Fossicker
Hey all,
Recently did a 4-day drive from the Gold Coast to Darwin in my new to me 2007 Defender 130. Sadly, the insane heat build up in the transmission tunnel that I remembered from my old 99 TD5 was still present and made for a pretty uncomfortable drive, even forcing the aircon to struggle. I plan on keeping this one around for a bit and really want to make it more comfortable for longer trips with the missus and young fella so here is a log of what I am doing to rectify the problem as I go along.
If you're interested in having some fun, going way too in-depth with an issue, testing some long-thought out theories on what/why things are hot and some alternative methods to rectify this situation, this is the place for you. If you've answered no to any of the aforementioned points, especially the first, then no problems but I don't need to hear about it. I know there are a a few options already out there, such as dynamat, external heat shields and new trim but I want to try something different. Some would say "it's a lot of effort to go to when you can already do X", but in the same breath, so is dynamatting the thing back to front or replacing the factory trim in the car (which I'll probably do later on anyway) both of which really just band-aid the problem. I'm hoping for another way which fixes the problem at it's core, plus its nice exercise to be able to grow my CAD and manufacturing skillset and have some fun along the way.
Due to where I live in the NT, I have good stretches of road that I can use as a test bed to get pretty repeatable and uniform drives without worrying about traffic. The plan is to only do one change/mod at a time as to properly test effectiveness of that option. On this and other forums, there is at best, anecdotal evidence only without a lot of hard data available on what fixes actually did what. I am aiming to provide hard data and comparisons of before and after by using thermal imaging cameras and other data points to demonstrate a substantial change (or not) for each thing tested.
Note - all of my internal trim removed and the cab is back to bare-metal. The trim was pretty **** anyway, and I'm happy enough without it, especially for testing as it makes things much easier to check with the TIC (Thermal Imaging Camera). Again - the aim is to kill the heat BEFORE it is IN the cabin, not band-aiding it by heatsoaking it internally. Once I have adequate results with the bare-cab I will go about re-trimming the cabin and insides.
Starting Point
Here's the starting point for my 2007 Defender 130 Ute.
De-catted.
Mid-muffler removed
Exhaust wrapped from decat until rear of cabin.
The above made a good difference to the felt heat in the cab for short-term drives, with things taking much longer to heat up but the issue still exists on longer drives. Feet are very uncomfortable.
Game Plan
Step 1 - Data collection
I'll be taking delivery of the TIC in the coming days and will go for a nice long drive to get everything to temp and take extensive pictures of the under-carriage, running gear and the cabin floor temps taking note of the ambient temp and time of day to ensure things are consistent I will do the same the following day to ensure I have a consistent base-line.
Step 2 - Plan
There seems to be a real lack of airflow or at least cool airflow in the tunnel which contributes to the significant heat build up here. The results of the above testing will determine the course of action going forward, but I've come up with a number of solutions both centering around the same premise - active cooling.
Step 3 - Fabricate and Test
I've designed up some hyper-aggressive wing-vents with pipe attachments which I can use to scoop cool air in from the front of the defender and channel it directly to where it's required. I've designed it with 38mm fittings, purely because I have a TONNE of pool tubing laying around. If this turns out to not be fit for purposes due to heat, or is going to become more permanent, I will look at other options. Changing the pipe diametre is trivial as the whole design is parametric. These will be 3D printed from PETG, material can be revised depending on suitability in actual use whether or not the solution becomes permanent. The wings stand 75mm tall at the front and are angled at the same angle as the wind-screen for no real reason, more just to try and fit in looks-wise haha.
Wingtop Vent.PNGWingtop Vent2.PNG
My first two inclinations of some possible fixes are the following - note these are based ENTIRELY of forum posts and bits of pieced together info. We'll see what the TIC reveals.
1. Break up the heat-bubble in top of the transfer box
Acting primarily on the theory that the top of the tunnel has a deadspace where air doesn't really move around properly, the plan is to feed cool air directly from the scoop to the space underneath the cubby-box panel to try and stop hot air from sitting stagnant in the void.
2. Actively cool the floor pans
The second option is to actively cool the floor-pan itself. I've designed a bent sheet panel out of 1.6mm ally which will attach to the underneath and is fed cool air from the scoop. This creates a heat barrier, similar to other products, but instead of just delaying the problem, the cool air feed actively cools this barrier and prevents the floor from heating up, potentially sucking heat out of the seat box areas as well. This runs externally, on the bottom of the floor pan from front of the drivers footwell to the back. I'll get some small sheet ally 'wings' which attach to the this panel to try and deflect and channel heat from the verticals of the tunnel and into the actively cooled pan. Note the nozzle direction is not optimal here - but its fine for my testing purposes.
floorpan-drivers.jpgfloorpan-drivers-bottom.PNG
We could also wind-up with a solution of both. We'll see.
Anyway there we go we'll see how we go and I'll report back.
Comments, questions or suggestions welcomed
Cheers,
Matt
ForumSage
SubscriberI have wondered if there is an effective way of generating a negative pressure zone at the back of the transfer case hump (under the cubby box) to suck hot air out of the area and vent it underneath the vehicle. Maybe with a couple of vertical pipes that should draw air downwards into the slipstream.
Regards,
Tote
Go home, your igloo is on fire....
2014 Chile Red L494 RRS Autobiography Supercharged
MY2016 Aintree Green Defender 130 Cab Chassis
1957 Series 1 107 ute - In pieces
1974 F250 Highboy - Very rusty project
Assorted Falcons and Jeeps.....
Master
SubscriberSound like a fun project and I am a fan of hard data.Originally Posted by DFender
For my son's Defender I made an aluminium Ebox for all the TD5 electrickery (ECU, ABS, fuse boxes, relays and earth points) and fitted it under the cubby box. I was concerned about heat build up affecting the ECUs so I applied 20mm of foil wrapped closed cell foam insulation on the underside (outside) of the seat box centre panel (aka transfer case hump?) and had the exhaust manifold, exhaust down pipe and centre pipe ceramic coated inside and out (not the rear pipe). The ceramic coating is supposed to minimise exhaust gas heat loss through the pipe wall, maintaining the exhaust gas temperature for improved flow. Unfortunately, I don't have before and after hard data but the Ebox has stayed cool even on long drives on 38 deg C days although it hasn't been tested under NT conditions or heavy towing.
I look forward to seeing your results.
Martin
The secret to happiness is to truly want what you already have
Oil leak?...Nah, sophisticated anti corrosion system!
'04 D2a TD5 Manual "Snowy" - Daily
'04 Def 90 TD5 "Hue" - New toy
'03 Def 90 TD5 - Son's toy
'16.5 D4 TDV6 - Gone
ChatterBox
SubscriberWatching with interest, I have the same model Defender which is about to undergo some dismantling, hope you come up with some great bits in time for me to incorporate in the re-assembly!
Fossicker
Hey all,
Bit of progress has been made so reporting back with some updates. Not sure if there is just a lack of interest or if most think this is a dumb idea and kept quiet as I asked but thanks to everyone that's taken the time to reply. I've got back to you below!
Taken delivery of the new 3D printer, got it calibrated and made some test prints. Parts Designed in 3 pieces that fit together - base, scoop and funnel. This allows for easy editing of any of the individual pieces and makes it super easy to print. Another good thing about the modular design, is that I can mirror all 3 parts and print the opposites if someone was to want them for LH drive Defender.
My prints are for the 'aircon' vent, so I haven't printed the funnel section yet. I also had some bed adhesion issues on this piece which turned out a mess, so I've added some extra internal brimming around the funnel hole. I got a base plate out of it though and can confirm the fit with the base, so I'm happy there. Note these prints are just out of PLA, purely for testing purposes (and because it's all I had at the time) but the final prints will be made out of PETG. Parts will be given a whip over with some sandpiper, primer and raptor coat to clear up the layers lines and ensure a uniform look with the bonnet.
Between the original design shown here and my second iteration coming soon - I've only made some minor changes:
1. I didn't like the hard lines at the top, so I've added a small fillet just to help blend things a bit.
2. I've added in some 'keying' surfaces and chamfers, which will help to mate the parts together and keep everything tidy.
Onto the pics!
-1745754264_20230528_115857_3065870_resized.jpg
On the press
20230528_120105_resized.jpg
Mounted up
20230528_120119_resized.jpg
Close up
newscoop.jpg
Version 2.0
We'll see how it goes!
I have often pondered this question whilst having my feet baked and the conclusion I get to is that instead of trying to venturi or suck air out, I'm probably better off forcing air cool air INTO the area, bringing fresh cool air and some movement into the mix to cool things in the first instance, and additionally push that air out so it can't sit and stagnate. We'll see!
Hard data coming soon! Lining up a few different parts to this before I get the TIC so I can avoid overrunning on costs. It's a hobby project after all haha. Would LOVE to have had results of the ceramic coating but will get some on how much of a difference the wrap makes when I get the gear. I'm very likely going to be doing the closed cell anyway, did you do it anywhere else or just the centre panel?Sound like a fun project and I am a fan of hard data.
For my son's Defender I made an aluminium Ebox for all the TD5 electrickery (ECU, ABS, fuse boxes, relays and earth points) and fitted it under the cubby box. I was concerned about heat build up affecting the ECUs so I applied 20mm of foil wrapped closed cell foam insulation on the underside (outside) of the seat box centre panel (aka transfer case hump?) and had the exhaust manifold, exhaust down pipe and centre pipe ceramic coated inside and out (not the rear pipe). The ceramic coating is supposed to minimise exhaust gas heat loss through the pipe wall, maintaining the exhaust gas temperature for improved flow. Unfortunately, I don't have before and after hard data but the Ebox has stayed cool even on long drives on 38 deg C days although it hasn't been tested under NT conditions or heavy towing.
I look forward to seeing your results.
Stay tuned POD!
Cheers all,
Matt
Master
SubscriberThat's impressive, well done!
That is what we all say to our nearest and dearest
Just be mindful that the wrap is likely to accelerate corrosion of you exhaust pipe, even if it is stainless steel. Even more so in salty environments.
I just did the centre panel, four layers of 5mm thick closed cell foam, foil covered roof sarking, stuck together with Sikaflex (total 20mm thick). The silver foil should reflect any radiant heat from the T/case or exhaust pipe...at least until it gets covered in oil. The rest of the underbody I sprayed on a 3-4mm layer of Wurth bituminous Underbody Protection as a sound deadener and stone chip protection. I was lucky in that I had the gearbox, T/case and fuel tank out so I could do the whole underbody. It certainly works as a sound deadener but maybe it also contributes to a reduction in heat transfer to the cabin.
Martin
The secret to happiness is to truly want what you already have
Oil leak?...Nah, sophisticated anti corrosion system!
'04 D2a TD5 Manual "Snowy" - Daily
'04 Def 90 TD5 "Hue" - New toy
'03 Def 90 TD5 - Son's toy
'16.5 D4 TDV6 - Gone
Fossicker
Alright - swapped the printer filament to PETG and got v2 of the scoops hot off the press.
Overall, I'm pretty stoked with the result. The interlocking bits worked PERFECTLY and the whole thing fits together seamlessly. Strength is EXCELLENT. I'm sure this could take a decent whack from a bird or other errant flying debris and live to see another day. A couple of thing though:
1. intricacies of the front grill is a bit of a pain and slows the print down considerably. The PETG filament can also very fickle meaning stringing and other overhangs don't play the game properly, so printing results were hit and miss in various sections as you can see.
2. My filleting of the top was also too fine to be seen in the print and really made no difference to the sharpness of the design.
I will change this design to be something less fiddly which should improve print times considerably and also deliver a better end result.
Will get it all sanded and all together and get some pics back but here it is on the printer.
20230531_103027_resized.jpg
OldBushie
Looks good, you will need to open the “air inlet grid” significantly as the turbulence and resistance that grate will generate will be very high and flow greatly reduced.
Other than that, nice modelling - I’d sand and paint the PETG for top of guard use.
Master
SubscriberThis is realy cool - if you could prioritise thread subscriptions - this would be at my top. Looking forward to seeing the results - and hopefully one day 'a kit' to replicate for those of us without the gear, know-how, or aptitude to do this. Great work.
Fossicker
Thanks Tombie, agree on all fronts. Yes - everything will be getting a quick sand, some primer and a quick dose of raptor coat to keep things even with the bonnet.
Thanks Towe! If it works out as good as I hope, I will be putting a kit together for sure.
Latest and likely final design opens up the air inlet significantly and reduces complexity. Playing around with the renderer - here is roughly how it should turn out.
renderedscoop.jpg
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