Best Header
 

My searches turn up very old posts. I wish there was a sticky on the header for comparison.

I plan to buy a header pretty soon, so I've been looking around. Currently for exhaust I have the HKS single exit, and racing beat non resonated test pipe.

BHR long tube looks amazing, but its cost accounts for the test pipe/ catalytic that it eliminates. ($1625)

Racing Beat ($536) has my favorite pipe design. Looks like the runners are simple and equal length.

And then there are other headers that look decent with a low price like obx($270) and turboxs($250).

Is racing beat the best way to go second to BHR?

The best way to go is to leave it stock.

fiffy!

Have a read... https://www.rx8club.com/series-i-aft...thread-266914/

Why would you say that?
Don't just do a drive by without an explanation.

Because the tangible gains from off basic bolts ons is basically nothing.

Racing Beat's is probably the best off the shelf header, but power gain is limited to less than 5 WHP. Not even the most finely tuned butt dyno will feel that. Not worth the money, time, and trouble.

... people love to bang their head on the wall ... :)

Please share your thoughts.

He has a thread on header theory.

There you go BC

Yes, I know, however the OP asked for opinions, and short of analyzing Team's thread and fabricating his own , the question still remains.
I don't think it's too much to ask for members' opinions beyond curt responses.
I try to be helpful as best I can, but admit I'm not much help on certain things.
I've read many different header threads also, and I'm interested in the answers the OP receives as well.
We who have been here a while know all about certain members' opinions on some things, but new members don't, and new information may be available that we haven't read yet.

best header has a turbo bolted to it but 9k will tell you thats stoopid too

The problem is that there is no "best" way to go, it all really depends on the owners goals.

All I can say, is that I have seen healthy RX-8's with header back setups make as much or less than some stock RX-8's on the dyno. I have installed quite a few and the only gains I have ever seen when adding a header, whether it be RB, Turbo XS, and the Ebay knock offs, have been in decibels.

Now if you are talking, a good free flowing 3" (true) exhaust from the header back, Speedsource header or something equivalent, and a good tune and intake then sure you can add 20WHP on a healthy engine with the right tuner on the stock ECU.

Informative and helpful, thanks.

I've seen some claims made, but not a whole lot of real owner feedback.

yep, the best one is already on there from the factory. You can believe anything else you want. Just cut the rear off and make everything 3" to the rear with a full flow muffler system, resonator, high flow cat converter, etc. and there you go.

Or go bury your head in the sand and have wet dream fantasies about how bad@ss a bundle of long snake pipes is. Your choice.

Thanks for clarifying.

pretty much summed up my thread, so to speak

which it's not a theory unless you want to ignore the proven results ...

I don't care for the RB one in particular; 1.75" OD 14 Ga tube is only 1.584" ID, way too small imo


.

So, TLDR; Chop off the rear of the OEM header and make it 3" all the way back. That's a nice KISS approach.

It'll be ok, but larger primary pipes are better

Again, the RB header with 1.75" 14 Ga tubes is only a 1.584" ID, that's less than the flow area of the smaller siamese port, let alone the larger end ports.

but I don't expect anyone to start listening now any more than 10 years ago ...

im seeing some strong opinions in this thread.....however if the motor in question has been streetported, would everyone still be opposed to an aftermarket header setup or is it more practical for the application?

right on cue ... lol



.

"cue"

had that first, wasn't sure and edited it, lol

for some reason queue seemed to make more sense, but I just checked and see cue is right. meh ...

????

trust me, it's obvious when you have results rather than an opinion

I beleive you, but I'd also like to get some insight on the subject as I am considering a street port for my rebuild and I was also considering headers so if they're not necessary even with a street port I can focus my money elsewhere

maybe this will help, but I doubt it ...

oh, you want to street port your Renesis and have even less engine life with the same performance?

be my guest ...

So this hasn't made much clear to me regardless of how many times I read it, Is there an aftermarket header that would be better than the stock one? I.e has the most gains over the competition/stock? Or should I get a shop to make one and if so, In what shape/style? Some legitimate answers would be nice.

Better in what way?

Prettier? Absolutely.

More HP? That's debatable.

Anything that claims to improve power using equal length runners or helping with scavenging is full of crap. Those concepts don't apply to the Renesis like they did on previous 13B's or piston engines.

The only improvement you can get is through decreased flow restriction.
https://www.rx8club.com/series-i-aft...thread-266914/

Taken from the link... Essentially since the motor has no overlap, exhaust manifolds do nothing because there's no such thing as exhaust gas savaging if there's no open port to pull it out of the engine...Hope that makes since to you, and why this whole Idea is chasing ghosts. If you want something that sounds a little different or looks better... go for it. Expect no gains though. As Team recommends, just make it as free flowing as possible. That's all you can do.

I dunno, after I put my exhaust manifold on I noticed a couple HP's..... :lol2:

What? Probably in the 2.4 - 2.5 HP range?

go with racing beat. they know what there doing, never been disapointed with there work, i have all there parts and the gains are in the pudding.

Which pudding would that be? Your butt dyno?

My Mani has a turbo connected to it :D

Did anyone else notice that BHR changed their header offering from equal length to just 1 7/8 primaries and CNC'd manifold port transitions? I want to upgrade from my revision.

Make that 13 years now and still counting, lolz ...

Care to weigh in on the apparent revision to the BHR header? Design wise, as it's still a pretty expensive piece. Charles seems to have made notes on what you were talking about in your theory thread. If you want to say it there, or take it to PM feel free, I'd just like to hear others thoughts on it.

Never go full blockhead, never.

Cryptic as ever :rollingla

Well you can nitpick all day long if you want, but it’s all for nought wrt engine output.

Otherwise 2” primaries merging smoothly (15* or 12* collector) into 3” single and minimal restrictions is all that matters performance-wise imo and is my recommendation. I don’t really see an issue with 1.875” tubes, but how you fit them up to the actual exhaust port shape might matter more.

If you want to play the length game then knock yourself out, but again, everyone is so tied into overlap valving engine methodology they just can’t accept that you can’t get anywhere near the resonance strength or powerband range on a zero overlap timing engine. Which a Renesis is unique among almost all engines in this regard. Otherwise I recommend individual flanges & tubes with slip fit connections for thermal expansion/contraction. T321 tubing is also best also due to high exhaust temps, especially if going thin-wall to save weight. If you were building a true resonance manifold the siamese center port would need to be a much smaller diameter and different length than the two main end port tubes too fwiw.

so while I did build a tubular header for this next go around, I have zero performance gains expectations over the extremely short length primary ultra-lightweight manifold race header that I originally built back in 2006. I had to retire it due to thermal stress fracturing finally taking it’s toll since it has no allowance for expansion/contraction. So the new header is built for that purpose with everything split apart into individual components with slip fit connections. The length is only for expansion allowance using thin 18 & 20 Ga. thickness T321 tubing.

I actually have a 3” extension piece to elimnate the three straight tube sections and locate the collector on the main primary connections just because it’s a bit lighter.

https://cimg3.ibsrv.net/gimg/www.rx8...cac8c5805.jpeg

matching up tube diameter to port area is a manufacturing decision. a real header is designed for the intended power. 1-3/4" is MORE than enough for 250 bhp (on the large ports, no less). 2.5" cat back is also more than enough. I'd like to see pressure drop numbers to prove otherwise, or acceleration tests. dyno test procedure won't show squat.

the most likely reason they go with 14 ga is because they use 304, which doesn't like heat, and makes it a little more durable. so if they don't add much hp, they'd darned well not crack.

scavenging has two purposes - starting intake flow, and reducing exhaust pumping, which I'd say it's the more important function. it just just as much to do as when you open the exhaust port as header size/length. people on this forum keep saying that intake porting does nothing...which tells me it doesn't need more intake overlap (i.e. scavenging). that would also mean bridge porting just encourages raw fuel out the tail pipe without much power gain (with the typical configuration). we need more investigation into intake pumping and intake ramming (between tdc and port closing).

Knock yourself out, Einstein.

You don't think people have already tried everything under the sun to make more power on these things ?

Have Racing Beat and felt no difference. Just louder. Also, it was a pain in the ass to install. I had to disconnect both motor mounts and put the engine on a host and shift it to the driver's side to get enough clearance to get the header on. it was a waste of time and money.

and boom goes teh dynamites ...

Welcome to the RX8... hahahah

https://cimg3.ibsrv.net/gimg/www.rx8...c09bdc0e6b.jpg

My take on the header controversy - a $140 alibaba taiwanese header, I chopped off the stock collector and welded on a 3" ID pipe with a v band. Cheap, not sure how effective though.