Kendo11 Posted December 11, 2016 Share Posted December 11, 2016 Quick question. How hot should I expect an aftermarket exhaust manifold to get on my NA? It's an OBX type stainless exhaust manifold. Before anyone says get a probe and check - the car is currently in bits. Just a rough idea would be great so I can look into wrapping/coating etc. Thanks Quote Link to comment Share on other sites More sharing options...
skippyboyo1 Posted December 12, 2016 Share Posted December 12, 2016 when i had my na i had a manifold made which resulted in the heat burning a hole in my re-circulation box after my airbox, i then added bonnet vents and never had aby heat related issues after Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted December 12, 2016 Share Posted December 12, 2016 It'll be hundreds of degrees for sure. Ive got a laser temp probe in the unit mate if you want to check Quote Link to comment Share on other sites More sharing options...
Al Massey Posted December 12, 2016 Share Posted December 12, 2016 May as well wrap it as it's in bits now. Quote Link to comment Share on other sites More sharing options...
Noz Posted December 12, 2016 Share Posted December 12, 2016 (edited) My idle was around 400-450 degrees C when warm. EGT probe on sixth cylinder. Your struggling to get a more accurate measure unless you use a reflective temp sensor gun to check it. A good estimate is the internal gas temp though from the EGT probe Edited December 12, 2016 by Noz (see edit history) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 12, 2016 Share Posted December 12, 2016 Being stainless and probably quite thin, its going to get/seem hotter than a cast manifold simply because it cant dissipate the heat so well due to the mass, but in reality its not going to get any hotter than the equivalent turbo manifold. Quote Link to comment Share on other sites More sharing options...
Kendo11 Posted December 12, 2016 Author Share Posted December 12, 2016 Thanks guys. It'll be hundreds of degrees for sure. Ive got a laser temp probe in the unit mate if you want to check That would be good mate I'll pop it round to you at some point. May as well wrap it as it's in bits now. Thats kind of related to the question - I've seen a few threads online about how wrapping can cause cracking, but then I've also seen a lot of high powered (and hot) cars get things like this wrapped. I was looking into Zircotec coating options but it seems pricey. Quote Link to comment Share on other sites More sharing options...
Kendo11 Posted December 12, 2016 Author Share Posted December 12, 2016 Being stainless and probably quite thin, its going to get/seem hotter than a cast manifold simply because it cant dissipate the heat so well due to the mass, but in reality its not going to get any hotter than the equivalent turbo manifold. Yeah as daft as it sounds it does 'seem' to be mega mega hot but general engine temps seem the same. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 12, 2016 Share Posted December 12, 2016 I would avoid spending too much cash on a cheap stainless manifold, as if it does crack ceramic coat will be wasted, usually cracks in stainless are stress related, so make sure its well braced, and if you want to just wrap it. Quote Link to comment Share on other sites More sharing options...
Kendo11 Posted December 12, 2016 Author Share Posted December 12, 2016 I would avoid spending too much cash on a cheap stainless manifold, as if it does crack ceramic coat will be wasted, usually cracks in stainless are stress related, so make sure its well braced, and if you want to just wrap it. Yeah I see what you mean. Think the ceramic coating would cost three times as much as the actual manifold. Quote Link to comment Share on other sites More sharing options...
David P Posted December 12, 2016 Share Posted December 12, 2016 (edited) The stock cast manifold has a heat shield to prevent such happenings, with the stainless steel jobbies one is not used because it doesn't look trendy. The trendy cure for this is to put the air filter next to it and use induction to extract this hot air into the engine? Edited December 12, 2016 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Shane Posted December 12, 2016 Share Posted December 12, 2016 I am not sure what temperature things start to glow but the cast manifold on my old NA was glowing after a few hours of hard driving down the route de soliel. We popped the bonnet at a service station and i was surprised to see it giving off an orangey glow. Quote Link to comment Share on other sites More sharing options...
Kendo11 Posted December 13, 2016 Author Share Posted December 13, 2016 Just going back to this with a few new ideas - does anybody know for definite what material the stock NA manifold heatshield is made of? Is it steel? Quote Link to comment Share on other sites More sharing options...
Al Massey Posted December 13, 2016 Share Posted December 13, 2016 Do you have one? If so stick a magnet on it. If it sticks, steel, if it doesn't, it's alloy Quote Link to comment Share on other sites More sharing options...
Kendo11 Posted December 13, 2016 Author Share Posted December 13, 2016 No mate, binned it ages ago. I think it's steel just not sure if it's a composite. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted December 13, 2016 Share Posted December 13, 2016 Im pretty sure its an ally sandwich, Ive got a TT one in the unit Quote Link to comment Share on other sites More sharing options...
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