Aluminum Muffler build and wastegate re-route

[turboglenn]

Well, after about a year of debating it (and about 7+ years of being sick of fart cannon exhaust noise) I've decided i'mgoing to use some spare 3" aluminum tubing and some sheet/plate that i have laying around and build a nice chambered muffler for the car. It will sit where the cat use to be and i'll be leaving said "fart cannon" in place for looks

I've also decided i'm going to re-route the gate which is another mental battle of been fighting within myself for some time now (if i drop too much HP i'll just un-do it)

I know many will complain i'll loose power with the chambered muffler but keeping losses to a minimumwillbe my engineering challenge (along with keeping db's low) I've been in way too many fast turbocharged cars with normal mufflers to worry about it hurting performance, and a couple extra PSI will make up for anything i might loose.

I'm the type that considers a thread in this section without pics to be useless waste of space, so i'mguilty for now but i'll hav epics up tonight of whatever part i get started on

I'm also going to re-install my methanol injection jets pre-turbo, and stick with a really small jet (like an M3) and urn pure methanol for cooling (i don't have any detonation issues to fight yet so cooling things down is my current goal) While i'm at it i'll probably add a -8 fitting to the intake pipe for the catch can setup i'm slowly working on putting together.

pics to come !!

 

[Bud92gsx]

Subscribed

 

[turboglenn]

Thanks!! And for anyone with experience trying out chambered mufflers in our situations, i'm always open to input on design and or what to do or not to do. I've got several ideas for the internal make up of the muffler but i'd be really grateful for any type of input or advice based on facts and or experience... I'm trying to get as quiet as possible without getting so restrictive that using a cut-out would be a better option

 

[Bud92gsx]

Too much talky talky(Billy Madison).Pics/drawings or ban Glenn.

 

[Chrispy0530]

Subscribed as well! Looking forward to reading your results as you progress through this.

 

[turboglenn]

, Ok well to avoid the upcoming ban for lack of lookie-lookies, here's what i got done since the post. I moved the alky injection to immediately pre-turbo inlet. Running an M5 jet(my smallest) and pure methanol (HEET) I programmed the haltech to trigger this again and got rid of the anti-lag which i don't need with this turbo and intake manifold now 8)


as for the muffler i'm still just loking at pieces of piping figuiring out how i want to piece it together (also realizing i'm gonna have to buy V-bands in both aluminum and SS in order to join an AL muffler to my SS exhaust ) it never ends(the spending and the work that is)

 

[Bud92gsx]

Starting to look sexy.

 

[bastarddsm]

Thanks!! And for anyone with experience trying out chambered mufflers in our situations, i'm always open to input on design and or what to do or not to do. I've got several ideas for the internal make up of the muffler but i'd be really grateful for any type of input or advice based on facts and or experience... I'm trying to get as quiet as possible without getting so restrictive that using a cut-out would be a better option

I run a flow master on mine..It's loud and sounds like poopy. Turbo cars need the straigh thru style muffler on them. Maybe a 3" glasspack where the cat would be?


Also recirculate that WG.. you won't loose power...They don't flow much gas out of them. At full boost and high RPM, it will be open around .050" How much can flow out of that?

 

[turboglenn]

I run a flow master on mine..It's loud and sounds like poopy. Turbo cars need the straigh thru style muffler on them. Maybe a 3" glasspack where the cat would be?


Also recirculate that WG.. you won't loose power...They don't flow much gas out of them. At full boost and high RPM, it will be open around .050" How much can flow out of that?

I will be keeping the straight through muffler on there but adding the aliminumunit to further the noise reduction. As for power losses through re-routing the gatethere's several factors, the most important being that when routed in too close to the turbine outlet (lesthan 18 inches i've been told) it disrupts the turbines flow as well as it being more air to go through the same 3" piping.

I've seen several dyno proven tests on the internet on everything from SRT's to RX-7's showing anywhere from a 30 to 50hp loss from re-routing a once open gate, then watching them get the power right back when setting it back to dump to the open atmosphere. (these were all in the 500whp level when tested)

THis knowledge has kept medumping atmosphere for a long time, but with the knowledge about re-routing too close t5o the turbine i wonder how much power a lot of people are giving up or not getting when they run mitsu style o2 housings or those aftermarket SS ones that have the gate route back in less than 5" fromthe turbine outlet.. I"m gonna route mine back inunder the oil pan most likely

 

[Bud92gsx]

Thata the last update

 

[Dert]

Does having it re routed less than 18" of the turbine really cause that much disruption? I mean why would company's like
Punishment built o2 housing with recirculated waste gates? That puts it back into the stream like 6-8" away from the turbine. (maybe that's the reason I have cooked my TiAL springs so many times?)

 

[turboglenn]

Thata the last update

not the last, just been busy trying to work and earn $$$'s to pay bills bro

Does having it re routed less than 18" of the turbine really cause that much disruption? I mean why would company's like
Punishment built o2 housing with recirculated waste gates? That puts it back into the stream like 6-8" away from the turbine. (maybe that's the reason I have cooked my TiAL springs so many times?)

from all the facts i've seen posted from dyno pulls and such, i would say YES it does make a differce. a to why companiesd make them with the routing so close, well, mitsu did it, so my not, also space would be a concern as well, but i think mostly if some one has an OEMmitsu o2 housing and swap to an aftermarket unit with the same design of routing back into the turbine's flow then they will feel a power gain either way, not knowig they could have gained much more with a properly setup and routed gate to turbine flow passage

 

[Seamus]

They are over ten years old, so I don't have the sheets anymore, and the car is long gone. But I lost a peak of 11 horsepower with a rerouted wastegate on a 1981 rx7 race car. What was worse, it also made my dyno plot choppy enough to almost look like ignition breakup or interference. This was on a switzer turbo that is very close to the modern s362 with a 1.06 divided housing and a 4 inch downpipe that went into an oval 4 inch nominal section under the car. The wastegate joined the exhaust about 6 inches before the end of the downpipe. Which made it well over 24 inches from the turbo outlet.

My best advice for quieting the wastegate is to find a used wastegate muffler for a porsche 930 and use that. That is MUCH better than using a small engine muffler. It looks like a briggs "sausage" style silencer, but it is straight through instead of baffled.

Lindsey racing makes an aftermarket version that they market as a 954 silencer, but i don't have any experience with it. It looks like it would not be as quiet. Kind of like comparing an oem muffler to an aftermarket.

I have searched far and wide and there appears to be no readily available straigh through small engine silencer that is an appropriate size. Most are far to large or are heavily baffled.

 

[LandSpeed-DSM]

Does having it re routed less than 18" of the turbine really cause that much disruption? I mean why would company's like
Punishment built o2 housing with recirculated waste gates? That puts it back into the stream like 6-8" away from the turbine. (maybe that's the reason I have cooked my TiAL springs so many times?)

Punishment and the rest sell the O2 housing with an external gate re-routed like that because as cheap as DSM owners tend to be now, they would have a harder time selling an O2 housing with a gate the recirculates farther back on the down pipe.

That would require purchasing the O2 housing, hardware, wastegate and a downpipe instead of just the O2 housing and gate.

 

[redyute1]

, Ok well to avoid the upcoming ban for lack of lookie-lookies, here's what i got done since the post. I moved the alky injection to immediately pre-turbo inlet. )

Why Pre turbo?

 

[Sirnixalot]

Because compressor blades are cheap and it makes the compressor wheel act larger than it really is.

I would have a check valve right before the nozzle...most of the compressor wear happens when drops of water drip into the air stream and strike the blades going full whirl.

 

[redyute1]

Oh ho i see

 

[GalantVR41062]

And if you BOV is vented to atmosphere you get a good spray of pure merhonal in your engine bay.

 

[bastarddsm]

They are over ten years old, so I don't have the sheets anymore, and the car is long gone. But I lost a peak of 11 horsepower with a rerouted wastegate on a 1981 rx7 race car. What was worse, it also made my dyno plot choppy enough to almost look like ignition breakup or interference.

11hp on how many hp? how bad was the chop?

 

[turboglenn]

Why Pre turbo?

Because compressor blades are cheap and it makes the compressor wheel act larger than it really is.

I would have a check valve right before the nozzle...most of the compressor wear happens when drops of water drip into the air stream and strike the blades going full whirl.

For the reasons stated above, except I don't use the compressor wheels are cheap theory since i never witnessed any wear on my last one when i sprayed into it for well over a year on a daily basis wth both water and methanol as well as mixes of both

The check vlave is the silver piece in the pic, right before the 90* black elbow, and i'm only running pure methanol right now, but might swap to pure water soon, I'm really only doing it for the cooling and the effect it has on air (making compressor seem bigger but spools faster too)

 

[Seamus]

11hp on how many hp? how bad was the chop?

Found it. It was about 3% The car made 353 @ 11psi with the wastegate exhausting to the atmosphere. The actual loss was 10.56hp. I don't have any numbers form higher boost tunes, because I left the wastegate divorced after that. I've never ran a rerouted wasetgate on a car since then. I have run a couple different silencer setup though on various cars. As mentioned before, the 930 wastegate silencer or the 954 silencer form lindsey racing both work well. My 1g has thewastegate mounted on runner 1. so it sounds different than a collected or 02 mounted wastegate. With my silencer on the dump pipe, i can't even hear the wastegate over the exhaust. When I reach full boost, it just sounds like my car has a slight ticking like an exhaust leak.

Like I said, those losses were a replumbed wastegate joining the exhaust a little over 24 inches after the dicharge. I don't have any proof, but i'd imagine this loss would grow as you got closer to the turbine outlet.It was also 4 inch piping. So i'd imagine the percentage of loss would rise with 3icn exhaust piping.