Skid Plates vs Heat

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Aluminum is a good heat conductor for a solid material, but it's only a "heat sink" when the geometry is such that the aluminum has a ton of cool surface area per heated surface area (IE a CPU heat sink). If it's just a sheet of aluminum it's a 1:1 ratio - I'm pretty sure it's a heat shield. Not a heat sink. The geometry makes the difference. Either way, I don't think it's worth worrying about here, but just figured I'd throw that into the conversation.

Which good conductor is not a solid material?


Aluminum is a good conductor because of it's atomic structure, that has nothing to do with it's geometry. Fins certainly make it much more efficient but it's not like it stops transferring heat from hot side to cold side just because the it doesn't have more surface area on one side than the other. Reference fanless laptops or fanless amplifiers built with aluminum cases. Aluminum is certainly reflecting some radiant heat back into the hot space, but the conduction and convection shedding the heat should win out.
 
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Nvm, don't care to argue any further.
 
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Kabanstva

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Don't shut your truck of when wheeling. That solves the problem of vapor lock. Would you rather have a truck that wont start fort an hour or a busted transfer case?
This. 100%.

I shut mine off at one of the high elevation passes in CO and got vapor locked. Had dissent skids installed at the time already but I doubt they had anything to do with it.
 

YezusLX

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I suspect the exhaust temp behind the cat might be low enough to allow for this cover. I am willing to give it a go nonetheless. Sometimes all it takes for an idea to work is ignoring the conventional wisdom. Maybe it melts, maybe nothing happens. But why would a multi-billion dollar automobile manufacturer spend money on R&D for a part on the same vehicle it sells elsewhere that will not function as designed? I presume temperatures on a diesel or petrol engine (outside the USDM) exhaust are warm enough to damage plastic panels regardless of emissions parts. I do not want to add additional weight as my hundo will likely not be off-roading beyond fire roads, cow pastures, and ranges. This has become such an odd discussion on here. Haha, If any skid trapped heat enough to damage things lawsuits, insurance investigations, and attorneys smelling blood in the water would follow purchases leading to the producer's ultimate bankruptcy. Maybe higher overall temps would just contribute to less overall efficiency? This could be mitigated by the actual need or use of more efficient fluids than OEM Toyota. But logic and reason are something I do not do well with it would seem.
 
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I am trying to buy this exact part and cannot locate the actual part number on Partsouq. Would you be kind enough to locate that number for me? Thanks in advance.
This says its for 98-02 trucks. I think I just selected the third on the list of 100 series variants listed on Paatsouq....
Screen Shot 2022-10-16 at 12.14.34 PM.png
 

jLB

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I suspect the exhaust temp behind the cat might be low enough to allow for this cover. I am willing to give it a go nonetheless. Sometimes all it takes for an idea to work is ignoring the conventional wisdom. Maybe it melts, maybe nothing happens. But why would a multi-billion dollar automobile manufacturer spend money on R&D for a part on the same vehicle it sells elsewhere that will not function as designed? I presume temperatures on a diesel or petrol engine (outside the USDM) exhaust are warm enough to damage plastic panels regardless of emissions parts. I do not want to add additional weight as my hundo will likely not be off-roading beyond fire roads, cow pastures, and ranges. This has become such an odd discussion on here. Haha, If any skid trapped heat enough to damage things lawsuits, insurance investigations, and attorneys smelling blood in the water would follow purchases leading to the producer's ultimate bankruptcy. Maybe higher overall temps would just contribute to less overall efficiency? This could be mitigated by the actual need or use of more efficient fluids than OEM Toyota. But logic and reason are something I do not do well with it would seem.

I’d really like for you to be correct, as this would be a somewhat reasonable “cover” on one of our daily drivers, that really don’t justify a full set of Slee/Dissent skids, and possibly a mild deterrent to catalytic converter theft. My concerns are based on my understanding that a catalytic converter doesn’t start functioning until the internal temperature reaches 400-600* range, and can reach 1200-1600* (internal) under load.
 

YezusLX

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I’d really like for you to be correct, as this would be a somewhat reasonable “cover” on one of our daily drivers, that really don’t justify a full set of Slee/Dissent skids, and possibly a mild deterrent to catalytic converter theft. My concerns are based on my understanding that a catalytic converter doesn’t start functioning until the internal temperature reaches 400-600* range, and can reach 1200-1600* (internal) under load.
Those temps are impossible to argue certainly. However, does it negate the use of the OEM or aftermarket heat shields on the cats? Are outside temps lowered as I suggested previously or not? I believe the temps are supposed to be lowered by some 50-70% in order to stop heat soak/transfer to the transmission or am I wrong about this as well? I am not trying to be adversarial here just trying to understand better. I totally get the argument about heat containment and the dangers it can potentially pose for critical components. But even having an OEM-designed bash plate contoured by millions of dollars of R&D seems mind-boggling to me. Why would Toyota waste the effort and more importantly the monies on this seemingly insignificant piece of plastic if it were to even remotely interfere with critical components?

Perhaps I am overthinking it here? Maybe it is more simple than that? Maybe with the California/50 state legal emissions catalytic converters, the aforementioned cover on IFS 100 series disrupts the flow of air under the vehicle causing a noise that American vehicle owners would/have complained about. Since Americans are lawsuit happy and frequently complain at Lexus and Toyota dealers, this was a preemptive move in order to eliminate this issue before it became one. Especially, since the vehicle was available nearly a year before coming to American showrooms. Maybe a quick search of previous recalls/TSBs/campaigns/general memos for vehicles in the TSM would reveal these were removed prior to distribution or during the P.D.I. process because it was found to make a noise at idle or while underway. Then later on it was just not included in the following iterations of the 100 series. I do believe there was a similar issue if memory serves of an Avalon or ES300 having Cat shields replaced under a TSB because they made noise or contact with undercarriage covers. If you look at the bash plates as stated earlier by other companies like ASFIR, Dissent, and Slee as an example they continue all the way back to the cross member and connect with the transfer case cover as well. Are they not simply just copying the R&D from the manufacturer? But again I am open to learning and being incorrect. Thank you in advance for correcting my ignorance. Sincerely (not sarcasm).
 

ga12r1

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I know Budbuilt did tests with their 200
Series skids monitoring underbody temps with and without skids and found no significant increase.
And the Budbuilts have a lot of coverage

38DB79BE-FC2D-4B02-94F8-827154CB3157.jpeg
 

YezusLX

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I know Budbuilt did tests with their 200
Series skids monitoring underbody temps with and without skids and found no significant increase.
And the Budbuilts have a lot of coverage

View attachment 3142311
Whoa! Nice photo. And with a significantly larger engine, trans, and radiator generating heat that's pretty indicative of skid plates being a non-issue for heat retention. I would logically conclude anyway. I guess the engineers have figured out a way to release that heat or add shields that mitigate the heat itself if this is the case. Pretty interesting.
 

jLB

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Those temps are impossible to argue certainly. However, does it negate the use of the OEM or aftermarket heat shields on the cats? Are outside temps lowered as I suggested previously or not? I believe the temps are supposed to be lowered by some 50-70% in order to stop heat soak/transfer to the transmission or am I wrong about this as well? I am not trying to be adversarial here just trying to understand better. I totally get the argument about heat containment and the dangers it can potentially pose for critical components. But even having an OEM-designed bash plate contoured by millions of dollars of R&D seems mind-boggling to me. Why would Toyota waste the effort and more importantly the monies on this seemingly insignificant piece of plastic if it were to even remotely interfere with critical components?

Perhaps I am overthinking it here? Maybe it is more simple than that? Maybe with the California/50 state legal emissions catalytic converters, the aforementioned cover on IFS 100 series disrupts the flow of air under the vehicle causing a noise that American vehicle owners would/have complained about. Since Americans are lawsuit happy and frequently complain at Lexus and Toyota dealers, this was a preemptive move in order to eliminate this issue before it became one. Especially, since the vehicle was available nearly a year before coming to American showrooms. Maybe a quick search of previous recalls/TSBs/campaigns/general memos for vehicles in the TSM would reveal these were removed prior to distribution or during the P.D.I. process because it was found to make a noise at idle or while underway. Then later on it was just not included in the following iterations of the 100 series. I do believe there was a similar issue if memory serves of an Avalon or ES300 having Cat shields replaced under a TSB because they made noise or contact with undercarriage covers. If you look at the bash plates as stated earlier by other companies like ASFIR, Dissent, and Slee as an example they continue all the way back to the cross member and connect with the transfer case cover as well. Are they not simply just copying the R&D from the manufacturer? But again I am open to learning and being incorrect. Thank you in advance for correcting my ignorance. Sincerely (not sarcasm).

I haven’t taken the time to look to see if the OE plate is intended for a 2UZ-FE, 1FZ-FE, 1HZ, 1HD-T, or 1HD-FTE equipped models, nor how the exhaust/catalytic converters/DPF are routed on these non US market models.

I don’t think the issue is so much heat transfer to the transmission, or transfer case. At this point, I suspect that the aftermarket plates have been in use long enough to prove that they do not cause immediate catastrophic failure. If you’re concerned, monitor the temps through a scangauge or similar, and change fluids more frequently.

Maybe it has to do with my time playing with exhaust on Mazda rotary engines, (which do run exceptionally hot, as they tend to send burning fuel out the exhaust) but I’m cautious of putting “melty things” near the exhaust.

Good luck!
 

YezusLX

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I haven’t taken the time to look to see if the OE plate is intended for a 2UZ-FE, 1FZ-FE, 1HZ, 1HD-T, or 1HD-FTE equipped models, nor how the exhaust/catalytic converters/DPF are routed on these non US market models.

I don’t think the issue is so much heat transfer to the transmission, or transfer case. At this point, I suspect that the aftermarket plates have been in use long enough to prove that they do not cause immediate catastrophic failure. If you’re concerned, monitor the temps through a scangauge or similar, and change fluids more frequently.

Maybe it has to do with my time playing with exhaust on Mazda rotary engines, (which do run exceptionally hot, as they tend to send burning fuel out the exhaust) but I’m cautious of putting “melty things” near the exhaust.

Good luck!
"Melty things" love it! I agree with the rotary. The Wankle design does run exceptionally hot. Even more so with forced induction. I appreciate the caution. I will see how this turns out. If it is useless or turns out to retain the heat, of course, it is relegated to the spare parts pile. But I think this would be cost-effective insurance considering how much I just wasted on a truck that was supposedly "baselined" by a member already. I paid the literal price for failing at my own due diligence and would now like to protect my investment so to speak. But not going bananas with steel or aluminum skids. Enough to keep the gravel away from spinning parts would be nice. Because one expensive "mod" begets many more expensive mods as we all well know. The ole "I already dropped a bajillion on this thing so I might as well on this too..." justification comes to mind. Haha, thanks for engaging with me @jLB.
 

jLB

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"Melty things" love it! I agree with the rotary. The Wankle design does run exceptionally hot. Even more so with forced induction. I appreciate the caution. I will see how this turns out. If it is useless or turns out to retain the heat, of course, it is relegated to the spare parts pile. But I think this would be cost-effective insurance considering how much I just wasted on a truck that was supposedly "baselined" by a member already. I paid the literal price for failing at my own due diligence and would now like to protect my investment so to speak. But not going bananas with steel or aluminum skids. Enough to keep the gravel away from spinning parts would be nice. Because one expensive "mod" begets many more expensive mods as we all well know. The ole "I already dropped a bajillion on this thing so I might as well on this too..." justification comes to mind. Haha, thanks for engaging with me @jLB.

Another lightweight cover option that might address your needs, without resorting to proper skid plates:

 

hoser

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This says its for 98-02 trucks. I think I just selected the third on the list of 100 series variants listed on Paatsouq....
View attachment 3142260
@YezusLX

I would be hesitant to buy this splash guard. It is specifically for HDJ100s. The HDJ100's use longer torsion bars as well, the frame and maybe captive nut locations are different. The HDJ 2nd Splash guard is also a different part number than the UZJ. There's a good chance it won't be a direct fit part.
 
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My middle plastic piece (stock skid 2) has two threaded inserts at the rear that look like they line up with the front part of skid three and I bet the rear bolt holes on the skid 3 line up with the captive nuts located on either side of the cross member. In retrospect I should have tried this myself for $210 plus shipping.
 

YezusLX

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@YezusLX

I would be hesitant to buy this splash guard. It is specifically for HDJ100s. The HDJ100's use longer torsion bars as well, the frame and maybe captive nut locations are different. The HDJ 2nd Splash guard is also a different part number than the UZJ. There's a good chance it won't be a direct fit part.
Good to know. I found that when I went to order it and put in my VIN# it does not show up as well. Guess I will go all in on the ASFIR set now. #Sadface
 

GTV

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Good to know. I found that when I went to order it and put in my VIN# it does not show up as well. Guess I will go all in on the ASFIR set now. #Sadface

It’s not going to show up because your rig wasn’t originally fitted with it. It *might* still fit. I’d even go as far to say I’d be surprised if it didn’t. It would definitely be an inexpensive theft deterrent if it does work out, I’d be half tempted myself if the OEM middle plate wasn’t a flimsy composite POS.

Thanks for entertaining the thought y’all. I’m one step closer to pulling the trigger.
 

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