Discussion
Right, now that the cooling issues are getting under control, I'm looking to reduce the under canopy temperatures as at the moment, the high temps. causes the throttle butterflies to stick and I'm even getting fuel vapourisation!
The way I see it, I can add additional vents to the canopy (scary, but have just ordered some vents to do this which look good) which force air in on the move and help let the hot stuff out when stationary.
Also, I'm considering wrapping the headers. I've been put off this in the past as I've heard that it can prematurely weaken the welds? It's also a shame to cover up all that nice stainless! There's two styles or wrap available, the traditional stuff and some 'sleeves' which clip around the headers. These are a looser fit (don't look so good) but maybe these are better for the metalwork?
Any suggestions/advice?
The way I see it, I can add additional vents to the canopy (scary, but have just ordered some vents to do this which look good) which force air in on the move and help let the hot stuff out when stationary.
Also, I'm considering wrapping the headers. I've been put off this in the past as I've heard that it can prematurely weaken the welds? It's also a shame to cover up all that nice stainless! There's two styles or wrap available, the traditional stuff and some 'sleeves' which clip around the headers. These are a looser fit (don't look so good) but maybe these are better for the metalwork?
Any suggestions/advice?
Chris
In this photo, notice what VanDiemen did with the louvers on the exhaust side of my F2000, one high, and one low.
http://home.attbi.com/~rosenracing5/wsb/html/view.cgi-photo.html--SiteID-718010.html
Hope this will be of some help.
Jack
In this photo, notice what VanDiemen did with the louvers on the exhaust side of my F2000, one high, and one low.
http://home.attbi.com/~rosenracing5/wsb/html/view.cgi-photo.html--SiteID-718010.html
Hope this will be of some help.
Jack
What about getting the exhausts ceramic coated?
I got a quote last week for getting my s/s headers done inside with the black TLHB coating and outside with Cermakrome and the silencer boxes done with Cermakrome on the outside only - £345+VAT or so. Might set you back a bit more to have yours cleaned as my exhausts are still unused
Don't exhaust wraps act like big tea cosies and keep the heat in for ages?
I got a quote last week for getting my s/s headers done inside with the black TLHB coating and outside with Cermakrome and the silencer boxes done with Cermakrome on the outside only - £345+VAT or so. Might set you back a bit more to have yours cleaned as my exhausts are still unused
Don't exhaust wraps act like big tea cosies and keep the heat in for ages?
davefiddes said:
What about getting the exhausts ceramic coated?
I got a quote last week for getting my s/s headers done inside with the black TLHB coating and outside with Cermakrome and the silencer boxes done with Cermakrome on the outside only - £345+VAT or so. Might set you back a bit more to have yours cleaned as my exhausts are still unused
Don't exhaust wraps act like big tea cosies and keep the heat in for ages?
Got mine (mild steel) coated internally and externally by www.camcoat.u-net.com
Did an excellent job, TLHB on the inside and satin black on the outside. Have yet to run engine yet so can't give an indication as to how much cooler they would be (I have an infra red temp reader thingy to check)
A year with a TVR has convinced me that I will never have another glassfibre car without coating the exhausts...
BTW I believe they can't coat manifolds internally once they have been used. I think the carbon on the inside tops the coating from sticking. Not sure if you could clean them well enough. Drop them an email - they very helpful.
>> Edited by bogbeast on Thursday 19th June 18:51
Ceramic coating the exhaust headers will reduce the surface temperature by about half. According to Car Craft Magazine from about 500 deg F to about 240 Deg F.
Many ZR1 owners I know coated their stainless headers to reduce underhood temp.
Wrapping them is good for race cars where you replace headers every year.
jeff schwartz
Many ZR1 owners I know coated their stainless headers to reduce underhood temp.
Wrapping them is good for race cars where you replace headers every year.
jeff schwartz
Dear Stig,
My Toyota Supra headers and turbocharger become red or even orange after extreme boost.
I wrapped them with the same fiberglass tape you used on coolant pipes.
Exhaust gas temperature is up to 800+ Celsius.
It’s common in turbocharged world.
Welds are still in good condition.
My Toyota Supra headers and turbocharger become red or even orange after extreme boost.
I wrapped them with the same fiberglass tape you used on coolant pipes.
Exhaust gas temperature is up to 800+ Celsius.
It’s common in turbocharged world.
Welds are still in good condition.
I've heard of moisture getting under header-wrapping and causing the metal to corrode, but nothing about welds in particular. Stainless should last pretty long, but even stainless will eventually corrode if exposed to dirty water long-term, esp. salty sea water.
Perhaps some sorta exhaust-coating or -wrapping (or at least -shrouding), BUT... Also perhaps heat-wrapping your fuel-lines, and -- if everything that needs to keep cool, from approx the height of the headers and upward, is BETWEEN the headers -- what about using heat-shield material supported by a structural plastic sheet (available at home-construction stores, up to approx 1/4" thick), one over each head and roughly triangular-shaped (cut to reach the firewall & contour along the inside of the rear clip, and not block the 6 vents alongside the overhead-scoop), so that the cool air from the Ultima's overhead-scoop keeps everything in there cool, plus gives even more of a ram-air effect on your airfilter? Basically, a massive cold-air box, with small outlets along your blower's belt, etc.
>> Edited by jhr8 on Sunday 22 June 09:00
Perhaps some sorta exhaust-coating or -wrapping (or at least -shrouding), BUT... Also perhaps heat-wrapping your fuel-lines, and -- if everything that needs to keep cool, from approx the height of the headers and upward, is BETWEEN the headers -- what about using heat-shield material supported by a structural plastic sheet (available at home-construction stores, up to approx 1/4" thick), one over each head and roughly triangular-shaped (cut to reach the firewall & contour along the inside of the rear clip, and not block the 6 vents alongside the overhead-scoop), so that the cool air from the Ultima's overhead-scoop keeps everything in there cool, plus gives even more of a ram-air effect on your airfilter? Basically, a massive cold-air box, with small outlets along your blower's belt, etc.
>> Edited by jhr8 on Sunday 22 June 09:00
jhr8, stainless is a hard material, and is known to crack under high vibration and heat. So wrapping the headers is not good on Stainless system as it will increase the heat in the tubing. Was told that if the thickness was less than 1.5 mm (16G) then not to do it. What's hard is also Brittel.
Ok, FINAL, FINAL edit: #1 There are many stainless steels, each with varying hardness. The required wall-thickness for the header would therefore be a Variable until you figure out what type/grade (of stainless) Ultima supplies, not necessarily "16g," nor any other Constant number. (But see also #3, for why *hardness* shouldn't even have much to do with wall-thickness.)
#2 Higher hardness is GOOD for not developing surface cracks (which vibration then exploits and opens-up until the metal fails). This is why most construction equipment is case-hardened. So I'm also not sure what prompted you to say that high hardness is the quality that's detrimental, or even very relevant (short of using something as brittle and *weak* as glass; BUT, for "brittle's" relevance to METAL: see #3 (why metals are different from all other materials, in that only metals are "DUCTILE") as well as my next post, and for "weak" see #4...
#3 Hardness has everything to do with wear, but little to do with strength. Note that for metals, *ductility* is the quality which is related to fractures, not hardness/brittleness. Therefore, I'm also perplexed as to why you related hardness, but not strength & ductility, to how thick the tubular walls must be??
i.e., The only relevance of hardness I can think of, is that artificial hardening (heat-Tx) of a ferrous metal will weaken it to get the increased hardness -- BUT the most popular grade for car exhausts, is grade 409, ferritic** and hi-temp (**A magnet would stick to it.) -- AND THIS GRADE CANNOT BE HEAT-TREATED (HARDENED). So what are you saying is the relevance of higher-than-norm hardness to stainless headers??
#4 I don't like wraps on ANY header, and think a metalic-ceramic like JetHot inside and out is best. But how much choice does he have?? There's:
Remove the headers, pay for an acid-bath (even if JetHot, etc. say that'll work...), then pay hundreds
OR
- a lot less time and cost.
If this were being done for power, I'd go for the Jet-Hot (IF possible...). But since he said underhood temps, I'd go with the wraps, but that's just my opinion...
>> Edited by jhr8 on Thursday 26th June 09:02
>> Edited by jhr8 on Thursday 26th June 09:27
Aha, "What's hard is also Brittel". Is this what we in the States would spell as brittle? The capitalization threw me at first, making me think you meant a trade-name for a material. That, combined with the "el" at the end REALLY threw me (either those wacky Brit spellings or a typo, but anyway...)
Their strengths and ductilities are nearly identical, but stainless doesn't lose *as much* strength as most other steels under high-temp conditions. You might have to do cyclical testing to make sure which steel is worse (or hold a Ph.D.), but look at it this way:
- both mild and stainless are often used in exhaust systems, with stainless being more expensive because it's a material that lasts longer (in any conditions)
- add the excess heat of heat-wrapping, which is even more heat than a normal exhaust sees; now mild steel loses more strength at hi temps than s/s loses, so which should be worse to cover with heat-wrap?
To anyone who already read: Sorry for the edits even after I caught the drift of this last sentence from Clive; I was figuring no one was awake, but forgot I'm on a mostly-Brit site! And nevermind the sets of #'s that were above; I got one set wrong, in my rush to revise the post!
>> Edited by jhr8 on Thursday 26th June 09:20
>> Edited by jhr8 on Thursday 26th June 09:40
Their strengths and ductilities are nearly identical, but stainless doesn't lose *as much* strength as most other steels under high-temp conditions. You might have to do cyclical testing to make sure which steel is worse (or hold a Ph.D.
), but look at it this way: - both mild and stainless are often used in exhaust systems, with stainless being more expensive because it's a material that lasts longer (in any conditions)
- add the excess heat of heat-wrapping, which is even more heat than a normal exhaust sees; now mild steel loses more strength at hi temps than s/s loses, so which should be worse to cover with heat-wrap?
To anyone who already read: Sorry for the edits even after I caught the drift of this last sentence from Clive; I was figuring no one was awake, but forgot I'm on a mostly-Brit site! And nevermind the sets of #'s that were above; I got one set wrong, in my rush to revise the post!
>> Edited by jhr8 on Thursday 26th June 09:20
>> Edited by jhr8 on Thursday 26th June 09:40
Stig:
Just like jschwartz said, wrapping the headers will reduce temps, but the life of your headers will be reduced greatly. All of the local on and off road racers here wrap thier headers (to produce more power) but they have to replace the exhaust every year.
Check into coating (inside and out) before wraping. Besides that ss is just too pretty!!
Just like jschwartz said, wrapping the headers will reduce temps, but the life of your headers will be reduced greatly. All of the local on and off road racers here wrap thier headers (to produce more power) but they have to replace the exhaust every year.
Check into coating (inside and out) before wraping. Besides that ss is just too pretty!!
Gassing Station | Ultima | Top of Page | What's New | My Stuff