fcdrifter13

I know the plans were sold to someone, then bought by another guy, then production stopped. Corksport doesnt show a header on there site that I am seeing and I havnt seen Ironeagle on here in a long time to ask about one. No mindtrain(sp?) headers are popping up either.

Is there an alternative to the RB that is available and around 400 and so dollars, or am i gonna have to build my own?

TerryD

Corksport discontinued there n/a header for the fc. i email them last month because i was looking for one. so i bought a used corksport header off a member here. it really sucks that companies stop production on parts for our cars.

diabolical1

iTrader: (3)

if you have the ability and tools, build your own. maybe i haven't looked hard enough (distinct possibility), but i haven't seen purpose-built/tuned headers in the price range you specified.

rxtuner79

iTrader: (1)

The only header that comes to mind (excluding your price requirement) is the Defined Autoworks header. I'd love to replace my RB with one but there just isn't enough information/comparisons/people running it right now.

Fleemer

For n/a?

Your stuck with Racing beat or something used.

Stay away from pacesetter.

Dak

Was the Corksport one any better than Racing Beat?

LargeOrangeFont

iTrader: (7)

You can get a stainless OBX new for about $225 shipped. I had one on my car for awhile. Quality was good and had a decent power pickup. I ran it with a RB catback and a resonator in place of the main cat.

The OBX header replaces the cast iron manifold, and the 2 precats.

Jager

iTrader: (10)

Seems like all the results have be very good though.

Dak

I forgot about the OBX header but personally I'd stick to the RB one before getting the OBX. The OBX's runners aren't equal length and the RB puts the O2 sensor in the collector, but it is an alternative.

beachFC

iTrader: (13)

I just pulled an SDJ header off of my car, but I gave it to my friend. Good luck finding another

LargeOrangeFont

iTrader: (7)

For bank for the buck I think the OBX is probably the best. I would not think twice about running one again if I had an NA rotary. It is less than half the price of a RB setup and probably 90% or more of the performance.

Yes I ran my wideband 02 in the OBX factory bung and had to use a heatsink for it. It is easy enough to add a bung to the OBX header in the collector if you wanted to though.

Also it is not some goofy length to preclude you from running a main cat if you wanted to.

fcdrifter13

Hmm plans have changed. After many maths i think i will build my own. I sold have never sold the SDJ i had. It was so good. But after looking at the math on everything yes I would get i bump but it will not work as well in the powerband i am wanting it to work in.

rxtuner79

iTrader: (1)

True, but the few examples I've seen are on pretty built up engines. I'd like to see some dyno results on regular S4/S5 engines that don't have rotors or housings from other series engines, crazy port jobs or intake setups. Basically what I want to know is on my S5 engine with full RB exhaust, Pineapple inserts and S4 intake what kind of gains I would see with the Defined... So I need someone with a similar setup that has more time and money than I do haha.

Dak

For the original poster's application it probably isn't a good choice. He wanted a SDJ( or SDJ copy) which is know to perform better than the RB. I don't think the OBX will out perform the RB as it has the same flaw as the RB( bends too soon after the flange) plus unequal length runners. Rotary Performance sells a Bonez cat that bolts between the RB cat and catback. All that said I will agree it is better than stock and should give a performance increase.

Dak

Unfortunately seems no one has put one on a near stock car. It's performance potential seems solid though. It is a work of art.

archaphil

iTrader: (1)

I have an RB street-able (collected header) with the secondary pre-silencer removed to a modified length pipe on a factory style cat, to a factory y pipe to OE style Bosal mufflers and it is a night and day difference on my S4 NA from the factory exhaust manifold/pre-silencer.

You are telling me, that if I lengthen the runners a bit on the RB I can squeeze some more from it? I have seen the Defined piece, and it is truly lovely to look at.

fcdrifter13

The big thing that kills the rb header for me is that it needs to go at least 3in before the first bend. This lets the wave stabalize before it turns, at least that is my understanding. Its also too long to be a short runner and too short to be a long runner. And the ports dont match a 6 port housing.

Dak

This is my understanding as well but I think all but the port mismatch can be fixed. If I ever get a welder and learn to weld I think I am going to cut up and modify my RB header so it has 3" before the first bend. I also want to build a long primary system that collects further back. Where will depend on whether I go single or stay with duals. I have already added a cone/taper to the pipe to smooth the flow into the header. Actually it is my understanding that the header pipe size is right it is the FC exhaust ports are too big. Quoted from this thread: https://www.rx7club.com/2nd-generati...st-na-1069668/

https://www.rx7club.com/attachments/...er-porting-jpg

Dak

They would have to be lengthened quiet a bit. Like as close to the rear of the car as possible. RB recommendation for a long primary is 120" to 125" for stock or street ports. The FC isn't long enough to do that by my measurements. Probably why the defined piece has all the bends it does. To add length. You could cut some out and shorten it for a short system. They recommend 22" to 25" as a starting point. These are starting points with the actual lengths determined by fine tuning on the dyno. Most don't have the access, time or money so you guesstimate I suppose by using what others have had success with and posted here.

If you meant extend the distance between the flange and first bend then yes.

archaphil

iTrader: (1)

well, I can certainly pop it off and start grinding then.

Just to clarify here, we are talking about the collected header or the true dual?

Dak

I think this discussion is about primarily the collected header but the true dual( uncollected) suffers from the same issues with the distance to the first bend and the port mismatch. The uncollected version would be the better one to start with for a long primary setup if one doesn't already have a header. They sell unassembled kits which may be even better if one is going to try to add the 3" to the first bend. No cutting it apart.

jjwalker

Holy **** that defined autoworks headers looks amazing...I want and may buy!

archaphil

iTrader: (1)

Interesting, I should get out my tape measure and see if there is even enough room with the RB before hitting the frame rail.

rxtuner79

iTrader: (1)

I'm in the same boat as you but I'm being told that the gains over the RB that I already have are probably not worth the cost. Definitely post some info up if you end up buying it.