That is what I thought.
So will this header effect the emission and if it would pass the smog in Calif.? (Obviously installed with the cats.)
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FS: NSX headers
- Thread starter MR2liter
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That is what I thought.
So will this header effect the emission and if it would pass the smog in Calif.? (Obviously installed with the cats.)
Don't see how headers could negatively effect emissions.
What you are getting is a better flow which should mean better combustion and evacuation of gases from the engine.
Your cats and sensors should take care of the rest.
I have no real world experience with this or testing, just my common sense.
Just my two cents.
Trev
I have 3300 miles on my Sos Refreshed engine and these headers with no problems and it feels good! No fitment problems either!!!
What you are getting is a better flow which should mean better combustion and evacuation of gases from the engine.
Your cats and sensors should take care of the rest.
I have no real world experience with this or testing, just my common sense.
Just my two cents.
Trev
I have 3300 miles on my Sos Refreshed engine and these headers with no problems and it feels good! No fitment problems either!!!
You are right!
My previous car S2000showed that well.
I buy toda's header and that not change anohow emissions vs original header.
Car Like 01-06 Civic TypeR which have catalysator in the header will fail emissions, if you change it to aftermarket header which dont have anomore catalysator with it.
There are two components of passing an emissions test, depending on the state in which you live. One is "are the parts legal?" In California, where about half of the US's sports cars are, you must have CARB approved emissions components. Each change to the engine must be CARB approved. I assume that all exhaust components, other than mufflers, must be CARB approved. If anyone can confirm if headers are a CARB managed component, let us know. It is expensive for manufacturers to get CARB approval - hence one reason why major vendor's stuff is more expensive than the smaller companies stuff which aren't CARB certified. CARB certified stuff says "CARB certified" all over it to help owners pass inspections.
The second is "passing a sniff test". Some states sniff, some don't. Some do it on a dyno, some do it in neutral. Your mileage will vary. Swapping headers should have almost no effect on passing a sniff test since all headers I have seen discussed on this list retain the catalytic converters. Taking your cats off is illegal in most states and should make you fail the sniff test.
There are two types of headers, in the larger sense, also. They are called "long tube" headers and "short tube headers" aka "shortie headers". All headers I have seen discussed on this list are shortie headers - meaning the are the same length as stock components and *retain the catalytic converters*.
Any header that does not retain the cats will be marketed for "off road use only" since it makes the car illegal to not have a cat.
Long tube headers, which do not retain cats, are much longer than shortie headers and cost much more. "Real race cars" tend to have long tube headers and do not have cats.
I hope this helps explain this somewhat confusing subject. But, be confident that all the main headers we are discussing on the various threads are shorties that retain the cats in normal use.
The second is "passing a sniff test". Some states sniff, some don't. Some do it on a dyno, some do it in neutral. Your mileage will vary. Swapping headers should have almost no effect on passing a sniff test since all headers I have seen discussed on this list retain the catalytic converters. Taking your cats off is illegal in most states and should make you fail the sniff test.
There are two types of headers, in the larger sense, also. They are called "long tube" headers and "short tube headers" aka "shortie headers". All headers I have seen discussed on this list are shortie headers - meaning the are the same length as stock components and *retain the catalytic converters*.
Any header that does not retain the cats will be marketed for "off road use only" since it makes the car illegal to not have a cat.
Long tube headers, which do not retain cats, are much longer than shortie headers and cost much more. "Real race cars" tend to have long tube headers and do not have cats.
I hope this helps explain this somewhat confusing subject. But, be confident that all the main headers we are discussing on the various threads are shorties that retain the cats in normal use.
so where are the before & afters?
I went ahead and bought the headers from MR2liter. This install is on a stock 1992 NSX with 142896 miles.
Here are the dyno results. The top line is the "with headers". The bottom line is the "before headers".
These headers added 12hp peak to peak difference. If you look under the power curve, you can see the gain of over 15 hp at 7000rpm. In fact, the gain of 15hp seems to range from 6800 to 7300rpm which is right in the area you need it.
Torque was up 8 ft-lbs at peak. Similarly, it was up more than 8 from 6800 to 7300 and from 5200 to 5900 (approximately).
Here are the dyno results. The top line is the "with headers". The bottom line is the "before headers".
These headers added 12hp peak to peak difference. If you look under the power curve, you can see the gain of over 15 hp at 7000rpm. In fact, the gain of 15hp seems to range from 6800 to 7300rpm which is right in the area you need it.
Torque was up 8 ft-lbs at peak. Similarly, it was up more than 8 from 6800 to 7300 and from 5200 to 5900 (approximately).
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Wow, thats great!
Now lets clarify that you left your cats on as you had before and that the muffler wasn't changed either.
So this is Stock car, header change out only.
Thanks
Trev
Now lets clarify that you left your cats on as you had before and that the muffler wasn't changed either.
So this is Stock car, header change out only.
Thanks
Trev
Confirmed.
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- 8 September 2006
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nice results
bump, anyone else with results?
I believe I bought the first set from Top Speed, but not the first to install them.
I will be taking mine off at the end of the month as my motor is coming out of my car for a few weeks. I will take some pics of the headers again and post.
I have 8,261 km's or 5,131 miles on this set of headers.
I enjoy them with my cats and flowmaster muffler.
Trev
I will be taking mine off at the end of the month as my motor is coming out of my car for a few weeks. I will take some pics of the headers again and post.
I have 8,261 km's or 5,131 miles on this set of headers.
I enjoy them with my cats and flowmaster muffler.
Trev
Good to see actual dyno results of the gains. Makes me wonder how much would be gained if you already have intake and exhaust done, 15+ peak? I think I am planning on getting these headers over the winter if the feedback continues to be favorable.
Yeah they seem like a decent header. I know the fitment question has come up before and the answer was kind of not clear to me so i'll ask again. If I plan to do the install myself, will the headers bolt right on to a 91 nsx. Is the fitment perfect or is there a little fabrication involved?
I have posted so much info and pictures on these headers I don't know if I can type anymore. lol
They just bolted up beautifully, no problems.
Quality is top notch.
If you cant see my posts or pictures or comments just let me know, I'm just working anyways. lol
Trev
They just bolted up beautifully, no problems.
Quality is top notch.
If you cant see my posts or pictures or comments just let me know, I'm just working anyways. lol
Trev
Hi, just to let you know, I took the plunge and bought a set!!!
excellent quality, all the bits to fit, welds are superb, no problems fitting them (apart from battling with rusted 15 year old exhaust fixings) and very pleased with the results. i fitted them myself, with normal tools (get some good 6 point sockets) took about 10 hours lying on my back under low ramps! I did take my time tho!
no idea if the cars faster or not, and not really that interested with the number of speed cameras over here, but it just sounds so much better, more rorty sporty! and that's with stock cats and exhaust.
to be honest, for $600 plus shipping you can't go far wrong. I was all set to chop them up and correct if necessary, but they slotted in perfectly, hooking up to the stock system no problems! the only problem is I have to keep getting on the floor to look at them, they are sooooo purdy!
the O2 extensions fit fine, the front one I re-routed back up to the top of engine under the cover (plenty of length!), then down the back, beside the rear sensor wire trunking. all hooked up without problems, and the O2 sensors are SO much easier to get to now!!!
anyway, enough rambling, just very happy with the product!
excellent quality, all the bits to fit, welds are superb, no problems fitting them (apart from battling with rusted 15 year old exhaust fixings) and very pleased with the results. i fitted them myself, with normal tools (get some good 6 point sockets) took about 10 hours lying on my back under low ramps! I did take my time tho!
no idea if the cars faster or not, and not really that interested with the number of speed cameras over here, but it just sounds so much better, more rorty sporty! and that's with stock cats and exhaust.
to be honest, for $600 plus shipping you can't go far wrong. I was all set to chop them up and correct if necessary, but they slotted in perfectly, hooking up to the stock system no problems! the only problem is I have to keep getting on the floor to look at them, they are sooooo purdy!
the O2 extensions fit fine, the front one I re-routed back up to the top of engine under the cover (plenty of length!), then down the back, beside the rear sensor wire trunking. all hooked up without problems, and the O2 sensors are SO much easier to get to now!!!
anyway, enough rambling, just very happy with the product!
did you feel any gain at all..?
it sounds better, feels stronger. Mine is an auto, but it does seem to pull better,and does build the revs quicker!!!! i did mean to hook up my g-tech pro SS dash dyno thing, but i forgot, too excited about the headers turning up!!!! sorry!!!
with the stock headers next to the new ones, there HAS to be a performance improvement!!!! you can see where i had to cut the rear primary pipe as the manifold bolts wouldn't come off, or were just inaccessable!! and you can see it's double skinned, just what you need when you hacksawing under the car!
and the pics should show what the header actually replaces!
with the stock headers next to the new ones, there HAS to be a performance improvement!!!! you can see where i had to cut the rear primary pipe as the manifold bolts wouldn't come off, or were just inaccessable!! and you can see it's double skinned, just what you need when you hacksawing under the car!
and the pics should show what the header actually replaces!
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Ray, its Trev here in Edmonton.
You are a friend of Alberts I think.
We are getting out tonite at St.Albert Casino if you can join at 6 pm.
I will have my car there with these headers.
Hope you can come. See the post in the Canadian section.
Trev - 953-1744
p.s. Albert has a lift!!!
You are a friend of Alberts I think.
We are getting out tonite at St.Albert Casino if you can join at 6 pm.
I will have my car there with these headers.
Hope you can come. See the post in the Canadian section.
Trev - 953-1744
p.s. Albert has a lift!!!
I'd pick a set up, sounding more and more like a good system to have. I just have to hold off on major purchases until this whole Tamoske fiasco is over... :frown:
it sounds promising and the price is very very reasonable. but i just cant get over the gtone headers... even though the prices are high... just love that sound. wondering what these headers + gtone exhaust would sound like..
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