Marietta 8

I've noticed no diff at all in underhood temps. Looks like I will try and get to the dyno tomorrow night. What you noticed on the other headers is actually the same on the OBX according to my pal that did the machine work. He said the reason it was such a bich to machine was because of the machined plate that had been welded. It's a shame that they didn't finish the machine work while they were at it.

We used Jet Hot on our first ITS car and it unfortunately came off in large sheets from the header (stainless). To be fair, I don't think the 8 will be subjected to the constant hi rpm's that we were at most of the time not to mention the difference in exhaust port design.

carbonRX8

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BoosTED

iTrader: (2)

If the JetHot came off inside the header wouldn't it clog the cat?

carbonRX8

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I hope you all dont mind me hijacking this thread with my blather about my own OBX header. As you saw above, I got it back from JetHot with their highest temp coating recently, and I have just finished installing it. THought I would post a brief.

The install was really increadibly easy for a header install. There were no fits of frustration, feeling like you were assembling a puzzle. I tried to remove the exhaust manifold while leaving the RH motormount in place, but it soon came apparent that the motor mount had to go. Turned out that the motor mount was a breeze to remove, once I found that I could access the bolts through the RH wheel well ( I just remembered I did not reinstall that flap. oops, gotta go do that.) All the bolts of the manifold came off easy, though two of them came with the studs. That worried me a little but I think it will be ok.

My biggest concern is of the secondary fresh air pump. The tube came off easy, but now my pump just blows into the engine bay. I am trying to figure out if there will be any negative concequences of just removing it completely for now. I may try to eventually (just for emmission inspection day) fab a bung to attach the tube or an extention thereof to blow into my header ox sensor bung. Then I could move the ox sensor down to infront of my cat (where there is a free bung.) That should prevent a cel.

The header slid right in and the JetHot coating withstood abrasion from the install very well. Bolting up was hella easy except for the bottom LH bolt on the header. The rear runner is very close to that bolt and prevented me from getting a torque wrench on it. In fact, it was hard just to get a box end wrench on it.

So all bolted up and no leaks. The air pump makes a racket for a few minutes. I cant tell a difference in sound at idle, but there is definitely a "rotarier" sound at higher rpms. I would suggest that the rpms spin up faster, though this could be placebo effect. I would also suggest that there were no horses lost with this install. In fact, my butt says there is more torque at about 4.5krpm to redline. But we all know the butt can lie.

Just my $0.02

lazi

nice write up... dyno numbers??

ddub

Interesting cobonRX8, can't wait to install mine and see.

Waiting on midpipe to do full exhaust all at once... I'm kind of slow.

carbonRX8

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I was trying to be patient and just install all at once, but I couldn't help myself. I did the pipe first. Big difference.

Of course if you have easy access to a dyno, wait and do them all at once or incrementally at the shop. If I could be so bold as to recommend an order, do the pipe first and then the header.

And no, lazi, I will not be going on a dyno any time soon. Not until there is a tunable option to justify the cost. I would agree that the info would be invaluable, but we will have to wait on Marrietta. Besides, a dyno on my car post-header really would not tell us anything unless I did a pre-header dyno. I will have to rely on my butt for now, and my butt tells me that the cost was worth it.

TeamRX8

iTrader: (25)

funny, the OBX header I had was not two welded pieces like the RE Anemiya header, it was just machined from a solid 1-pc billet to look the same, that's why the air injection ports aren't completed

carbonRX8

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Yes. You are correct. What did I say to confuse?

TeamRX8

iTrader: (25)

not you, Marietta8 implied that his machinist told him the OBX was two welded pieces, that wasn't my experience



Now the tubes are welded to it, outside of that there must be a communication issue.

kw1k

wow? so how much longer till we get the dyno results

Marietta 8

Ok, it's done. I'll have to post the sheet on Monday but the bottom line is that there was no gain and actually a small loss. The area under the curve is minimal so that is good and I do plan to keep it on the car but there is a loss of roughly 1hp and a couple lb/ft of torque. It was a bad hair day for dynoing (humidity high) but cf should account for it and my particular car has been VERY consistent regardless of weather, date, time, planet alignment, etc.

Next thing to test will be the Twin Power. I really don't expect much if anything but this is based on past experience on n/a rotary cars. I have seen very nice gains on turbo rotaries with the twin power so those of you with Greddy kits might want to try it but you'll have to test it yourself since I have no plans of going turbo on my 8.

Anyway, I'll post the sheet early next week after I get Dynolab to email the file to me.

carbonRX8

iTrader: (1)

Well, I am not going to argue. I was betting that you were going to come back and say that you lost some up near red-line, but gained a little around 4500, cause that is what I feel. It is possible that what I am doing is interpreting some nice sounding resonance at 4500 rpm for more gut. All in all, I too will probably keep this on my car for a while, but I cant recommend it. IMO, all it does is allow you to remove the weight of the air pump and produce some nice sound (which, really, is pointless). Maybe, just maybe there may be an expantion of the tq curve low in the rpm, that is car specific. Actually, I am going to a speed shop Monday for a new exhaust. maybe I can convice them to stick the car on the dyno to clear up my delusions.

What cat are you running, M8? Sorry, don't see it in your sig.

Marietta 8

Stock cat with RB cat back and intake. I really need to look at the graphs carefully to see where the gain/losses are and if I can find the one from the Amemiya test will add that too. It's really a double edged sword that the engineers at Mazda got this thing worked out so well. I guess we'll see what RB comes up with on their header design and hopefully it won't outweigh the stock manifold by 20 lbs!

olddragger

iTrader: (3)

he is running a stock cat with a jic ? Titanium catback. he tried the sr high flow cat/midpipe and lost about 1 hp from that, so he replaced the stock cat on the car. He has a mutant car anyway--he rountinly dynos over 200 with a Revi intake, light flywheel(ACT) and used to be a RB catback exhaust. He also has the ssr comp lightwheels (I know I know shouldnt matter)
HEY CHARLIE I BET YOU CAN GAIN THAT HP BACK IF YOU PUT YOUR RB CARBACK ON AND SELL ME THAT JIC FOR A LITTLE MORE THAN YOU PAID FOR IT!lol. I have to keep trying dude!
olddragger

Moostafa29

What is "Twin Power"?

toca

didnt expect to see any gains out a of a obx product

rkostolni

Its very possible that you guys would get better gains out of those headers, as well as your other mods if you had a way to adjust A/F and timing. Such as an emanage, canzoomer, or best of all an Interceptor. I don't think you're ever going to get much hp out of this car without first addressing the tuning.

toca

yes these parts like header s wont show much just bolting on but i feel after u tune for the header u see some nice gains

TeamRX8

iTrader: (25)

I have an RE Anemiya header I can loan you to try as an alternate if you can get it done and returned soon

so how much lighter was the OBX over the OE manifold? I know the RE header is lighter than the OBX by just a small amount, it will be lighter still when I get done with it

carbonRX8

iTrader: (1)

Agreed. With the ability to tune, bolt-ons become great additions as opposed to mediocre ones. However, that does not negate the possibility of getting some gains without the tune. Do you have $1.6k to loan me so I can order a int-x? My next 3x$1.6k is going into suspension and seats, so I wont be seeing a int-x for a little while.

The OBX header was negligibly lighter than the stock manifold. I saw no diff on a bathroom scale.


Toca, posthoc predictions of negligible benefit are worthless. Besides, the OBX is basically a knock off of a RE Anemiya or some other +$1000 header. For <$300 is was a very cheap experiment.

TeamRX8

iTrader: (25)

there are a couple of features on the RE header that are better than the OBX, but for the avg enthusiast the OBX is a great value and readily available too.

So, what did you see for a weight on the OE manifold? I'm looking at maybe reworking my RE header to lighter tubing and a better merge collector possibly using a v-band clamp type assembly to eliminate the OE flange/gasket and allow smoother flow transition to a mating custom light gauge midpipe, so I can probably knock off a few more pounds.

carbonRX8

iTrader: (1)

17lbs. (Just went down and weighed it again.) Like i said, it is on a bathroom scale (the diff between me and me+ the manifold) If I remember, I got about 15 for the header. The manifold is a lot lighter, just by feel, than I expected.

AlexCisneros

http://www.hksusa.com/products/?id=840&rsku=6094

carbonRX8

iTrader: (1)

So what are you thinking? Just for S&G lets say you start with CNCing the heavy baseplate. You could easily get 2 lbs off that. How 'bout this: Since we now know that semi-equal length runners arent doing ****, make a 3-2-1 header similar to the stock manifold, only instead of heavy cast, use stainless. That would be mega light. Hell, if you couldn't find someone to do a one-off, I would help pay for the setup if you could find someone willing to knock-off five pieces or so. I am sure that you could find 3 buyers. (though if you can do a one-off, do that. I am not being pushy, just trying to help)