The best headers

[mikeycamp28]

So I'm looking into headers for my car and I'm not sure which ones would go best with my rpi catback. looking for the best sound note and best performance gains, any feedback would be great guys

[Someone?]

Stock headers are awesome, youll want to do a primary cat delete X pipe or test pipes, but you sure dont want to change headers.

[the_road_less_traveled]

The price for headers far exceeds the reward, if anyn over stock headers.

[Bx Tpr]

Originally Posted by Dashman

OEM

Equal length headers with spiked collectors from the factory. OEM wins.

[SouthShoreM3]

I don't know if you guys saw ACMs post about a SC M3 and the schniedmann (spelling) headers. For their cost, thy made good gains with the S65 SC.

[Dave07997S]

Originally Posted by SouthShoreM3

I don't know if you guys saw ACMs post about a SC M3 and the schniedmann (spelling) headers. For their cost, thy made good gains with the S65 SC.

That is on a 600+rwhp S/Cd motor...that was also retuned for the headers. For normally aspirated S65s until you are pushing 500rwhp OEM is by far the best.

Dave

[THE-FN-MAN]

Originally Posted by mikeycamp28

So I'm looking into headers for my car and I'm not sure which ones would go best with my rpi catback. looking for the best sound note and best performance gains, any feedback would be great guys

Get some (ant brand) and report back to us how they do!

[Mit_Boost]

For an N/A motor, the money is better spent on a tune/full exhaust. Also, there's no guarantee on an N/A car that there will be similar gains.

On an N/A car, (some) back pressure is necessary to make HP. Active experimented with larger diameter exhaust piping on an N/A E92 M3 track car and found they lost power because back pressure decreased.

When you go FI (super or turbo charged), you want the exhaust to be as free flowing as possible. With the ACM car (it was an ESS 600 BHP+ kit) that point the Schmiedmann headers were able to yield a 20 WHP / 15 WTQ gain for the ~$1800 headers.


If you want to juice every pony out without building the motor, then a 650 BHP supercharger kit, full exhaust and headers are the way to go. Otherwise, your money is better spent somewhere else. IF you really want the headers, then Schmiedmann, RD Sport & SuperSprint I believe all make headers for the S65. I'm not sure if RD Sport updated their design, but I do remember their stroker motor cars had a small dip early in the powerband because of the header design.

[flipm3]

I would love to see the results of headers on an average full bolt-on S65B40, but as others have said, I wouldn't really expect too much.

Supersprint hasn't fully offered their headers to the market yet, but they have shared their interested in developing a forced induction application.

From what I've seen actually produced for the market, Schmiedmann and RD Sport seem to be the main options out there. The Motorsport24 headers seem to just be a rebadged Schmiedmann set but with a bigger price tag. I believe Gintani might have developed a custom setup many years ago as well.

[dparm]

The stock headers are very impressive for a mass-production vehicle. I think you'll be disappointed with the $-to-power ratio you see from something aftermarket (unless your car is wildly modified, i.e. SC).

[flipm3]

^

[spool twice]

I'd like to see what a good set of long-tube headers will do on a bolt-on only S65.

On a side note, has anyone looked into developing a spacer to increase air volume for our intake collection chamber? (if anyone has a 350Z/G35 VQ35DE backround, you'll know what I mean)

[regular guy]

Originally Posted by Mit_Boost

IF you really want the headers, then Schmiedmann, RD Sport & SuperSprint I believe all make headers for the S65. I'm not sure if RD Sport updated their design, but I do remember their stroker motor cars had a small dip early in the powerband because of the header design.

These Schmidmann and M24 headers are believed to be made from the same design RD Sport originally rejected. The original RD headers were short tube, 42mm tubes. RD abandoned the design because it didn't make any power. M24 and Schmidmann are believed to be getting these RD designed headers from the same fab that made them for RD Sport after RD abandoned the design. I have the dyno files from the original short tube header development.

Here's a comparison between the RD (M24/Schmiedmann) headers and stock. They seem to make slightly more torque than stock, but overall power is the same.



Following the short tube header design, RD design a long tube "Tri-Y" design. That's the design you refer to as having a "small" torque dip. I thought it was rather large. Here's what that looked like.

Originally Posted by flipm3

I would love to see the results of headers on an average full bolt-on S65B40, but as others have said, I wouldn't really expect too much.

Supersprint hasn't fully offered their headers to the market yet, but they have shared their interested in developing a forced induction application.

From what I've seen actually produced for the market, Schmiedmann and RD Sport seem to be the main options out there. The Motorsport24 headers seem to just be a rebadged Schmiedmann set but with a bigger price tag. I believe Gintani might have developed a custom setup many years ago as well.

For NA, even FBO stroker NA, these headers didn't help. For supercharged, they appear to add between 15-18whp.

[kawasaki00]

For the long tube headers switching to a H pipe and not a X pipe will fix the torque dip.

[pbonsalb]

Stepped headers might also preserve or even enhance torque.

[Notnug]

The OEM headers are a nice piece. I would do full cat-deleat with x-pipe and sport exhaust. By far the best power for the money. These headers are a pain to install and really won't get much for the work involved. I feel like the question of back pressure is a never ending discussion and is based a lot on the specific vehicle, its engine and its specific parts. Certain engines will benefit more from back pressure than others. Active's experiment with the E92 is interesting and could well be true.

[MrStinky]

Can we all agree no car benefits from back pressure but rather the faster gas velocity that smaller diameter piping offers? Hard to believe that myth of needing back pressure still dominates the car world

[the_road_less_traveled]

Originally Posted by MrStinky

Can we all agree no car benefits from back pressure but rather the faster gas velocity that smaller diameter piping offers? Hard to believe that myth of needing back pressure still dominates the car world

Glad I wasn't the only one thinking this. Designers can use the existing back pressure to tune the exhaust and achieve max power. Essentially the system is tuned so that the Incident Wave pulse is the same frequency as the transmitted wave to increase scavenging.

[BPMSport]

I think ACM picked up roughly 20whp on a supercharged car. I'm thinking of putting them on my car in a few months. Will be interesting to see the gain. I'll probably ceramic coat them too. The price isn't too bad. There is no question that the factory headers are excellent.

As far as the first dyno in post #13, looks like different RPM limits - would have been nice if all had been equal there. Do you have the DRF's to post? Would be interesting to see AFR as well for those runs.

The E6x M5/M6 pick up quite a bit with headers, but they have a different design than the E9x which is a bit more restrictive.

[Sales@Evolve]

Here are the facts on after market headers.... there are no facts.

There are a few headers out there but no one knows anything about if they add power or not.
Why? Because no one recorded the ignition timing, afr not really tested on equal conditions (IAT's etc).
The results are inconclusive. They might not do anything because the stock headers are indeed good but still no one knows.
We have restarted a project and will see if some very elaborate designs might work. If they don't work then you can forget it.
What we will have to do is create a fixed ignition calibration for this so we can isolate, amongst other conditions, the power gained from the headers rather than continually running the car on the dyno and hope we hit the same ignition and afr targets and other compensation maps do not intervene. So we remove dynamics adaption from the equation.

There is no question that the gains will be nothing like the gains from our tubular headers on the S62 and S85.
The S62 has just an incredibly poor design (on purpose by BMW) and the S85 has large restrictive CAT's and very crimped pipe work and poor flow. Similar in design with equal length but restrictive.
On the S62 we will pick up 25rwhp
On the S58 as much as 40-50rwhp

One of the evolve team will come up in a while and post the above headers with their evolve replacements.

Then you will see there is actually no where like that on the table. Lots of people say their are good but no real analysis with images has been done.

Our personal opinion is that if we are lucky and the pipe diameter of the primaries is too small then we have a chance at getting 10 hp. Of maybe the overall volume could be bigger maybe.
We might be wrong, proper conducted testing will be the proof and not some random non data logged runs from each test....

[regular guy]

Originally Posted by Sal@Evolve

Here are the facts on after market headers.... there are no facts.

There are a few headers out there but no one knows anything about if they add power or not.
Why? Because no one recorded the ignition timing, afr not really tested on equal conditions (IAT's etc).
The results are inconclusive. They might not do anything because the stock headers are indeed good but still no one knows.

Sal, it's easy for people to discount the RD Sport tests and their results are often overlooked for a variety of reasons. But it's pretty hard to ignore or forget the Dinan and Supersprint tests.

Both Dinan and RD Sport collected this data during their header development. I've personally seen it and have access to some of it. I got permission to post the dyno graphs above, but I never asked for permission to post the logging data. Without permission, I won't post it.

We have restarted a project and will see if some very elaborate designs might work. If they don't work then you can forget it.

Dinan spent six+ months on S65 header design. During one visit, they showed me no less than 13 different S65 header designs -- both short tube and long tube designs along with different collector designs as well. Dinan found no benefit to header designs even on their stroker motors. I'm going to step out on a ledge and say Dinan's tests are exhaustive and definitive -- possibly more exhaustive than the SuperSprint tests (which also found no benefit). I've never seen the Supersprint results, so I'm only going by what I've read. It will be interesting to see if Evolve can do anything more than this.

What we will have to do is create a fixed ignition calibration for this so we can isolate, amongst other conditions, the power gained from the headers rather than continually running the car on the dyno and hope we hit the same ignition and afr targets and other compensation maps do not intervene. So we remove dynamics adaption from the equation.

Dinan did their tests on their engine dyno with a stand alone ECU. That would be the best approach to control engine environment. At the end of the day, the factory ECU is still a black box without access to 90+ % of it. The Dinan approach would be superior and more controlled than above. Of course I'm assuming Dinan knows how to do scientific experiments with controled variables. But given Dinan's pedigree and experience, I think that's a pretty safe assumption.

There is no question that the gains will be nothing like the gains from our tubular headers on the S62 and S85.
The S62 has just an incredibly poor design (on purpose by BMW) and the S85 has large restrictive CAT's and very crimped pipe work and poor flow. Similar in design with equal length but restrictive.
On the S62 we will pick up 25rwhp
On the S58 as much as 40-50rwhp

One of the evolve team will come up in a while and post the above headers with their evolve replacements.

Then you will see there is actually no where like that on the table. Lots of people say their are good but no real analysis with images has been done.

Not sure where you're getting this information. Doesn't matter, it's incorrect.

Our personal opinion is that if we are lucky and the pipe diameter of the primaries is too small then we have a chance at getting 10 hp. Of maybe the overall volume could be bigger maybe.
We might be wrong, proper conducted testing will be the proof and not some random non data logged runs from each test....

Again, not sure where you're getting this information. Weren't the Supersprint tests pretty exhaustive? They seem forgotten here.

Regardless, I look forward to whatever you discover even if it's the same thing that three vendors before you discovered.

[Sales@Evolve]

Good points.
I went through the supersprint results and no timing logs taken but they did report an increase in mid range.

As for Dinan. No disrespect but ever since the s62 we've seen throttle bodies, headers, strokers etc not making their power even in conjunction with each other.

We will try it again but with also controlling the dme.
Point is that I do not think anyone has really seen what headers can do and then what happens if tuning is done.
Could the exhaust cam with headers be advanced or retarded in different areas to take advantage of say better scavenging for example.

10rwp would be amazing. ... but probably wishful thinking.