I would recommend to leave the headers as they are, which is unmodified and let the heat shield do its job. The main reason is that moisture will accumulate between the heater and the heat wrap. Since it has nowhere to evaporate, it will allow the header to rust, regardless of what it is made from.

 

I have wrapped stock headers. Made the engine bay noticeably cooler, and I believe this also helps performance slightly by keeping energy in the exhaust flow (it's not obvious but all the little things do add up when you are normally aspirated). The stock metal heat shield doesn't do any of this, it's just there so nobody gets burned working on a hot engine. I've heard the "moisture problem" discussed before but those hot exhaust pipes dry out the wrap in no time. And hotter exhaust flow helps the catalytic converter work most efficiently which is helpful if you go with a hi-flo cat. People diss this mod but I like it, money and time well spent.

 

I agree this is a useful mod for the 4g69 in keeping cool the underhood componets. I had my oem headers wrapped for a few years until I took it off partly because it was unwrapping at the base anyway. I would like to do it again but the header and dp(maybe even the CAI)with that new lava wrap

 

i like it.... more pictures are good of upgrades and how to's i think would be great for beginners (can't spell) and it would give people a level of how hard something might be... like upgrading your turbo would def be harder than just upgrading your intake.... and in some instances like an eclipse you have to take off the tire and remove the plasctic cover for the underdrive pulley.... simple install if you can change your belts you can change your underdrive pulley.... and another thing i think you missed would be gauges ( to monitor your stuff) and maybe some harnesses if your brining it to the track and def a DOT/FIA approved helemt.

 

I wouldn't recommend this to anyone living in colder areas as the throttle can stick from not being warmed up by the coolant ice can form Inside the TB from humidity, Mix of cold temps, and condensation

Read the first post of this and you will understand http://forum.mazda6club.com/engine-d...nt-bypass.html

 

Uh, what language was he speaking? Lol, looks like I'll reconnect it during the winter...thanks. Ain't hurting, nor apparently helping anything, disconnected during the summer.

 

Hahaha I know right that's like some serious engineering ***t right there

 

As i said before this does nothing :P

This does not make it run cooler you would need extremely low temperatures for the TB to freeze. Get some phenolic spacers for both the TB and IM and you will drastically reduce temperature on that section of the engine bay. That link although informative and providing some nice assumptions it shows zero cooling effects and zero HP. Some people there were saying that 0.26hp is better than nothing and so on and that it's an ok "mod" to do....What OP on the link didn't say is that the Dittus-Boulter he used has a 15-20% error so people over there saying "wow 0.26hp i gotta do this mod" is stupid. Besides the TB gets more heat from the IM doing contact with the head than getting heated from a small coolant line and radiation heat soak from just being were it is.

 

Hey MIVEC...smile, it aint that bad, really, you'll live another day.
And it appears that you didnt catch that, I implied that what you said you said, that you said that the mod didn't do much. I think I butchered that one, lol!

On a side note:
I'm curious what your thoughts are on this. Why would the Mitsubishi engineers decide to use coolant to warm the TB if the IM does a better job? You would think they did done rigorous testing, came up with a problem, and then a solution. Just remember, "I'm not really sure," is a good answer too. And if spacers are elected then leave the coolant lines attached?

 

It's to keep constant flow so no water will accumulate in it and freeze and this would most likely happen if you live in freezing weather.. I can't see it happening at 50f weather since water cant freeze at that temp.. Keep in mind these guys get paid thousands of dollars to think of this stuff there might be another reason why it's all to make the car a more smooth ride so keep that in mind some people might want that .25 and want to risk that chance of the throttle sticking that's up to them..

The spacers seem legit I can see that greatly reducing air temp

 

so I elect spacers... do I leave the coolant lines?

 

make a loop where the throttle body would have been...

 

Well to be fair I did the mod the moment I realized the TB had that line since I never had a car with that system so why start now, obviously i noticed it does crap after but it's not like we have massive winters here

To answer your side note I am a mechanical engineer with 4 credits left on his curriculum. Being one doesn't make you a mod expert or any more of a car expert. There are many members here that are way more car savvy and mechanically inclined than me on that aspect but I do understand all of the technical aspects and theories of internal combustion engines and so on. That link that RacerX posted covers a topic that is my bread and butter...Heat Transfer. To be fair to mitsu's engineers and engineers in general they don't always make things logical to the mod enthusiast or people into performance. They make what the regulations ask and what is safe for a person oblivious to car maintenance and how a car works. If engineers would think like us more and less on how the company and regulations want them too our CMC would be a little bit accessible

What is obvious to you is something that is needed to be made fool proof for the guy behind you. Take the EGR for instance something some say its not necessary but engineers need to put it there for emission issues. Same goes for multiple cats, using electronics instead of drive by wires for TB's, fuel cut off and countless more items or systems that are a pain for performance.

Phenolic spacers work as insulation and depending on the material its made of you will lower temperatures of certain areas of the engine bay. It will not give you HP gains but will allow you to sustain the efficiency you currently have for your engine, less heat soaking and less critical areas working at high temps. With the spacer between the head and IM on some cars you can put your hand on the IM and leave it there and feel nothing....try that with the 4g69 like you have it now.

You use insulation for headers also with the wraps etc etc. Deleting that small flow of coolant is not a bigger factor as insulation.

 

I already did the bypass Crans, per my photos upthread and honestly don't have any intention of using spacers, but I was just trying to understand the "ifs" and "thens" to all of this. Thanks MIVEC for sharing your qualifications for it does let the forum know to whom they are speaking to and whether or not they can put their trust in what you're saying, unlike myself who's forte is NOT engineering, or internal combustion at that. Got any emergency medical questions? I MIGHT be able to answer a few of those...

 

speaking of header, do these look like rrm ones? the guy claims they are but he seems iffy and i know kijiji can be sketchy, thanks in advance for any help http://ontario.kijiji.ca/c-ViewAdLar...AdId=366430111