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I just wanted to ask what everyones views on air temp is and how important it is to keep under control.
in my car, my average air temp is 32-41C depending on the time of day. anything above 38C is usually because ive been doing a few pulls or its just especially hot. i stay out of boost with anything above 41C and will wait until it cools down to at least ~39 before going into boost again. i would call it paranoia but i DO NOT want anything to happen to this motor for something as silly as a high IAT. whenever i meet another FD owner i always ask what their air temps are.
i just wanted to bring the conversation here and see what you guys thoughts were on the subject.
33-35°C if I’m in motion, it’ll go up a couple degrees if I get on it, but generally come down pretty quick. If I’m stuck in slow moving traffic then I’ll see low to mid 40s, will return to high 30s as soon as I start moving. I only take my car out in mid 80s or below weather tho.
You're using an air box? What's your set up? I should have detailed mine in the first post. I plan making an air box that will tuck neatly into behind the headlight. It's hard to describe but it will be needlessly complex for the sake of the look I'm going for. Also should note I'm using a vis (scoot) hood and I'm v mount with a fast ait in the stock location.
Since you're talking (mostly) about air to air heat exchangers I think it's important to note the ambient temperature and even humidity. A south-easterner's 45C might be a North Californian's 35C.
Also, what boost is being run? There's a direct correlation between pressure increase and temperature. PV=mRT
Even better would be to talk about air temperature as an increase from ambient.
I run about 13PSI on the stock twins With M2 medium SMIC and M2 intake. From what I recall my temps on the street are generally 5-10 degrees F above ambient. Call it 30-40C depending on the day. We are usually in the upper 90's here. High humidity.
Under repeated boost (repeated cloverleaf interchange romps) my temps are 40-45C. Same at autocross except I will heat soak close to 50C in grid and quickly cool off once the car is moving. Plan to put some insulation on the IC this winter.
The stock intake and IC were actually a little cooler at first. When I got into repeated boost events or autocross, then it would start running away. The M2 is slightly hotter at first but is consistent and doesn't run away.
I don't worry too much about temps because I have logged my knock and have plenty of fuel. If you're that paranoid about it maybe look into AI? It's on my list.
Stock IC can see 60-70 deg. C easily. It heat soaks and can't get rid of the heat, there's not enough mass and surface area on the IC.
In the 40's is a comfortable place to be. You will see higher temps after a heat soak - run the car, park it on a hot day. The temps should start coming down once you get the car moving and get some air flow through the IC.
Of course, temps will be lower depending on ambient temps, humidity, etc.
Water injection is a great way to go to add that extra level of security. Drops intake air temps like a rock.
You're using an air box? What's your set up? I should have detailed mine in the first post. I plan making an air box that will tuck neatly into behind the headlight. It's hard to describe but it will be needlessly complex for the sake of the look I'm going for. Also should note I'm using a vis (scoot) hood and I'm v mount with a fast ait in the stock location.
GReddy V-mount no A/C, fast AIT and twins on 14psi.
AI is on my list 100%. Its just a little expensive and I have a few other things on the car to take care of first. My goal is to never have an air temp above 40c..... under load anyway.
More importantly, I'd like to hear what the dangers of too high an air temp is. I understand how it works but would like to hear how others feel about it. Is driving around with a 60c air temp and boosting 15psi to red line not a risk? Even when the tune is compensated for such conditions, is it still not dangerous?
Hard to say if there's a hard and fast "danger' temp. There's so many "what if's" involved. In general, the hotter the air, the less power you will make, and the higher the likelihood of detonation.
This is why AI is such a great thing on our cars. The AEM kit isn't very expensive and really cools things down nicely. You don't have to use fancy Boost Juice or anything, just blue windshield washer fluid does the job great. It also helps decarbon the internals of the engine - the carbon many times creates hot spots for detonation to occur, so that's a win-win.
It depends on the safety margin of the tune and how it responds to higher temperatures. The stock hardware heatsoaks (including the sensor), but there is a big margin built into the stock ECU tune. So you lose performance but it doesn't blow up.
With custom tunes you basically have to reduce power as temperatures increase, pulling spark, adding fuel, and if the ECU supports it, reducing boost.
if that's what needs to be done, doesn't that indirectly mean that air temperature should be kept under control. Not saying that anything above X is dangerous but it seems like there should be a line. At what point are you pulling power so much that you say "it's just too hot"
Using FC Edit... For fuel I start adding between 50C and 80C (50C adds none added ramping up to 5% more fuel at 80C).
I have my Inj vs AirT linearized to correlate with actual air density up until 50-80C having a 0-5% ramp up in fuel. That is on top of a conservative AFR.
The stock Inj vs AirT table is all screwy up so don't try to read too much into that. There is significant overfueling in the hot range and then they pull fuel out as it gets colder.
I still use the stock PFC table for IGN vs AirT. The stock PFC doesn't start to retard timing until 60C.
Maybe someone can give you a hard cutoff # with actual testing to back it up. *shrug*
There's always worst case scenarios that you should ideally have something planned for; altitude changes, really hot summer day with A/C on heatsoaking at a stop light, that kind of thing.
There's always worst case scenarios that you should ideally have something planned for; altitude changes, really hot summer day with A/C on heatsoaking at a stop light, that kind of thing.
Agreed. And that's really up to each owner to determine what that might be. My tuner (Chris, at RP) told me when he tuned the last car that he could have squeezed a bit more out of it but decided not to because in the event we get a really cold day it might be a problem. Since Dallas rarely gets snow I can drive the car year round. And there are other factors owners might want to plan for. Leaving a margin of safety is always a good idea.
The key to thermal management is to only allow ambient outside air into your intake airbox and IC airbox (if SMIC), preferably a ram air and high speed pulling fan (both in the airbox and on the IC) setup like mine. Also, underhood ceramic coating(either barrier or disperant as needed) of every pipe and manifold helps too. After my rebuild at the beginning of this year, every time I full boost on a still twin setup I actually see my AIT temp go down as the boost continues even without my WMI on. With WMI, it's even gets better. I draw in cool air and the IC becomes more efficient with speed (better heat exchange with increasing cooling air velocity). I posted logs proving this earlier this year in another post.
Just notice your cooling panel, did LRB offer them in CF or did you wrap yours?
i got it wrapped by a shop here in tampa. i wanted to do the shiny carbon wrap that looks like real carbon but it actually looked pretty bad. they showed me the "dry carbon" look stuff and it was much better
Originally Posted by mikejokich
The key to thermal management is to only allow ambient outside air into your intake airbox and IC airbox (if SMIC), preferably a ram air and high speed pulling fan (both in the airbox and on the IC) setup like mine. Also, underhood ceramic coating(either barrier or disperant as needed) of every pipe and manifold helps too. After my rebuild at the beginning of this year, every time I full boost on a still twin setup I actually see my AIT temp go down as the boost continues even without my WMI on. With WMI, it's even gets better. I draw in cool air and the IC becomes more efficient with speed (better heat exchange with increasing cooling air velocity). I posted logs proving this earlier this year in another post.
wow... thats pretty impressive. i see the cut out in your bumper is likely a tremendous help with that as well. i have the "scoot" hood and i get similar results when moving. i posted about it a while ago how my air temps drop when going into boost. i have the same approach as you where everything needs to basically be thermally independent of everything around it, if that makes sense. nice set up. thanks for sharing
That’s a super U SMIC similar to the Knight Sport one, I think made by a shop in Australia.
Originally Posted by ItalynStylion
@mikejokich what the heck intercooler is that? I've never seen anything like that before.
Correct. It is the Australian version of the Knightsport U-type IC but slightly bigger. This U-type IC double cools the charge air and has a surface air that is 5X more than stock and almost 2X more than the Greddy SMIC. The efficiency is around 85-86%. With ceramic coating the fins with dispersant, the efficiency goes to almost 90% by my testing. If you add the provided carbon fiber airbox that draws ram air from the grill area and that fact the I added two 300cfm Spal puller fans on the backside, the efficiency stays at speed and even when stopped at a light. This easily outdoes any SMIC and probably even rivals a smaller v-mount setup without the major hassle of a v-mount installation. I can stay boosted for long periods of time when at speed and never see my AIT temp go up and again even go down from before the boost was initiated. Also, the solenoid you see to the right near the battery sprays liquid CO2 (trunk mounted bottle, next to WMI tank) onto the IC fins from a button I installed in the dash. This even cools the fins of the IC down to -80F so that the efficiency go above 100% during an approx.60 second time of spraying and immediately thereafter.
Mike
Correct. It is the Australian version of the Knightsport U-type IC but slightly bigger. This U-type IC double cools the charge air and has a surface air that is 5X more than stock and almost 2X more than the Greddy SMIC. The efficiency is around 85-86%. With ceramic coating the fins with dispersant, the efficiency goes to almost 90% by my testing. If you add the provided carbon fiber airbox that draws ram air from the grill area and that fact the I added two 300cfm Spal puller fans on the backside, the efficiency stays at speed and even when stopped at a light. This easily outdoes any SMIC and probably even rivals a smaller v-mount setup without the major hassle of a v-mount installation. I can stay boosted for long periods of time when at speed and never see my AIT temp go up and again even go down from before the boost was initiated. Also, the solenoid you see to the right near the battery sprays liquid CO2 (trunk mounted bottle, next to WMI tank) onto the IC fins from a button I installed in the dash. This even cools the fins of the IC down to -80F so that the efficiency go above 100% during an approx.60 second time of spraying and immediately thereafter.
Mike
I doubt it would be as efficient as a vmount using equivalent ducting, equivalent core, and equivalent MAP.
By its very design, a double pass core will have a higher pressure drop at equal flow volumes compared to a single pass.
I doubt it would be as efficient as a vmount using equivalent ducting, equivalent core, and equivalent MAP.
By its very design, a double pass core will have a higher pressure drop at equal flow volumes compared to a single pass.
I agree the pressure drop of a dual pass is higher than a single pass for comparable surface area IC's. As for efficiency it depends on the efficiency we are talking about. The true IC efficiency ratio used to compare IC's by manufacturers and auto engineers is inherently greater in a dual pass design as compared to any single pass of the same footprint exchange surface area. The overall system efficiency of a dual pass IC setup like mine as compared to a smaller (as I stated) v-mount is debatable and would be difficult to measure in the field accurately. I would agree with you that a larger v-mount setup would be more efficient at decreasing the charge temp but at a corresponding higher pressure drop than even a setup like mine. But as I stated, IMO when you factor in the time, expense(although the U-type IC's are not cheap), and work to upgrade to a v-mount, I would much rather just drop in this IC into the stock location, leave the battery, radiator, and everything else alone, add two fans, and then I am done. Cannot beat the bang for the buck, hassle, and time spent as compared to a v-mount even if a v-mount is overall slightly more efficient.
Mike
Last edited by mikejokich; 10-09-19 at 03:40 PM.
Reason: error
AI is on my list 100%. Its just a little expensive and I have a few other things on the car to take care of first. My goal is to never have an air temp above 40c..... under load anyway.
More importantly, I'd like to hear what the dangers of too high an air temp is. I understand how it works but would like to hear how others feel about it. Is driving around with a 60c air temp and boosting 15psi to red line not a risk? Even when the tune is compensated for such conditions, is it still not dangerous?
Also wanting to know if there is a real risk on driving or wot with air temps in the 60C tuned by a reputable tuner is any harmful for the engine. the water seal from my engine where blown last year and I didn't find a cause to it, never overheated the coolant or overboosted the car. Bought a new Mazda oem engine from irp after that.
I live in Panama, Central America where the average temperature is 33C and humidity of 86%, I have a diy Large SMIC with petit cool charge 3 ducting, the core is from cx racing and I also added a spal puller fan.
At iddle in traffic the car air temps go up to 60C-70C and while driving above 50mph it get colder to 43C.
Remember, these cars were developed in Japan by Japanese people driving around in hot humid climates that are just like Panama. Average high temperature in Hiroshima is 32C in the month of August. Higher air temperatures Require richer mixtures and more retarded spark. Ideally you don’t reach those high temperatures too often (good cooling, water/meth injection if you want to go that route), but if you DO reach the temperatures, you have to adjust. Some of it depends on the baseline temperature at which the fuel and AFR were tuned. SAE standard is 25C, room temperature is 20C, but most of us don’t have climate controlled labs for tuning.
Also wanting to know if there is a real risk on driving or wot with air temps in the 60C tuned by a reputable tuner is any harmful for the engine. the water seal from my engine where blown last year and I didn't find a cause to it, never overheated the coolant or overboosted the car. Bought a new Mazda oem engine from irp after that.
I live in Panama, Central America where the average temperature is 33C and humidity of 86%, I have a diy Large SMIC with petit cool charge 3 ducting, the core is from cx racing and I also added a spal puller fan.
At iddle in traffic the car air temps go up to 60C-70C and while driving above 50mph it get colder to 43C.
That's really hot. A few things off the top of my head:
- CX racing intercooler isn't going to use the most efficient core
- If you haven't already, extend the duct into the bumper opening as far as possible/tolerable using sheet metal
It's a little worrying that @jonahau's setup is still reaching such high temperatures since it's essentially what I'm moving to, to try and combat high IATs (HKS RS intake and M2 medium IC).
Current setup:
Stock IC
Stock Intake
AEM AI (water only) cold side
Triumph fast reacting IAT sensor
Average cruising temperatures (out of boost and after a cold start) around town are low to mid 50C, this is Bay Area so very temperate, ambient temps around 24C.
AI isn't setup to come on until 5 PSI, so unless I'm pushing the car, I won't get any benefits of AI BUT at the sametime, I am afraid to boost when the car was sitting at 76C (!!!) after a hot start. Once I got going, it started coming down but was still in the 60s until I got on the highway.
Any other people running the AEM AI kit have different settings that may help with my situation? Mine are 5 PSI start, 22 PSI max.
10-03-19, 10:57 PM
Air Temp Discussion
