IAT Temps

After a while of cruising and stuff... the car will never lower its IAT temps less than 130ºF. This is not on boost.. under boost I am seeing about 180s with 9psi..

Is there a way to lower the normal IAT Temps???

The intake is probably heat soaking and so is the 90º elbow.

I was thinking on ceramic coating it to reflect the heat or something.. any thoughts????

This is with a vortech S-trim...

Get an intercooler or 2.. I've never seen temps over 180 degrees with boost exceeding 15#'s .. Cruising, I see below ambient.. This is with an ATI D1 and their twin intercoolers..

--Sean

How can you see temps below ambient if you use ambient air to cool the incoming charge????

I thought that was only possible with an aftercooler and ice.. :confused:

Anyways.. the intercooler is the next step.. I have an oil cooler which I wanted to use between the engine oil and the supercharger oil.

Not exactly sure how I see it, I just do.... I've seen 60degree temperatures on 70 degree days, etc.. As it get's colder, the temperature drop becomes even more severe.. I've seen temps below 30 degrees when it was close to 40.. Beats me how it happens, it just does :)

--Sean

Yeah... its probably a calibration thing.. anyways... I will get an aftercooler.. but not now...

I will stay with the 9psi for the moment... if I do get the 500rwhp I will tune it for that and leave it there.

If you dont want to invest in a after/intercooler than you might want to check out alky/injection systems like the smc unit Check over at the turbo buick forums as they have had good experiences with them.:)

It is impossible to get the IAT below ambient using an air/air intercooler. The factory IAT sensors aren't all that accurate, which explains the sub-ambient readings.

Using some thermodynamics laws, assuming 60 degree ambient, 72% adiabatic efficiency, and 14 psi boost, my IAT should be 210. However, the IAT sensor only shows 175 - 180 degrees, which is impossible.

Highlander, I'm currently looking into my options for intercoolers because I think I can gain alot of power at my boost level. What kinds of power gains are most people getting?

Mike

On a 90-degree day under normal cruising conditions, I see IAT temps in the 110 - 130 range, depending on stop-and-go or highway cruising.

At the track with pre-run temps in the range above and with 14-psig boost, I normally see 140 - 150 degrees at the end of a 1/4-mile pass. However, when I have my water/alcochol turned on, the IAT temp lowers slightly below ambient, typically around 85 degrees. I believe the water/alcohol is the primary reason why I'm able to run 36 degrees of timing at WOT, even with 14-psig boost.

I dont know how much are people getting.. but I didn't get what I expected...

The other thing... what formula did you use for that PV=RNT?

What did you gain?

It's not quite as simple as PV=nRT, since that's the ideal gas law and air is not an ideal gas. Also, it doesn't take into account the sub-100% efficiency of compressors.

First, you have to find the temperature of the air assuming adiabatic compression:

T2 = T1 * (p2/p1)^((k-1)/k) k=1.4 for air

Don't forget that the temps and pressures must be converted to absolute, so add 460 to the Fahrenheit temp, and add 14.7 to the psig pressure before using the formula.

Then, using temperatures, look up the enthalpy ('h' in B/lbm) of air at both ambient (h1) and compressed (h2i) conditions. A "Properties of Air" Chart can probably be found on eng-tips.com.

Next, use the following formula to find the actual 'h' of compressor discharge air.

h2 = ((h2i - h1)/nc) + h1 nc=.70 - .74 for most compressors

Finally, using h2, look up the temperature of the air in the chart mentioned above. Don't forget to subtract 460 to get back to Fahrenheit.

Mike

I expected to gain around 100rwhp from:

393rwhp that I had with:
Paxton supercharger... 4.5psi
215/220 cam 114lsa
shorty headers 1 5/8

Now I got 450rwhp with:
Vortech S-trim pumping 9psi and sometimes 10psi
224/236 cam XE 114lsa
Ceramic Coated 2300ºF LTs hooker 1 3/4

I think there are still some tunning issues that need to be adressed... I need a smoother fuel curve... but in all it was around 12.5:1.

I would've expected you go gain 20 hp from the cam (~2 hp/degree increase) and 60 from the boost (~13 hp/psi boost increase). So, you're new rwhp should be around 473 or so.

But what do I know, my crap isn't running right either.

I gained 50+ rwhp by running the Crane HI6R box on 1 instead of 1.5 degrees/psi. When I tried to lower it to .7, it gained 60 ft-lb of torque on low end, but the knock retard kicked in with 12 degrees of retard and killed the power. If I were to use race gas and proper timing, I think I could gain another 30 rwhp, which would put me about where I should be.

Mike

Do you have intercooler or aftercooler??? How much total advance are you seeing on the logger???

I have to run at 2º/psi if not It will knock... My total advance was 36

No intercooler or aftercooler here.

When I was running 9 psi, non-intercooled, with 10.8/1 compression, I could put it on 1.5 deg/# and get no knock retard.

Maybe you're getting false knock.

Mike

Then why putting the knob back to 2 will straigthen things out??? Maybe its my msd :confused:

Check out this datamaster file if you have time

http://netdial.caribe.net/~highland/32deg.uni

or

http://netdial.caribe.net/~highland/32deg.zip

If you have any other suggestions... please let me know...

Its running leaner now than before.. dont know why the heck...

What about the vortech intake tube (metal) it gets super hot....

Can that have an effect on why after the IATs raising a bit they actually stay high and not come down as before???

Thanks

Originally posted by The Highlander
Do you have intercooler or aftercooler???

They're the same thing.