Exhaust Options...

[RM1SepEx]

So, I finally started working on #17 again after a long cold winter. Battery Died, thankfully the Optima that I was using was less than 3 years old and was replaced, no questions asked! I hope to be hanging body panels this week...

So far everyone seems to have went very minimal on the exhaust. I've run mine with the FFR adaptor and my stock downpipe, sounds pretty good, a bit loud. https://www.youtube.com/watch?v=nGG2yl7MFd0

I've just purchased a 3 inch bell mouth downpipe and a flowmaster high flow 3 inch cat to stay legal and pass inspection. Andrew recommended the setup to use with my Accessport and a stage 2 tune.

I'm considering a 3 inch stainless muffler as well, http://www.ebay.com/itm/OFFSET-OFFSET-3-INCH-EXHAUST-OVAL-MUFFLER-SILENCER-M-/360389108740?pt=Motors_Car_Truck_Parts_Accessories&hash=item53e8dd6404&vxp=mtr or the magnaflow polished equivalent #14239

Metalmaker and Wallace18 (Chris and Tom) have simple downpipes and straight out... Wayne's looked similar but I can't be sure.... Can we use this thread to sample some exhaust setups and build some sort of library?

[bompus]

Please.. I'd love to see detailed pictures of installed exhausts from the turbo back. I'm personally wanting to the following type of setup, but I'm worried about finding room for it all:

Turbo -> Downpipe Flange -> O2 bung [6-12 inches after turbo] -> High-flow cat ( Magnaflow 59959 - 8 inches? ) -> Muffler/Resonator ( Aero Turbine AT3030XL - 26 inches? ) -> Exit

I'm sure there are other builders looking for something similar. Ditching the combined muffler/resonator idea and going straight muffler would take up 14 to 18 inches depending on the type. Vibrant has a 9" length muffler, but I'm sure it doesn't cut the noise down as much as a longer design.

I would hate to buy an expensive aftermarket "bolt-on" downpipe to only have to hack it up to fit bung/cat/muffler where they are needed. Right now I am assuming I'll just need to tow it down to the exhaust shop and have them fab it up with the proper bends with me providing the cat and muffler. I'm thinking of a dual exit tip through the center of the rear as others have done so I don't have to factor the exhaust pipe into ground clearance.

So basically, I as well am looking for pictures and ideas for exhaust setups, preferably something close to what I specified above.

[metalmaker12]

There is not enough room for all that, you might get a cat an short exhaust but than you will have limits on exits. If you want a under rear cover center exit you will be very limited to maybe a high flow 7-8" cat and onto your bends to get out under the center of the rear. It you go twin tip center exit up high you can get a short exhaust and twin short cats/ or resonators to tips. It all depends on your bellmouth angle, exit location and how quiet or loud you want it. I am still planning on making an exhaust kit within 6 months.

[Jaime]

Any chance a dual outlet muffler can be transverse mounted under the transmission?

[metalmaker12]

Yeah that could be done, but straight out is best option for power

[JeromeS13]

Kinugawa dump pipe (for the VF37 twin scroll):

http://shopping.kinugawaturbo.com/turbodumpdownpipesubaruvf36vf37twinscroll3.aspx

Vibrant 3" straight through muffler (picture on Amazon is not accurate):

http://www.amazon.com/dp/B001N1R8S2/ref=pe_385040_30332190_TE_M3T1_ST1_dp_2

And a Vibrant 3" high flow catalytic converter (installed with v-bands to make easily swapable with a test pipe):

http://www.amazon.com/dp/B0018082A6/ref=pe_385040_30332190_TE_M3T1_ST1_dp_1

Quick video (sorry for the poor quality):


http://www.youtube.com/watch?v=zBx9AYiKGHE&list=UUxbdnwpfymM7uWZ9AQ2GrHg&feature=share

[Mechie3]

I want to try something like this. Considering cutting out the bottom rear opening and instead of putting in the mesh, putting in a machined brace like this. Cutting down the transmission as originally suggested by Bob and detailed by subarugears.com will help.

http://lotusrace.com/wp-content/uploads/2012/05/Photo-of-the-Lotus-car-back.jpg

Another option:

http://www.lotustalk.com/forums/attachments/f157/49897d1174502276-exige-s-aftermarket-exhaust-lotus-002.jpg

[Bob_n_Cincy]

Hi Craig
I like it, I was thinking along those lines also. Inlet top right, 2 elbow outlets.
27261

[RM1SepEx]

I don't see how you can get a muffler transverse across the back with the transaxle so close to the rear of the car. even cutting it shorter, you need 6 inches or so

[Bob_n_Cincy]

I don't see how you can get a muffler transverse across the back with the transaxle so close to the rear of the car. even cutting it shorter, you need 6 inches or so
I should have this much space
27264

[RM1SepEx]

That might do it... I like JeromeS13's solution straight through with a small muffler

27265

[wleehendrick]

That might do it... I like JeromeS13's solution straight through with a small muffler

Ditto... I'd buy that from a vendor: bell-mouth outlet, optional cat, shorty muffler, single exit out the rear mesh; simple and effective. It would save the hassle of having it custom done locally.

[gwarden]

Ditto... I'd buy that from a vendor: bell-mouth outlet, optional cat, shorty muffler, single exit out the rear mesh; simple and effective. It would save the hassle of having it custom done locally.

I don't need the cat but sure would buy the rest

[wleehendrick]

I don't need the cat but sure would buy the rest

I don't need a cat either, but may run a small, high-flow one. It would be nice to have the option since every state has different requirements.

[Mechie3]

http://gglotus.org/ggrace/exigesport/exige4.jpg

Another cool image. Less exhaust and more trans showing.

[flynntuna]

That look screams form follows function. I like it a lot.

[flynntuna]

http://gglotus.org/ggrace/exigesport/exige4.jpg

Another cool image. Less exhaust and more trans showing.


You can put your example on steroids.

[Jaime]

I should have this much space
27264
I'm looking to do something similar. I have my transmission apart right now and it looks like the shift shaft is supported by needle bearings in two places:

27412

Your proposed cut line would remove one of them. Do you have any ideas how to keep the shaft supported and still cut that much off the back of the transmission?

[Bob_n_Cincy]

I'm looking to do something similar. I have my transmission apart right now and it looks like the shift shaft is supported by needle bearings in two places:

27412

Your proposed cut line would remove one of them. Do you have any ideas how to keep the shaft supported and still cut that much off the back of the transmission?

Hi Jaime
I have not got mine apart yet as I am busy on my wiring.
I was only expecting a sleeve bearing as a needle bearing doesn't work well for the in and out motion.
Pleased take a picture of what's in the hole. I know there is a seal on the shaft. I was just going to cap that.

I have considered extending the shifter shaft and supporting in on the forward end. I was hoping not to have to do that.
Thanks for the feedback
Bob

Edit
I can see the needle bearing in this picture.
27414
I will have to replace this with a sleeve bearing.
Bob

[Mechie3]

An oilite bushing should work well though it'd require likely boring a new recess.

[Jaime]

I just took a closer look at the Subaru setup...

27418

It's four rows of tiny ball bearings. There's no way a bushing will be a fraction as smooth as that. I think the only way to do it would be to pull the rear bearing, shorten the tail, and machine out a new place for the bearing and seal. The big problem is the neutral switch. It's about halfway down the channel and the shaft has a big notch there. Even if you got a bearing in the right place and relocated the neutral switch, you'd have to repair the shaft or the bearing wouldn't be on metal. Honestly, I think you'd have to replace the shaft.

[Bob_n_Cincy]

I just took a closer look at the Subaru setup...

27418

It's four rows of tiny ball bearings. There's no way a bushing will be a fraction as smooth as that. I think the only way to do it would be to pull the rear bearing, shorten the tail, and machine out a new place for the bearing and seal. The big problem is the neutral switch. It's about halfway down the channel and the shaft has a big notch there. Even if you got a bearing in the right place and relocated the neutral switch, you'd have to repair the shaft or the bearing wouldn't be on metal. Honestly, I think you'd have to replace the shaft.

Thanks Jamie,
I've never seen a bearing like that in my life.
I will have to brainstorm this. I agree with Mechie3 that an "oilite bushing should work".
I don't think all the rest of the sliding shafts in this transmission have those bearings.

I'm not even sure what the neutral switch does. It is an input into the engine ECU on my donor. Maybe it kicks off the cruise control.

By any chance, can you read the number on the bearing?
Or maybe I can get it from as Subaru dealer.
Bob

[Jaime]

27422

My concern is that all the forces on that shaft are about three inches off-axis. The factory setup with ball bearings four inches apart holds up well to off-axis forces. If you cut that down to a 22mm bushing (the size of the longest one available at McMaster Carr), the peak bearing force is multiplied by a factor of five. Also, the slop allowed by the rod to bearing tolerance is multiplied with a shorter effective bearing length.

I'm thinking of doing something like this:

http://www.subarugears.com/P1080223.JPG

That will give a lot of space under the shaft. I also want to run the shifter cables parallel to the transmission. I'll need to make a bellcrank mechanism for the rotational input.

[Bob_n_Cincy]

27422

My concern is that all the forces on that shaft are about three inches off-axis. The factory setup with ball bearings four inches apart holds up well to off-axis forces. If you cut that down to a 22mm bushing (the size of the longest one available at McMaster Carr), the peak bearing force is multiplied by a factor of five. Also, the slop allowed by the rod to bearing tolerance is multiplied with a shorter effective bearing length.

I'm thinking of doing something like this:

http://www.subarugears.com/P1080223.JPG

That will give a lot of space under the shaft. I also want to run the shifter cables parallel to the transmission. I'll need to make a bellcrank mechanism for the rotational input.

Jamie,
I totally agree the one 22mm bushing would not be enough.
Option 1:
I think 50mm-75mm (2"-3") would work. (2 of the 22mm bushings)
Then I can cut off 5" to 6" of the protrusion in the above picture.

Option 2:
Support the shift shaft forward of the shift arm. Original bearings in front and behind the shift arm. Then I can cut off all but an inch of the protrusion shown above.

Can someone move all the transmission shortening post to a new thread?
Bob

[Xusia]

Is there an option 3 where you ditch that shaft and act directly on the parts it would act upon?

[Bob_n_Cincy]

Is there an option 3 where you ditch that shaft and act directly on the parts it would act upon?\
Well yes
You could put 2 way electric solenoids on the 3 bars and paddle shift.
27451

A project that would take 5 to 10 times the effort as above. I want to be go karting in a couple of months.

I just thought of and old school shifter that has the gating in the shifter itself.
Bob

[FFR-ADV]

http://gglotus.org/ggrace/exigesport/exige4.jpg

Another cool image. Less exhaust and more trans showing.

I like where you are going with the rear cutout:

27469

Please excuse the quick cut/paste, but it gives the idea. The FFR 818 CF rear diffuser could look like this with a nice exhaust showing....

Cheers!

[Erik W. Treves]

I don't see how you can get a muffler transverse across the back with the transaxle so close to the rear of the car. even cutting it shorter, you need 6 inches or so

mount it over the tranny - flat - not standing up

[Xusia]

\
Well yes
You could put 2 way electric solenoids on the 3 bars and paddle shift.
27451

A project that would take 5 to 10 times the effort as above. I want to be go karting in a couple of months.

I just thought of and old school shifter that has the gating in the shifter itself.
Bob

Why would you need solenoids? Just plumb the cables into the housing and act on that arm the shaft acts upon. What am I missing?


I like where you are going with the rear cutout:

27469

Please excuse the quick cut/paste, but it gives the idea. The FFR 818 CF rear diffuser could look like this with a nice exhaust showing....

Cheers!

I'm seriously considering going this route. Solves a lot of "problems" I've been cogitating on.

[Bob_n_Cincy]

Why would you need solenoids? Just plumb the cables into the housing and act on that arm the shaft acts upon. What am I missing?

Hi Xusia
Take a look at this post on my thread.
http://thefactoryfiveforum.com/showthread.php?12534-MRG-MotorSports-818S-Build&p=142490&viewfull=1#post142490

Plumbing the left-right cable through the side of the case and attaching it to the arm would be very easy.
The forward-reverse cable would be very difficult.
So I will do both outside the case.
As an option I may not use cables at all.
Bob

[Xusia]

I read all that previously. I guess I just don't have a good enough idea what the inside of the transmission looks like or how it works. From the pics, it seems doable. But regardless, if you have another way, go for it!

[RM1SepEx]

Wow, what happened to my thread for exhaust options? It turned into a how can we shorten the transaxle 6 inches... Second request: Can this portion be split into a separate thread please???

[gwarden]

Wow, what happened to my thread for exhaust options? It turned into a how can we shorten the transaxle 6 inches... Second request: Can this portion be split into a separate thread please???
I agree every time I see an update to this post I hope its useful information about building an exhaust.

[Goldwing]

OK, back on topic, sort of. Anybody have a shoe horn? It's the perfect shape but about 20%+ too big. Found this camaro SS muffler cheap on Craigslist. Cheap enough I could sell it for more, but... I bet the sound level would be more my liking. For those of you much further along, how ridiculous is this? In Mythbusters speak: plausible or busted?

27494
27495

[Bob_n_Cincy]

I like Stickshift84 exhaust.
Does anyone make a straight bell mouth or is this custom only?

See picture:
http://thefactoryfiveforum.com/attachment.php?attachmentid=27499&d=1395541396

[Wayne Presley]

I like Stickshift84 exhaust.
Does anyone make a straight bell mouth or is this custom only?

See picture:
http://thefactoryfiveforum.com/attachment.php?attachmentid=27499&d=1395541396

That was a curved bellmouth cut short.

[Goldwing]

I had been thinking along Jerome13's idea highlighted above:
27504

I still want to keep a high flow cat which fits nicely on the downward turn of a downpipe. I've been looking at a few mufflers that have both pipes on the same end to add into the otherwise straight run out the back. Either short and laid flat, or if there isn't enough room stand it on its side to tuck behind the rear wheel. I've only found flowmaster or spintech's so far. That's when the camaro muffler jumped out at me to experiment with. Anyone know of other sources for a u-turn routed muffler?

[Goldwing]

I am also trying to preserve trunk space over the transmission, so lower profile is preferred with the above setup.

[RM1SepEx]

OK, back on topic, sort of. Anybody have a shoe horn? It's the perfect shape but about 20%+ too big. Found this camaro SS muffler cheap on Craigslist. Cheap enough I could sell it for more, but... I bet the sound level would be more my liking. For those of you much further along, how ridiculous is this? In Mythbusters speak: plausible or busted?

27494
27495

Can you say HEAVY? :o :(

I like JeromeS13 too but the little muffler looks absolutely useless to me, it has zero volume for expansion of gasses. I'm trying to use the high flow cat going down and across with the muffler like StickShift84 but low to allow a trunk. I have the bellmouth and the cat now to play with... My welding isn't up to snuff right now for finish work on exhaust tubing. I'll tack and get a friend to tig it for me. I'm almost ready to hang body stuff and I'll have some stuff to play with the available space

[metalmaker12]

That was a curved bellmouth cut short.

It is custom setup I welded it. FFR flange cut down and 4"pipe to 3". The 4" was shaped to fit inside flange. Nick and I fit it all up. The exhaust is easy if you exit were Jerome, nick and Erik have, it gets more tricky when design one like I have or want to go up high. I have a v band on my setup now so I can experiment more.

[Xusia]

What kind of exit options are there with the diffuser though? Isn't out the bumper pretty much the only one?

[Stickshift84]

I figured I would clairfy what I did for everyone...

1.) I cut one of the flanges off of the FFR supplied exhaust adapter.
2.) I modified the flange by opening up the 2.5" ID hole to 2.5" x 4.0" (aka 3.5" oval).
3.) I ordered a 3.5" oval to 3.0" round stainless transition from spintechmufflers.com
4.) I had Chris (metalmaker) weld the transition to the flange.
5.) Finished with muffler and O2/wideband bungs and a custom exhaust hanger to the transmission.

After doing this I basically had a straight shot out of the turbo into a 3" round pipe. From this the options are endless. I toyed around with doing dual outlets through the upper section of the bumper but decided an option for trunk space would be better. If you look through spintechmufflers.com you will see they make custom mufflers with endless configurations and sizes. They are not cheap though.

I decided on a pypes stainless race-pro offset in and out to get the transition I wanted (straight through packed muffler). I can say that if you want quiet to get a chambered muffler. While this packed style muffler quiets it down some (not crazy loud like metalmakers straight pipe exhaust), it could be quieter.