Experimenting with Intake Air Temp. Request for comments.

juld0zer

Where did you get the 95*F figure? I'm very interested in reading more about this topic as over here in Australia, we experience ambients over 30 degrees celsius for half the year. But from general driving experience this summer i think you're on the mark. It could be even lower like 30*C/86*F as that's when i start feeling the bog on take off.

What i can say is relocating the IAT sensor by way of a separate IAT sensor (think of the GM HSRK sort of thing, except a ghetto version) was the best thing i've done to address the heatsoaked sensor issues. My IAT sensor (a thermister type) is installed inside the bank 2 air intake duct (the barrell between the airbox and the fascia).

I chose bank 2 because firstly i was misinformed on a thread somewhere. But in the end it seems that the radiator piping around bank 1 airbox/duct radiates a lot of heat so if i was to do it again, i'd stick with bank 2 and put up with running the extra wire.

It's mounted about 2.5" from the mouth as that's the closest i could get a flat surface to mount it with a grommet. IATs are within 2*C while cruising on a cool day/night. On a hot day you can't avoid hot air wafting upwards from the radiator and being drawn in while the car is stationary but within a few seconds from take off, i'm within 5-8*C of ambient (based on the outside temp onboard sensor).

As for the foil wrap, mine overlaps a few mm over each section of tape and that's the way it should be. The places i wouldnt do extra layers on is the side which faces the front of the car as that's where mine looks quite snug. Every other side you have sufficient room to go nuts

SouthArk370Z

I wish I could remember where I saw it. I think it was on this site but a Q&D search didn't turn up anything.

Thanks for the input.
The front of the filter box was fairly easy to do and I ended up with no overlap for most of that area. It looks like covering the bottom of the filter box is going to be a PITA. I plan on looking online for a blanket-type insulation for the tubes between the MAFs and TBs.


I may have found a thermometer.
4-channel temp logger on eBay. Comes with two sensors. Extra sensors can be had for $2-5.

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

juld0zer

I actually found the bottom and the front-most side the most annoying the do. These were the sections i used the smallest and most pieces of tape. The ribbed areas you can either make an incision and split it over each side of the rib or just tape over the rib and press it down on the centre (looks neater).

For the post MAF tubes, i'd probably recommend the neoprene heat resistant mitt material i used on the tubing where the MAF sensors are mounted. Cant seem to find a source to buy this stuff in bulk (or as sheets) though I think i'm still keen on getting silicone replacements for the post MAF accordions.

I'll upload some pics of my airboxes (they look like charcoal chickens wrapped in foil!)

juld0zer

ImageShack Album - 27 images

I dont have any photos of the wrapping around the MAF tube though.

SouthArk370Z

Yours looks a lot like mine (pics in a comment above) except my outer foil gives a slightly smoother look.


I ordered the thermometer I linked to above and 4 waterproof sensors with 2-meter leads. The thermo is coming from Thailand and the sensors from China so it may be a while before I get them. (Why are there no dealers for this kind of stuff in US?)

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

juld0zer

yeh it does, mine's just more patchy like a pile of band aids hahah!

Do you guys have Radio Shack still around or similar electronics/DIY shops? Surely someone's put together a kit before and mass produced it. There might be some schematics available on the net to build your own but i'm not too good with soldering. It took me over an hour to solder that thermister onto the tip!

The sensors are Maxim DS18B20. I've dealt with Maxim IC in the past and they've sent me some samples so if you're interested in making your own you could give that a go. Not sure if they still give samples. Otherwise it shouldnt be too hard to buy the chips locally or on ebay. Let me know how you go because i've always wanted to know what the temperature of the air is (using an independent measuring device).

The thermister i used had almost identical resistance at 20*C but i'm not sure of the rest of the scaling.
I have a feeling my external IAT sensor reads 1-2*C warmer than the ambient temp indicated on the dash cluster - that's something i can live with. However i've seen the IAT temp match the onboard ambient temp so i could be wrong.

I did the Modshack fangvent mod on the weekend (had to do it slightly differently as the AUDM model has airbag sensors mounted on the fang vent plates) and i think it's a step backwards in terms of how quickly IAT drops after moving from a stand still. Maybe it's the black plastic ducting i used which is soaking heat and holding heat within the 65cm snorkel.

Maybe the ram air effect is only achievable if one mounts the snorkels exactly as Modshack and others did - directly in place of the fang vent plates. I couldnt do this so i just have two pipes with bell mouths zip tied very close to the fangs. My theory is that the diameter of the bell mouths is much smaller than the diameter of the entire radiator grille area, therefore takes longer to displace the (hot) air available to the airboxes. The air pressure via the radiator grille would also be higher than the air pressure thru the bell mouths, exacerbating the slow displacement of warmed air (assuming the same vehicle speed).

I'm also noticing my fuel level dropping quicker but i'll give it a couple of tanks & report back. Could be just me being extra aware of things. I need another very hot summer day to test the fang vent mod as well.