Lets Talk IAT's...
 

So after seeing my car on the dyno and datalogging it for a bit, IMO my IAT's are waaaaaay high. :( On the dyno I saw a max of 172deg and I am wondering why? This was on a 60deg night! I am thinking of changing out the LET HE for the NW Supercooler and flushing the whole coolant system. For those of you that have datalogged, can you please post up what kind of IAT's you are seeing in hot and cold weather?

Re: Lets Talk IAT's......
 

In low 80's, highest IAT was 187*.
In mid to low 60's, highest IAT was 172*.

Both of these peaks were with the engine at full operating temperature. I've seen lower peak IAT's when I've run with the engine temp right around a full tick mark below middle on the dash temp gauge.


I have the stock HE running a new Bosch pump with Needswings coolant seperation kit. I've never datalogged without the seperation kit, and have not done any logging with the kit opened. Plan on doing that at some point to see how effective the coolant sep. kit is.

Re: Lets Talk IAT's......
 

Well its funny you should mention this because I have the NW separation kit as well and I had mine closed during the 172 deg run. I decided to open it just to see if there was any difference and it went down to 158 deg on the next pull?? I mean this could be just a fluke, but it is weird right? I am going to have to do more testing on this........

Re: Lets Talk IAT's......
 

Your high, When you flush use like prestone and drain it into a clean rag to record the material that comes out. I was suprised and looking for conformation that others have the same gunk. Made all the difference to me and you might do this before you ditch the current inadequate H/E.

THe difference will suprise you, flushing and also the bigger H/E. Woody

PLEASE PHOTO AND RETURN TO LET US KNOW, THAT PASTE HAS TO LIMIT THE HEAT EXCHANGE RATE. wOODY

Re: Lets Talk IAT's......
 

This is good advice that I'll need to take soon. When I replaced my intercooler pump back in the summer, there was a greyish paste-like substance caked on the pump impeller. If it was there, there's no telling how much is in in the HE and intercooler itself.

Re: Lets Talk IAT's......
 

Yeah, I am going to flush mine as well. My car has 52k on it and I am pretty sure it has never been done. :rolleyes:

Re: Lets Talk IAT's......
 

Distant, when datalogging i noticed a huge difference in my supercooler(thanks woody), and the LET unit...we are talking like 30-40 degrees less with the supercooler. This was determined by readings via the dash daq on a buddys car(LET HE) and then directly on my car(Supercooler). Now just to keep all considerations fair i had the johnson pump and he had stock pump so take this fwiw. Not sure if that made any difference.

Re: Lets Talk IAT's......
 

Wow! That is crazy! :( Yeah, not sure how much the pump mattered, but I also noticed a big difference in cross><hairs IAT's and mine. Not sure exact numbers but his was much lower with the supercooler.

Re: Lets Talk IAT's...
 

Re: Lets Talk IAT's...
 

distantpulse did you bleed the system after the sep. kit? sounds like an airblock.
i have dj's supercooler and i love it. i run a bit higher engine temps in the summer due to the cooler being in front of the rad but nothing excessive.
i dont have datalog capabilities yet but before the supercooler s/c shutdown was a daily thing in the heat. since the install with a cm30 and separation i havent had a single shutdown whether racing or sitting in 100* heat car just runs great

Re: Lets Talk IAT's...
 

With LET HE and combined cooling systems..............high of 187


LET HE and separated cooling systems.............high of 170



LET HE, separated cooling systems and custom 3 gallon trunk mount resevoir running 100% water/ice combo(with switch inside cabin to turn on pump on demand)...........high of 110







All temps were datalogged at the dragstrip

Re: Lets Talk IAT's...
 

Chris,

Sorry to bust your bubble... But a couple things changed. We changed the tune, and then saw the drop in IAT. Additionally, once we did a 3rd gear pull instead of 4th gear pull your IATs only got up to about 140... :D

I'm always there for ya. Let me know when you get your SL55 fuel pump in...

Re: Lets Talk IAT's...
 

with my current mods on a 70* day my data log showed a 153* max IAT up to 140mph full street run

Re: Lets Talk IAT's...
 

I noticed an improvement in three areas with the supercooler.


1. Lower operating IAT
2. Reduced IAT at WOT
3.Quicker IAT recovery

Re: Lets Talk IAT's...
 

distant,

also thought about something else last night... your fuel pump issue would definitely cause your IATs to be higher with the car leaning out a bit... I'd be curious to see where your IATs are at once you replace the fuel pump with the SL55.

Re: Lets Talk IAT's...
 

Thanks Matt, all good points! :cool: Did you get me a price on that baby? :p

Re: Lets Talk IAT's...
 

Can you express the logic behind this statement?

Re: Lets Talk IAT's...
 

Another good point. The lean conditions could definitely cause a high IAT. We will get it all figured out eventually. lol.

Re: Lets Talk IAT's...
 

Distant, are you gonna do the SL55 fuel pump for sure?

Do you have a fp sensor at the rail to verify your bigger pump is actually allowing for more pressure to reach the injectors, as well as something to record your AFR's?

Re: Lets Talk IAT's...
 

I am more than likely going to the SL55 pump. I know Rob is working on a fix for our fuel issues as we speak. I am just not sure what the details are with that. Right now I do not have a fuel press gauge installed, but it wouldn't be a bad idea at this point. Could I just run a gauge off the fuel rail into the cabin?? I do have have a wideband A/F gauge to monitor the A/F ratios. According to Dave (Bulldogger), when he switched from the stock pump to the SL55 pump, they had to scale back the injector duty cycle to 80%. That is huge! You really do not want to come near 100% duty cycle on the injectors as you probably already know. ;) :cool: