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-   -   DIY Full Titanium Exhaust Discussion (https://www.miataturbo.net/race-prep-75/diy-full-titanium-exhaust-discussion-98438/)

aidandj 10-31-2018 12:00 PM

Slowly lower the heat until you see the puddle start to solidify. Don't just cut the heat.

G19Doug 10-31-2018 02:43 PM


Originally Posted by LukeG (Post 1508798)
I bought a Furick BBW, but it only does a 3/32 tungsten and I need to use a 1/16 on the tubing. So for now I'm just pumping 35cfm through a #8 pyrex cup as practice. Will be getting a furick cup for a 1/16 tungsten when I can figure out which one to use.

I thought about stainless but titanium is so gorgeous when done right.

What I do is just grind the 3/32 to a much more acute angle over a distance of maybe 10mm. Then you can run the big cups.

G19Doug 10-31-2018 02:46 PM

I've made a few Ti bike exhausts for friends. The last one was a 2.5" one for a turbo bandit 1200. Totall made from pie cuts it juiced a shed load of gas and was pretty tedious. The ting that i find is the puddle seems abit more sticky compared to stainless. Doesn't flow as well.

LukeG 10-31-2018 04:18 PM


Originally Posted by G19Doug (Post 1509104)
What I do is just grind the 3/32 to a much more acute angle over a distance of maybe 10mm. Then you can run the big cups.

Nice! I'll try that. thanks!

phocup 02-09-2020 01:26 AM

Hey Luke, any update on how this turned out ? What setup did you end up with ? I just got an AHP 201XD and a tank of argon .. so my mind is racing with possible projects .. but my welding experience so far has been pretty much making boogers with a flux core .. but i have a scrap yard near me with ton of alum / stainless practice material for cheap. No TI though ( unless I wanted a 1" thick slab for a tabletop or something ).

Any also for anyone else experience with ti .. how does the Vibrant Ti stuff compare vs TiCon ? They seem to be available for much cheaper.

curly 02-09-2020 10:50 AM

We used vibrant for our lucky dog car. We get a great deal and a coworker agreed to weld it for us. Turned out gorgeous. I will say endurance racing quickly burns out your $300 vibrant ti resonator. I’ll try to get a pic or two soon.

curly 02-09-2020 10:51 AM

Meh, just check out race invader’s page, couple pics of the exhaust and header for our ecotec swap:

LukeG 02-09-2020 01:21 PM


Originally Posted by phocup (Post 1561729)
Hey Luke, any update on how this turned out ? What setup did you end up with ? I just got an AHP 201XD and a tank of argon .. so my mind is racing with possible projects .. but my welding experience so far has been pretty much making boogers with a flux core .. but i have a scrap yard near me with ton of alum / stainless practice material for cheap. No TI though ( unless I wanted a 1" thick slab for a tabletop or something ).

Any also for anyone else experience with ti .. how does the Vibrant Ti stuff compare vs TiCon ? They seem to be available for much cheaper.

I ended up needing so many custom pieces to get the exhaust to work, I had no choice but to go stainless. I'm sure I could have gotten everything to work in Ti eventually, but it would have been a $10k exhaust. Also, stainless seemed to care less about a back purge. I started out trying to back purge every piece and literally needed to refill my 125cu ft argon tank every other day. That was stupid. Stainless exhaust is perfectly fine without a back purge. This isn't some aerospace grade structural component I'm trying to post on instadouche.

TiCon (stainless bros) are amazing. After spending a couple grand with them over the years, they assigned me an account manager LOL. That's how you know your builds have gotten out of hand, you start getting assigned account managers from your parts suppliers.

Scaxx 02-10-2020 12:27 AM

Saying that stainless doesn't need a backpurge is just downright wrong. Don't spread that misinformation. It makes the weld brittle as well as taking the stainless qualities out of the weld. Not to mention the brittle sugaring on the backside that can absolutely destroy anything downstream of it in a turbo situation. It also helps the puddle flow and the stability of it. Do what you want with your own components but don't spread misinformation.

phocup 02-10-2020 12:51 AM


Originally Posted by LukeG (Post 1561738)
I ended up needing so many custom pieces to get the exhaust to work, I had no choice but to go stainless. I'm sure I could have gotten everything to work in Ti eventually, but it would have been a $10k exhaust. Also, stainless seemed to care less about a back purge. I started out trying to back purge every piece and literally needed to refill my 125cu ft argon tank every other day. That was stupid. Stainless exhaust is perfectly fine without a back purge. This isn't some aerospace grade structural component I'm trying to post on instadouche.

TiCon (stainless bros) are amazing. After spending a couple grand with them over the years, they assigned me an account manager LOL. That's how you know your builds have gotten out of hand, you start getting assigned account managers from your parts suppliers.

Man .. I need to step my spending game up .. I dont think I'm any where near assigned account manager levels .. #goals :rofl:

As for the gas usage .. I only got the 80cu tank .. google tells me that should last me ~4 hrs of welding .. I knew back purging the would take more gas but 125cu ft every other day is crazy. Might have to pick up a second bottle just for back purging. Were you using anything like a purge plug ?

LukeG 02-10-2020 02:38 PM


Originally Posted by Scaxx (Post 1561780)
Saying that stainless doesn't need a backpurge is just downright wrong. Don't spread that misinformation. It makes the weld brittle as well as taking the stainless qualities out of the weld. Not to mention the brittle sugaring on the backside that can absolutely destroy anything downstream of it in a turbo situation. It also helps the puddle flow and the stability of it. Do what you want with your own components but don't spread misinformation.

When is the last time you saw a stainless exhaust fail from not being backpurged? I've had conversations with multiple people who make stainless exhausts for a living and all of them told me backpurging a stainless exhaust to weld it is not essential. Is it perfect, no. Does it work, yes.

Scaxx 02-10-2020 03:52 PM

Yeah, I've seen people say that too, you know what their true reasoning is? It's because it costs time and money, not because they're worried about doing it right. There is a right way and a wrong way to weld stainless. Not purging is wrong (solar flux works too Aidan ;)). Just because someone does it for a living doesn't give them validity in my book, I've seen more half-assed fabrication jobs by "professionals" than I'd like to admit.

Justify it all you want, but don't go around telling other people it's fine.

Here's an article from Burns on welding stainless if you really need sources.

https://burnsstainless.com/blogs/art...tep-guide-2019

"And that brings us to proper welding techniques.

We always recommend TIG welding as it leaves a beautiful strong weld bead, though MIG welding is also acceptable – but frowned upon by header-snobs.

When welding stainless steel, it is important to back purge the weld with Argon.

This will prevent the formation of carbon precipitates that will weaken the weld.

It also helps control the temperature of the heat affected zone resulting in a properly golden-colored weld."


TeamRX8 04-28-2020 12:02 AM

I just use 20 Ga T321 and it can take the heat and stress fatigue better over time, occasionally 18 Ga. up close to the engine due to higher rotary temp

IMSTuner 05-01-2020 07:29 AM


Originally Posted by Scaxx (Post 1561821)
Yeah, I've seen people say that too, you know what their true reasoning is? It's because it costs time and money, not because they're worried about doing it right. There is a right way and a wrong way to weld stainless. Not purging is wrong (solar flux works too Aidan ;)). Just because someone does it for a living doesn't give them validity in my book, I've seen more half-assed fabrication jobs by "professionals" than I'd like to admit.

Justify it all you want, but don't go around telling other people it's fine.

Here's an article from Burns on welding stainless if you really need sources.

https://burnsstainless.com/blogs/art...tep-guide-2019

"And that brings us to proper welding techniques.

We always recommend TIG welding as it leaves a beautiful strong weld bead, though MIG welding is also acceptable – but frowned upon by header-snobs.

When welding stainless steel, it is important to back purge the weld with Argon.

This will prevent the formation of carbon precipitates that will weaken the weld.

It also helps control the temperature of the heat affected zone resulting in a properly golden-colored weld."

I'm wondering if they were referring to the old migs. A lot of the new migs are more complex and has way more features like the HTP pro Pulse.

TeamRX8 05-01-2020 11:30 AM

having been employed in stainless steel fabrication for the last 25 years; they do good work, but good luck purge welding tubing with MIG ...

that said, for lap/slip joints and welding tube to thick plate flanges it can probably do a good job with proper fitup. The biggest issue with Ti though is the gas shielding is extremely critical compared to aluminum or stainless as has been well discussed already. I don’t see MIG serving that purpose well. Employing the the wrong technique is no different than empowering people not up to the task; you only end up with bad, expensive mistakes and issues piling up faster. It may not be apparent until stuff falls apart in short order. As anyone who ever built an aluminum exhaust found out.

contrary to popular belief, Ti is not very compatible with high exhaust temperature; the stress fatigue strength falls off too much past 500*F You can make it thick enough to avoid the reliability issue, but then weighing cost, weight, availability (until the last several years or so Ti was very hard to source out) then light gauge stainless wins imo. Use the more expensive T321 at the front and T304 is sufficient in the rear even with 20 Ga. Then there’s always 22 Ga inconel if you want to go true baller ...



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