it coming.

The earlier ones were not as easy to read as the samples was done in longer intervals.

The latest one are great! I am still trying to absorb it all.

Did you put the water jet in front of the IC?

Gelf
17-11-2004, 11:10 AM
I took on board what JohA had said about injecting at the highest possible boost trigger point. After i repeated all the previous set ups i had tried at 2 x second, i decided to stick with the 0.4 and 0.5 jets and record temps with trigger points starting low 4psi and then 7,10,13,14and 15 psi.

masterp2
28-11-2004, 03:52 PM
In reading the results it would be very helpful if you could chart boost on the right hand y axis. Some way to see where on the graphs that WI is taking place.