Max exhaust temp for downpipe / Which jet-hot coating to get?
 

I've been searching like mad, but have been unable to find the exhaust temp upper limit through the downpipe. Does anyone know?

I found a posting here that said that 1600F coatings will suffice for a downpipe:
http://www.fd3s.net/polishing.html
(just search for 1600F and you will find the specific mention easily)

I'm planning to go the jet-hot route to coat a new DP from rx7-store, but need to decide which jet-hot coating will work.

The choices:
1) Sterling Silver
- up to 1300F, after which it fails. So no go! :mad:
- color: matte black, blue and cast-iron grey

2) Extreme Sterling MC-15
- up to 1450F without discoloration
- after 1450F, coating will become dull/grey
- after 1700F, coating will blister/flake off
- same corrosion resistance as the Sterling Silver :D
- slightly better insulation qualities that Sterling Silver :D
- color: slightly duller finish than sterling silver; some texture & orange peel look

3) Jet-hot 2000
- up to 2450F (2400F accoridng to e-mail info) :D :D
- does not provide as much insulation as other coatings :(
- color: flat black,blue or grey finish; gritty texture on outside


Question is .....
Anyone with long-term experience on Jet hot MC-15 or 2000? Especially MC-15?

My first choice is MC-15 but I am wondering how uniform the dull/greying is on the DP? I know Jet-hot 2000 will survive the temps but my priority is getting the best insulation out of the pipe.

Car is a 94 FD completely stock, no plan for power mods and starting on the reliability mods. DP is the 1st thing I'm doing.

I went with mc15 it looks good after 1,000 miles.

get 2000 and wrap her:)

Friend had his headers coated in his ls1. After about a year coating was chipping and headers had rust.

Read posts #10 and #11, and PM Rich (GoodfellaFD3S) for more details :icon_tup:

https://www.rx7club.com/showthread.php?t=635221

PM paximus here on the forum
he works for HPC and could probably get you a good deal on your coating and let you know what would work best

Good to know, any discoloration?

Decided to coat vs wrap, not do both :)

What kind of coating, was it jet-hot?

Just PM'd him .... I wonder if Rich does his own coating now? Hmmm ....

Thanks, will do that.

Will check with him, thanks.


If anyone has anything else to add please do. I am still wondering how hot exhaust temps are at the DP. I know in some cases, people have commented on coating failure without mentioning the coating type, that is why I'm not ruling out Jet-hot at this time. I know the regular sterling silver 1300 will fail, but the MC-15 might be ok.

paximus inbox is full. :(

i went with jet hot also and i do remember them giving a

No-Nonsense, Simple Warranty Life-Time Rust-Through Protection. Jet Hot backs its coatings with a life-time guarantee against rust-through on new components when all exposed surfaces of the part have been coated with Jet-Hot. If the metal beneath the coating rusts through, we will repair and recoat the par at no charge. 3yr Guarantee of Satisfaction. If you are dissatisfied with Jet-Hot within 3 yrs from the original date of purchase, we will recoat the part at no charge one time with the same coating originally specified.

from the warranty card .

Lifetime > 3 years
:)

which coating did you use? how long since, how many miles? and how does your dp look?

MC-15

only about 2000 miles so far


Great!
but you now looks are just a small thing.
its been shown that jethots coatings are less than half the temps so it should free up some horsepower just from decress in engine and engine bay temps!!

they also can coat in different colors. if im not mistaken.

Jet Hot backs its coatings with a life-time guarantee against rust-through on new components when all exposed surfaces of the part have been coated with Jet-Hot.

so lifetime for rust through protection

3yr Guarantee of Satisfaction. If you are dissatisfied with Jet-Hot within 3 yrs from the original date of purchase, we will recoat the part at no charge one time with the same coating originally specified.

3 years is a long time!!

bryant, thanks .... I am honestly looking at the MC-15. It's actually quite affordable compared to some of the other coating costs out there, and it looks like it will withstand the temps of the FD dp (which at this point, I still don't know how hot they get).

I'll have to decide soon, as I am planning to put the DP in BEFORE i start driving this summer, so time's ticking.

How many feet did jet-hot use for their cost calculation to coat your dp? Just trying to figure out an estimate of what MC-15 will cost.

it was 15.00 per foot for 3" diameter tubing and 10% discount for ordering online.

Find the post by "Carlos A. Iglesias" on this page.

For the lazy bums:

From: "Carlos A. Iglesias" (Rotary@san.rr.com)
Sent: 01 January, 2001 10:03 AM

Here's a couple of personal observations about durability of coatings. Sorry, no quantitative performance numbers:

TURBOS: Fagettaboutit ! Between my Jacksonville amigo, Dean Colver and I, we've now gone through three different attempts to coat the turbos exhaust sections, and none of the (hi temp) coatings have come close to standing up to the heat. They all disintegrate within a couple of thousand mile. This includes BCE's Stainless Ceramic and Swain's White Lightning on my car, as well as JetHot 2000 on Dean's car. That adds up to well over a $1000 is coating failure, so if I ever find the a coating that holds up to our turbo rotary infernos, I'll be it's unrelenting herald in the RX-7 community.

ROTOR FACES: After on approximately 5k miles, Swain's "piston" Coating had moderate flaking on most of the rotor faces. The part that stays on is good for cleanup, but personally, I'd rather spend the $350-$400 that Swain would charge on upgrading my oil coolers or radiator. Atleast I know that that will last.

DOWNPIPE/MIDPIPE: 1600F coatings are sufficient. The White Lighting is VERY thick and provides the best barrier here.

TECHLINE COATINGS: I've used the DIY Cermakrome coating extensively on none exhaust exposed components, and I am very happy with it. I've even used it on the turbos heatshields, and it has help up In my eternal optimism, I've ordered their 2000F Black Satin to try on my new turbos. Atleat at $50, there is little to loose. They also have a special "extreme heat" coating call MCS that they only sell to professsionals, but if this Black Satin falls by the wasteland of the rotary inferno, I may try to convince them to sell it to me. I think my ability to promote the product would make it worth their while.

NON-EXHAUST: If you're looking for a professionally applied, hi polish coating that is not part of the exhaust system, I'd recommend BCE or Airborne. Both have ceramic coatings with near chrome finishes.

That was linked in my first post, reference to the 1600F coating ... however, the post was over 6 years ago. I reckoned it was time to revisit this matter, with latest and greatest. Surely coatings have evolved since then.

Oops! I'm sure that Carlos made a newer post here with more info, but it's not turning up in my searches. IIRC, he said the Black Satin (2000-degree rated) held up on the manifold.

I found it! (Rynberg's comment about search not working prompted me to try Google.)

Anyhow, this is Carlos' killer post. The rest of the thread is probably worth reading as well.

:D

Thanks Eggie.

No problem. I thought I was going crazy when I couldn't find that post, so win/win!