Simple Exhaust Questions
 

I hate starting things like this but; i'll be starting my turbo 6PI build here in a few and I've been looking over exhaust components.

I only have a 2.5" T3 flange coming off of my turbo and I was playing with the thought of using stainless steel on the entire system. The problem with that is I'm not even sure it's necessary that close to the turbo (to be stainless). I was planning on using the T3 flange adapter that goes from 2.5" T3 to 3" V-Band. The only thing I have against that is that it's not stainless.

I'm also looking at the Engine to Header flange that Racing beat sells, they do not list it as either mild or stainless, but again would it matter when it's that close to the turbo?

I am planning on running 3" stainless back to the 3" stainless pre-silencer, then off the Y-pipe going to a 2.5" dual exhaust setup again with stainless.

Am I just being anal about this? Or should I really invest in trying to find some stainless steel flanges?

From my experience, the hardware is more important than the piping. But also, it depends on where you live. Down here in the TN, I can use whatever and have zero corrosion. When I was in Chicago, only SS would do.

I live in virginia and so I see everything, they also salt and sand the roads so the parts i listed will be fine I think. I'm just concerned about the flanges as converting a standard stainless T3 flange to a V-band might be a real big pain in the ass.

ATP Turbo?


-Ted

What do you mean when you say "i'm not sure its necessary to be stainless (that close to the turbo)"

I wouldn't use anything else. If I had some mild tubing laying around and felt like it - I may use that - but stainless is where its at for exhaust IMO. I've found it can distort alot while welding though.

But yeah, ATP turbo has *EVERYTHING* you could want for building that. Minus perhaps an engine flange. IIRC, they have a T3 to 3" vband adapter they sell:

Here's one: http://www.atpturbo.com/Merchant2/me..._Code=ATP-FLS1

Another: http://www.atpturbo.com/Merchant2/me..._Code=ATP-FLS1

It does seem wasteful to go from 2.5" to 3"... with that bottleneck in there, there's either not going to be nearly enough flow to justify a 3" pipe, or there will be enough, but you'll have some serious backpressure issues in the manifold pre-turbo. Finding a T3 to 3" adapter might help, but it really depends on the size of the turbo itself.

Is it a real T3? Because they're very small turbos for a 13B, even on the smallish size for a 12A, really. Even a hybrid T3/T4 is going to have the smaller T3 exducer, which is bound to create a huge flow restriction unless you're running low boost (6 psi as a guesstimate, you'd need an exhaust backpressure gauge to find out where your "max" is) and have a large external wastegate which dumps back into the downpipe.

I would say take your time and invest your money right the first time.

go all 3" and all SS piping..

and IMO (external gate that dumps to atmosphere FTW)


I also feel that a presilencer is junk.. IME (with racing beat) the presilencer only held up for maybe a month then it did not silence anything.

Holy helpful posts batman!
Yeah, I've checked with them. I will address the problems when I answer the other people below and you'll see why I'm asking for opinions on this problem.
I have a Turbonetics 60-1 F1-62 Four Bolt T3 Turbo. If you read the bit about the first flange you posted, it's constructed out of mild steel. They do not sell an SS version of that flange which means I'd have to buy a V-Band flange and a regular T3 four bolt flange and have my friend weld it together. Not impossible but a little more work intensive than going with that mild steel flange.

The other option would be to just get the SS T3 flange and weld the pipe directly to it and avoid using the V-band at the Turbo.
Turbo is a 60-1 F1-62 .77AR Turbonetics Inc Turbo. I'm not planning on running that big of boost pressure since this is HI-Compression. I'll be keeping an Eye on exactly how much boost I'm dumping into the engine.
I'd rather have a presilencer than not as a visual inspection is still mandated by the state and a presilencer is usually mistaken for a Cat if I do not have one.

As for the Engine to Header Flange I saw MazdaTrix sells a SS version of it. I'm wondering though that with these prices if it won't be cheaper for me to just design them up in Inventor and shoot them over to the machine shop to get cut (talking about the flanges).

Would I need to worry about anything if I just made the Engine to Header flange out of a solid piece of SS? Where if you compare it to what MazdaTrix makes it looks to have some amount of relief on the back side of it, not sure if it's just for looks or actually is functional.

I also have an external Wastegate that will be dumping into the down pipe because I already get enough attention from the police. I need no more.

The other question I have would be this: Will I get a quiet enough exhaust note with just using a single 3" inlet 3" outlet muffler that racing beat sells or would I be better off sticking with a Y-Pipe and a 2.5" inlet and 2.5" outlet mufflers?

You don't *need* that piece to be SS. Your turbine housing isn't SS anyways. The SS Vbands you'll use after the adaptor will all fit together fine.

I'd highly recommend avoiding that. You want an easy to remove connection at the back of the turbo.

Whether you use the SS flange by Mazdatrix, or make your own, you can be certain either one will need to be surface ground afterwards. Mild will not be as easily warped.


More mufflers will always be quieter. Offset inlet/outlet will kil alot of noise.

3" single exhaust is NOT quiet.

Thanks Classic. I have a few more questions and desire some more opinions. This is my first Custom exhaust project.
Rojer that. I was looking at it the prices of everything and from ATP the V-band SS flanges are about $20 each. So if I were to make V-Band connections for the entire 3" sections I would need $100 worth. I was thinking of just using the adapter and 1 V-band at the turbo as per your following suggestion. Out of curiosity however how much does it cost to get a flange surface ground and where can it be done?


So I really should go with Mild steel on the engine to header flange then. While I was pricing everything out I came up with a total price for all the flanges to be $242 from ATP and MazdaTrix. This includes:

1. Down Pipe flange (V-Band) Stainless Steel
2. 4 3" Stainless Steel 2-bolt Flanges (For the Pre-Silencer)
3. 4 2.5" Non-Stainless 2-bolt Flanges

To me that seems quite expensive. I'm pretty sure I could just design them up and shoot them out to be Cut for cheaper than picking them up individually like that over the shelf. I think I'll do that and get a quote, depending on what you tell me about grounding I may just do that and design them all, not to mention I could then get stainless steel and not really worry about the shipping. :)


I don't think the mufflers they offer in racing beat are offset. I'll check Summit and see if I can't find a less expensive SS one that is Offset.

You could always get coated mild steel.

Cost will vary but any machine shop can easily do it. When I needed to have the flange on my Greddy log manifold surface ground it cost me $40 at a local place.


Yeah if you can have them made cheaper just get them cut. Main reason I go to ATP is because when I'm doing a project like this, I'll just order everything I need since they have it all. Its just easier for me, but just do whatever's easiest/cheapest for you. If I could have that stuff made real local I would......


Yeah summit will have CHEAP mufflers. And don't sweat offset entry/exit killing flow. You should be able to see straight through if you hold the muffler up, but as I'm sure you can envision, sound get cancelled from bouncing around inside them vs. shooting through a tube.

Cheap as in quality, or cheap as in cost? I found some 304 stainless one's that are offset for about 76 each. Not a good buy? I think they're magnaflow.

Alright, I did a price out work sheet on everything I'd need minus the piping. Here's a file of it of 4 different groupings/setups:
The Good Version
The HTML Version
I didn't do two final setups using a regular flange and V-band both in stainless steel, but you get the general picture here.

Suggestions, or comments?

EDIT cheap as in cost. Nothing wrong with a stainless packed magnaflow. I ran one for about 3 years before I changed my entire setup.

The spreadsheets look good? Just depends on what you want to run I guess. I should mention, that I'm using vbands for all my connections (at the turbo, bottom of down pipe and back of midpipe/cat section) but they are difficult to get to seal 100%. There's no "exhaust leak" noise from mine, but if you remove the clamps you can see where a little gas has escaped around 2-3% of the v-band