2007 Exige S Intercooler Air Flow Study

[robains]

dmh, what is your issue dude? It passed tech and I just got my log book signed off (yes one that is accepted by SCCA). You didn't answer my question, how is it any more a safety issue than any other failure in a car??

Like any system, if it is done right, it's not a safety issue. So what's next, prevent the use of synthetic oils because they don't dissipate and absorb as well as standard oils?

[dmh]

Originally Posted by robains

dmh, what is your issue dude? It passed tech and I just got my log book signed off (yes one that is accepted by SCCA). You didn't answer my question, how is it any more a safety issue than any other failure in a car??

Like any system, if it is done right, it's not a safety issue. So what's next, prevent the use of synthetic oils because they don't dissipate and absorb as well as standard oils?

On the street I don't care if you spray or not but as a LCS sponsor who would like to see the series expand east I have an interest in not reading about rules violations and/or "rule creep" rationalizing. Hey, this is not personal at all -- I'm just trying to head you off at the pass in a friendly way.

Our shop performs national tech inspections for a few sanctioning bodies and we see safety mistakes quite often. Do you think because it was passed by some an SCCA safety scrutineer that it is legal and/or safe?
SCCA: Water Spray Systems
"Water may not be sprayed on any intercoolers, radiators, etc. Water spray systems may only be used to inject water into the brake ducts."

The reason intercooler spraying has been prohibited by every road racing sanctioning body that I am aware of is to protect others on track. It's not necessarily about a failure but rather knowingly leaking/squirting/dribbling fluid in your engine bay. (All other fluids are contained.)
Just ask yourself this question: Would you like it if you were rounding a bend and some guy with an intercooler spray system somehow got water on his tires which lead him to crash into you?

[robains]

You can play the "what if" game til nobody shows up to a race -- is that what you want?

Which is more dangerous a failure in a poorly installed Accusump that dumbs oil on the track, or a failure in water spray system that dumps water on the track?

If I were to follow your logic of making everything a safety issue, then we really should NOT be racing period. If these are the LCS rules for racing, then count me out.

This sounds more like an issue of not wanting to deal with such a system so lets ban it. Or worse yet, someone (aka a series sponsor) is selling a "more safe" approach to reducing IAT but it'll cost you $4000 vs. $400. Cause then we get a new sponsor who can sell there $4000 system.

I know the deal, this is not new news to me, if that's how you want to play, then go for it.

P.S. For the record, my original Water spray system that failed was installed by an LCS Series sponsor, you got issues, then take it to them.

[Smoky]

Robains, you are comparing intentionally introducing liquid onto the track surface (via spraying) vs unintentional oil/coolant/etc fluid dispersement from a mechicanical problem. Doesn't quite add up.

Dmh is just trying to save you a turnaround at a tech inspection. Maybe you've passed, so far.... you've been lucky. But I would not want to race on a track with a car spraying water all over the place. It's just irresponsible (for you to do it, and for me to race with you if you do spray).

Safety first. Performance second.

[dmh]

Originally Posted by robains

You can play the "what if" game til nobody shows up to a race -- is that what you want?

Which is more dangerous a failure in a poorly installed Accusump that dumbs oil on the track, or a failure in water spray system that dumps water on the track?

If I were to follow your logic of making everything a safety issue, then we really should NOT be racing period. If these are the LCS rules for racing, then count me out.

This sounds more like an issue of not wanting to deal with such a system so lets ban it. Or worse yet, someone (aka a series sponsor) is selling a "more safe" approach to reducing IAT but it'll cost you $4000 vs. $400. Cause then we get a new sponsor who can sell there $4000 system.

I know the deal, this is not new news to me, if that's how you want to play, then go for it.

P.S. For the record, my original Water spray system that failed was installed by an LCS Series sponsor, you got issues, then take it to them.

I don't know what you mean when you say no one will show up to race. There is no intercooler spraying allowed anywhere and yet the tracks are full.

This is not about a failure of the engine lubrication system but rather intercooler water spray systems. Read what Smoky wrote.

The object is not to outlaw racing because it is dangerous but rather to limit the danger (to you and others) with sound, well intentioned rules.

This is not about banning intercooler water spray systems as they have been banned for a very, very long time. How can that not be clear? Is the safety of others lost on you? (What you are arguing for is to allow them in.) Nor is this about any LCS sponsor, their workmanship, or products.

[Smoky]

So...back on topic....any more data runs apk?

[apk919]

Originally Posted by Smoky

So...back on topic....any more data runs apk?

Good question! I've been working with integrating an Innovate data logging system, but have been having trouble with the unit that logs OBD-II data... it's causing my tach and speedo to go to zero intermittently, and messing with the fuel gauge too. Otherwise I'm getting a good log of intercooler outlet temperature. I still need to add the extra thermocouple module, and I'd like to resolve the dash gauge issue too.

So the answer is: not yet, but hopefully soon.

[nak]

Originally Posted by Monsi

water isnt gonna just hangout in your intercooler and restrict airflow(if your intercooler is hot enough to flash boil water you have SERIOUS issues) its going to absorb heat and evaportate and if it doesnt air will push it out

even if the air didnt push it out it would still absorb heat and evaportate

there is no way for water spray to increase charge temps unless the water you are spraying is hotter than your intercooler(and even then it might evaporate fast enough to help), thermal energy only flows from a high concentration to a low concentration...

if water spray increased charge temps then how come you dont start to detonate when it rains?

It's about flow rate.

If the water doesn't evaporate (the IC is not hot enough to flash the water to steam) or move through fast enough (low air flow was what got us here in the first place), that water will heat up (a good thing) and then stay there (a very bad thing). If the water build up restricts air flow, the heat isn't being carried away by air and the hot water isn't being carried away. Fine fins and low air pressure could make it happen. The hot water blocks incoming cool water as well. If the water heats up enough and blocks airflow well enough that heat flow into the water is lower than the heat flow into the dry air used to be, the IC performance drops.

If the water evaporates or flows through quickly, it should carry away more heat than air alone. This should be the normal case. Like most everyone else, I was thinking that adding water mist can't make the IC worse. Unless it kills the flow by clogging up th IC.

I think we both agree that the only real steady state cooling comes from mass flow through the IC.

[IamBatman]

The scenario you are describing is very unlikely, unless you are spraying goo on your intercooler. When water heats up, it is going to want to evaporate. It is very unlikely that water sitting on the intercooler will build up so much that it will restrict flow sufficiently to heat up your air. 1. Water is not viscous. 2. If you air flow is not fast enough to overcome a bit of water, you have other problems. Even if air does not flow completely though the intercooler, the air flow causes evaporation. (try blowing on a bowl of hot soup) 3. again, when water heats up, it evaporates and the conversion from liquid to gas from takes significant heat away from the surface.

I still say, either spray inside the intake or add some fans and be done with it. Spraying on the IC may not harm performance, but its not worth the trouble.

[Monsi]

Originally Posted by nak

It's about flow rate.

If the water doesn't evaporate (the IC is not hot enough to flash the water to steam) or move through fast enough (low air flow was what got us here in the first place), that water will heat up (a good thing) and then stay there (a very bad thing). If the water build up restricts air flow, the heat isn't being carried away by air and the hot water isn't being carried away. Fine fins and low air pressure could make it happen. The hot water blocks incoming cool water as well. If the water heats up enough and blocks airflow well enough that heat flow into the water is lower than the heat flow into the dry air used to be, the IC performance drops.

If the water evaporates or flows through quickly, it should carry away more heat than air alone. This should be the normal case. Like most everyone else, I was thinking that adding water mist can't make the IC worse. Unless it kills the flow by clogging up th IC.

I think we both agree that the only real steady state cooling comes from mass flow through the IC.

if there isnt enough airflow to keep water from "clogging" the IC, you arent moving and are still better off with the water as it will continue to evaporate

water spray only increases charge temps in imagination land

[Shorty111R]

Late to this thread - but what a kickass high school science project this would've made!

[lwein]

[html][html][html]

[/html][/html][/html]I don't know what you mean when you say no one will show up to race. There is no intercooler spraying allowed anywhere and yet the tracks are full.

This is not about a failure of the engine lubrication system but rather intercooler water spray systems. Read what Smoky wrote.

The object is not to outlaw racing because it is dangerous but rather to limit the danger (to you and others) with sound, well intentioned rules.

This is not about banning intercooler water spray systems as they have been banned for a very, very long time. How can that not be clear? Is the safety of others lost on you? (What you are arguing for is to allow them in.) Nor is this about any LCS sponsor, their workmanship, or product

Don,no luck with the Speedmax intercooler?-your thoughts here would be of interest--Lee

[dmh]

[quote=lwein;1082481
Don,no luck with the Speedmax intercooler?-your thoughts here would be of interest--Lee[/QUOTE]

Lee-
I haven't ruled it out and ought to contact them again. The Mini Cooper S in Koni ST runs a dual air & water setup from Pace. Yet, I just keep thinking: if you are going to use water why not just make the entire setup for water? I have a heat exchanger already done that is capable of cooling for our needs.
Don

[Mag]

Ok finally got the sensor done correctly. Using a thermocouple at the roof scoop, one pre cooler, and MAP IAT post cooler.





Ambient 26~28C, Relative humidity 87%
Prior to run, cold car: roof 28C, pre 30C, post 30C
RLS IC

20minute hwy run, intermittent spurts run through 3rd gear to redline, then cruise. Avg. speed 65-75mph

roof opening sensor
Avg - 32C
Max - 39
Min - 29

Pre IC
Avg - 73C
Max - 101C
Min - 59C

Post IC
Avg - 47
Max - 60
Min - 41

@ 100C pre, IAT was 56-59C

5 hard pulls, 2nd gear rolling starts through redline 4th gear, duration 3mins

roof scoop opening

Avg - 35C
Max - 42C
Min - 30C

Pre IC
Avg - 88C
Max - 113C
Min - 66C

Post IC
Avg - 59C
Max - 74C
Min - 46C

@113C pre, IAT was 70C

After run and cruising speeds 3rd gear range for additional mins, pre IC mid 65C, post IC 51C.

Next up: Stock IC, RLS IC + dual shroud interior spal fans, RLS IC + dual fans + RLS water inj.

[Smoky]

This post gets better everyday. Can't wait to see the deltas against the stock i/c. Great work!!

[dmh]

235* F pre-intercooler, not even on the track. You'll see about 55*F more at speed!
IAT around 160*F. Yup.
The intercooler taking out 110*F.
Didn't someone already give these figures?

(There are gauges that track pre and post i/c temps!)

I've got an rls intercooler for sale in the parts market forum -- about 30% off list!

[Mag]

Originally Posted by dmh

235* F pre-intercooler, not even on the track. You'll see about 55*F more at speed!
IAT around 160*F. Yup.
The intercooler taking out 110*F.
Didn't someone already give these figures?

(There are gauges that track pre and post i/c temps!)

I've got an rls intercooler for sale in the parts market forum -- about 30% off list!

I agree, these figures are suprisingly high. But data's just data until proper analysis is applied.

this data set is new. used a bakelite spacer to try and seperate the sensor from the pipe temps. The post IC temps are off the IAT.

There was plenty of speed. 235F was at 105mph, duration 3mins constant ripping on engine, redline every gear. I'd say that's pretty close to a lap or two on the track.

Note Max temps occur only momentarily, and revert closer to the avg temps.

The temps at the sensor do not only capture air temps:

My guess is the head cylinder blow by oil/moisture/gas is hitting the pre IC sensor. head temps are the hottest, so with oil temps near the pan around 100C~110C +, oil /gas from the head hitting the sensor at 113C is not suprising. When pipes are off, notable oil collected around flanges. As well when I pull the thermocouple probes out post test, there is oil/fluids coating the sensor.

Compression, then decompression on outlet side of IC produces some moisture which may account for the large differences in temps. Also of note, it is very hot and humid climate here.

Another test will try in the future is to install an oil catch can that does not re-route the oil blow by/moisture back into the engine. I suspect this will make a significant difference.

[dmh]

Three minutes is a walk in the park. Just ask the Mini Cooper or Cobalt Koni ST racers/owners about heat soak.

What I was getting at was I have more than enough data about intercooler temps.

[Smoky]

No such thing as too much data.

[dmh]

Originally Posted by Smoky

No such thing as too much data.

Not as long as it is valid.
But what is being done here has already been done by neumerous people numerous times. What information do you think is missing or needs to be answered?