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GWR have a roadstersport catted header just out on which I'm keen but this header has been developed for an LHD car. Looking at the OEM shielded header on the NC, there "looks" to be an couple of cm clearance between the shield(which contains the OEM cat) and the steering shaft.

Now the cat on the new header is down near the flange and there appears to be plenty of room down there in the RHD NC. The steering shaft is up high relative to the exhaust.

My question is anyone who has fitted aftermarket headers , do they not any difficulties with the steering shaft? I am assuming that after market headers require a bit more sideways room.

thank you for any replies which may assist my decision.

(I have also asked similar question to GWR).

cheers
Chris

Chris, your car will still not be legal with this header installed until it does an emissions test.
Brian has suggested that the cat in it will easily pass US emissions except in California.
I'd suggest that the normal RS header will give better performance and later if you wish to pass emissions fit the midpipe with free flowing cats that's being developed here in Oz.

Mazda must have had a reason for the heat shield on the OEM cat...it probably gets very very hot! and an unshielded cat in that area might not be a good move.

FYI I am I retested in the catted roadster sport street header too, I asked them if it would fit right hand drive manual NC1. They replied they have not tested one, but see no reason why it wouldn't fit.

BTW If I was to paint this header flat black, would it look obviously after Adler with no heat shield etc? I'm worried about yellow stickers and insurance problems...

Ollie

I am also interested in the catted header.
It would bring less attention than the non catted header and it may even pass emission testing.
I am watching with interest the development of this.

Sailor wrote:Chris, your car will still not be legal with this header installed until it does an emissions test.
Brian has suggested that the cat in it will easily pass US emissions except in California.
I'd suggest that the normal RS header will give better performance and later if you wish to pass emissions fit the midpipe with free flowing cats that's being developed here in Oz.

Mazda must have had a reason for the heat shield on the OEM cat...it probably gets very very hot! and an unshielded cat in that area might not be a good move.

Rob a couple of questions / observations if I may

1.Any car with the factory header removed and replaced with straight extractors will fail emissions test. And shouldn't pass rego inspection. ??
2.A catted header, albeit with less power gain, would have to come close to passing emissions. California emissions are very strict...but more so than our ADRs? Doesn't the NC have 2 cats? The one on the header I thought was for cold start emission reduction.
3.Who is developing the mid pipe?
4.The cat could be shielded or wrapped? What is the heat going to affect in that area ?

Having asked those questions I might just give the whole idea away and leave the car alone.....and enjoy it for what it is.... 50/50 atmo

cheers
Chris

opilot87 wrote:BTW If I was to paint this header flat black, would it look obviously after Adler with no heat shield etc? I'm worried about yellow stickers and insurance problems...

Ollie

Ollie, I'd look at ceramic coatings over paint. Significant heat reductions

I'll look into ceramic coatings - don't know much about them. My main concern was appearance over heat though, a shiny header will look obviously aftermarket, painted flat black maybe less so.

Ollie

Hmmm wish that they stay shiny.....Mine are shades of blue

I'm actually thinking of ceramic coating my roadstersport headers at the moment. My under hood temperature is getting hot now that it is spring.

Chris Gough is going to try add a double cat on the oem midpipe to pass the emissions. Will be needed for the turbo kits

Sailor wrote:Hmmm wish that they stay shiny.....Mine are shades of blue

Yep mine are blue too. ‘Spose that after 3½ years you’d expect that though.

opilot87 wrote:I'll look into ceramic coatings - don't know much about them. My main concern was appearance over heat though, a shiny header will look obviously aftermarket, painted flat black maybe less so. Ollie

You need to keep the heat shield in place to protect the ABS system and the brake & clutch lines from the heat given off by the headers. There’s a lot of heat.
Also with the shield in place it would take a knowledgeable person to pick that there are non-standard headers fitted.

Here are some under side pics of the RHD NC. Brian Goodwin isn't sure if the catted header will work. but here are the pics.

1. Steering shaft

2.Another view of shaft as it passes the manifold

c

Charlie Brown wrote:You need to keep the heat shield in place to protect the ABS system and the brake & clutch lines from the heat given off by the headers. There’s a lot of heat.
Also with the shield in place it would take a knowledgeable person to pick that there are non-standard headers fitted.

I was under the impression the standard hear shield wouldn't fit with the new catted header? Good if it does. Anyhow looks like there are some questions over if it will work on aus-spec cars. As I don't think there is anywhere that specialises in MX-5's in Perth ( anyone know any good places for works / servicing? ) I think I'll hold off until some clever people have experimented with it a bit more.

Ollie

opilot87 wrote:

Charlie Brown wrote:You need to keep the heat shield in place to protect the ABS system and the brake & clutch lines from the heat given off by the headers. There’s a lot of heat.
Also with the shield in place it would take a knowledgeable person to pick that there are non-standard headers fitted.

I was under the impression the standard hear shield wouldn't fit with the new catted header? Good if it does. Anyhow looks like there are some questions over if it will work on aus-spec cars. As I don't think there is anywhere that specialises in MX-5's in Perth ( anyone know any good places for works / servicing? ) I think I'll hold off until some clever people have experimented with it a bit more.

Ollie

I'm no mechanic, but the top heat shield should be ok, but all the shielding around the OEM manifold probably wouldn't, then there is the issue of where the new header cat sits. There is obviously
room down there for it but will the sensors get in the way of something?

c

LuckyCat wrote:

opilot87 wrote:

Charlie Brown wrote:You need to keep the heat shield in place to protect the ABS system and the brake & clutch lines from the heat given off by the headers. There’s a lot of heat.
Also with the shield in place it would take a knowledgeable person to pick that there are non-standard headers fitted.

I was under the impression the standard hear shield wouldn't fit with the new catted header? Good if it does. Anyhow looks like there are some questions over if it will work on aus-spec cars. As I don't think there is anywhere that specialises in MX-5's in Perth ( anyone know any good places for works / servicing? ) I think I'll hold off until some clever people have experimented with it a bit more.

Ollie

I'm no mechanic, but the top heat shield should be ok, but all the shielding around the OEM manifold probably wouldn't, then there is the issue of where the new header cat sits. There is obviously
room down there for it but will the sensors get in the way of something?

c

The heat shield I was referring to was the top one attached to the body, not the one wrapped around the first CAT. The CAT's wrapped heat shield definitely wouldn’t fit around the Goodwin setup.

If you want I can measure the clearance between the “standard” Goodwin header and the steering shaft. With this information you may be able to get Brian to give you an answer on clearance.

If it helps at all, I've taken these photos in the past with RS headers installed. I've enquired about the new PPE Long tube header but they believe tube #3 comes out farther than the goodwin RS headers and may hit the steering column.

Photos: https://picasaweb.google.com/107028541956969488229/RHDExhaust?authuser=0&authkey=Gv1sRgCKfO89vl5uuDUQ&feat=directlink