intercooler sprayer

[strx7]

My race car usually see's 25 - 35 deg IAT under full load race conditions,
but the hayabusa turbo MRS with the water cooled Intercooler see in the 40's for IAT.

I would have thought much higher than 50 and you would start running into problems.??

Its obvious that the south island has a colder climate than the north island haha.

I'd possibly expect those kinda temps at taupo/manfield during winter.
S4/5 rx7's (and probably anything else with a top mount interheater) do see some high inlet temps especially when upping the boost above their efficency zone.

[Mr Revhead]

Matt usually runs summer though on some hot days.
Last time I saw the MRS run it was too bloody hot

[strx7]

to have IAT of 25 degrees in boost, the ambient temp would have to be sub 20s.

I've been at taupo in summer where the air temp above the track surface is 40+

[matt dunn]

to have IAT of 25 degrees in boost, the ambient temp would have to be sub 20s.

I've been at taupo in summer where the air temp above the track surface is 40+

IAT can be lower than ambient with a good intercooler.

Most of my runs are during the summer when ambient air temps are in the 20's, apart from the odd wet event, but those are easy to spot on the logging as speeds boost and throttle trace are well down on normal.

When I get a chance I will look up some more logs as the MRS logs pre and post IC temps as well as ambient temp.

[Mr Ree]

Im about to do a bit of a data logging session once my new intercooler arrives this week.

Im going to use pre and post cooler temp gauges, and run them in my current intercooler, which is a China spec, B&P 600x300x76, under varying loads, taking note of ambients temps, and then swap to my new one which is a slightly less China spec, T&F 600x300x76 HDI core, and do exactly the same run of tests.

Nothing like back to back comparisons to tell the whole story.

I might even consider taking the core with me Taupo next time I hit the track to get really conclusive data, as its pretty hard to simulate prolonged WOT on the street.

[strx7]

to have IAT of 25 degrees in boost, the ambient temp would have to be sub 20s.

I've been at taupo in summer where the air temp above the track surface is 40+

IAT can be lower than ambient with a good intercooler.

Only ever seen that once & personally dont believe it can happen easily unless you spray some kinda of evapourating liquid (alcohol or similar) onto the core to suck that much temp out of it. The intercooler is just a HUGE heatsink, the instant you start pumping compressed air through the core which is at 100+ degrees the intercooler just starts slowly heating up. When i saw it, was a Very cold winter morning, ambient temp was about 5 or 6 degrees, as an experiment, I sprayed some misted water onto the intercooler core, went for a short drive. I was hardly ever on boost, and tried to maximise airflow through the intercooler while minimising boost to warm it up, after about 10 minutes i had inlet air temps 1 degree colder than ambient.

At the end of a 6-8 laps race I'd expect the inlet air temp to be 20+ degrees above ambient. Depending on your logged data I would honestly start looking at weather the temp sensors are reading accurately or possibly the difference is to do with where the temp sensor is placed???. Most of my data has been collected by running a digital temp guage on my dash. Have probably driven 30,000km+ observing it on my landcruiser.

[Grrrrrrr!]

If you are getting inlet temps below ambient there is either something colder than ambient involved (ice box etc) or a significant pressure drop/gas expansion involved.

Or as strx7 says, your data-logging needs calibrating.

[Stott69]

Has anyone got photos of thier temp probe setups?

[Tranquil]

Engine temp (coolant or lubrication fluid temp if air cooled) is the other piece of the puzzle. The inlet charge as it transits through the inlet manifold, inlet ports and inlet valves into the cylinder is being heated due to physical interaction with engine components which operate at 70 degrees+. Engine temp = inlet temp.

Some ECU's utilise charge temp as a input which is a composite value combining IAT and engine temp. Idea behind this is that IAT can change rapidly (maybe not so much on the circuit, more common out on the stage) utilising IAT as the primary ignition and fuel correction input is likely to result in over / under correction as IAT fluctuates.
Charge temp is significantly more consistent in the sense that a 2 second spike in IAT is unlikely to impact engine temp in that two second period, meaning you can map to suit.
If you want to get pro, the charge temp value could also be factored to include the cooling capacity of fuel and/or Anti Detonation Injection evaporation pre-cylinder.

If coolant temp AND IAT temp start rise beyond your norms thats when you need to pull timing, add fuel (or more ADI fluid) reduce boost and/or revolutions. A short term IAT spike is meaningless in the grand scheme of things, if your running the risk of poping an engine due to minor changes in IAT - your doing it wrong!

FWIW Adding alcohol to an intercooler spray fluid in a typical FWD layout (incl 4wd) with a front mounted IC sounds like a fire risk to me?

[rollaholic]

i wouldnt have thought the amounts of alcohol involved would pose a serious fire danger, particularly mixed with water

[Mr Ree]

I think thats the main reason for the 50/50 mix, to reduce/eliminate fire risk.

Not to mention running 100% meth isnt going to be good for certain lines/connections.

[Grrrrrrr!]

Specific heat capacity of water is almost twice that of alcohol, so too much alcohol might actually be a bad thing cooling wise as well.

[2jayzgte]

Why worry about sprayers for a road car I don't understand why you would bother.

Now if you were seeing expanded track sessions then yes maybe it would be worth it but for pretty much anything else I don't really see the point.

[Mr Ree]

Fully agree ^

Except for cars with top mounts

[rollaholic]

i've read some interesting articles on the subject, specifically about road cars too. the guy was getting some good gains, but obviously it depends alot on the efficiency of your core.

[matt dunn]

i've read some interesting articles on the subject, specifically about road cars too. the guy was getting some good gains, but obviously it depends alot on the efficiency of your core.

Turbo efficency comes into it to,
depends if the air coming into the intercooler is 50 or 150 degrees.

[Mr Ree]

Thats right ^

You would see far greater gains on a car with a tiny turbo, being pushed far beyond its efficiency, but not so much with a big turbo, flowing lots of air, but nowhere near as heated up.

My new intercooler arrives today, so I will weigh it to compare it to the heavy arsed China one thats in my car currently.

[gt4dude]

I still got my sprayer crankin,

it's good, it alleviates heat soak

can tell because when the tutu goes away, a spray and a boost brings it back.

boost controller can run a lower gain setting for the same spoolup when being sprayed


these are my buttons, real handy location

http://youtu.be/TWBpmga54Hk