2Lucky2tha7

iTrader: (3)

I'm looking to see what turbo manifold options are available for a cosmo RE setup. It's on an engine I built probably 5-7 years ago, and it has a large streetport on both the intake and exhaust (and TII exhaust diffusers, not the baby RE ones). The owner wants to run pump gas only, is looking for 420-490 rwhp and generally wants power from around 3k - 8k. A friend of mine pointed me towards the S360 series Borg Warner turbos and seeing all the great reviews about them and the durability, that is what I am preferring to go with.
After a good deal of reading, it would seem that the S360 or S363 would be the best fit. Considering he may only see 18psi at the absolute most, the S360 seems best. Or maybe the S363? I was also wanting to get a larger A/R than the 0.81 they typically come with.
This leaves just the manifold. I know Turblown makes an amazing manifold, but the owner's budget doesn't seem to allow for it. He's not too keen on spending more for the manifold than he is for the turbo. Granted, it does cost almost $1k, but you get what you pay for. That being said, I was then looking to see what else would work. I know there is the HKS mani, but I was wondering: since the RE intake manifold design is very similar to the FD's design, and seeing as it sits higher above the exhaust ports and tucked in closer than the s4 and s5 manifold designs, would an FD manifold work in the FC frame? If so, I figured it would allow for a few more cost effective options. Maybe a Greddy manifold?
The manifold will determine whether the turbo gets a divided or undivided housing, and the turbo size determines what manifolds would work. Considering I generally know which turbo will go in it, what cost effective - and well built - manifold would work?
I'm a bit unsure where to go with this, so any input would be welcomed. And any input on the turbo sizing is welcomed too!
Thanks!

j9fd3s

iTrader: (3)

i think with the Cosmo engine in an FC, you can run either an FC or FD manifold.

with the HKS (and the cast greddy) manifolds the FC manifold puts the turbo kind of far forward and out, which with the cosmo intake will give you tons of room.

the HKS cast FD manifold puts the turbo closer in, as the kit allows you to keep the airpump, but the cosmo intake is like the FD, so this should be ok. if anything it will limit the turbo size, HKS likes to put big wheels in smaller housings.

GrossPolluter

iTrader: (1)

The cast manifold is the best choice for someone on a budget and durability. They don't flow the best though. I went with bnr because after ecu and fuel upgrades, the bolt on turbo was my choice, but if i could do it ask over again, i would save and do a real turbo upgrade

2Lucky2tha7

iTrader: (3)

In that case, I'm gonna look around to see what fd divided manifolds are available.

GrossPolluter

iTrader: (1)

It's interesting you mentioned that. What was the clearance issue with fd vs fc manifolds? Just the intake manifold? I always assumed it was the chassis or the front cover that was the limitation.

2Lucky2tha7

iTrader: (3)

I wanted to share a thread i came across earlier with some decent info. Further down the page - I think it was post #12 and some others as well:
is HKS cast manifold bad choice? - RX7Club.com

2Lucky2tha7

iTrader: (3)

In terms of divided manifolds, so far I'm only finding the Turblown (originally stated), HKS divided (fd), Full-Race (same cost as Turblown, just not as good), all the ebay cheap crap and finally one from some company called Kinugawa, which sells an fd tubular t4 manifold for $400 and uses 1.6" - 1.7" runners instead of most other places that run about 2" or more. (Turblown's manifold runners are 1.5"). One site that sold them claimed they came from japan. Another forum mentioned something similar. Don't know, never heard of them.
I'm gonna keep looking to see if there are any other options.
BTW, does anyone think that running the FD HKS manifold with an S360 or S363 will result in contact with the intake manifold of the RE?

GrossPolluter

iTrader: (1)

Thanks for the info. I really should have went with a cast manifold over the bnr. Oh well, I'm still in the fc world, i might just have to do a custom manifold next time. The only thing that stopped me was redoing my fuel line.
I don't want to be the stereotypical rotary that blows at the track

j9fd3s

iTrader: (3)

Mazda did a two phase implementation. starting with the cosmo engine they angled the ports up, and this gets the intake closer to the block, which allows them to put the turbos closer to the engine.

and then the FD has the frame rails higher (and the engine lower i think), to get better suspension geometry.

so if you tried an FC manifold in an FD chassis the turbo would hit the frame rail.

but since cosmo/FD into FC chassis gives you the most room, i think you can run either manifold.

Jeff20B

iTrader: (13)

2Lucky2tha7, Turblown uses schedule 40 pipe which is 1.9" OD and 1.6" ID. Pipe is sized differently than Tubing.

Another option, and one I'm looking at doing for myself, is to get some 1.75" OD tube with an ID of 1.6". It is 11 gauge wall thickness. Not as thick as Turblown's schedule stuff, but the same ID which is what you want. Will it last as long? Who knows. Still better than eBay crap.

Turblown

iTrader: (12)

I guess I need to make that more clear on the website

2Lucky2tha7

iTrader: (3)

So I talked to the owner and he has to pass on the Turblown manifold due to cost (even though it would do the best job) and settle for a less expensive divided manifold. So it looks to be either the divided HKS cast mani or that (supposed?) Japanese manifold for $400+. I'm also in no position to make one for him either.
Now it leaves just the turbo. Either one will get the 1.00 a/r divided turbine housing to keep the egt's down, but I'm not sure which would be best, either the S360 or the S363.

GrossPolluter

iTrader: (1)

You will need the bigger of the 2. Saw you were looking for over 400whp, you might even want a bigger turbo than the ones you just mentioned

2Lucky2tha7

iTrader: (3)

The key is that I want the turbo to run in it's efficiency range. Seeing as he may not exceed 18 or even 19 psi, but may in fact run between 15-17psi most of the time, the bigger turbos like the s366 will be too oversized for his application.

2Lucky2tha7

iTrader: (3)

Just ordered the BW S363 with the 1.00 turbine housing, so he's either going to opt for the HKS FD cast divided manifold, or he will order all the necessary pieces to have a manifold made locally using 304SS sch. 40 piping. It'll be interesting to see how this setup works with the 9.7 rotors.

coxxoc

iTrader: (3)

I'm using the HKS cast fd manifold on a 1.0 t67. There are no fitment issues. I know BW hot sides generally have a larger outside diameter than Garrett though.

2Lucky2tha7

iTrader: (3)

You're right, the BW hotsides are larger. Hopefully it will clear though. Worst case scenario? I'll add either a Mazdatrix exhaust mani flange or a divided T4 flange as a spacer for better clearance.
Seeing as you're running the old HKS 50mm wastegate, how difficult was downpipe fitment around the wastegate? I'm looking at using the Tial adapter from Banzai Racing along with the Tial 44mm wastegate and was wondering how much clearance is available for the exhaust pipe...

coxxoc

iTrader: (3)

The old HKS 50 mm has large fins on it. The fit is quite tight. It has about an 8 mm gap between the wastegate fins and downpipe at their closest points. I think the Tial design will give you more room to work with.

misterstyx69

iTrader: (142)

Just to chime in..
The HKS Cast manifold for the FC has holes that do not quite line up with the exhaust on the engine.
I noticed this after taking the manifold off and examining where the soot had accummulated from the exhaust.
I used a dremel and widened the holes inside to make the openings a bit bigger.You could also make the wastegate area a bit bigger too as it seems smaller to the liking and I run a 50mm JGS wastegate.

The good part of the manifold is the Wastegate flange is multi-holed to allow you to position a Square type flanged wastegate in different ways...Then again I used a V band adapter.

2Lucky2tha7

iTrader: (3)

UPDATE:
The 3rd gen HKS divided cast manifold and BW s363 turbo fit just fine. The closest the turbo comes to the engine is about 1/2" - 1" away.