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Taking out silencers


JackPalmer27
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Slowly upgrading my Lupo but cheap. Thinking off making it louder, and was wondering if anyone has or has heard a lupo with just the stock exhaust system but with silencers taken off, I don't want it to sound like a tractor but as wondering what it would sound like with silencers taken off and if I was to weld a new pipe in instead?

Thank you

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Just bought the boy his first lupo 1.0 and it came with a stainless straight thro with a twin tip tailpipe and it's been de-cat'd. Sounds awesome but it is loud. More rally prepped Scooby loud lol.

It's wicked tho FairPlay

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Slowly upgrading my Lupo but cheap. Thinking off making it louder, and was wondering if anyone has or has heard a lupo with just the stock exhaust system but with silencers taken off, I don't want it to sound like a tractor but as wondering what it would sound like with silencers taken off and if I was to weld a new pipe in instead?

Thank you

Yes.

You can either take off the backbox and put in a straight exhaust pipe. Will cost you about £8 if you do it yourself. I like this option.

Or, you take the backbox apart, remove the baffles. Weld back together. Easy.

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Yes.

You can either take off the backbox and put in a straight exhaust pipe. Will cost you about £8 if you do it yourself. I like this option.

Or, you take the backbox apart, remove the baffles. Weld back together. Easy.

Sorry to jump on this thread and ask about a different model but does the same stand for the Tdi Lupos?

Can you take out the silencers and Cat to make it a straight through system?

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Sorry to jump on this thread and ask about a different model but does the same stand for the Tdi Lupos?

Can you take out the silencers and Cat to make it a straight through system?

Hey flip flops, I don't see no reason why, my t4s a 2.5tdi with stainless straight thro and it's been decat'd no baffle boxes or nowt sounds nice and passes mots fine ??

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How does a diesel car manage to get round the MOT's without a cat? Dubbersdoo i always thought it was an emissions fail, do the tdi's not need them?

Skezza i can not stand the things lol, they are so restrictive. I'm interested to know if you can pass an MOT without one in. I wont bother having a pipe made up i'll just have a new bit welded in.

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You don't necessarily need a cat on a diesel as they don't have 'emissions' tests as such - they just have a smoke test. Just make sure you retain your lambda sensor.

If anything, you will get more performance gain on a TDI than on any other model of Lupo. A decat and freer flowing exhaust will allow the turbo to spool up quicker and you will definitely get a noticeable performance gain.

...even more so if it's mapped!

It will sound quite good and very 'boosty'.

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You don't necessarily need a cat on a diesel as they don't have 'emissions' tests as such - they just have a smoke test. Just make sure you retain your lambda sensor.

If anything, you will get more performance gain on a TDI than on any other model of Lupo. A decat and freer flowing exhaust will allow the turbo to spool up quicker and you will definitely get a noticeable performance gain.

...even more so if it's mapped!

It will sound quite good and very 'boosty'.

I will keep the lambda sensors in, i'm not going to take them out. Cats are so restrictive, if i can do away with it without much hassle then i will remove it then :). It's provisionally booked in on Saturday to have it done.

I'm going to get it mapped too. I'm not chasing bhp numbers or loads of speed but just something that makes the drive a little more fun. I'm going to see if i can buy a CAI for it, if not i'm going to make one up that takes the filter outside of the engine bay. I've bought the car mainly for my Mrs when she passes her test so i can't go too mad but I'm going to be driving it too :twisted::D

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I'm going to see if i can buy a CAI for it, if not i'm going to make one up that takes the filter outside of the engine bay.

Don't get too hung up on the whole 'cold air feed'. On a turbo car, you see huge intake temps regardless of whether or not your filter is fed cold air. It is the job of the intercooler to cool the charged air before it enters the inlet manifold. Money would be a LOT better spent on an uprated intercooler than it would on a filter. Just get a nice big cone filter with plenty of surface area. If you are able to isolate it from heat-soak then great - if not, don't worry too much.

And another thing... Don't get it mapped til you've done all the mods you wish to carry out.

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Look, I'm going to put FlipFlops out of his misery here, Cooper, the filter on a TDI is located exactly where he wants to relocate the filter, that's why me and DBlock were laughing about his plans to do so. The filter on both an SDI and TDI are pretty much located in the same place which is just above the lip on the front splitter by the wheel liner, almost identical to the photo he posted. I forget which side for some reason.

At the end of the day, it's down there for a reason, it's a CIA, straight from the factory (hey, those guys who actually engineered the car do know something about vehicles after all). I can assure you that any plans to relocate the filter will result in higher temps or bitter disappointment when it renders absolutely no noticable benefits.

Don't uprate the intercooler either. Go for an intercooler water spray system.

And for gods sake don't fit a big cone filter either. This isn't a Vauxhall Corsa. If you fit a cone filter you WILL lose performance, you will lose economy and you will almost certainly experience much higher temperatures, because unless you're willing to put the time and effort in to plum in a proper cold air intake, then the OEM system will be FAR superior to yours.

If you're desperate to install an aftermarket air filter, just so you can say you've installed an aftermarket air filter, you may as well get one that replaces your OEM filter so you can experience the benefits of your OEM air intake system.

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Look, I'm going to put FlipFlops out of his misery here, Cooper, the filter on a TDI is located exactly where he wants to relocate the filter, that's why me and DBlock were laughing about his plans to do so. The filter on both an SDI and TDI are pretty much located in the same place which is just above the lip on the front splitter by the wheel liner, almost identical to the photo he posted. I forget which side for some reason.

At the end of the day, it's down there for a reason, it's a CIA, straight from the factory (hey, those guys who actually engineered the car do know something about vehicles after all). I can assure you that any plans to relocate the filter will result in higher temps or bitter disappointment when it renders absolutely no noticable benefits.

Don't uprate the intercooler either. Go for an intercooler water spray system.

And for gods sake don't fit a big cone filter either. This isn't a Vauxhall Corsa. If you fit a cone filter you WILL lose performance, you will lose economy and you will almost certainly experience much higher temperatures, because unless you're willing to put the time and effort in to plum in a proper cold air intake, then the OEM system will be FAR superior to yours.

If you're desperate to install an aftermarket air filter, just so you can say you've installed an aftermarket air filter, you may as well get one that replaces your OEM filter so you can experience the benefits of your OEM air intake system.

I assumed he was mentioning a filter as he was after the extra noise (hence why he wants a straight through exhaust), but I agree, if you're happy with the standard filter then there won't be any gain from changing it in this application.

The reason I mentioned a large cone filter is based on my own experiences (which is a damn site more than a lot of people on this site have!)

When my 1.8t Lupo was on the Dyno using the standard AGU airbox coupled with the Lupo cold air feed, the mapper told me try fitting a jetex cone filter which he had in the top of his tool box. Upon doing so, the peak power increased instantly from 208bhp to 214bhp, with a marginally smoother torque curve and it held its power a lot higher in the revs range, proving that flow is in fact more important than 'the dreaded heat soak'. On a naturally aspirated engine I agree this may not be the case, but we're talking turbos here, where more boost and higher temps is better than less boost and lower temps.

You're definitely better off with a larger intercooler, mounted at the front of the car. Spraying the intercooler whenever you 'think' it's getting warm isn't feasible and is not a lossless system. Fit the intercooler and forget about it, knowing it's doing its job from the minute you turn the engine on to the minute you turn it off. Then, and only then, if you're still seeing high intake temps with an uprated intercooler it's time to look at other options.(mounting, spray, fans etc)

Experiment and see what works for you - dare to break the trend!

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On 18/08/2015 at 1:08 PM, Cooper_GTI said:

Experiment and see what works for you - dare to break the trend!

Edited by FlipFlops
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I assumed he was mentioning a filter as he was after the extra noise (hence why he wants a straight through exhaust), but I agree, if you're happy with the standard filter then there won't be any gain from changing it in this application.

The reason I mentioned a large cone filter is based on my own experiences (which is a damn site more than a lot of people on this site have!)

When my 1.8t Lupo was on the Dyno using the standard AGU airbox coupled with the Lupo cold air feed, the mapper told me try fitting a jetex cone filter which he had in the top of his tool box. Upon doing so, the peak power increased instantly from 208bhp to 214bhp, with a marginally smoother torque curve and it held its power a lot higher in the revs range, proving that flow is in fact more important than 'the dreaded heat soak'. On a naturally aspirated engine I agree this may not be the case, but we're talking turbos here, where more boost and higher temps is better than less boost and lower temps.

You're definitely better off with a larger intercooler, mounted at the front of the car. Spraying the intercooler whenever you 'think' it's getting warm isn't feasible and is not a lossless system. Fit the intercooler and forget about it, knowing it's doing its job from the minute you turn the engine on to the minute you turn it off. Then, and only then, if you're still seeing high intake temps with an uprated intercooler it's time to look at other options.(mounting, spray, fans etc)

Experiment and see what works for you - dare to break the trend!

Uhuh and was it reproducable? Did you try to run it with no air filter at all? My feelings are, for most seemingly unexplained things, there are rational scientific explanations. I always believe science is a far better tool than "I fitted a cone filter to my 1.6 Golf and it went vroom vroom".

That's an impressive increase from something as poxy as just a cone filter. I'm just wondering if there was something else wrong with your OEM setup. Still, I am willing to be proven wrong.

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Filters can make a difference especially when tuning higher performance cars no doubt, but only on petrols.

Diesels are designed to run lean. I can bet you any money my filter on my 1.4 tdi is bigger than the one on your 1.8t (not a contest just trying to explain). I get that when your running a petrol car and you start pushing the bhp a *properly* designed intake can net you power. I get that but not on the tdi IMO. The filter on this car is the roughly the same size as a 6 cylinder 330d engine. Remember diesels run lean and fill with air each stroke so it's using a hell of a lot more air than a petrol will. No throttle body on diesels.

Secondly putting on an intercooler will help temps but remember how little the turbo on the tdi is. On the 1.9tdi it's a great idea. Even a slightly larger on the 1.4 causes big lag. That tiny turbo can't cope with it.

Lastly flip flip thinks it's exactly like his r32 which it isn't. " it worked on that so it will work on this". Nope sorry. If you don't want my advice I want give it actually I probably won't bother anymore since you don't get it. You think diesels have lambda sensors that shows how much you don't understand these engines but it's your time and money crack on. I'll be watching for the lulz.

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A quick example. A filter for an evo with a 4g63 that needs a better filter to hit roughly 400/400.

K&n filter size 157mm by 127mm or 15.7cm high and 12.7 cm across.

A lupo tdi filter 25.2cm high by 10.1cm. A much much larger surface area.

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In the scenario I explained, the original airbox made higher torque earlier in the rev range, but then tailed off a lot quicker. This is how the general public as a whole like cars to perform - "ooh, it's got a lot of poke" And that's not referring to 13x10 banded steelies

I'm going to say this is due to the inlet tract being longer and there is a large volume of air ready to supply the engine. But as the revs rise, the airbox becomes a larger restriction and hence cannot keep up with the demand.

Yes Skezza, it was reproducible as the car did 5 or 6 4th gear runs (as we all know, you have greatly reduced cooling on a dyno, so if inlet temps were an issue they would certainly stand out here) and the new filter required alterations to the map in order to gain more power. The filter in the 1.8t airbox had done no more than about 50 miles, albeit an aftermarket affair from GSF.

I didn't try it without the filter, but I'm 90% sure that it would have gained more power. The ideal situation, broadly speaking(!!) for engine breathing is to make the inlet/outlet paths as unrestrictive as possible, hence why we fit larger exhaust, throttle bodies, flowed heads, large valves etc...

I'm by no means an expert, but I've read a lot of books and had a lot of experience with building budget engines and getting max bhp using simple engineering methods (camshaft timing, manifold/exhaust tuning, inlet runner lengths etc) which are often overlooked by people with bulging wallets and egos.

Another thing that armchair tuners like to claim is that car engines need backpressure. From what I've found this is a load of tosh. On a 4-stroke engine there is plenty of overlap between the exhaust/inlet valves and anyway, it's not like you're going to be scavenging unburnt air/fuel from half way down the exhaust. Any scavenging you are getting has happened in the manifold.

2-strokes however are a different story.

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In the scenario I explained, the original airbox made higher torque earlier in the rev range, but then tailed off a lot quicker. This is how the general public as a whole like cars to perform - "ooh, it's got a lot of poke" And that's not referring to 13x10 banded steelies

I'm going to say this is due to the inlet tract being longer and there is a large volume of air ready to supply the engine. But as the revs rise, the airbox becomes a larger restriction and hence cannot keep up with the demand.

Yes Skezza, it was reproducible as the car did 5 or 6 4th gear runs (as we all know, you have greatly reduced cooling on a dyno, so if inlet temps were an issue they would certainly stand out here) and the new filter required alterations to the map in order to gain more power. The filter in the 1.8t airbox had done no more than about 50 miles, albeit an aftermarket affair from GSF.

I didn't try it without the filter, but I'm 90% sure that it would have gained more power. The ideal situation, broadly speaking(!!) for engine breathing is to make the inlet/outlet paths as unrestrictive as possible, hence why we fit larger exhaust, throttle bodies, flowed heads, large valves etc...

I'm by no means an expert, but I've read a lot of books and had a lot of experience with building budget engines and getting max bhp using simple engineering methods (camshaft timing, manifold/exhaust tuning, inlet runner lengths etc) which are often overlooked by people with bulging wallets and egos.

Another thing that armchair tuners like to claim is that car engines need backpressure. From what I've found this is a load of tosh. On a 4-stroke engine there is plenty of overlap between the exhaust/inlet valves and anyway, it's not like you're going to be scavenging unburnt air/fuel from half way down the exhaust. Any scavenging you are getting has happened in the manifold.

2-strokes however are a different story.

I think there is some logic to the back pressure argument, I think the problem is that people misunderstand back pressure and it's role and relevance. Also, people wrongly assume that bigger is better, and when they find out it's not, they blame 'lack of back pressure'. Take Billy the ****. He's a ****, naturally, so he drives a Honda Civic, he fits a massive 3 inch straight through exhaust and then finds it feels underpowered and laggy. He incorrectly blames the lack of back pressure (seeing as that's what he's removed), when the reality is, he's killed his flow velocity by installing a much wider pipe. Calculating your exhaust diameter is somewhat of a mathematical process and just whacking a great big pipe on it won't necessarily give you the performance characteristics you desire.

That's why I tend to believe that most car manufacturers have the exhaust pipe diameter pretty spot on.

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I've heard "pulsing" is quite important on N/A's. On turbos reduce any restriction IMO better and faster spool up.

The point I'm trying to make is petrol turbo tuning is not diesel turbo tuning. Petrol N/A tuning isn't turbo diesel tuning.

Skezza I'll maybe agree for N/A cars but not for turbos. OEM's want a nice sound nothing too loud. Wack a huge pipe in and do some other mods and the car will spool faster, make more power and be more responsive. A guy I know had an evo. Running 400ish bhp. One day it just started running pants. Turns out the pipe had gotten squashed and was restricting flow!

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I've heard "pulsing" is quite important on N/A's. On turbos reduce any restriction IMO better and faster spool up.

The point I'm trying to make is petrol turbo tuning is not diesel turbo tuning. Petrol N/A tuning isn't turbo diesel tuning.

Skezza I'll maybe agree for N/A cars but not for turbos. OEM's want a nice sound nothing too loud. Wack a huge pipe in and do some other mods and the car will spool faster, make more power and be more responsive. A guy I know had an evo. Running 400ish bhp. One day it just started running pants. Turns out the pipe had gotten squashed and was restricting flow!

Ahh, yes, but you're talking about a guy who's pipe was actually damaged. My point is, fit an aftermarket big bore exhaust to something like an Evo 8 and I just don't see you getting huge benefits. These cars are highly tuned from the manufacturer, why would they skimp out on something like an exhaust?

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Ahh, yes, but you're talking about a guy who's pipe was actually damaged. My point is, fit an aftermarket big bore exhaust to something like an Evo 8 and I just don't see you getting huge benefits. These cars are highly tuned from the manufacturer, why would they skimp out on something like an exhaust?

Well because most of these cars come from Japan and they have strict laws about noise and emmisons. The FQ's are jdm cars but modded by Mitsu UK with bigger hks exhaust etc etc. that's the only way to get to 360+. Cars are built to a cost. All of them from a lupo to a maybach. Profit is their game and they would cut corners where possible. Why aren't exhausts made of stainless steel?

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