Lights ZR1

Hi all.

I recently replaced my factory bricks with a forum member, which were flawless somehow, with DMS reinforced OEM bricks. I mostly cruise on the highway, if I did any track work, C&R for sure! This is maybe the 4th or 5th actual highway cruise since the bricks. There was next to no oil in the housing, a nice surprise, and all the fins on the bricks were mint! This was with 9,300 miles on the car.

While cruising on the highway, IAT1 sits at ambient, IAT2 sits 14-18 above that always. Even in traffic, IAT1 rises somewhat fast, IAT2 is like “nah I’m good,” and sits where it is. Sometimes IAT2 is lower than IAT1!

Today here it’s hot. Like 100, but no real humidity. I decided to do a pull 2-3. IAT1 was reading 103-104, IAT2 was reading 115 or 117. Almost as soon as I floored it, IAT2 started to rise, by the time I hit a bit into 3rd it was at 128! I could literally watch the numbers tick up on Dashlogic the longer I held WOT. I let off once I saw 128, it started to fall pretty quickly after. If I go WOT at lower RPM IAT2 doesn’t move.

Some recent life and work events have me a bit anxious, is this just normal IAT2 behavior especially in hot weather? I don’t have any data on temps before any of this and that is on me. Ugh.

On another note, we also changed all the fluids in the car. However, the supercharger oil is still original, and I’m not sure if anything can really be done about it, as you can never get all of it out.

Rokket

The factory tune doesn't pull timing until IATs reach 140.

Cruising, I am 25-30 over ambient. Under WOT (usually 3rd to 4th gear pulls), I have hit 150s in the IAT2 department but my IAT2s fall quickly afterwards. I have a Synergy Motorsports trunk tank with EMP pump. Edelbrock HX, and C&R bricks. Without meth or nitrous, there is no better combo for dealing with IAT2s (you can add ice to the tank if you are racing and that would help more). I have 1" lines to and from tank. They go down to 3/4" in and out of the bricks then back to 1" going into the HX.

It makes sense as long as you are WOT, the IATs will start and keep rising. How quickly they recover is important.

Your experiences mirror everyone elses and you have nothing to worry about. It is all normal.

Lights ZR1

Thank you for the quick response.

IAT2 began to drop a couple moments after I let off. A mile or so down the road it was back to 117 and dropped further to 115.

Rokket

You're welcome. If you want the C&R bricks, wait until Black Friday. I am sure they will be on sale at a few places then.

Lights ZR1

Thats good to know.

I tried it again, this time only a 3rd gear pull. It jumped from 117 to 124. Dashlogic updated after I let off. Took a mile or so to return to 120 and then 117 shortly after.

Spaceme1117

It’s a supercharged engine. IAT’s will go up when you get into boost.

I have a “poor man’s” ZR1; GS with E-force and ZR1 cam. My IAT’s run 20 to 30F above ambient. So yesterday in 95F weather, the car was around 118F in just normal cruising. Would bump up to 125 when getting on it. But my upgraded cooling system (larger Edelbrock heat exchanger, Cordes supercharger reservoir, supercharger spacer plates), allows temps to recover pretty fast.

Gum1993

This is totally normal IAT2 temps. I recently went through leaking bricks that were hitting 180 190 IAT2 temps when doing a pull. After the pull it would take ages just to go under 150. It was total cringe. I replaced them with C&R bricks, expansion tank, Hx, and synergy lines and outlets. Car runs amazing and with these crazy hot temps here sometimes cruising with all those upgraded cooling mods i cruise around 120 125 IAT2s with semi traffic stop and go with the crazy heat. But at night im down in the 110s cruising. In the morning heat my IAT2s after doing full pull to 4th 5th gear doesnt go over 140 ever and recovers quickly. At night with somewhat cooler temps it barely goes over 125 after some long hard pulls. So what youre seeing is totally normal and actually very good for just reinforced bricks! Im guessing your car is stock which would make sense. I wouldnt be worried till youre hitting over 150IAT2s and not recovering quickly.

Hib Halverson

I suspect the delta-T from IAT1 to IAT2 will be affected by a number of factors, but one will be if there is any air in the charge air cooling system. If there is air in the system, it will tend to let IAT2 run higher than normal. When the two IATs are not "behaving" correctly, purging the system might help

Lights ZR1

This is my feeling as well. My dealer has originally done my supercharger coolant. And then when we did the isolator and bricks it got bled again. 14-18 degree delta is about what I’ve always seen cruising.

Apocolipse

Iirc the iat2 is calculated by the computer it’s not an actual sensor

Rokket

There is a sensor in the lid.

Gum1993

I dont personally see issue with your IAT2 temps from what you have mentioned. Given the heat thats been around the country it kills our cars but granted doing pulls in this weather and staying under 130 IAT2 i think is totally normal with no need to worry. I was cruising yesterday with 85 degree weather and no sun and my IAT2s were around 98 to 105. When i get on it they go up to around 115 then recover. Last weekend we had sunny humid 100 degree weather and cruising i was around 120 IAT2s on highway. I personally think you are worrying for no reason but bleeding the system wont hurt to make sure the bubbles are out. But again i see no problem with your IAT2s. How was the outside weather at the time you were driving it?

Lights ZR1

100+ degrees. Any pull that involved second, temps jumped 10 degrees almost immediately. 3rd like 5 degrees. It would take about a mile for it to recover to prior temps, but it would start to drop after a few moments. The system is bled.

Gum1993

Ya i dont see a real problem with that especially with it being 100plus degrees. You gotta remember a SC engine intake temps will rise no matter what once you are hitting boost and with weather like that its not gonna enjoy it as much. Heat really does kill our cars and i personally dont plan driving my car anymore with the weather being this hot. I just recently went through a whole IAT2s issue which is why im seeing no problem with yours. I would go out and test it at night with 80ish degree weather and see how it acts. If you arent recovering quickly and its going up above 130 IAT2 at night with somewhat nice weather then thats when i would be concerned personally.

Lights ZR1

They recover quickly, I just had no temperature data before these new bricks. In traffic, IAT2 doesn’t move and IAT1 actually rises above it. I checked the fill port, definitely full.

The humidity was very low, only reason I drove it in such weather.

Gum1993

Your car is operating perfectly. I wouldnt be worried about it. Go drive it and enjoy the beast! Like i said when my bricks were slightly leaking and had air bubbles in my system one pull and i was in the 150s and it wouldnt recover at all. Your car is running like it should.

Lights ZR1

Will do and thank you!

More than anything I wasn’t sure if it should take a mile or so of freeway cruising for temps to recover.

Gum1993

With the weather you are driving in its totally normal. Like i said go try it and see how it is at night with good 80s weather. You will know and notice how much the heat kills our cars. Runs like a different car in nice weather.

Lights ZR1

Nice weather has been rare here lately.

Heat soaked after parking for instance, IAT2 comes down quick from 160+, usually as soon as the engine is started. Couple miles of driving and it’s back down to where it should be usually.

ky13

IAT1 is integrated into the MAF. Purging the system will only help IAT2