OBX Stainless Steel Manifold Fitment on FC
01-29-03, 06:39 AM
#1
Banned. I got OWNED!!!
Thread Starter
Join Date: Sep 2001
Location: Pensacola, FL
Posts: 311
Likes: 0
Received 0 Likes
on
0 Posts
OBX Stainless Steel Manifold Fitment on FC
Me and Dale Clark test fitted an OBX stainless manifold off of ebay (meant for an FD) onto his motor last night. The results while not suprising were not as good as I would have hoped. The manifold isn't very close to fitting at all. The pictures can be found here PICS. These tests fits were done with a .81a/r exhaust housing, this means even more spacing/moving will have to be done with a 1.0 or 1.15 divided housing. We have a couple of ideas to get it to work, but then you get into wether or not its worth spending the money to get a cheap manifold to work, especially when the HKS Cast really isn't much more money (or any at all) and works pretty well over all.
Specific problems were:
We had to grind the flange a bit to get it to clear the tension bolt, after this the manifold physically bolted on as expected. However the turbine housing was WELL into the lower intake manifold. We then spaced the manifold out a bit by placing a bolt approximatley the same size as the existing flange (basically doubling the width of the flange) and bolted it back on, the turbine housing still hit and it then became obvious that the LIM would need the ACV and split air pipes casting taken off as the down pipe would hit them even if the turbine housing fit, which it still did not. The rest of the pictures are comparo's of the OBX and HKS cast. All in all the manifold will need some pretty agressive spacing and modification to fit.
Daniel
Specific problems were:
We had to grind the flange a bit to get it to clear the tension bolt, after this the manifold physically bolted on as expected. However the turbine housing was WELL into the lower intake manifold. We then spaced the manifold out a bit by placing a bolt approximatley the same size as the existing flange (basically doubling the width of the flange) and bolted it back on, the turbine housing still hit and it then became obvious that the LIM would need the ACV and split air pipes casting taken off as the down pipe would hit them even if the turbine housing fit, which it still did not. The rest of the pictures are comparo's of the OBX and HKS cast. All in all the manifold will need some pretty agressive spacing and modification to fit.
Daniel
01-29-03, 08:25 AM
#3
RX-7 Bad Ass
iTrader: (55)
Yeah, I was impressed with the quality of the OBX manifold - if nothing else, it's a helluva lot lighter than the HKS cast! 
The only reservations I have about the manifold is it could probably use some bracing from the main tubes to the flange - I can see the welds on the engine flange eventually cracking from the weight of the turbo and having the downpipe pulling on it as well.
Regardless, you're looking at a substantial amount of engineering to make it work.
Remember, the HKS cast manifold is $295 *RETAIL*, fits perfectly, and is BULLETPROOF - that thing is solid and very well made. Guys have made well over 400 HP with that manifold!
Dale
The only reservations I have about the manifold is it could probably use some bracing from the main tubes to the flange - I can see the welds on the engine flange eventually cracking from the weight of the turbo and having the downpipe pulling on it as well.Regardless, you're looking at a substantial amount of engineering to make it work.
Remember, the HKS cast manifold is $295 *RETAIL*, fits perfectly, and is BULLETPROOF - that thing is solid and very well made. Guys have made well over 400 HP with that manifold!
Dale
