Exhaust Spacer Mod?

[Strudul]

AKA an exhaust leak

 

Before I get shouted at, I'm not planning on this being a permanent thing, it's for testing purposes only, but I'd like some expert opinions on the potential downsides. I keep thinking I'd like a little more from my exhaust, but as it's my daily, i'm don't know whether the extra noise would get on my nerves eventually. They sound good in real life and on videos, but that's not the same as having to listen to a loud drone for 2 hours. Now, I know it will never sound as good as a proper exhaust system, but it seems like a pretty good way to trial a louder exhaust for nothing and get some idea of what to expect.

 

For those who don't know, it involves unbolting the mid-pipe and putting spacer washers between the flanges like so:

 

This mod gets a lot of hate and everyone that brings it up on forums seems to get flamed, but you guys are pretty civil, so I thought we might get some better results here.

 

So, the pros are you get a louder and (in some people's opinion) better sounding exhaust.

 

As for the supposed cons...

- Reduced back pressure

- Disrupted flow

- Power loss

- Lower MPG

- Fumes entering the cabin

- Extra heat under the car affecting anything nearby

 

However, I can't seem to find any supporting evidence for any of these. Just a load of people shouting at each other and throwing insults about.

 

From what I can gather though:

- The reduced back pressure and disrupted flow wouldn't make any difference

- The power and mpg loss would be minimal if not negligible

- The exhaust still goes through the cats and is far enough back to not cause a problem with fumes

- The exhaust gases are cool enough at this point to not damage anything

 

Can anyone weigh in with some solid advice?

 

Cheers

[Jetpilot]

Yes, just buy a remote operated exhaust valve, loud/quiet at the flick of a button, this isnt barry boys

Edited March 10, 2017 by Jetpilot

[Strudul]

Yes, just buy a remote operated exhaust valve, loud/quiet at the flick of a button.

Isn't that just an expensive exhaust leak?

[Jetpilot]

Tell that to Ferrari, Porsche etc etc, its just by passing a silencer as and when you require

[KyleR]

Ref back pressure and power - I'm pretty sure it'll result in a noticeable loss in power. When I bought my first zed it had the typical break between the backbox and mid pipe. I thought it sounded OK but very loud and droney, so needed fixed. The very first second I drove it after getting it fixed I could feel the difference. I was disappointed with how quiet it was, but it pulled much better, so was a worthwhile trade off.

[Aashenfox]

 

These are true...

- Reduced back pressure

- Disrupted flow

Resulting in...

- Power loss

- Lower MPG

These are debatable...

- Fumes entering the cabin

- Extra heat under the car affecting anything nearby

 

 

Especially with N/A power, I understand it's important to have the right amount of restriction, with turbos you generally want as much flow as possible. You can **** about with exhaust systems to gain high or low end improvements to a point using higher and lower flow and pulse characteristics, which have definitely been utterly destroyed by your hole. I don't know a great deal about it to be honest, just read a few layman articles, but I feel confident regurgitating it. This is why a 'tuned' exhaust system is supposed to be so beneficial, and why we buy them. A lot of people correctly say that many aftermarket exhausts add no or negligible power, and they are right, but that isn't always what the exhaust makers are aiming for, they're trying to change the area under the power curve in some way and many products achieve that. Having said all that, yes, I bought my exhaust for the noise with absolutely no consideration for MPG or power, but then I also reasonably expect that the system won't make WORSE power than the restrictive stock Y-pipe design (despite being ebay tat, it is a true dual), so I feel I'm in a win-win situation. Which brings me round again to buying an exhaust system instead of making holes in the one you have. You will like more noise, there's no need to test that, get a system known to make a nice noise, it should be every Z owner's first mod.

 

P.S. What's with the ghetto mods lately dude? Student loans getting on top? Not meaning to prod you in a sore spot, tell me to f off if you like!

[Jetpilot]

Whilst in theory your right, I would hazard a guess not one single exhaust has been made and tuned to suit a 350 and they certainly arent made trying to change the area under the power curve, you can buy loud exhausts, quiet exhausts and some in between and none of them will perform differently to any degree.

Edited March 11, 2017 by Jetpilot

[Ekona]

There is no pro to having an exhaust leak, but many cons.

 

That's possibly the most retarded 'mod' I've ever seen on here.

[Lexx]

Save yourself the cost of the washers and stab a screwdriver into the back box half a dozen times.

 

Im a believer in "do it right, do it once". This "mod" is nothing more than a bodge.

Sorry man, I knownyou didn't want flamed. My advice is to save and buy an aftermarket exhaust.

[Aashenfox]

Whilst in theory your right, I would hazard a guess not one single exhaust has been made and tuned to suit a 350 and they certainly arent made trying to change the area under the power curve, you can buy loud exhausts, quiet exhausts and some in between and none of them will perform differently to any degree.

 

Granted.

[lmc]

Whilst in theory your right, I would hazard a guess not one single exhaust has been made and tuned to suit a 350 and they certainly arent made trying to change the area under the power curve, you can buy loud exhausts, quiet exhausts and some in between and none of them will perform differently to any degree.

 

I agree totally. I also think imo that with this in mind probably none of them justify there over inflated price tags.

I also think that if any of our uk traders invested a bit of time and money to make a reasonable sounding with and quality exhaust with no drone for sub £600 they'd clean up.

[colesl4w]

Even though the intentional destruction of the exhaust is after the cats, there is still a massive amount of carbon monoxide passing through.

 

Imagine the grief a family would feel if you passed out at the wheel due to inhaling too much CO, plowing into their innocent son, killing him. Imagine the pain of court hearings etc. Then, when they think they have suffered enough, the court shows exhibit F. Exhibit F is this thread. They read through each of the comments, and finally, they show that photo you linked of the intentionally installed giant hole in your exhaust. For them to know that such a tasteless mod exists on this earth would just be insufferable. They would never recover.

 

On their son's grave, it would read, 'Why didn't OP just get an Ark Grip from Tarmac???'.

Edited March 11, 2017 by colesl4w

[Strudul]

Thanks for the advice

 

P.S. What's with the ghetto mods lately dude? Student loans getting on top? Not meaning to prod you in a sore spot, tell me to f off if you like!

Louvre - I'd like to think this isn't ghetto. Invested a hell of a lot of time in designing and making it to ensure it's done properly and blows away any existing product.

Tyre Lettering - Again, planning to do this properly like the pros do rather than cheaping out and doing it ghetto with a tyre pen.

Plasti Dip - Arguably ghetto, but again this was for testing purposes to see what looked good more than anything. I can photoshop stuff, but its different when you see it in the flesh. Personally I think it's turned out rather well and will probably get bits painted / wrapped properly in the future. The only part that went wrong was the front bumper, but that was a problem with the bumper itself and I believe a pro job would have caused th same issue.

Steering Wheel cover - Still in the planning stages as I can't really start it easily without taking my wheel off or getting another, but as with the other mods, I'm wanting to do this properly and invest the time and money to achieve a good result.

 

Always preferred DIY / ghetto mods though. If you can achieve a similar result for a fraction of the cost, I don't see why you wouldn't at least attempt something. Not to mention it allows you to develop your own skills and feels pretty good when you pull it off. Problem is I have lots of free time to think about mods I'd like to do

 

There is no pro to having an exhaust leak, but many cons.

 

That's possibly the most retarded 'mod' I've ever seen on here.

Want to explain how having a better sounding exhaust isn't a pro?

 

Or maybe give some evidence to prove that any of the cons are actually noticeable and not just theoretical BS?

 

Save yourself the cost of the washers and stab a screwdriver into the back box half a dozen times.

 

Im a believer in "do it right, do it once". This "mod" is nothing more than a bodge.

Sorry man, I knownyou didn't want flamed. My advice is to save and buy an aftermarket exhaust.

So you are saying I should waste £1k on an aftermarket exhaust just to find that I can't stand it and have to either live with it or remove it? When instead I could spend 5 minutes installing a washer or 2 and have a pretty good idea of what it would be like?

[Strudul]

Even though the intentional destruction of the exhaust is after the cats, there is still a massive amount of carbon monoxide passing through.

It's a question of whether it can actually enter the cabin through normal driving though. Most of it will disperse into the air anyway and (from watching a few vids) most of the exhaust still comes out the back.

[Jay84]

Also an mot failure if its blowing. I know you'd put it back before mot, but you gotta also think its under your car where its wet and salty, and your allowing moisture inside. I admit probably not by much. corrosion build up will make it harder to return to stock.

[Strudul]

Also an mot failure if its blowing. I know you'd put it back before mot, but you gotta also think its under your car where its wet and salty, and your allowing moisture inside. I admit probably not by much. corrosion build up will make it harder to return to stock.

Well aware of that, but it will only take 5 minutes to revert to stock, plus the MOT isn't until September, and I'm only planning to test it for few days / weeks.

 

I think I already have a stainless steel system, but I'm not sure. The guy who owned it previously mentioned something and a lifetime warranty.

Edited March 11, 2017 by Strudul

[Aashenfox]

My HKS replica cost me about 190 quid off ebay US brand new. Even after delivery and import duties, I had it on the car for a total of about 350 quid. A true dual cat back system with sexy burnt tips. I don't know why it's so cheap, I expect it might rust if it gets wet, and the polish isn't the same as a premium product, but I don't take my car out in the rain and we don't get much here anyway, so I'm not fussed about that. Besides, even if it it did only last 3 or four years in the soggy UK climate, it's still a bargain for the price, and you can still just keep getting it welded up. The sound isn't as refined as others like the ARC of course, but everyone who's heard it loves it, I like it, I'm genuinely thrilled with it for the money. It fitted perfectly out of the box and for me it has a very nice (almost stock silent) character at village speeds and really roars when you step on it.

 

http://www.ebay.com/itm/301952892888

Edited March 11, 2017 by Aashenfox

[Strudul]

And there are plenty of people / forums that flame people for buying reps rather than the proper thing....

[Ekona]

There is no pro to having an exhaust leak, but many cons.

 

That's possibly the most retarded 'mod' I've ever seen on here.

Want to explain how having a better sounding exhaust isn't a pro?

 

Or maybe give some evidence to prove that any of the cons are actually noticeable and not just theoretical BS?

Because it's a ******* exhaust leak! You cannot genuinely need explaining why a leak at the exhaust is Not A Good Idea At All.

 

You're p*ssing hot exhaust gases over components that aren't supposed to have them, any idiot can see that's a terrible thing to do. No exhaust will ever sound the exact same as a sodding leak, neither will you ever be able to replicate that tone, so why bother? It has no purpose whatsoever.

 

There are a billionty different exhaust for the Zed out there, and I guarantee you one of them will meet your tone/noise/looks demands. You're not trying anything big or clever by this, it's the kind of thing I'd expect a 17 year old to do on his first Corsa.

 

Get out there, listen to a few different exhausts on a meet, and pick one. There's plenty out there for £600 already that are quality.

[Jay84]

If it is a stainless system and you go down the replacement route, I call dibbs on your old one

[Strudul]

Because it's a ******* exhaust leak! You cannot genuinely need explaining why a leak at the exhaust is Not A Good Idea At All.

 

You're p*ssing hot exhaust gases over components that aren't supposed to have them, any idiot can see that's a terrible thing to do. No exhaust will ever sound the exact same as a sodding leak, neither will you ever be able to replicate that tone, so why bother? It has no purpose whatsoever.

 

There are a billionty different exhaust for the Zed out there, and I guarantee you one of them will meet your tone/noise/looks demands. You're not trying anything big or clever by this, it's the kind of thing I'd expect a 17 year old to do on his first Corsa.

 

Get out there, listen to a few different exhausts on a meet, and pick one. There's plenty out there for £600 already that are quality.

Honestly, yes. I want someone to explain why it's bad because nobody seems to actually be able to provide that information. I understand why it could be (as per the OP), but under the conditions as far as I can tell it wouldn't actually cause any problems.

 

As I mentioned in the OP, due to the location of the leak the exhaust gases escaping are not that hot. People have reported being able to leave their hand nearby without it being uncomfortable. Also, as again previously mentioned, most of the exhaust will still flow through and exit out the back.

 

Once again, as I said in the OP, it won't replicate the tone of a proper system, but a leak will undeniably make it louder, which is enough for the purpose of the test.

 

I know it's not big or clever, I clearly stated that I am well aware it's an exhaust leak and am aware of the alleged problems...

 

And another thing I mentioned in the OP, listening to an exhaust for a short period of time is not the same as having to live with it on a daily basis.

 

Did you even read the OP or just the title?

[Strudul]

If it is a stainless system and you go down the replacement route, I call dibbs on your old one

Is there a way to tell?

[Olly350z]

Have to agree with Ekona. Its an exhaust leak, not an aftermarket system. Any well known branded exhaust will have gone through some kind of R&D (the extent depends on the brand) for how it'll fit, sound, high and low tone, frequency resonance and more.

 

Given the location of where you could do this, and I stress that you dont, would be either the end of the Y pipe or at the backbox. Either would make the car sound awful imo. Ive seen some ghetto mods, but this is one of the dumbest...

[LRF4N]

"Ekona: Get out there, listen to a few different exhausts on a meet, and pick one"

 

This. First thing I would've suggested. A lot less hassle than making a leak

 

Although if you really want a leak that's a lot more technical than making some holes in it I'll give you that

 

When my exhaust was leaking I did enjoy going into underground car parks I'm not gonna lie lol. But you can't replicate it with a proper exhaust

 

I see what your saying- do this 'mod' as an experiment to see if you can live with it but I'm pretty sure you've made your mind up that you want one. Take off your flame suit, listen to some local zeds and decide which one you want

 

If your pockets are deep enough find yourself a veilside exhaust

[Strudul]

Have to agree with Ekona. Its an exhaust leak, not an aftermarket system. Any well known branded exhaust will have gone through some kind of R&D (the extent depends on the brand) for how it'll fit, sound, high and low tone, frequency resonance and more.

 

Given the location of where you could do this, and I stress that you dont, would be either the end of the Y pipe or at the backbox. Either would make the car sound awful imo. Ive seen some ghetto mods, but this is one of the dumbest...

Which I explicitly stated I knew in the OP

 

Most people report that it sounds much better, except for being able to hear the leak itself.

 

"Ekona: Get out there, listen to a few different exhausts on a meet, and pick one"

 

This. First thing I would've suggested. A lot less hassle than making a leak

 

Although if you really want a leak that's a lot more technical than making some holes in it I'll give you that

 

When my exhaust was leaking I did enjoy going into underground car parks I'm not gonna lie lol. But you can't replicate it with a proper exhaust

 

I see what your saying- do this 'mod' as an experiment to see if you can live with it but I'm pretty sure you've made your mind up that you want one. Take off your flame suit, listen to some local zeds and decide which one you want

 

If your pockets are deep enough find yourself a veilside exhaust

Haven't really decided at all, Sure, I think I'd enjoy it most of the time, but if it's gonna be unbearable on long motorway journeys then it isn't worth it and I don't want it...

 

 

 

Unless someone can provide some substantial reason not to, I'm gonna do it just to prove you all wrong, because I'm failing to see how it's any more "retarded" than a BGW or any cosmetic mod that matter - No actual benefits, just a load of extra weight, drag and money. It'd be a nice experiment to get some factual results rather than just making crap up and calling it stupid.

Edited March 11, 2017 by Strudul