butterfly effect

My stage 3 kit is $1200. I am looking for a big company to manufacture and market the product hopefully US. I have a lj torana fitted with a 500 hp chevy , dual 3" exhaust fitted with my stage 3 kit. I am going to make a demonstration video soon to explain the operation. Hyperflow Technologies , now dead , used to market it. Not many people know about it. I sold some to Evotechnics Motorsport in Abu Dabi. One of the good features of this system versus bimodal mufflers is when you want to swap vehicles you can remove the kit .

If you check out my stage 3 active system , www.activeexhaustsystems.com.au you can see the advantages. Drones are usually caused by high flow systems that are in cruise mode with low gas flow rates. With my kit when in low performance mode there is a generated back-pressure , regulated. The drone is gone. When tripped into high performance mode by tps switching max flow is achieved. It is a closed loop system which is fully adjustable. There is no loss of performance only less noise most of the time and no drone.

The system appears to have a natural resonant point that is inconvenient. It is all a black art. Repositioning any component in the exhaust will have an effect. This sometimes can't be done. I presume it has a balance tube or x pipe. If not fit a balance tube. If it has either of them temporarily block one pipe at the exit and go for a short drive and see if the drone is gone. Big chance it has. Bigger mufflers will probably have a positive effect. Active systems rid this problem. Anyway do the block test . (Active Exhaust Systems)

I can supply either a 3" or 3.5" muffler / resonator combo without any stepdowns that have max flow and a deep , quieter sound. AES is the name. If you want to go quieter check out active kits at www.activeexhaustsystems.com.au

409 rusting like mild steel. I don't think so. I don't know where you get your information from but I would be changing sources.

I am but a small fish in a big pond but my mufflers are designed to give the best possible performance without being influenced by other requirements such as sacrificing performance for cheapness.

Try AES mufflers for high flow , no stepdowns, deep ,quieter sound.

I can supply a 3" resonator 5" diam. or 3.5" bore , 4.5" diam. 409 s.s. perforated tube with expansion joint , packed with inox (high temp.Both 400 mm long.

A pic of my muffler tester. A great tool for r&d. Only works for absorbtion mufflers which mainly operate on the higher frequencies resulting in a deeper sound.

This technology to test absorbtion , non baffled mufflers , has been around since the 1950's. It speeds up the development process to find the optimum ingredients to suit the application. Obviously there could be a variation in the real world but it is surprisingly accurate. It works for me.

Try again.

Pic of absorbtion muffler tester.

It all depends on the flow rate of the original muffler compared to that of the replacement. I f there is a substantial difference then the answer is yes.

Ok. I have a testing apparatus. I will put a pic on soon. What it comprises of is a large garbage can ( plastic} with a 7" diam muffler inside it surrounded by rockwool. Inside the muffler is a 6" diam speaker. The exit pipe from the muffler also exits the top of the garbage can. I then ( via a cd) excite the speaker with an exhaust noise sample relative to the vehicle the muffler is to be fitted to. The muffler to be tested is connected to the exit pipe coming out of the garbage can. I set my db meter to record the max reading. The reading I got for a 7" diam muffler was the same for a 7" deep but 9" wide ovalised version so it appears that the packer had maxed out initially. Actually I was surprised. They were identical length. I think the same thing will happen for a 3.5" bore muffler at 8" diam.

My AES 3" , 7" diam. rear muffler with a resonator is quiet. I havn't db'd the combo but I expect it to be legal. I did some tests recently and found that the combination of a 3" perforated tube fitted to a 7" diam. housing is about as good as it gets. If the housing is ovalised so the crosssectional area is increased resulting in more packer nothing is achieved in the quietening department. If the length is increased it will become quieter but there is a limit.

The AES active exhaust was originally marketed by Variflow Technology then Hyperflow Technologies and now AES. I designed it and was associated with the other companies. I am now getting organised. I was thinking of finding a company such as Sound Performance in the US to market it. Made in larger numbers the price would come down. At the moment I sell the stage 3 kit for $1000. I found that most don't understand how it operates. It replaces bimodal mufflers , Varex being a very nasty version. HM Headers in Australia market bimodal mufflers. Wortec in the UK do the same. They are expensive. I will soon make a video explaining the operation of my system. The end result e.g gtr32 fitted with 4" exhaust system also fitted with large , straight through mufflers and 4" stage 3 kit is a quieter free rev up to 10 db , drone elimination and quieter on part throttle. It works beautifully. Earlier on Croydon fitted several with success. The valves that I made are greatly improved. I know these kits are not for everybody but for the older guy who has spent much on his very powerful machine it is the icing on the cake. That is why companies such as Ferrari, Maserati , Corvettes etc use bimodal mufflers.

The muffler is 7" diam. and 500 mm long. It might be a little squeezy in the length department. If so it will be reduced. The bigger the muffler is the quieter it will be without hp loss. It is fitted ith a 409 s.s. perforated tube. It is packed with a mixture of stranded fibre-glass and inox which gives it a higher temp. rating.It has a quieter, deeper sound. If the muffler was intended for circuit racing the fibre-glass would be discarded and replaced with gtb or inox. The perforated tube also has an expansion joint to stop metal fatigue when hot. The resonator is 4.5" diam. and 400 mm long. It has same perforated tube and packed with inox.

My pics.

Check out the stage 3 AES active exhaust , www.activeexhaustsystems.com.au. It does it all.

A pic of my new 3 1/2" bore rear muffler with absolutely no stepdowns. High flow with a deep , quieter sound.

Woops.There will be NO power robbing stepdowns.

I can supply rear muffler 3.5" bore , 7" diam. 500 mm long almost flat spun ends or with exit coned end , mild steel, externally tigged , 409 s.s. perforated tube with expansion joint to prevent fatigue , quiet deeper sound, $400. Same specs but 3" bore $380. Don't have dimensions for resonator yet. It will be something like 5" diam and 400 mm long.There will be power robbing stepdowns. This package will work well. If 500 mm long proves to be a difficult to fit I will come back to 480 mm. Time will tell.

If there is a problem with the muffler or resonator a restriction point can sometimes be indicated by heat marks , brown usually. The only accurate way to find the culprit is to pressure test the system on load. The starting point is engine side of cat. The reading is the summation of all restriction in the exhaust.Repeat this process in front of the remaining components. Where the pressure drops indicates that closest component towards the engine is the culprit. If there is no pressure drop , remains high then it will be the rear muffler.

The rear muffler 3.5"bore, no stepdowns, for the gtr 32 I think can be 500 mm long and 7" diam. Flat spun ends are preferable rather than a cone version because the muffler contains more packer but a combination can be used if prefered. Not too sure yet about max resonator specs. It will be interesting to db the result. I expect it to be good. Even with a 3.5" exhaust it would be preferable to go to 4" from turbo to 3.5" resonator. The exhaust flow rate will increase by an unknown but reasonable amount. Could be better than expected. The dreaded drone can always be a problem with big systems on low , cruise mode. It is a bit of a lottery. Most times you win but sometimes not. Acoustics is a complicated science.Helmholz tubes can eliminate them. My stage 3 active exhaust kit destroys them.

I was recently told that it is common practice with some japanese high performance aftermarket exhausts including those intended for nissan gtr's to fit restrictors or stepdowns as they are called in the mufflers to obviously reduce noise levels. That will be achieved but unfortunately at the expense of flow capacity as is being found out when performance modifications are carried out on the engines. I will soon make available a rear muffler and resonator , both round , mild steel , 3.5" bore size at a reasonable price. I now have access to s.s. 3.5" perforated tubes which I imported. These mufflers will have a deeper , quieter sound and max flow. They are painted charcoal grey. I never intended to make shiny , look at me mufflers just something that does the job efficiently.