Sky-high IAT2 temps

[Lane]

I'm out on the track today and the weather is sunny and around 80 degrees.  This, of course, meant that my SPA gauges were locked up and not of much use, but that's not really my current issue...  During the course of a 15-minute session, I'm seeing IAT1 temp of around 100 and IAT2 of 188!  What the heck is with that?  Came in off the track after one session and the car was idling very low with a bit of a stumble.  Haven't yet checked for any stored codes.

Not sure how to attempt to diagnose the temperature issue.  Coolant level is at its expected location on the sight glass behind the seat and I verified that the aftercooler fan was operational.  Could this be a case where the aftercooler pump is suspect?  If so, what's the best way to go about testing it?  I suppose I should also get out the manual and go through the purge process to make sure there's no air in the system, although I don't know how it would have gotten in there recently.  Anyway, any suggestions for good ideas on diagnosis would be appreciated.

Otherwise, was a great day at the track and the car was outstanding.  I'm running R888s in the rear at under 10% of their life left and I swear they keep getting better and better.

Update - Pump has 12v when car running, pump runs when car off and 12v power supply connected to it.  Aftercooler fan blows in correct direction (upward).  No codes of consequence were found in the ECU.

[silver]

just cuz the pump is working doesn't mean you have flow.........I have extensively worked on this problem with help from Positron and Darth....it has sucked the life out of me and I haven't driven my car in months because i'm so fed up with the High IAT2's

PM me if you want me to save the hair you have left cuz mine is falling out...better yet I'll PM you my phone number and explain what I've found out and you can draw your own conclusions of where to go next.

[positron]

Yep, pretty normal for original set up. Not saying it's good only that's excected for that configuration when used in an extended high boost situation in moderately high ambiant temps.

Check out my shifter cart thread around here somewhere. Also see Tom's web page for his solution since that shifter cart rad has been discontinued. 

[Heywood-Yablowme]

Take an infrared heat gun and check your coolant system temperatures from the intake outlet, to the front cooler, and back to the engine(or reservoir).There should be a pattern of hot coolant leaving the intake(hottest,let's say 150ish),down to the inlet of the heat exchanger(a bit cooler,130ish),out of the exchanger (coolest,95ish) and back to the intake or tank. If the temps are off,like very hot coming out of the intake(188),cool at the exchanger (90)and cool at the reservoir,there is no flow.
Those numbers I made up,however, you should see that type of cooling pattern if all is well.  I attended a two day 80 degree weather event recently and my IAT's never went over 120 degrees.I pushed the car extremely hard.   I have no mods to my system.

[positron]

Hey wait.... Trackday? First things first. Post up some pics!

[positron]

Oddly enough, my logged data shows that each track has it's own personality to engine performance and data. With respect to IAT2's, some depending on how long I'm at WFO ie long boost event/long straights and hills versus lots of twisties will profile distinctly different data profiles.

Sometimes on data review you can tell what portion of the track you are on by throttle position, duration and engine load. So I'd say few data comparisons are able to compare equitably. Sucking up air on a sunny day with darker asphalt will yield a higher temp than a same temp day with an overcast. Similar to tire reaction to same situation.

With my vertical cart rad, I rarely engage the horizontal fan under 85*F as sometimes it will actually increase temps from track surface.

[Lane]

[quote="Positron"]
Yep, pretty normal for original set up.
[/quote]

[quote="Banned"]
I attended a two day 80 degree weather event recently and my IAT's never went over 120 degrees.I pushed the car extremely hard.   I have no mods to my system.
[/quote]

Well, now - those two statements seem to be at opposite ends of the spectrum for being the same pieces parts...

[quote="Positron"]
Check out my shifter cart thread around here somewhere. Also see Tom's web page for his solution since that shifter cart rad has been discontinued. 
[/quote]

Thanks for the tip, I've looked at Tom's offering on his site.  I'd prefer to look for a problem and see if I can address it before throwing $2000 at it to replace the whole cooling system.

[quote="Positron"]
Hey wait.... Trackday? First things first. Post up some pics!
[/quote]

I was driving and didn't really take any.  These were graciously provided by a fellow participant.




The track is a little twisty and winding (overhead pic here).

[positron]

120 F or C? I call BS on 120F IAT2 on the original Brammo set up, if the belt is connected to a Heaton blower. I only see those temps at 50*F ambient. Post up the data logs of +40*F delta temps and I'll buy the next round.

Silver gets more than that going down the freeway with not-going-to-jail boost application.

The short coming with the horizontal B&M up front is that it can't recover reoccurring consecutive boost applications, even if the pump is running correctly, which it's not even running the same direction GM recommends..

I experimented with the horizontal fan running down and it will actually add heat to the water from the engine rad wind.

By the by, it doesn't pull boost until >=212*F and only at 90%, but it does pull a shed load of timing 6-9* at those temps, which increases engine temps, runs like a 3 legged dog etc etc..

oh.. cool pics, looks like a lot of short burst full throttle apps..

[Heywood-Yablowme]

Sorry,no data logging files.I was using a hand held scanner for data stream.I also checked a few spots on the system with my infrared temp gun to make sure all was well. Believe what you wish.Or not. My stock brammo tune runs strong.Strong enough to be the fastest car on track for two days.That is why I have not messed with it..yet.

[positron]

Very well.. you win..

[Heywood-Yablowme]

Yea,I did win that event....but I'm not looking to "win" a discussion regarding IATs. I am reporting what I saw, on my car,in a similar situation.Why would I want to lie? If my IATs were elevated,and power was down,I would be the FIRST to be looking for a cure. So far,my stock tune and setup has been more than reliable,has excellent throttle response,plenty of track power,and no overheating issues of any kind. Maybe I am lucky? The only component on the engine I have changed has been the muffler.I even have the "bad" original 300hp GM stage III tune. I optioned out of the brammo "upgrade".

[DarthChicken]

I'm betting you saw IAT1 temps at 120 degrees, not IAT2

[Heywood-Yablowme]

Geezo....don't you think I know the difference? If my IAT1s were 120,my car is probably on fire..

I'm gonna try the Aeroforce Interceptor setup and will be able to data log with them,although I don't believe the data is exportable.Might be..

[silver]

Banned? can you explain how your temp reading from outside the motor will reflect actual numbers from inside the motor?

For example, if IAT2 temps are takin inside the manifold, then how can you get that temp with an external reading of the manifold? 

I'm sure I'm missing something from your explanation.

[Heywood-Yablowme]

Good question. I have found my IAT2's to be about 20-30 degrees warmer than the coolant temperature leaving the intake,heading for the front mounted heat exchanger.No,I can't actually put the infrared on the actual compressed air entering the cylinders,but there is a relationship between what the intercooler coolant temps are running and what I am seeing on the scanner for IAT2's. I am not seeing elevated IAT's,ever. I have run a dozen 80 degree+ days,and have not run into heat soak problems or a lack of power. Once again,maybe I am just plain lucky,and have a happy car.   Maybe it has something to do with my magic fuel additive,or the snake oil I run in the crankcase..I dunno. Maybe I am full of sh1t and just make things up to create controversy.