Where is the heat coming from??????

[DrumrBoy]

OK, I'm out of ideas. I have a 98 GTS and the "box" in front of the firewall on the driver's side (the same box that the PCM attaches to) get really hot.

Alot of people mount their VEC2/VEC3 on top of this box and when folks pull into a show (or at a local VCA meet) I generally go over and check the heat on the electronics and that box......its hot but nowhere near as hot as mine gets.

Mine gets hot enough that you can't keep your hand on it (or the PCM) for more than a second. Frikkin' hot.

So....., I thought exhaust leak. Sealed the elbow connector at the collector.....no leak.

Maybe the 5-into-1 collector leaking....switched to belangers, no leak.

Maybe the lower alumiinum heat shield is missing....nope, its there.

So ***? I do not have factory or aftermarket heat shields at the top of the header (near the header/head flange) but never did, and this seems to be a more recent issue.

Interestingly, tha passenger side with the plastic "box" for heat/air, doesn't get very hot....no melting/compromise issues there at all.

Has anyone ever encountered this and know how to address it?

 

[dave6666]

I've noticed that on my car before - living in Texas where it's 110 degrees some days - and I attribute it to heat from the exhaust and air flow out the rear of the hood. If I idle the car for a while sitting there I will notice it. If I pull in the garage and shut the car off I won't. I do have my custom heat shields for my Belangers which cover them very well.

Right in front of the PCM is where I mounted the relays for controlling my 3 fans. I do not use the factory system any more. I noticed when doing some testing work there that the relays were really hot. Enough so to check them again later. And they were not hot after park / cut engine / pop hood.

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[01sapphirebob]

Do you still have cats on the exhaust? A lot of people have said if you get rid of the cats or at least switch to hi flow cats the heat will almost disappear.

OK, I'm out of ideas. I have a 98 GTS and the "box" in front of the firewall on the driver's side (the same box that the PCM attaches to) get really hot.

Alot of people mount their VEC2/VEC3 on top of this box and when folks pull into a show (or at a local VCA meet) I generally go over and check the heat on the electronics and that box......its hot but nowhere near as hot as mine gets.

Mine gets hot enough that you can't keep your hand on it (or the PCM) for more than a second. Frikkin' hot.

So....., I thought exhaust leak. Sealed the elbow connector at the collector.....no leak.

Maybe the 5-into-1 collector leaking....switched to belangers, no leak.

Maybe the lower alumiinum heat shield is missing....nope, its there.

So ***? I do not have factory or aftermarket heat shields at the top of the header (near the header/head flange) but never did, and this seems to be a more recent issue.

Interestingly, tha passenger side with the plastic "box" for heat/air, doesn't get very hot....no melting/compromise issues there at all.

Has anyone ever encountered this and know how to address it?

 

[DrumrBoy]

Bob, thanks.....no-cats, I took them off a long time ago.

Dave, thanks for the comments. Mine is hot hot hot whether I'm idling or pulling into the garage and shutting off. It seems like the box just gets hot and the PCM gets its heat conducted from the box.....I'm thinking I could put a little offset so there's an airspace between the box and the PCM which might help, but that would just address the symptom, not the cause.

One question Dave (on the relay pic)....do any of those relays control a fan that has a role in keeping the box cool? I don't notice any problem overheating or anything else fan-related....

 

[dave6666]

No those relays control the 3 fans on the radiator. Nothing to do with the footwell enclosure. I just had the pic available, and those parts were what made me go damn, those parts sure are hot. It was while I was testing the install and my initial thought was the wires were overheating. Not the case, gotta be heat from that big aluminum thing with the 10 holes in it.

Are you sure this is not just an existing thing that now you've noticed it your mind is creating a problem of it? Just a thought. You know how the mind of a car guy works.

 

[DrumrBoy]

You're right, I'm sure its not a new phenomenon.....I probably noticed it when I started messing with and upgrading the PCM a few years ago....first to a VEC 2 and the to the AEM that I have on there now. Messing around in that area made me notice how hot it got.....and heat and computers don't always like each other.

Once I noticed I began comparison-checking other GTSs to see if they were all the same.....mine seems to be hotter than the rest.

I've never had a problem with it, but I just can't get comfortable with a computer getting so hot you can't keep your hand on it for a three-count! Maybe I'll rig up a big-ass fan to blow directly on the PCM...or put a cool-tank inside the box....

 

[Russ M]

On my car everything was heat wrapped from the turbo's on and it was like that before them also and there is very little heat in the area. Odds are that its caused by all the exhaust heat, just wrap everything except for the header and you will notice a big difference.

 

[KNG SNKE]

Your not the only one. I have my VEC mounted there and even before I was super charged, even before I put full exhaust and even now it gets burning hot there. I posted up a thread about this a long time ago because I know electronics hate heat and I can't for the life of me figure out why the VEC is still functional. I could not physically touch the vec for more then 1 second. It was burning hot.

 

[dave6666]

Material properties play a role in why the side with the AC - made of plastic - feels cooler than the side of the footwell - made of steel.

The thermal conductivity of plastic versus steel is about 400 times less. Steel being the better conductor of heat. Also in play is heat capacity which is how much energy it takes to cause a rise in temperature of that material. Plastic takes 4 times as much energy as metal. So in a like for like setting, the steel takes the heat out of the hot air way better than plastic. But whereas plastic would be deformed at 300 degrees, metal is still OK. So it does have it's limits, but it makes a good insulator compared to steel.

 

[DrumrBoy]

On my car everything was heat wrapped from the turbo's on and it was like that before them also and there is very little heat in the area. Odds are that its caused by all the exhaust heat, just wrap everything except for the header and you will notice a big difference.

This will be my next step. Thanks.

JK about the fan and the cool tank......

 

[2snakes4us]

JK about the fan and the cool tank......

Why not put a aluminum heat sink on it to draw away the heat just like a CPU on a motherboard or video card and a small fan ?

 

[DrumrBoy]

Possibly, but if the heat was originating outside the box, wouldn't the fins do as much to pull heat in as away (you can tell from the question, asked sincerely, that I'm not a thremodynamics genius)

 

[Tom F&L GoR]

The passenger side has the hole in the hood under the speaker grill; the driver side does not. I since used a hole saw and added the hole in the hood under the driver's speaker grill. At traffic stops, with the AC on (or the high speed fan running) I see a lot of heat waves, so perhaps you just need a left side vent.

Nadine posted a nice description a long time ago that included putting weatherstrip on the cut edge. Easy mod, can't go wrong.

 

[RT/ED]

I echo Tom's suggestion regarding cutting a hole under the grill on the drivers side. I did this several years ago and the heat coming out is amazing. No worries with water, been in down pours with no issues.

 

[KNG SNKE]

I echo Tom's suggestion regarding cutting a hole under the grill on the drivers side. I did this several years ago and the heat coming out is amazing. No worries with water, been in down pours with no issues.

No good for VEC users though.

 

[dave6666]

VEC = cave men still do it

SCT = Jetsons

 

[KNG SNKE]

Very few Roe's running SCT and since I don't have a local tuner worth a **** I'll stay with the VEC.

 

[Bird325]

So, if you're not running a VEC, take the chain saw to the driver's side and cut a hole?

 

[DrumrBoy]

Three ideas, thanks folks, I'm gonna try 'em all.

1. Hole in driver's side hood under "speaker' grill

2. Thermotec wrap from 3/2 joint through elbow

3. Offset and insulate PCM from box

#2 will take me a while but I'll report back on the effect of the changes.

 

[dave6666]

Are you actually solving a defined problem here? Is the fact that the footwell area is hot causing any confirmed issues?

 

[DrumrBoy]

I think the problem is defined (PCM picking up conducted heat from the box) but there has been no ill consequence from this problem thus far, if that's what you mean.

It could be that the PCM will be fine forever at 250 degrees (just a guess there) but there may be an issue down the road so I'm figuring dropping the temp on the box (or at least what is transferred to the PCM) couldn't hurt.

If there's a negative consequential effect of reducing the box temp, then I may be doing the wrong thing. I haven't thought of any ill effects of dropping the box temp or insulating the PCM from the box. Is there (or might there be) one?

 

[ViperTony]

So, if you're not running a VEC, take the chain saw to the driver's side and cut a hole?

You could install the Vec cover...I seem to recall Damn Yankee did this but I don't remember who makes the Vec cover.

 

[ViperTony]

Three ideas, thanks folks, I'm gonna try 'em all.

1. Hole in driver's side hood under "speaker' grill

2. Thermotec wrap from 3/2 joint through elbow

3. Offset and insulate PCM from box

#2 will take me a while but I'll report back on the effect of the changes.

Well, my hood is off so I'm going to drill out the hole under the driver's side 'speaker' grill tonight. I can't find Nadine's pictures but if anyone has pics of the process please post. I figure a 3-3.5" hole saw should be about right.

 

[dave6666]

It could be that the PCM will be fine forever at 250 degrees (just a guess there...

I think your guess could be way off. You said you could touch the metal, but not for a 3-count. That would put it below what burns skin, which is 130 F.

In regards to the electronics, a commercial standard is 40 C, or 104 F. The PCM may be in excess of that standard.

WikiAnswers - At what temperature does skin burn

 

[KNG SNKE]

You could install the Vec cover...I seem to recall Damn Yankee did this but I don't remember who makes the Vec cover.

Was made by jmb and no longer produced.

 

[dave6666]

Was made by jmb and no longer produced.

Send me a pic. I'll start production tonight

 

[plumcrazy]

didnt a guy from the NE club do one from plastic or tupperware that looked good too ?

it might have been a CD case

 

[dave6666]

Martha Stewart invades CAAP

 

[plumcrazy]

look here:
http://forums.viperclub.org/rt-10-gts-discussions/597453-roe-vec2-vec3-waterproofing-location.html
http://forums.viperclub.org/rt-10-gts-discussions/591192-waterproofing-vec2.html
http://forums.viperclub.org/rt-10-gts-discussions/588937-waterproofing-vec2-finally-happened-me.html

 

[ViperTony]

JackB made a cover from Sunbrella material: