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View Full Version : Front fender or side exhaust. Thoughts on this?



dylansi
06-10-2013, 12:45 PM
Has anyone tried or thought about running a front fender or rear straight exhaust? For the rear having the pipe exit before the rear tire? I seen this done on many turbo cars and not sure if this is an option for us. I know that this type of exhaust would all but eliminate any back pressure, so I was wondering, do our cars need back pressure to run effectively? I also know that without a proper aftermarket programable ECU, this would cause at least one CEL due to the o2 sensor(s) not being utilized, would there be any other CELs that could possibley throw the car into limp mode?

THIS

http://www.srtforums.com/forums/attachments/f119/12431d1096731342-side-exit-exhaust-pics-viper-exhaust.jpg

OR THIS

http://honda-tech.com/attachment.php?attachmentid=114293&stc=1&d=1268623281

Thanks

sfhpawel
06-10-2013, 12:59 PM
I'm running a straight technically... no CEL. I think you'll need an aftermarket sideskirt with more depth to fit that in there. The sub frame is relatively flush to the current skirt height, dunno if you'll find room.

For the funny looking front fender... oh boy... lol... you'll def need the Front Mount intercooler and you'll possibly have room if you remove the existing side intercoolers.

Idk it just might work, I have never seen it personally. I cant imagine being stuck in traffic on a beautiful Fall day with the windows down and exhaust plummeting in my GF's face. I sure as hell wouldnt have the exhaust outlet on the drivers side ;P

BigDaddySRT
06-10-2013, 01:12 PM
I'm running a straight technically... no CEL. I think you'll need an aftermarket sideskirt with more depth to fit that in there. The sub frame is relatively flush to the current skirt height, dunno if you'll find room.

For the funny looking front fender... oh boy... lol... you'll def need the Front Mount intercooler and you'll possibly have room if you remove the existing side intercoolers.

Idk it just might work, I have never seen it personally. I cant imagine being stuck in traffic on a beautiful Fall day with the windows down and exhaust plummeting in my GF's face. I sure as hell wouldnt have the exhaust outlet on the drivers side ;P

You won't get a CEL unless you start messing with the Catalysts.

dylansi
06-10-2013, 01:12 PM
I'm running a straight technically... no CEL. I think you'll need an aftermarket sideskirt with more depth to fit that in there. The sub frame is relatively flush to the current skirt height, dunno if you'll find room.

For the funny looking front fender... oh boy... lol... you'll def need the Front Mount intercooler and you'll possibly have room if you remove the existing side intercoolers.

Idk it just might work, I have never seen it personally.I cant imagine being stuck in traffic on a beautiful Fall day with the windows down and exhaust plummeting in my GF's face I sure as hell wouldnt have the exhaust outlet on the drivers side ;P

^^^ That made me laugh.

Anyway. I dont think for the rear exit it needs to be quite as nice as that. Maybe just the pipe exiting there. So I was thinking, mandrel bent piping from the manifold or turbo back to exit before one of the wheels. With this setup you could probably have o2 sensor bungs welded into the pipe and run an o2 defouler to offset the extra flow. I think this would net the best possible power from our cars granted it doesnt need the back pressure. Not including it would probably sound amazing.

dylansi
06-10-2013, 01:14 PM
You won't get a CEL unless you start messing with the Catalysts.

Running a straight pipe from turbo back would probably mess with those

sfhpawel
06-10-2013, 01:23 PM
^^^ That made me laugh.

Anyway. I dont think for the rear exit it needs to be quite as nice as that. Maybe just the pipe exiting there. So I was thinking, mandrel bent piping from the manifold or turbo back to exit before one of the wheels. With this setup you could probably have o2 sensor bungs welded into the pipe and run an o2 defouler to offset the extra flow. I think this would net the best possible power from our cars granted it doesnt need the back pressure. Not including it would probably sound amazing.

well... depends. what car you have? because... techincally Abarth is already running a straight pipe.. (headers, downpipe with cat, flexpipe that turns in to midpipe, then just bent nice looking tubes with tips) the earlier 2012 Abarths had the suitecase muffler. Which was just a big hollow case.

on the 500T however there is a muffler. I did a delete and have a straight pipe exit. Sounds just like an Abarth.
I am running a RoadRace ecm. My datalogger shows 136 hp with 211 Torque. I def think it was a combination of the ecm and exhaust to give me such high torque numbers.

I am on the fence weather I lost hp because of the muffler delete. But I never made a baserun...

dylansi
06-10-2013, 01:53 PM
well... depends. what car you have? because... techincally Abarth is already running a straight pipe.. (headers, downpipe with cat, flexpipe that turns in to midpipe, then just bent nice looking tubes with tips) the earlier 2012 Abarths had the suitecase muffler. Which was just a big hollow case.

on the 500T however there is a muffler. I did a delete and have a straight pipe exit. Sounds just like an Abarth.
I am running a RoadRace ecm. My datalogger shows 136 hp with 211 Torque. I def think it was a combination of the ecm and exhaust to give me such high torque numbers.
I am on the fence weather I lost hp because of the muffler delete. But I never made a baserun...

I have an Abarth. What I would do is eliminate the down pipe, then cat, and run the pipe straight back only adding in one bend (thus reducing the number of bends) for the exhaust to exit, most likely right before the pass side tire/ wheel well area. Also I would increase the inside diameter of the pipe as much as possible, I would shoot for 3" (I havent measured to see what can fit.) Also having o2 bungs welded in so that the stock sensors could be utilized.

Not sure if I would keep the stock exhaust tips still there or install aftermarket ones, for visual purposes only. Losing the tips all together may not look that nice.

sfhpawel
06-10-2013, 01:54 PM
to add to your rear pipe placement... I have mine dropped, not as slammed as other members, but I think you'll be able to get away with a pipe sticking 'under' the sideskirt. Compared to the front, the sides of the car are MUCH higher. Its typically the middle/under the car thats the lowest. I would advise being careful though... If you snag something with this kind of set up, you are endangering the exhaust all the way up to the downpipe.

Its like waving your arm out the window, instead of snapping off your wrist, your risking ripping your arm off from the shoulder. If you go this route, make sure they do a legit job, it'll require some thought, and new hangers obvi :)

I'm just being skeptical, thats all. Let us know what you decide.
Good luck!

sfhpawel
06-10-2013, 01:56 PM
Nice nice, I'm looking forward to the catless DP. Just not ready for it yet.
No tip will give it a raw look, with the right angle, and the location you choose might make it look sick! all depending on the overall theme of your car!
You can always add tip later :) I'd love to see pics when you do it

sfhpawel
06-10-2013, 01:59 PM
you def have room for a 3" in there. Theres a channel running under that car that looks like a drive shaft could fit there. I'm tempted to find a salvaged r32 and dropping in the AWD in there! ahhh wishful thinking.

From doing some research the midpipe is actually one of the weakest points of the entire system so you SHOULD see some great gains. the mid is a 2.25" if i am not mistaken

dylansi
06-10-2013, 02:31 PM
Yep just looking for some improvements in the flow. The cost of 3" mandrel bent pipe will probably be the same as one of the vendors exhausts. This is counting that I have it done right, like you said adding hangers where needed and o2 bungs. From previous cars and doing this most shops are dead on with their measurements, most the time doing it by visualization. I will have to stop at one of the local shops here and see if they think it is feasible. I havent looked under the car since last oil change and wasnt even thinking about going this route. So I may need to get under there and see what I am will be working with, i.e. keeping it tucked.

I could possibley even reuse the stock cat to keep Al Gore happy. Not sure how much sense that would make though.

I would go with the raw pipe look. Was refering to the stock rear tips and leaving them there so that there wasnt two huge holes coming from the diffuser.

MAZ
06-10-2013, 02:51 PM
If you are rocking a fender exit exhaust, you'd better be doing sub 10 sec 1/4's otherwise that's just silly

Ryephile
06-10-2013, 04:32 PM
If you are rocking a fender exit exhaust, you'd better be doing sub 10 sec 1/4's otherwise that's just silly

At that point you also get 10,000 internet points and can upgrade to a hood-exit exhaust. :rockon:




Yep just looking for some improvements in the flow. The cost of 3" mandrel bent pipe will probably be the same as one of the vendors exhausts. This is counting that I have it done right, like you said adding hangers where needed and o2 bungs. From previous cars and doing this most shops are dead on with their measurements, most the time doing it by visualization. I will have to stop at one of the local shops here and see if they think it is feasible. I havent looked under the car since last oil change and wasnt even thinking about going this route. So I may need to get under there and see what I am will be working with, i.e. keeping it tucked.

I could possibley even reuse the stock cat to keep Al Gore happy. Not sure how much sense that would make though.

I would go with the raw pipe look. Was refering to the stock rear tips and leaving them there so that there wasnt two huge holes coming from the diffuser.

Time for custom fab. 3" down pipe, high-flow cat, and a 500T rear bumper valance with a single 3" raw exhaust tip.

Please don't get caught up on big radius mandrel bends hurting power until you're pushing way past 400 HP. For now, with a stock turbo, the exhaust is not the major restriction.

dylansi
06-10-2013, 05:15 PM
If you are rocking a fender exit exhaust, you'd better be doing sub 10 sec 1/4's otherwise that's just silly


At that point you also get 10,000 internet points and can upgrade to a hood-exit exhaust. :rockon:





Time for custom fab. 3" down pipe, high-flow cat, and a 500T rear bumper valance with a single 3" raw exhaust tip.

Please don't get caught up on big radius mandrel bends hurting power until you're pushing way past 400 HP. For now, with a stock turbo, the exhaust is not the major restriction.

My point is with this is to spend roughly the same amount as a prefabed exhaust, by making a custom that will flow better.

I wont ever see over 400hp but i figure if I am going to spend the cash why not do this now instead of in the future having to buy another exhaust because the aftermarket kits are too restrictive. Dont get me wrong, I like a lot of the prefabed setups now, just thinking I could do it right the first time (by right I mean less restrictive.)

dylansi
06-13-2013, 02:07 AM
Went to the automotive self service center in my neighborhood today and put my car on the lift. Looks like a straight exhaust will definitely work. I think you could either run it straight back to were it makes the bend towards the drivers side rear wheel, then put a slight downward bend into the pipe toso the exhaust exits onto the road. Or you could have one bend at the same place the first bend is on the stock exhaust and route it right over toward that driver's rear wheel. From there either add a slight downward bend so the exhaust blows on the ground or add tip and have the exhaust exit right in front of that wheel. Either way it should easily work. Has me wondering what kind of performance you would see from this and how it would change the sound.

I have a question for those of you that have a down pipe already. How difficult was it to remove the stock cat and piping? When I looked underneath it looked to be a major PITA. I didn't look under the hood to see if you would access some of those bolts from there.

Jjm4life
06-13-2013, 04:10 PM
If you are rocking a fender exit exhaust, you'd better be doing sub 10 sec 1/4's otherwise that's just silly
This

At that point you also get 10,000 internet points and can upgrade to a hood-exit exhaust. :rockon:

Time for custom fab. 3" down pipe, high-flow cat, and a 500T rear bumper valance with a single 3" raw exhaust tip.

Please don't get caught up on big radius mandrel bends hurting power until you're pushing way past 400 HP. For now, with a stock turbo, the exhaust is not the major restriction.

And this.

Unless you're building a drag car, you will just making a ton of noise for no reason. Ever driven a car with an exhaust setup like that? Its retarded.400whp is low anyway. The guys i know with drag setups run 650+ on their DEDICATED track cars, not their street cars.

shagghie
06-13-2013, 04:15 PM
I know deathshead and others running the catless DP notice a market improvement. I larger mid-pipe, too, should still help her breath better than stock. And there's at least one shop that is looking at 300+ hp out there... ALL that said, I like the look/feel/sound of stock exhaust just fine and wouldn't ever entertain an exit that's not in the back. The honda looks like its bung hole is on it's ribcage.

dylansi
06-14-2013, 02:55 PM
This


And this.

Unless you're building a drag car, you will just making a ton of noise for no reason. Ever driven a car with an exhaust setup like that? Its retarded.400whp is low anyway. The guys i know with drag setups run 650+ on their DEDICATED track cars, not their street cars.

I appreciate everyone’s comments here I just want to clear some things up.

First it was just an idea outside of the norm rather than to buy a pre-fabricated exhaust for $700+ that is nothing you can’t have a shop do for you. Plus this way you have the option of increasing the pipe inside diameter thus increasing flow, power, and throttle response. I was just trying to come up with ways to eliminate some restrictive bends and increase the diameter to bring out the exhausts full potential. I see no reason to buy a 2.5" inside diameter or smaller for "x" amount of money to only want or need more flow down the road.

If you want to bring the issue of noise into the picture don’t you think our cars make a ton of noise already, big bark with a little bite? There will really be no difference in the exhaust I am considering (I am not going to run a fender exhaust, I should have changed the threads title) than stock except for removing the cat and increasing diameter. Our exhaust from cat back is straight pipe anyway so I don’t think it is going to be that much louder. If you have heard any turbo car running a straight pipe they all sound relatively the same (gargling and popping) except for those Subarus. And yes I have heard/been in cars with a fender or straight free flow exhaust...I love the sound.

I know deathshead and others running the catless DP notice a market improvement. I larger mid-pipe, too, should still help her breath better than stock. And there's at least one shop that is looking at 300+ hp out there... ALL that said, I like the look/feel/sound of stock exhaust just fine and wouldn't ever entertain an exit that's not in the back. The honda looks like its bung hole is on it's ribcage.

Yeah the fender exit was a far shot and not something I am going to do. After looking underneath and thinking about it for a few days I may just keep the same stock exit using a custom exhaust using 3" inside diameter piping. Either just having it exit as one pipe on the driver’s side where it exits now, or making a custom dual pipe coming out the stock exit. Need to go to the shop next week when I have off and get this done instead of just talking about it.

Thanks for all the input. I figured someone lurking around here has experimented with this by now.

Jjm4life
06-14-2013, 03:17 PM
you could always develop a wastegate dump. im sure that will come along sooner or later. on an electronic cutout before the cat.

dylansi
06-14-2013, 04:53 PM
you could always develop a wastegate dump. im sure that will come along sooner or later. on an electronic cutout before the cat.

a wastegate dump is a great idea...I am suprised it is not out yet. Any vendors working on this? I wonder if a universal one will work (just need the correct mm inlet maybe 38mm?), then just extend it so the gasses are expelled underneath the car But doesnt our setup have an internal wastegate? I may be confused.

If it is external we would need a decent length tube. I have also seen setups that have the dump tube welded into the down pipe so the noise isnt out of control. That is probably what I would do.

dylansi
06-14-2013, 08:48 PM
http://www.youtube.com/watch?v=hpkif7x4zPA


Dart running a full 3" turbo back exhaust. Just emailed then to get some info...doesnt sound overly loud at all

They also have the ported TB at $125, also asked if that will work with our car or not. I cant see why not

DS Ocampo
06-15-2013, 02:07 PM
I ran 3" on my 2012 abarth like that and it lost so much low end tq.. Car felt so slow.. Let my brother drive it and said the same thing.. Put stock back on and had a custom 2.25" axle back with a true Y .. And felt better than stock and wayyyyy better than 3" pipe

dylansi
06-15-2013, 02:28 PM
I ran 3" on my 2012 abarth like that and it lost so much low end tq.. Car felt so slow.. Let my brother drive it and said the same thing.. Put stock back on and had a custom 2.25" axle back with a true Y .. And felt better than stock and wayyyyy better than 3" pipe

Hmm that is interesting. Maybe the loss of back pressure took away from your low end because of it being pre-boost, but could you tell a difference in higher RPM range? NA cars with a large exhaust tend to suffer (lose torque) in the low RPM range but gain it back in the higher RPMs. Did you have it dynoed? Was the exhaust from turbo back or cat back? What other mods did you have?

I believe you but I can't understand why it would lose that much power considering roughly 60% of our motor's power is made from the turbo, so at full boost you should see an increase of power.

What I plan on doing is turbo back pipe exiting the drivers side exhaust outlet now. No Y or split into dual. Is this roughly what you had with your 3"?

dylansi
06-18-2013, 12:38 AM
Went to a local shop here. They said they can do everything I want. But they suggested buying a cat-less down pipe or down pipe with a high flow cat first. Bring that in or install it then come back for them to do the custom pipe. I am now almost sure I will run 2.5" back to a single exit out the driver's side exhaust cut out. I will either then leave it with the other side open or buy a 500T rear valance and install that.

This seems promising as they quoted me $350 at most and do mandrel bends.

So I need some more help here, has anyone ran this; ABARTH 500 MULTIAIR ( GT1446) HIGH PERFORMANCE CAT & DOWN PIPE From TMC? It is very expensive when I could buy a decat down pipe from ATP and then install a 100 cell or 200 cell cat for around the same price. Also has anyone come up with a fix for the o2 sensor extension? If I do the later route I will need it and cant seem to find one.

Thanks