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Hi all,
I'm planning to get my GReddy Ti muffler repacked, and want recommendations on the type of material to specify for rotary heat. As we all know, "high temp" anything in a piston engine context that most are used to is often not sufficient on a turbo rotary track car.
Hey Peter, a while back I found some ceramic refractory insulation on the mcmaster-carr website that I was planning on giving a try once I got my contraption running. You could probably use it in addition to stainless steel scrubble or wool. https://www.mcmaster.com/products/re...lity~flexible/
Last edited by SETaylor; Jul 22, 2024 at 01:20 PM.
Hi all,
I'm planning to get my GReddy Ti muffler repacked, and want recommendations on the type of material to specify for rotary heat. As we all know, "high temp" anything in a piston engine context that most are used to is often not sufficient on a turbo rotary track car.
Recommendations/experience/results? Thanks!
Ive got a turbo Ls3 but its gonna put out some heat so im going to use this ceramic wool as its good to 2500f.
Other options are Basalt fiber good to 1500f repeated and 1800f it becomes brittle and degrades.
fiber glass is even lower than that and will degrade after the first time you run your car hard.
scrubble handles the heat well but doesnt muffle noise worth a ****. It also rusts and you do not want that corroding inside your titanium muffler (mixing oxidizing metals and heat is not a good idea)
A heap of guys did home builds on Ausrotary about a decade ago. I think the conclusion was best life/sound suppression was perf tube, thin wrap of stainless (scouring pads even) then "rockwool" ceramic insulation. These guys turned conventional glass packing to marbles/smoke in short order.
pretty much tried it all; metal wool, scrubble, rolled up metal mesh, many various ceramic/synthetic etc wool products
SS scrubble lasts forever, but the sound damping isn’t very good
regular steel wool tends to mat/pack down and it’s steel, which the inherent moisture within an exhaust system will turn it into rusting mush in short order and the carbon will eventually destroy stainless steel.
rolled up metal mesh is what some of the WC/GrandAm 20Bs ran in their mufflers, but heavy and little sound damping was my experience
pretty sure I have a big box of heavier gauge SS wool around though, pm me your address and I’ll fill and send a box your way if you want some.
but I use a motorsport ceramic wool muffler packing product from Germany (by SP Schalldämm Technologie) called Silent Sport Premium that quieted down, lasted in the rear mufflers, and is super light with my Renesis comp engine (~1650°F EGT). Used to be able to buy it in the USA, but now difficult to find here:
I think the consensus on material is ceramic wool or ceramic fiber, I've got three different recommendations for brands that all look into but that seems like the ticket. I'm going to put in a new center muffler as well but I'm considering just having them open up a brand new muffler take out the fiberglass stuff that comes in most and go ahead and put the ceramic stuff in so I'm not revisiting this again in six months to a year. Thanks everybody!
Other options are Basalt fiber good to 1500f repeated and 1800f it becomes brittle and degrades.
fiber glass is even lower than that and will degrade after the first time you run your car hard.
scrubble handles the heat well but doesnt muffle noise worth a ****. It also rusts and you do not want that corroding inside your titanium muffler (mixing oxidizing metals and heat is not a good idea)
The scrubble from Profabrication is 304ss, so it will last a little longer. I use these along with a cat (to keep noise down on the street) in my system: https://www.rx7club.com/market/1158570 I have yet to see the scrubble break down and rust from heat cycle related fatigue. Not a big cost to repack every few years if doing a lot of track events.
The scrubble from Profabrication is 304ss, so it will last a little longer. I use these along with a cat (to keep noise down on the street) in my system: https://www.rx7club.com/market/1158570 I have yet to see the scrubble break down and rust from heat cycle related fatigue. Not a big cost to repack every few years if doing a lot of track events.
347ss is the best version of stainless for heat and the 2nd is 321ss, 304ss degrades and will rust eventually. It also doesnt reduce noise very well at all hence the need for your catalytic converter to quiet it down. It might be worth doing scrubble around the perforated pipe then use the ceramic wool packing around that for the best of both worlds?
Im going to be running 3.5” titanium from the turbo back and plan on running 2 ceramic packed mufflers (home made magnaflow style).
you make a decent product, I hope you wont take too much offence to this but you need more heat in your welds and you need to move faster. You’ll use less filler and gas, and the stainless will also not overheat (causes the gray colors in your welds). Took some time for me and adjustments on my welder to get it just right but your welds will be stronger and look better.
I never had T304 scrubble rust or breakdown, and have never seen 321 or 347 scrubble offered any where ever. Which only applies to strength stress, and I don’t seeing it being applicable to scrubble in a muffler.
I have a bag of the Silent Sport Premium that was posted above I could send you Peter, but might be best to verify how big the muffler cavity is to make sure it will be enough.
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