ChrisUUC Posted October 12, 2010 Share Posted October 12, 2010 Anyone? Thanks Chris Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted October 12, 2010 Share Posted October 12, 2010 Your car will lose power/torque running one of these. Quote Link to comment Share on other sites More sharing options...
ChrisUUC Posted October 12, 2010 Author Share Posted October 12, 2010 Really ... Why? What would you suggest? Quote Link to comment Share on other sites More sharing options...
Zugara Posted October 12, 2010 Share Posted October 12, 2010 What about hks style dual exhaust! Will these lose power etc. Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 12, 2010 Share Posted October 12, 2010 I take it is due to lack of back pressure? Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted October 12, 2010 Share Posted October 12, 2010 I take it is due to lack of back pressure? back pressure is a myth Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 12, 2010 Share Posted October 12, 2010 I take it is due to lack of back pressure? back pressure is a myth Is it? could you explain how? Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted October 12, 2010 Share Posted October 12, 2010 Actually, there is slight misconception in terminology that needs to be cleared up. It is not that a certain amount of backpressure is needed for optimum performance. A well designed exhaust system should not only relieve backpressure, but go one step further and create a vacuum in the system. When the next cylinder's exhaust valve opens, the vacuum in the system pulls the exhaust out of the cylinder. This is what's termed "scavenging". It just easier to call it as needing a little backpressure than it is to explain a balanced airflow system to the average guy on the street. The physics of airflow dynamics dictate that the pipe should be only be big enough to handle a given volume of air or in this case exhaust gases. Whether it be an exhaust system or a A/C duct in your home first consideration is the proper tube diameter. Many people think "Bigger is Better", but this is not the case. The smallest diameter that will handle the airflow of a given volume of air at a given air velocity should be used. This small diameter will generate the velocity (air speed) needed to "Scavenge" or create a vacuum in the pipe. In the case of a internal combustion engine, if the pipe diameter is to small for the engine it will pull hard at low rpm's but at some point in the higher rpm's the tube will not be able to flow as much air as the engine is pumping out, and the engine will "clock out " early, not reaching its potential peak rpm. In this situation it would require going one size larger in tube diameter. This is why the general rule of thumb is that the maximum exhaust pipe for a normally aspirated multi valve engine operating under 8000rpm should only be .75 to 1 time the displacement of the engine in litres. This vacuum in the exhaust system also has a big effect on the intake side as well. Because the vacuum is pulling the exhaust out of the cylinder this creates a stronger vacuum pulse on the intake side that pulls a stronger air/ fuel charge into the cylinder. If the pipe diameter is to big the Air ( Exhaust) become lazy and wants the intake side to push it out so in the case of an engine the intake charge gets contaminated with exhaust gases. If the pipe is to big for an application this can also cause restriction in airflow because it is moving to slow and will actually start to back up in the pipe. This is an over simplified overview in airflow dynamics but you should get the general idea. Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 13, 2010 Share Posted October 13, 2010 Actually, there is slight misconception in terminology that needs to be cleared up. It is not that a certain amount of backpressure is needed for optimum performance. A well designed exhaust system should not only relieve backpressure, but go one step further and create a vacuum in the system. When the next cylinder's exhaust valve opens, the vacuum in thesystem pulls the exhaust out of the cylinder. This is what's termed "scavenging". It just easier to call it as needing a little backpressure than it is to explain a balanced airflow system to the average guy on the street. The physics of airflow dynamics dictate that the pipe should be only be big enough to handle a given volume of air or in this case exhaust gases. Whether it be an exhaust system or a A/C duct in your home first consideration is the proper tube diameter. Many people think "Bigger is Better", but this is not the case. The smallest diameter that will handle the airflow of a given volume of air at a given air velocity should be used. This small diameter will generate the velocity (air speed) needed to "Scavenge" or create a vacuum in the pipe. In the case of a internal combustion engine, if the pipe diameter is to small for the engine it will pull hard at low rpm's but at some point in the higher rpm's the tube will not be able to flow as much air as the engine is pumping out, and the engine will "clock out " early, not reaching its potential peak rpm. In this situation it would require going one size larger in tube diameter. This is why the general rule of thumb is that the maximum exhaust pipe for a normally aspirated multi valve engine operating under 8000rpm should only be .75 to 1 time the displacement of the engine in litres. This vacuum in the exhaust system also has a big effect on the intake side as well. Because the vacuum is pulling the exhaust out of the cylinder this creates a stronger vacuum pulse on the intake side that pulls a stronger air/ fuel charge into the cylinder. If the pipe diameter is to big the Air ( Exhaust) become lazy and wants the intake side to push it out so in the case of an engine the intake charge gets contaminated with exhaust gases. If the pipe is to big for an application this can also cause restriction in airflow because it is moving to slow and will actually start to back up in the pipe. This is an over simplified overview in airflow dynamics but you should get the general idea. I have heard of scavenging on a type of 2 stroke before but never knew it works like this. Cheers for clearing that up Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted October 13, 2010 Share Posted October 13, 2010 The DC system just seems to cause a drop in midrange torque we have found ( I actually run one of these on my JDM car) I have cars with indentical mods as cars with DC systems on and they all give more mid range torque. The HKS super sound master isnt full true dual is connects to a stock Y pipe so you get the full scavenging effect from the connected headers, The copies thou we have found have inferior silencers causing bad flow, I think the pipework Diameter is smaller as well than the genuine HKS systems. I still think you cant be a set of de-cats ( resonated or not ) XYZ with race cat and a stock UK system and a remap, this sounds real nice without being raspy or loud. Mark Quote Link to comment Share on other sites More sharing options...
Neilp Posted October 13, 2010 Share Posted October 13, 2010 Have you any results on the scorpion exhaust on the dyno? Just wondering since it only has a 2.5" bore centre section. Quote Link to comment Share on other sites More sharing options...
M13KYF Posted October 13, 2010 Share Posted October 13, 2010 always loved the sound of the DC Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted October 13, 2010 Share Posted October 13, 2010 yes they sound awesome, thats why it is still fitted to my JDM. Quote Link to comment Share on other sites More sharing options...
ChrisUUC Posted October 13, 2010 Author Share Posted October 13, 2010 Hmmmm If i got one cheap enough id maybe go with it but failing that .,, HFC's ... stock system ... panel filters ... remap (in time) Ill maybe open this also up to any exhaust if theres any nice second hand ones out there ... No nismos though as the price wont allow me Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted October 13, 2010 Share Posted October 13, 2010 Hmmmm If i got one cheap enough id maybe go with it but failing that .,, HFC's ... stock system ... panel filters ... remap (in time) Ill maybe open this also up to any exhaust if theres any nice second hand ones out there ... No nismos though as the price wont allow me tannabe sounds great motordyne exhaust is good, think it makes good gains as well. Team Lizard have it fitted to his race car. Quote Link to comment Share on other sites More sharing options...
ChrisUUC Posted October 13, 2010 Author Share Posted October 13, 2010 I love the sound of the tanabe medalion touring?? ... Whats the price on them? Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted October 13, 2010 Share Posted October 13, 2010 as good as $900 don't know if its better for you to ship from the US or from the UK think its about 900 quid in the uk. Quote Link to comment Share on other sites More sharing options...
Androo Posted October 18, 2010 Share Posted October 18, 2010 when you say power loss.... i presume you mean <5whp etc.... I didnt notice diddy squat with my TD, other than a fantastic noise Quote Link to comment Share on other sites More sharing options...
Lexx Posted October 18, 2010 Share Posted October 18, 2010 5zigen pro-racer A-Spec FTW Although I am biased. This fitted with a set of the Nismo Dual CAI sounded amazing Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted October 18, 2010 Share Posted October 18, 2010 when you say power loss.... i presume you mean <5whp etc.... I didnt notice diddy squat with my TD, other than a fantastic noise not any kind of a loss that the butt dyno would pickup. Quote Link to comment Share on other sites More sharing options...
Zugara Posted October 18, 2010 Share Posted October 18, 2010 What about this bad boy? http://www.wotm.com/ingecaex035.html# Quote Link to comment Share on other sites More sharing options...
DoogyRev Posted October 18, 2010 Share Posted October 18, 2010 I love the sound of the tanabe medalion touring?? ... Whats the price on them? From what I understand you also need a Tanabe Y-pipe as well else it wont fit The Medalion on its own does not come with one. Sounds nice though Quote Link to comment Share on other sites More sharing options...
DoogyRev Posted October 18, 2010 Share Posted October 18, 2010 What about this bad boy? http://www.wotm.com/ingecaex035.html# Rolled tips would be my choice Quote Link to comment Share on other sites More sharing options...
Zugara Posted October 18, 2010 Share Posted October 18, 2010 What about this bad boy? http://www.wotm.com/ingecaex035.html# Rolled tips would be my choice Looks nicer than the miltek. Quote Link to comment Share on other sites More sharing options...
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