I installed these sleeves over the radiator hoses. The results are you can actually touch the sleeves without getting burned. Vendor is Heat Shield Products.

 

The nomex sockfrom Halltech. I have two of them double thickness
on my intake tube. If the radiator hose happens to touch the nomex it doesn't
matter as the stuff doesn't transfer heat. So it will not heat the intake tube.

 

The more this keeps popping up, and the more I think about this, the less I know for sure about the whole system.

Here's what I do know:

• Heat flows from hot things to cooler things, and how quickly it flows depends on what it's flowing through.
• Heat flows quicker through aluminum than through rubber, and it flows even slower/less through insulators like fiberglass and nomex.
• I'm fairly certain that @FYREANT isn't trying to maximize efficiency at low RPM's with the throttle closed (maximizing MPG and such). He's got a supercharge on this thing, and I'm guessing he wants maximum efficiency at or near peak HP and peak boost conditions, not loafing around town at 1200 RPM's with 24" Hg of vacuum behind the mostly closed throttle plate(s?).
• We've got three fluids/volumes involved here. We've go the air inside the aluminum intake pipe, we've got the coolant inside the rubber hose, and we've got the air surrounding the outside of the pipe and hose in that immediate area.
• I'm fairly certain that when the car is moving over 20mph, the air surrounding the pipe and hose will be the coolest of the three.
• I'm sure the coolant inside the rubber hose is hotter than the surrounding air.

Here's some stuff I'm pretty sure of:

• I'm pretty sure the air inside the intake pipe, when it's under significant boost, will be hotter than the surrounding air. I base this on the choice of material, aluminum, which is a good conductor of heat, and which will carry heat from the hotter side to the cooler side. Using aluminum on this pipe to cool the intake charge only works if the intake charge is hotter than the surrounding air. If it was the other way around, the engineers who designed the system would probably have used stainless steel, possibly with a ceramic heat barrier coating.
• I don't think @FYREANT has mentioned any intercooler, so I'm pretty sure we have a supercharger attached to a pretty aluminum pipe which goes to the throttle body and intake.

What I'm not sure of at all:

• I don't know the actual engine coolant temperature when the thing is operating and fully warmed up.
• I don't know the actual intake air temperature (hopefully at the throttle body or at that end of the aluminum pipe) when the thing is at maximum boost.

Without knowing that, you don't know which fluid is heating the other where the aluminum pipe and the rubber hose are touching, and you don't know if you want to reduce heat transfer there, or increase it.


I'm almost certain that wrapping the aluminum pipe is the wrong approach here. I'm pretty sure that under full boost, the aluminum is taking heat out of the air in the pipe and heating up the surrounding air, and that's something you don't want to slow down with a nomex sock.

What I'm completely unsure of is whether, when operating at maximum boost, the air in the intake pipe is hotter than the coolant. If it is, you wouldn't want to insulate the rubber hose, either. That hose would be drawing more heat out of the intake pipe where it's touching, and would be further reducing intake air temperature under boost.

There's no question that at idle, or loafing around town, where it's touching it will be putting heat into the intake air. That won't help fuel economy or engine efficiency when there's high vacuum behind the throttle plate(s?). But if you're tuning for maximum power and acceleration under boost, then efficiency at idle and while cruising at high intake vacuum isn't your goal. You wouldn't have spent the money and the time putting the supercharger on it if your goal was maximum MPG and maximum efficiency at high vacuum.

 

Thank you! I will look into this!

Do they make nomex for the radiator hose? I don't want to wrap the intake tube if at all possible.

here are a few things to help with the uncertainties:

- As you suspected I am not trying to maximize gas mileage since this is an 830HP monster lol. It IS street driven, and will see plenty of time sitting at stop lights.

- Yes there is most certainly an intercooler. I am running a full A&A V3 Ti trim kit with pulleys to make the blower operate a bit over max impeller when at redline RPM's.

- Actual coolant temp when car is warmed up and sitting idle in an open area is approx 200* with ambient around 90*. When ambient is 100+ coolant temp reaches up to 220*. Remember, I have a 160* stat with proper tuning for it.

- The air outside of the intake tube is hotter then the IAT in the tube due in part to the fact that I live in FL where it is hot, humid, and muggy most of the time.

- Engine temp at WOT and peak HP is not a concern at this point as the car is spraying a metric ton of pure methanol which cools the intake charge and combustion chamber down during hard pulls.

I can gather IAT temps when the car is idling and also driving, but again I'm just trying to solve a specific portion of the engine compartment temperature equation at this point. I'm swapping over from my Summit 160* stat to an LMR 160* stat this weekend (this summit one is garbage and possibly the root cause of all my temp concerns), and will be wrapping the headers and X-pipe with heat wrap. I will probably do these in stages so I can mark individual improvements. The third and final piece for me, is the radiator hose heat dissipation itself. Sounds like I will be adding some form of fiberglass sheilding from either Nomex or Heat Shielding Products over the hoses and calling it a day.

Ant

 

I performed scans and graphed the results of IAT at various vehicle speeds.

The results were posted on an earlier thread but as vehicle speed decreased, IAT increase. Sitting at a stop light, the IATs increased rapidly to almost 160° but at 50 + mph, IAT were 5°-10° above ambient. I had a Haltech at one time and always had an issue of the coolant hose touching the filter housing. That set up had the most change in IAT, so I switched back to the stock assembly.

The location of the air filter and intake tube is not ideal. Close to the motor and radiator hoses. At higher speeds, more air (and cooler) is moving thru the radiator, and keeping temps down somewhat. As you slow down, less air and the hotter air from the motor takes over. My tests showed this to be the case.

I did add the insulation sleeves which helped a little. Lets face it, these cars get very hot under the hood. Its an oven. Insulating the coolant hoses, intake tube and filter box will help somewhat. But at low speeds and air movement thru the radiator is low, IAT will increase. Now if you could completely isolate the air intake system from under hood heat, that would be the ultimate solution. May a big scoop on the hood......well no.....that would be ugly.

 

I would send the Headers to JetHot for coating. The wrapping? I would pass on. The Jethot is amazing allows your Headers to cool quickly and seeming much less heat under the hood. Love Jethot coated headers!

 

All you needed to do is add the Nomex sleeve to your Halltech.
It stops heat transfer.

 

You don't wrap the Nomex It is sleeve made in the right size to slip over your intake tube like a heavy sock. No reason not to put one on.

I have two I put on one then added a second one as well over the
top. My intake tube is protected from the heat. Easy!

 

Right. Pardon my quick wording lol I knew that about it being a sleeve. Do they make it in sizes small enough for the radiator hose? Would love to sleeve the rad hose with nomex. But due to aesthetics won't be wrapping the intake tube.

 

It is much better now than 10 to 15 yrs ago. Old stuff burn off crack's off then RUST. If you get the better stuff from jethot now it does stay on the tube's better plus now they do the inside of them also. Plus 100% about the heat being a lot less under the hood.

But the wrapping if you put the claimps on each tube at the top so they don't come off after a little time the wrap also does a very good job. I had my c5 with 2 inch runners jethot plus I wrapped them also this works even better than one without the other.

 

I'm sure the tube starts cold then it is heated by the under hood heat from the radiator not so much from the intake air which is preblower
so still should ambient. Something the Nomex is trying to keep cool. Nomex that I use is a sock NOT a wrap.

 

OK, so I have to give you points for best re-use of used socks and underwear here. You're using nomex socks like these? That's definitely clever. Cut the toe out and you've got a "sleeve" with a bend (at the ankle of the hose) already knitted right in.

Do you need to measure the hose with a Brannock Device to get the right size sock?

As for which pipe we're discussing, @FYREANT has this kit:


We're discussing the radiator hose on the passenger side touching that shiny aluminum pipe that runs to the throttle body in the middle of the picture.

That pipe is most definitely under boost!
Your test results are from the stock setup? Or were you testing the A&A supercharger setup in the picture above?
That's a really nice looking kit, and it looks pretty well engineered.
That should be true at idle, or cruising on the streets at low speeds, low throttle openings, no boost. Under boost, that's physically impossible.
Well, I don't have a lot of time, I have a busy weekend ahead and I need to leave "real soon now." Please excuse me if I'm a bit short and abrupt (maybe a bit mean sounding) with my answers.

I care about IAT and engine temp at WOT at peak HP. I don't want to read on here anything that starts with "Racer_X told me to try this and when I did, one of my pistons melted." I'll try to help, but without enough information, I can't really make an informed recommendation.

I was looking at your thread from a couple years back showing the pipe we're talking about when you installed the Alky kit. I'm a bit concerned that your IAT sensor isn't reading accurately when the methanol(/water) starts flowing.

I've seen IAT sensors positioned about where yours is that were brought to me. Two of them were brought in on engines with severely damaged internals, and the last one came on a twin turbo Nissan that was running very poorly. By the time I sorted out that Nissan, he was at over 1000RWHP.

Every time I've seen IAT sensor that close to a methanol/water nozzle, the IAT sensor was giving false (very low) readings. In some cases, the readings were false enough, and the engine was pushed far enough based on those false readings to cause a very expensive failure.

Have you run back to back with the stock IAT sensor in the stock location, and with your relocated sensor, and verified that they agree with each other at high airflow operating conditions (wide throttle opening, RPM's over 2500, high intake manifold pressure/boost)?

The stock IAT sensor is quite accurate under those conditions. It's known to be inaccurate (usually reads high) at idle, and under low load/low throttle opening/low RPM conditions. That's why the factory maps don't pay any attention to the IAT sensor under low RPM/low load/low throttle opening conditions. That's also why smart tuners don't use it under those conditions. As long as you ignore it when you know it's wrong, there's nothing (definitely no HP) to be gained by relocating that sensor.

Under boost, with your methanol(/water solution) flowing, I'd trust the stock sensor over your relocated sensor unless I had back to back runs that show your relocated sensor agrees pretty closely with the stock sensor. If they differ by more than a few degrees at WOT, high RPM's, under boost, the stock sensor is the one I'd trust. A wet IAT sensor is not only useless, it's dangerous to the engine.
Again, I'm most interested in accurate IAT sensor readings under boost, full throttle, approaching redline. My goal with boosted engines is IAT<ECT at 90% of redline RPM at full throttle, full boost.

I've done serious work on a few dozen boosted engines over the years, but I've only achieved that goal a few times. It's not an easy goal to hit. If you're achieving that, and your IAT is below ECT with the stock IAT sensor, I'd be very impressed.

Usually when a boosted engine gets to me, the first test runs show IAT>ECT+50F. The highest accurate IAT I've seen was 348F, and that was on a street driven "rice rocket" that was obviously set up very poorly. That was when it was brought to me. When I was finished with that one, IAT's were under 240F, and he had over 100 more HP at the wheels out of a small turbocharged 4 banger.

 

Those are atrociously high ITA's
Funny stuff the Nomex is not socks and underwear. The A&A kit's ? About 8 years ago I was installing kit's on the C-6's. Also had 1 on my 2014. Since I like the LT4 Z06 much better than the C7 and the lt1 which I was always working on..
Glad I have the Z06. A few easy mods! Around 750 hp no meth, pump 92 gas. Stone reliable.

 

My IAT's are nowhere near as high as 240+ at high rpm. My IAT sensor was relocated intentionally for the purpose of meth failure detection. That's its primary focus. IAT1 (the relocated sensor) reads just a few degrees under IAT2 which is in the intake manifold. So the sensor is reading accurately. Spraying directly before the sensor allows me to use the sensor to detect if the meth pump fails as the IAT would spike abruptly so as to cue the tune to yank the timing back agressively.

The concept that the intake charge is cooler than the air in the open engine bay I feel is still valid as the air outside the tube is much higher temp than the air the supercharger system is breathing in from the fender well filter because of all of the heat radiating from the exhaust in the engine bay which is also very close quarters.

My set up is meth dependent for supplemental fuel at high rpm's/redline. It is impossible for me to get you IAT readings without the meth spraying or without the IAT sensor in its current location. My meth install pics from years ago are no longer valid anyway, I have a new kit, with a different charge tube and have slightly adjusted placement of the sensor and nozzles.

I don't consider your response to be mean in anyway, or abrupt. However, this thread is focused on radiator hoses and reducing the heat they put off. My methanol nozzles and IAT sensor location have no place in this thread. If you were saying that the nomex heat shielding over the hose would in turn cause the engine to run hotter and therefore cause higher IAT's which would then compund from there then that would be relevant.

Again I appreciate the response, but please stick to the specific topic at hand here.

Ant

 

First, Ant, I'm impressed with what you have. When I saw "IAT2" in your post, I was really impressed.

People bring me some sketchy stuff sometimes, but you seem to have things well sorted out.

If you've got a second IAT sensor in the manifold that you know is staying dry, and it's running below ECT at full boost, you're in great shape.

I'm pretty sure you'll be fine sticking a nomex sock with the toe cut out, nomex sleeve or any kind of nomex or woven fiberglass insulation on your radiator hose(s).

 

Thank you.

All C7's actually have both IAT1 and IAT2 actually. IAT1 is typically in the MAF (which mine is broken out) and IAT is read via the temperature MAP (TMAP) sensor on the drivers side of the intake manifold. Im my case, I use an LS9 MAP sensor. It stays plenty far enough away from the meth to ensure the meth has properly atomized by the point it reaches it.

I went ahead and ordered a couple of the Heat shield Product sleeves for the radiator hoses. Will have comments on fitment as soon as I try to put them on this weekend.

Ant 🐜