Thanks for all the info Team!


Yea that's what I was worried about with the manifold being the sole support for the turbo.

So it sounds like Schedule 40 304 SS is the way to go. I've come across a couple sources for it, like McMaster-Carr but they seem way over priced on tight radius bends, Grainger and Online Metals only carry straight pipe from what I see.
Do you know of any good sources for these materials?

I would consider my power goals to be very reasonable, I'd be happy with somewhere around 325rwhp, if this build results in more great. I was planning on using a Tial V Band Housing, and most likely something from Comp for the Turbo, maybe an Oil Less CTB-30R. I have to contact Comp and get more info from them and see if they have any flow maps available for the different compressor wheels(55, 58, 60).

Do you by any chance know the size of the V Band flanges necessary for the Turbine inlet and outlet of the Tial housing, I can't seem to find that info on their website.

 

Comp turbo won't release the maps. I can get you a deal on a comp turbo unit if you like...

Welding technique is more important than material. You will have to use weld els as mentioned, they are the only thing that has tight enough radii.

 

Why won't they release the maps? Seems counter intuitive to me, people want to see what they are actually buying.

Without the maps then what compressor wheel size would you recommend?
Please PM me a price on an oil less CTB-30R with a Tial Turbine Housing.

I think my welder is more than capable, but is there anything specific I should make sure he's doing.

Thanks

Edit: I asked in my previous response to Team but you probably know the answer to this question. What size V band flanges are required for use with the Tial turbine housing? And does Tial include the weld flanges and clamps?

 

The CTB-30R designation is the disc potato replacement and comes with that turbine housing, so don't get hung up on that designation. They can pretty much match up any compressor cover/wheel size to any turbine housing/wheel size. You will probably want a CT2 B cover mated up to the appropriate TiAl depending on what sizes you end up with, but it never hurts to ask what smaller alternative may be available for your goal as size matters for the RX8 chassis. The oil-less is a bit longer in length, something to consider if you intend to work around the OE engine bracket/mount, but not much.

TiAl uses special v-bands sized for their housing. GT28/30/35 all share the same inlet/outlet size despite the frame differences. Not any old v-band will bolt up, though some might be close enough to work if you had that info, not really worth the chance IMO. Just get the right thing and be done with it. They are sold separate in most cases, packaged together in others, just read the fine print and ask if you are not sure. The inlet is designed for a 2.125" OD x 16 Ga tube (2" ID) connection to fit it x 3" OD overall and tapers down quickly from there internally, which you can easily machine an adapter to tie in a smaller tube/pipe. If I was using a smaller tube/pipe I might merge them into one common pipe just prior to the inlet, machine an adapter with an OD to mate with the inlet V-band and an ID that is the OD of your pipe, and then have that pipe pass through the v-band and with some massaging extend into and mate somewhat closely with the internal taper of the housing as far in as it can go. I just might.

You will be surprised by how small the housing is and how quickly and small it tapers down to internally. By doing it the way I describe you are simply carrying and maintaining the flow velocity as far as possible into the housing where it is going to amp up considerably from there, rather than letting it suddenly expand and then taper down again, which is going to cost you exhaust energy in the process. You need to make sure that you will have room enough to slide the turbo back off this internal pipe projection and on/off within the chassis.

I can understand your desire to build it yourself, but don't discount Turblown as a source for what they can provide at a reasonable price, if even only the parts you may need. The T304 sch pipe fittings are so cheap and the weight difference between Sch 10 and Sch 40 for a manifold this size is nothing to be concerned about. You have a good welder so that is not a concern either. T304 is more likely to crack outside the weld because of the temperature vs material dynamics. The heavier wall will resist this much more, but it is probably less of a concern for a street car that doesn't get flogged a lot vs a competition car that does. Still, the cost and weight difference is not huge. The only downside I see is that it requires more time from the welder, but not that much for a good welder with a good machine and the necessary filler wire sizes. The welds matter, but the thicker it is the more leeway for fudging the quality. A quality welder just gives it that brick poophouse factor. Cracked manifolds suck.

... of course mind you I haven't done it. I'm just a frustrated FI wannabe who makes this stuff up in his wet dream fantasy just as the forum experts here say .... srsly


.

 

I have to start looking into the turbo details a lot more, I've been focused on researching other aspects of this build. I'll be talking to Turblown and Comp Turbo about what my options are. I'm not really too worried about working around the OE engine mount, in fact with the design I'm envisioning I doubt it would work with the OE mount.

Not too surprising that they use a proprietary size, I'll just get the flanges through Tial then. Yea all 3 will be merged into 1, we'll have to see how that will actually work when it's being built. Would it be ok to use 16ga tubing for the collector and connection to the V Band, maybe use 321SS here and 304 Schedule 40 for the rest?

Thanks for this info, I understand what you're saying and will try to do this if possible.

I'm not discounting what anyone here can do, I just haven't seen a low mount manifold released yet that offers a completely optimal design.

Yea they seem very cheap but McMaster Carr seems to charge an excessive amount more for the tight radius bends.

These prices are for Schedule 40 90 Degree Bends, Long and Short Radius:
Pipe Size Wall Thick. (R) Price Each
1 1/2 0.145" 2 1/4" 45605K515 $8.16
1 1/2 0.145" 1 1/2" 45605K213 $35.99

LOL

 

the large radius are actually 2.5"R, the short radius are a bit pricey but necessary, you might look for other less expensive sources but McMaster is quick & easy

as for it going down to one pipe, I said right before the turbine inlet. Reread what I wrote about the turbine housing i.e. it gets a whole lot smaller than a single pipe by a significant amount. If it really concerns you then don't do the extension. You still have only a 2" ID to mate to regardless, and this applies all the way up to the largest GT35 housing.

and don't forget a big wastegatethat transition is a critical point and with the heat, vibration,

I'm not even comfortable with 16 Ga. T321, the heat & vibration at a critical location makes me nervous, thicker T321 tubing is rare, fittings rarer still. You don't have a lot of room so forget about a long optimal angle transition, everything on the RX8 is a compromise, that's just what you have to work with

but again I had a dream about all of that too ...

 

short 1.5" Sch 40 90s a bit cheaper here

http://www.acestainless.com/butt-wel...-304l/s90-h4wn



didn't see anything on ebay, but sometimes stuff is buried under a crappy title or description there

short elbows are harder to make, lots of scrap, specialty use, etc. so they cost more


.

 

McMaster Carr has the long radius bends listed at 2-1/4, http://www.mcmaster.com/#stainless-s...ttings/=geibwk

I understand what you're saying about the extension into the turbine housing and that the diameter gets a lot smaller. So you're saying merge all 3 into 1 Schedule 40 1.5" pipe that I would be using for the rest of the manifold, make an adapter/spacer for the difference between the OD of the Pipe and the ID of the V Band, correct? Then extend the pipe through both V Bands into the Turbine housing as far as possible.

A 44mm Tial Wastegate should be sufficient right, considering that's a larger diameter than the ID of the Schedule 40 piping.

From what I understand of what you're saying the 16ga tubing/collector won't even be necessary.

Thanks for the other sources, I understand why the tight radius bends cost more but to cost more than 4 times the amount of the longer radius is a little excessive if you ask me.

 

and I'm saying that they are 2.5"R, but then again maybe I was having a dream ...

nobody uses tight radius bends unless they have to, so the volume used between the two is substantially different plus all the other difficulties I mentioned. There's a reason most of the mandrel bending suppliers can't even bend lighter wall tubing that tight

I did find some really low cost 1.25" Sch 40 T304 short radius elbows; $9.50 each.

I also found some 1.66" OD x 12 Ga T304 tube 90 deg elbows (1.44" ID) on a 1.63"R for about $16.50 each and they also have 45 deg and 135 deg in the same size/radius for a little less/more respectively

otherwise if you find them at a lower price please post it up

I'm saying you won't have enough space to fit a nice long merge collector

the pipe projection into the Tial housing will only be about 1/2" - 3/4" depending on your pipe OD plus the TiAl inlet v-band is 1/2" deep to the turbine housing entrance

.