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FS: NSX headers
- Thread starter MR2liter
- Start date
Is it fair to assume that with a Manual tranny we may see 20-25whp improvement and a little more TQ as well?
I would assume you would not achieve that much h.p. from headers only.
I would assume you might reach that with headers and an exhaust system.
It is assumed and might even be proven somewheres on here that removing the cats and replacing with test pipes will only gain you 1-2 hp if that and also give you a smelly exhaust!!! lol
Thats all I really know as of Oct 1/2007. Besides I'm only 46.
Trev
I would assume you might reach that with headers and an exhaust system.
It is assumed and might even be proven somewheres on here that removing the cats and replacing with test pipes will only gain you 1-2 hp if that and also give you a smelly exhaust!!! lol
Thats all I really know as of Oct 1/2007. Besides I'm only 46.
Trev
- Joined
- 8 September 2006
- Messages
- 74
Trev is right. I would say that 20-30whp is possible with a full exhaust. I would also suggest keeping your cats in tact for more back pressure.
the dyno's for the most part speak for themselves and look great.
I'm more worried about longevity...since it isn't a ball and socket design i'm wondering if these header's will be more prone to cracking say after 20K miles... I've read of DC headers having cracking issues
do you have close up pictures of the welds?
I'm more worried about longevity...since it isn't a ball and socket design i'm wondering if these header's will be more prone to cracking say after 20K miles... I've read of DC headers having cracking issues
do you have close up pictures of the welds?
I was wondering, why did you remove them???
Probably because he broke the front engine mount.
Had to do a little work so thought I would take pictures a I like toooooooo!!!!
Trev
Trev
If you got me a better price, I'd be willing to do a DYNO, on my low mileage 91 with ARK DTS Exhaust and AIS/Unifilter Intake. :smile:
How about a group buy?
I will be getting these soon for my 91 how much is an exhaust setup? are you guys on ebay? i thought i saw these?
- Joined
- 29 May 2007
- Messages
- 439
Are these an equal length header? I noticed that the Fujitsubo headers appear to produce more power as do the Cantrell headers. However, since my car is supercharged would the power differences between headers be lessened or amplified? For example, on normally aspirated car Header A makes 10 more HP than Header B. On supercharged car does Header A and Header B make the same power? Or does Header A now make 20 more HP than Header B?
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I will try to answer the best I can.
I was going to measure my header tubes Friday morning but got too busy at work, so its funny that you should ask about this question. I do believe and will confirm that these headers are equal length. I'm dam sure of it!
I haven't seen any side by side exacting dyno test's that prove one header is better than another on the stock 91 nsx.
I have seen individual tests and nice gains.
Try looking at Science of Speeds header section.
You will see that all the headers show great gains with a free flowing exhaust.
You should expect to see 20 hp or more which is great.
It would be great to have all major headers at one shop with one car on the same day and with cats left on and one muffler, like a comptech used for all sets of headers. Now that would be testing and we can have discussions from there about who's is best or better at what rpm range. But for now, we have to guess and have long discussions about what we think.
For around 700.00 to get these headers, you should do ok.
Then again, who knows, til the next discussion or thread starts.
Post in the Forced Induction section maybe and see what the boys think over there about which header worked best for them so far. Its all relative though unless you use the same car and just swap out the headers and leave all the rest the same.
Hope this helps. My headers are still on the shelf for a month or so, so if you want any details or measurements or anything, just let me know.
Trev
I was going to measure my header tubes Friday morning but got too busy at work, so its funny that you should ask about this question. I do believe and will confirm that these headers are equal length. I'm dam sure of it!
I haven't seen any side by side exacting dyno test's that prove one header is better than another on the stock 91 nsx.
I have seen individual tests and nice gains.
Try looking at Science of Speeds header section.
You will see that all the headers show great gains with a free flowing exhaust.
You should expect to see 20 hp or more which is great.
It would be great to have all major headers at one shop with one car on the same day and with cats left on and one muffler, like a comptech used for all sets of headers. Now that would be testing and we can have discussions from there about who's is best or better at what rpm range. But for now, we have to guess and have long discussions about what we think.
For around 700.00 to get these headers, you should do ok.
Then again, who knows, til the next discussion or thread starts.
Post in the Forced Induction section maybe and see what the boys think over there about which header worked best for them so far. Its all relative though unless you use the same car and just swap out the headers and leave all the rest the same.
Hope this helps. My headers are still on the shelf for a month or so, so if you want any details or measurements or anything, just let me know.
Trev
Well I just measure each runner roughly with a peewee tape measure.
Not rocket science but as close as I could do without straightening each pipe out, its not going to happen guys!
Back
Cylinder #1 is 36.5"
Cylinder #2 is 35.5"
Cylinder #3 is 36.5"
Front
Cylinder #4 is 33.5"
Cylinder #5 is 33.5"
Cylinder #6 is 34.5"
So they are close in groups.
Once again this was done with a peewee tape and not measured down the center of each pipe.
So what good is it? Don't know but interesting.
Trev
Not rocket science but as close as I could do without straightening each pipe out, its not going to happen guys!
Back
Cylinder #1 is 36.5"
Cylinder #2 is 35.5"
Cylinder #3 is 36.5"
Front
Cylinder #4 is 33.5"
Cylinder #5 is 33.5"
Cylinder #6 is 34.5"
So they are close in groups.
Once again this was done with a peewee tape and not measured down the center of each pipe.
So what good is it? Don't know but interesting.
Trev
If you want to get really anal about it, try measuring the volume of each primary tube. You could seal the flange end of the header. Then, use a tube or funnel to fill just one of the pipes. Measure how much fluid went in. Then, repeat.
The way gasses move through headers is complex. Equal length is but one factor. Typically, equal length gives the engine a higher absolute peak output but not necessarily more torque overall.
And length and diameter are also important, as is volume, the number of bends, internal friction, how efficient the collector is, etc, etc. In fact, because it is so complex, the only measurement that really can be shown to determine if one header is better than the other is power output over a wide RPM range.
As far as I know, there haven't been discussions (at least lately) on where the NSXes peak torque output should be, either. It could be that an engine that has a peak of 260rwhp at 6000 rpm is faster/quicker than one with 262rwhp at 6800rpm. (or vice-versa - I just made that up.) When analyzing the last few hp, the exact shape and peak of the torque curve becomes more important than simply peak power output.
The concept of "area under the (power) curve" is most important.
YMMV
The way gasses move through headers is complex. Equal length is but one factor. Typically, equal length gives the engine a higher absolute peak output but not necessarily more torque overall.
And length and diameter are also important, as is volume, the number of bends, internal friction, how efficient the collector is, etc, etc. In fact, because it is so complex, the only measurement that really can be shown to determine if one header is better than the other is power output over a wide RPM range.
As far as I know, there haven't been discussions (at least lately) on where the NSXes peak torque output should be, either. It could be that an engine that has a peak of 260rwhp at 6000 rpm is faster/quicker than one with 262rwhp at 6800rpm. (or vice-versa - I just made that up.) When analyzing the last few hp, the exact shape and peak of the torque curve becomes more important than simply peak power output.
The concept of "area under the (power) curve" is most important.
YMMV
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