Smart Header for the 451 - Page 2

Doug Thorley Headers · 12-12-2008, 12:39 PM

It will more than likely throw a CEL but it will not affect driveability or mileage. We will be working on a simm soon. As far as noise goes we tested one with the stock exhaust and it actually sounded pretty mellow and sporty. Again, this is a true bolt on header that does not require any modification and all the stock components can be easily reinstalled if needed.

Thanks

mendo · 12-12-2008, 01:24 PM

Cool, Thanks!

lowndex · 12-12-2008, 07:15 PM

Anyone able to post the graphs big enough to read?

mendo · 12-12-2008, 11:50 PM

it would be great if they posted the numbers,
We all love DATA!!

lowndex · 12-13-2008, 06:41 PM

Quote:

Originally Posted by Doug Thorley Headers

We have just finished prototyping a header for the 451. It is designed to be a bolt on application that will work with either the stock muffler or one of our after market ones. These are race applications only and are not smog legal. Our first run has already been sold to Smart Madness so you can contact them to get your car ready to go do some autocross events. The header is a stepped header, unlike most other headers out there that uses a standard size tube to the collector, we really went all out and started with a smaller primary tube and then stepped it up a size even before the collector. This gives the exhaust the best possible performance. I have attached a picture to show what it would look like but keep in mind this is a prototype and it is not shown in ceramic coating. Speaking of ceramic coating, that is the only way they will be sold, so that we keep the temperatures down to a minimum.

A few issues/questions:

* Will this product be sold from DTH or from SmartMadness only?

* Please publish the dyno graphs in pdf form so we go blown them to read easier.

* If I mate the product with my DTH dual-tip exhaust, how much louder is the exhaust note than present? Basically, how loud is this puppy? Can I use it, illegal or not, for everyday drivng? Or is it too loud for around town (like Smartuki).

GHammerly · 12-14-2008, 11:29 AM

Quote:

Originally Posted by lowndex

* If I mate the product with my DTH dual-tip exhaust, how much louder is the exhaust note than present? Basically, how loud is this puppy? Can I use it, illegal or not, for everyday drivng? Or is it too loud for around town (like Smartuki).

Should be louder, I know the catalytic converter really helps to reduce the noise level, my Miata had a hollowed catalyst and after installing a new aftermarket one noise came down a bit.
It is illegal to use aftermarket headers on public roads, even more illegal without a catalyst especially in California. If you do this you will have to swap to the OEM exhaust manifold that incorporates the catalyst before each emissions inspection, not a problem for some people.
Personally I don't like to drive around without a catalytic converter stinking up the air, you could use this header and rig up a custom installation of a catalyst and muffler, this way it would burn dirty for a little longer on cold start but would be just as clean afterward.

lowndex · 12-14-2008, 12:21 PM

Quote:

Originally Posted by GHammerly

Should be louder, I know the catalytic converter really helps to reduce the noise level, my Miata had a hollowed catalyst and after installing a new aftermarket one noise came down a bit.
It is illegal to use aftermarket headers on public roads, even more illegal without a catalyst especially in California. If you do this you will have to swap to the OEM exhaust manifold that incorporates the catalyst before each emissions inspection, not a problem for some people.
Personally I don't like to drive around without a catalytic converter stinking up the air, you could use this header and rig up a custom installation of a catalyst and muffler, this way it would burn dirty for a little longer on cold start but would be just as clean afterward.

I doubt the stock cat will work - waste much of the power gained from the custom header. What we need is a full exhaust system: manifold to exhaust to hi-flow cat to hi-flow muffler to tail pipe. I have such a system on my Mercury Marauder, which benefited significantly from the $2K plus investment.

SmartTech · 12-15-2008, 11:08 AM

i can answer a few questions.
the header will be available from any vender that wants to sell it, not just smart madness (i have few on order now)
with this hear there is no cat in the exhaust system, ie it is not street legal. how ever you can always put the cat back on when it comes times to pass emissions very easily.
as for the dyno graphs i will make a pdf version and post it on my server when i get a copy from DTH.
the header does have sports for both o2 sensors, how ever the rear or down stream one will registar the cat is inefficient and will throw a CEL eventually. DTH is working on fix for this but it may or may not happen, just they they are working on it.