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| Author | Subject: SC exhaust help |
 manthos
Seasoned Pro  Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #101
So here is a question coming from a novice as you guys are far more knowledgeable than me, why are some LB seeing 250-260 and why am I only seeing 230 what do I need to do to get closer to the 250 mark?________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
 Posted 26th May 2016 at 17:00
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rich_w
Seasoned Pro  Location: Havant, Hampshire Registered: 29 Jul 2004 Posts: 5,412 Status: Offline |
Post #102
It can depend on many different things.- engine health - compression, condition of fuel system, sensors etc - Exhaust back pressure - fuel used - Camshaft timing - air filter cleanliness And lots of other things. I would start with the exhaust. I did a high boost build, customer was disappointed as it only made 300 BHP. After looking over the car, the back box was not straight through type. No idea what make it was. Anyway, changed the exhaust system, back on the dyno, and it put out about 385 on a stonking hot day. Shows what difference the exhaust can make! ________________________________________ Contact Details:rich@lynxpowerengineering.co.uk 07732 822546 |
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Posted 26th May 2016 at 17:34
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #103
Ok thanks rich that will be my first step________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 26th May 2016 at 17:47
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roland rat
Yeeeah Rat fans!  Location: Swansea Registered: 29 Nov 2006 Posts: 22,282 Status: Offline |
Post #104
So as i've previously asked where did you take the car to be rolling roaded after I had the exhaust/decat fitted? |
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Posted 27th May 2016 at 11:59
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #105
AP Tuning (APT) in Norfolk they do all of Carl Chambers race cars and are known to have an accurate RR one that doesn't blow out stupid big figures. They also do all the time attack evos________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 27th May 2016 at 12:16
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armzsc6
Seasoned Pro  Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #106
rich_w wrote: manthos wrote:  can you guess what pipework that is size wise? That's 2.5" Pretty sure that must be 2" pipework or at least not quite 2.5".... The silicone joiner between the inlet manifold and the top pipe is a reducer there by the looks of it? Here's my original setup with 2" pipework along with smaller cooler and a reducer off the inlet.  And here's the larger 2.5" with straight coupler not reducer.   Have a measure up but if the top connector is a reducer then it's 2" might just be a bad pic.... ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 30th May 2016 at 11:25
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #107
Yes there is a reducer at the top like on your first picture I will have to measure it but from looking at your photos it looks like the 2" photo however I have high boost intercooler and im sure there is no reducer off the bottom of the cooler to pipes just comes straight off same diameter. did you see a difference going to 2.5" pipework and are you still running LB________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 30th May 2016 at 12:00
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #108
Just looked at it but didn't measure and think it's 2.25 ________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 30th May 2016 at 12:29
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #109
What size is the intercooler though... the low boost one uses 2" pipes from the charger all through to the inlet. The charger outlet itself is also 2" but they welded on 2.5" elbows for high boost pipes.I'd put money on you having the smaller forge cooler but put some pics up. Would explain 230bhp better. Yes I noticed a decent gain in low down torque and a bit in top end. Not quite night and day difference but we'll noticeable. ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 30th May 2016 at 17:31
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #110
The intercooler is much bigger than the low boost ones________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 30th May 2016 at 17:48
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #111
click herehave a look here there is a photo of the intercooler where a previous owner took it off ________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 30th May 2016 at 17:55
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #112
Yup that's definitely high boost cooler. Mines bigger than that though but conning off for a smaller one this week if I get time. ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 30th May 2016 at 19:54
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Day666
Seasoned Pro  Location: Bristol Registered: 20 Apr 2013 Posts: 5,209 Status: Offline |
Post #113
Pete / Seb both your cars looking great  |
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Posted 30th May 2016 at 20:00
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #114
Day666 wrote: Pete / Seb both your cars looking great Cheers bud but mine looks exactly the same as it did the last time you saw it lol. Sunroofs coming out and real carbon bung going in and new intercooler and upgrade to 19 row oil cooler this month before pugfest then get the cage in when we get time. I'd like to get my carbon bonnet back on it too but funds won't allow atm it needs a lot of work and got wedding to pay for at the end of the year  ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 30th May 2016 at 20:29
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #115
Pete I love your orange and black theme you have it spot on in the engine bay. I would love to do something similar, but as the manifold is already china blue I was going to spray the strut brace china too and have started polishing the cam covers already but I'd love to do some mad colour like you have. pink is a cool idea but would probably not look great, yellow might be cool or as I'm thinking of gold wheels I could do gold manifold and strut brace. not sure though ________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 30th May 2016 at 20:50
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clen666
Seasoned Pro  Location: Co. Durham Registered: 12 Feb 2009 Posts: 2,401 Status: Offline |
Post #116
Bigger isn't always better  Larger bore has the capacity to flow more air but if it's bigger than necessary then gas velocity is reduced. No engine needs back pressure - it's trying to get rid of exhaust gases as fast as possible, it doesn't want any restriction, but the smaller pipe diameter (eg 2.5" instead of 3" ) will provide a higher gas velocity for that situation if correctly calculated. ________________________________________ Team 'unintentional rat look' |
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Posted 31st May 2016 at 09:26
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #117
manthos wrote: Pete I love your orange and black theme you have it spot on in the engine bay. I would love to do something similar, but as the manifold is already china blue I was going to spray the strut brace china too and have started polishing the cam covers already but I'd love to do some mad colour like you have. pink is a cool idea but would probably not look great, yellow might be cool or as I'm thinking of gold wheels I could do gold manifold and strut brace. not sure though Cheers I like it and it stands out like anything at a car show. I got the strut brace and manifold powder coated 4 years ago before I even fitted the charger kit. Every car show I've been on stands particularly with other 306's I've watched people walking past not even bothering to look at any of the cars on the stand just thinking "oh look a load of old peugeots..." then spotting the bright orange on mine and all being drawn to it good few people gathering round it lots of pics etc. Definitely catches people's eye. Yellow would pop quite well against the china blue. I do love the gold wheels with the china actually think it pulls it off quite well. So if you fancy being different and not giving a f**k what other people think then go for the gold theme. Think it cost me £40 to get the inlet done and £35 to get the strut brace done. So even if you didn't like it wouldn't cost the earth to change colours. ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 31st May 2016 at 13:55
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #118
clen666 wrote: Bigger isn't always better Larger bore has the capacity to flow more air but if it's bigger than necessary then gas velocity is reduced. No engine needs back pressure - it's trying to get rid of exhaust gases as fast as possible, it doesn't want any restriction, but the smaller pipe diameter (eg 2.5" instead of 3" ) will provide a higher gas velocity for that situation if correctly calculated. Not sure I aggree with no engine needing back pressure... turbo yes 100% aggree but even from my own experience these engines make less torque and mid range with a decat than they do with a cat. And since mines been supercharged I've had several exhaust setups. The latest being a 2.5" stainless tig welded sections exhaust with maximum flow. It had no centre box originally and the car felt gutless midrange and low down. Also no better top end than it had with a 2.25" powerflow. I then cut a section out of the centre and fitted a Jetex / Simons stainless centre box and it instantly had more low down and more top end pull too from just a little back pressure. Also it stopped my ears from bleeding ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 31st May 2016 at 14:05
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phillipm
Seasoned Pro  Location: Rotherham Registered: 15 Oct 2006 Posts: 20,607 Status: Offline |
Post #119
That's just down to loosing the resonance box when replacing the cat - there's an expansion chamber in the OEM one.________________________________________ - Bespoke rollcages/additions/adjustments. Half cages right up to complete custom spaceframes - MSA/FIA spec, CDS, ROPT, T45, etc - PM meEmail me! Custom-made polybushes available - need an odd size or fitment? - anything from batch work to one-off pieces. |
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Posted 31st May 2016 at 15:50
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welshpug!
Capt Pedantic  Location: Bigend, Wales. Registered: 27 Mar 2007 Posts: 25,817 Status: Offline |
Post #120
engines never need "backpressure" they need the correct flow and pulse tuning, which as Phill pointed out you alter quite a bit with the lack of chamber where the cat is.he's correct that if the pipe is too large then the air will stall. ________________________________________ need a part number? get on here - http://public.servicebox.peugeot.comBring on the Trumpets. |
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Posted 31st May 2016 at 16:34
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #121
Too right it will people wack a 3" bore exhaust on and wonder why they lost power lol________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 31st May 2016 at 16:37
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #122
Sorry to thread hijack a bit but its already been talked about... been planning on fettling the restrictor ring slightly for a long time now.Been out in mine for first proper thrash since August last year watching the AEM wide band readings. Showing as rich as 11.5 occasionally when first flat out but mostly stays around 12.5 all through the rev range 12.9 occasionally at very highest. Last time I had it rolling roaded at KAP'S new dyno in Canterbury the did AFR readings for me and said it was very good and safe all the way through and looking at the graph it was 12.5 most of the way through. Will be changing intercooler for an Apexi one that's more normal high boost size as the one I have currently is stupidly big too large for such little boost. (The core is 24" x11" x2 3/4" so will see how it is after that but I'm willing to try machining the ring out 0.5mm and see what happens. I don't know a great deal about AFR'S on forced induction but have always been told 12.5-13 is fine so if I leaned it up slightly toward 13 or just over at times would it still be ok. What's a number I wouldn't want to see?  obviously anywhere close to stoichiometric is far too lean under boost ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 2nd Jun 2016 at 00:03
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armzsc6
Seasoned Pro Location: Crowborough Registered: 22 Mar 2008 Posts: 3,445 Status: Offline |
Post #123
manthos wrote: So here is a question coming from a novice as you guys are far more knowledgeable than me, why are some LB seeing 250-260 and why am I only seeing 230 what do I need to do to get closer to the 250 mark? Another thing to check is take off the throttle body and measure the internal diameter of the restrictor ring as i said before when I bought my kit it came with 2 rings and the smaller one was fitted originally. But I soon swapped it for the larger one before the first dyno day and even then it made 244bhp on the smaller intercooler. ________________________________________ Black power baby! SUUUUUPERCHARGED Seat Leon FR TDI 190BHP 300lbft daily gti-6 killer :p 12x 306's owned so far Cambelts, clutches, service work carried out on All makes and models, Peugeot Citroen / mitsubishi specialist. Pug planet / Citroen Lexia diagnostics / code reads available. |
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Posted 2nd Jun 2016 at 00:05
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manthos
Seasoned Pro Location: Norwich Registered: 29 Apr 2009 Posts: 1,966 Status: Offline |
Post #124
Thanks pete your so much help________________________________________ Team SUPERCHARGED I LIVE FOR THE 306 Old Project thread Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url = |
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Posted 2nd Jun 2016 at 00:26
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rich_w
Seasoned Pro Location: Havant, Hampshire Registered: 29 Jul 2004 Posts: 5,412 Status: Offline |
Post #125
armzsc6 wrote: Sorry to thread hijack a bit but its already been talked about... been planning on fettling the restrictor ring slightly for a long time now. Been out in mine for first proper thrash since August last year watching the AEM wide band readings. Showing as rich as 11.5 occasionally when first flat out but mostly stays around 12.5 all through the rev range 12.9 occasionally at very highest. Last time I had it rolling roaded at KAP'S new dyno in Canterbury the did AFR readings for me and said it was very good and safe all the way through and looking at the graph it was 12.5 most of the way through. Will be changing intercooler for an Apexi one that's more normal high boost size as the one I have currently is stupidly big too large for such little boost. (The core is 24" x11" x2 3/4" so will see how it is after that but I'm willing to try machining the ring out 0.5mm and see what happens. I don't know a great deal about AFR'S on forced induction but have always been told 12.5-13 is fine so if I leaned it up slightly toward 13 or just over at times would it still be ok. What's a number I wouldn't want to see? obviously anywhere close to stoichiometric is far too lean under boost It would be better if you could keep it in the 12's - it sounds like it's running pretty much spot on. 12.6 is roughly where you will find maximum power. My old car use to run in the high 10s or low 11s right at the top, for piston cooling, so sometimes it's a balance between finding reliability and power, particularly on a fairly high compression boosted engine  ________________________________________ Contact Details:rich@lynxpowerengineering.co.uk 07732 822546 |
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Posted 2nd Jun 2016 at 09:18
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