ACE vs. OEM Header - Temperature Comparison
 

Like many of us, I was curious what would happen to under hood temperatures after replacing the stock header with an ACE Type B 350 header. So, I set about doing some measurements and logging the results.

MEASUREMENT DETAILS:

Before installing the ACE header I installed four Type-K thermocouples in four different locations that I was concerned about - oil pan, ignition coil #1 (due to the failures), and the front roll bar bushing which is close to the overpipe. These thermocouples were left in place for both header installations and all logging that occurred.

http://img.photobucket.com/albums/v6.../Oil%20Pan.jpg

http://img.photobucket.com/albums/v6...%20Rollbar.jpg

http://img.photobucket.com/albums/v6...on%20coil1.jpg

The thermocouples have extremely low mass, and reacted very quickly to air temperature change. That being said, their absorption of radiant heat would be different as compared to the oil pan, ignition coil and the roll bar bushing. So, it is possible that the true temperatures of these components would be different than the measured results. As such, consider these measurements in relative terms, rather than absolute.

DRIVING/LOGGING:

The driving I did consisted of two different runs for each header. One was a simple drive to work with a cold engine, the second was on a closed course consisting of three laps. In both cases there were slight variances that are described in the datazap logs at the links below.

NOTE: The ACE header was installed without any thermal coating/wrapping. The logs were all done at approximately the same ambient temperature (0C +/- 3C). The engine/transmission under panels were installed in both cases.

"Drive to work":
http://datazap.me/u/r2/ace-vs-stock-...data=6-7-17-19

"~Hard driving"
http://datazap.me/u/r2/stock-vs-ace-...-9-11-20-22-24

Conclusions -
I'll let everyone make their own conclusions but a summary of my observations:

-The stock heat shields work quite well to slow the flow of heat into the engine compartment
-The lower mass and lack of shielding of the ACE header caused temperatures to rise and fall faster than the OEM piece
-On average, the ignition coil #1 saw similar temperatures between the two headers, with higher absolute temperatures being seen with the ACE header, and higher average temperatures with the OEM header
-The rollbar bushing temperature was MUCH higher on average with the uncoated ACE "overpipe" as compared to the stock unit. I have since installed some shielding to protect the rubber there.
-Rear oil pan temperatures were on average higher than the front, likely due to more consistent airflow over the front

What are your thoughts?

Wrap or ceramic coating. Always do it. Dont skip on the save money idea on this wrap vs that. Quality will ensure the longeivity of not only that part, but subsiquent parts effected by the radating heat; i.e. those bushings.

I love to see real data.
I do think a better question would be the difference with a coating and or wrap as that would be a more normal install.
Keep up the good work. More data the better.

Based on my understanding of why wrap is bad for headers, Isn't ceramic outer coat just as bad? I have this idea about just coating the inner surface. Seemed like an ok place to bring it up.

I mean... Did you expect to see anything different? LOL Get it ceramic coated, or better yet jet-got coated, then retest. It would be interesting to see a ceramic/jet-hot vs. stick compairisin.

Wrap isn't nearly as bad as the interwebs make it out to be... It's bad if you want your header to only last ten years instead of fifteen.

I wouldn't mind getting an extra 5 years out of a $1700 piece of hardware, especially if they're no longer available in 9. :D

But I get what you're saying.

That's why you ceramic coat or furnace paint first... Some sort of sealant to keep whatever moisture your wrap holds to the header from causing rust.

Wrap is pretty cheap but a coating can be a couple hundred dollars

I absolutely love information like this, thank you for all your hard work!

I would also be interested in seeing temps on a coated header versus stock. Are you planning on any more testing?

I think swain tech white lightning is the best coating. When I finally can afford an ACE header, I will coat it and wrap it. Wrap holds moisture against the raw metal leaving it exposed to risk of oxydation. If you ceramic coat and wrap a header you should be fine. Ceramic coating acts as a complete seal against the elements. If you manage to find a place that doesnt include coating the inside of the header along with the exterior, walk out and don't look back.
White lightning is a real ceramic coating, and not a blend like most powder coaters use.
I've used wrap on mild steel headers with only some BBQ high temp paint, and they've lasted 5+ years and showed no sings of wear when I sold them off.
I also have done ceramic coating from www.performancecoatings.com with wrap on high HP rotary builds that showed zero signs of wear after years of daily driving in Seattle, of all places.

Good research ! :thumbsup:



humfrz

I plan to reinstall the thermocouples this summer and do some logging during auto-x this summer to see how hot things get. I know it was unbearably hot after a 2 minute run under the hood with heat radiating off the OEM header. In a perfect world I would have measured things then but didn't have the equipment to do so.

I'm also thinking of protecting the accessory belt from radiant heat. So, I have plans to build a small aluminum shield to protect the lower belt pulley and also do some before/after measurements.

I think that everyone agrees that a thermal coating is the best solution and I would love to do a comparison to see the results. As an alternative, after some logging during auto-x in a few months I might find temperatures to be too high for comfort and wrap the header then. We will see this summer.

Remember that the OEM header also has a cat, which retains a TON of heat.

Since there's interest, if anyone is willing to do this kind of thermal testing with the ceramic coating CSG offers, we'll be willing to offer you a rebate or store credit when your data is posted. PM me directly to purchase and claim.

R2: Define "best". Wrapping imho isolates temps a bit better, and is cheaper. Coating might be better for long-term keep. No coating/wrapping might be better if you invest money into something with better returns for buck. No clear "best" in all possible ways, to each his own.