Anybody tried an aluminum exhaust?

I remember that car! I was shocked the first time we happened to line up at the beginning of the straight. Its VERY rare for anyone to out-drag us. I was not mentally prepared for that (especially since I was expecting you to have a 12A...)

Honestly a couple times I was trying to line up on the back straight with you all. Sucks that I had to let off 2/3rds of the way down so I could make the turn. Then you'd go flying by. I don't think anything out dragged us that day. I appreciated the clean racing and enjoyed dicing it up. It was a nice introduction to crap can racing.

Went through 11 sets of pads that race. In retrospect RockAuto Clearance pads may not have been the most wise choice!

Tom Heath wrote: When I was living in Japan, the rich dudes were using Titanium cat backs with Inconel (!!!!) downpipes. Ever priced raw Inconel?

Not only is it expensive, but for an exhaust, it makes pretty much no sense at all. Weird. Must be like those guys that gold plate their wheels.

"I got sick of throwing $100 bills in the shredder this morning, so I decided to spend as much money as possible on this wheel for no reason."

Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light.

I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job.

Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Dave spot...Dave point...whatever, the point is I remembered, and therefore should be receiving a cookie any minute now.

I prefer Macadamia or Snickerdoodles...

DILYSI Dave wrote: Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light. I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job. Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Stainless is corrosion resistance enough for an exhaust system, and 'handling high temperatures' is indeed true, but to what gain? The temperatures there are not high enough that regular old Stainless would be a poor choice.

Disclaimer, I am an engineer. Choosing high price exotic materials every time is lazy, especially if they really aren't good choices. Nobody wants to hear this, but a guy who can engineer a bracket to hold five things on a Camry for $2 is a better engineer than the guy who gets to engineer an engine on a Ferrari.

tuna55 wrote: Disclaimer, I am an engineer. Choosing high price exotic materials every time is lazy, especially if they really aren't good choices. Nobody wants to hear this, but a guy who can engineer a bracket to hold five things on a Camry for $2 is a better engineer than the guy who gets to engineer an engine on a Ferrari.

But which would you rather do?

tuna55 wrote: Nobody wants to hear this, but a guy who can engineer a bracket to hold five things on a Camry for $2 is a better engineer than the guy who gets to engineer an engine on a Ferrari.

Disclaimer: I'm an engineer too, and no engineer would make that conclusion without more data to support that thesis.

DILYSI Dave wrote: Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light. I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job. Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Would that have been SMF legal still? Now you've got me wondering about the exhaust on the Escort.

tuna55 wrote:

Tom Heath wrote: When I was living in Japan, the rich dudes were using Titanium cat backs with Inconel (!!!!) downpipes. Ever priced raw Inconel?

Not only is it expensive, but for an exhaust, it makes pretty much no sense at all. Weird. Must be like those guys that gold plate their wheels. "I got sick of throwing $100 bills in the shredder this morning, so I decided to spend as much money as possible on this wheel for no reason."

F1 cars have inconel exhausts, makes perfect sense why you would stick one on a Honda.

Dave Coleman? never heard of him, until this thread, but i'm a fanboi now. project miatabusa speaks to me on so many levels.

92CelicaHalfTrac wrote:

DILYSI Dave wrote: Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light. I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job. Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Would that have been SMF legal still? Now you've got me wondering about the exhaust on the Escort.

I am wondering about that to for the Yugo.

92CelicaHalfTrac wrote:

DILYSI Dave wrote: Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light. I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job. Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Would that have been SMF legal still? Now you've got me wondering about the exhaust on the Escort.

Yep. Rules say that exhaust has to exit behind the driver or to the side. Front bumper dump would exit to the side.

Now, I was concerned about being able to get the car quiet enough, and put my odds on being able to pull that part off at 50-50.

DILYSI Dave wrote:

92CelicaHalfTrac wrote:

DILYSI Dave wrote: Why no sense? Inconel is super corrosion resistant and handles remarkably high temperatures, and titanium is equally corrosion resistant and uber light. I agree that it's a retarded way to spend money on a street car, but not because of the lack of suitability for the job. Had I moved forward with further mods on my Civic, they were going to invovle a 3" titanium straight pipe right off the turbo, dumping out the front bumper like the previous MX6.

Would that have been SMF legal still? Now you've got me wondering about the exhaust on the Escort.

Yep. Rules say that exhaust has to exit behind the driver or to the side. Front bumper dump would exit to the side. Now, I was concerned about being able to get the car quiet enough, and put my odds on being able to pull that part off at 50-50.

Well... i meant with no cat. Or does street mod not require cats?

No cat required.

DILYSI Dave wrote: No cat required.

Thanks!

Looks like further hackage of the baller Corksport exhaust will be required for the greater good.

THE GREATER GOOD.

Not sure if this helps but the later J35's have a built in Al header on the head.

Btw I'm a massive fan of Dave Coleman's work and although it sucked to loose SCC at least there's Motoiq to fill the void.

ProDarwin wrote:

DILYSI Dave wrote: "Don't start with that "you need backpressure" horseE36 M3. It isn't true." You and me baby. One of these days we will correct this myth.

One of the best myths! Right along side "torque wins races" and the hub-centric wheel myth.

Man, we should get together on this. I'll handle the myth about water moving too fast through the radiator to cool the engine off. These four myths comprise about 95% of my automotive tech nerd-rage.

I hated to see this topic degrade into nothingness.

In reply to Scargod :

Well then, let's revive it. I finally answered my on question and the answer is NO you cannot get away with an alunimum exhaust. It worked fine on the street, but once Miatabusa was reliable enough to survive a track day, the exhaust melted! It was also really loud. Not just out the tailpipe, but straight through the walls of the tube. Rebuilding the back half in stainless steel dramatically cut down on the noise coming up through the floor. Its a shame, because the car weighs a total of 2016 lbs now, and with the aluminum exhaust, I'm pretty sure I would have been under 2000.

Holy crap a 10 year bump that resulted in a super useful response- unheard of!  I remember seeing this back in the day and had "you can maybe get away with aluminum exhaust tubing if you don't hit it with anything" tucked away in my mind ever since.  I appreciate the update and would also like to figure out where another 16lbs might be hiding on Miatabusa.

Too bad on the result, but thanks for the update!

Just curious, how bad did it melt? Did the whole exhaust turn into aluminum splatters on the track or did one or more welds let go? One of the most common failures I've had on the track is welds in the exhaust coming apart even with conventional materials, I've had it happen to a custom-made exhaust and a big-money HKS piece.

^ I routinely run exhaust systems made from the same aluminum tubing I use for intercooler pipes without incident both on street and autox cars. no melting or cracking in my experience. As titanium materials and techniques have become more mainstream and pricing has entered reality that's probably the better answer unless you have a lot of aluminum on hand and are trying to be economical 

In reply to eyesoreracing :

So, the Miatabusa lives?

I was following back in the day, but eventually everything went silent...