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Title: Exhaust Possibilities and more Post by: Shiano on June 25, 2007, 09:22:08 AM Ok. I guarentee i will come off as retarded for the first few of my posts on this. just bare with me....
Lets talk about the Torque Factor related to Exhaust setups. When you answer one of these questions, put the number in front of it so that others can easily reference the question in the future when we are done talking about chicken and sheep and DT bringing sexy back. lol (ex: 1. Well the answer is...) With smaller engines, to keep the torque up in the green range [good range], you use a smaller exhaust pipe. However, if you go too small, it caps off the torque gain and starts reducing the HP. With larger engines, you can increase this pipe size because there is MORE exhaust going through these pipes. Therefore, the exhaust pressure is kept in the green. 1. Does the Compression Ratio of the cylinders have anything to do with the size of the pipe you should use to keep your optimum back pressure [for Torque reasons]? 2. On the 420A, would it benefit from 4 oval pipes coming off the head [they are horizontal ovals] and gradually twisting into four vertical ovals [ 0000 ] and THEN merge into one circular pipe, as opposed to the standard oval-to-circle tube that happens within 6 inches of the exhaust leaving the engine? 3. What exhaust factors contribute and are the main cause of High End Torque loss? [ex: going from 70-80mph and it takes awhile in 5th] 4. Would a decrease in High End Torque cause the transmission to have to reach a higher RPM in order to acheive interstate speeds. [On average, 80mph for a 5spd 420a is 3400 Rpm. Say Ivan and I were side by side. His tach reads 3400 while my tach reads 3900-4000 rpm.] Now I probably don't have everything right or worded right, but anyone who knows any answer to these 4 questions will understand what I'm trying to get at. I now release the floor for discussion on this. Title: Re: Exhaust Possibilities and more Post by: admin on June 25, 2007, 12:49:58 PM airmass long tube header.. I don't know if they still make them or not..
that's your answer.. more torque is better.. with the 420a however.. the gains are to be had in the cylinder itself and in the head... the exhaust ISNT the problem.. you can bolt on everysingle header to your hearts content.. and they'll all be within a few hp of each other.. BUT your low end torque will go all to crap. airmass.. or stepmatch the exhaust flange on the cast manifold and open up the output to the downpipe to 2.5".. nothing you can bolt on will be better.. the intake manifold is where all the gains are to be had.. and in the head itself.. it is the problem.. it's upside backwards and down.. not to mention castings shifts in the head that don't lend themselves to "awesomeness". btw.. port matching.. making everything the same size and to flow smoothly.. looks good until it slams into the cat.. and you have a reversion wave travelling backwards up the exhaust to the head.. step match that biatch.. http://hytechexhaust.com Quote HyTech has been the leader in race engine exhaust technology for the past 21 years, with numerous championships in SCCA, USAC, Trans-Am, World SportsCars, Dirt Track and NHRA Drag racing series. HyTech's innovative approach to exhaust development has catapulted it into the forefront of the racing industry. (http://hytechexhaust.com/images/whowe/reversion01.jpg)HyTech incorporates ANTI-REVERSION ® patent 6,336,471, stepped pipes and sequential cylinder pairing into all of its exhaust systems. HyTech began designing and manufacturing exhaust systems in 1984 with the introduction of its anti-reversion header for popular Formula Fords. Since then with the help of numerous engine builders from all aspects of racing HyTech has gone to dominate the SCCA road racing series with the Formula Fords, Formula 2000, SP 2000, and Toyota Atlantic Series. By the early 1990's HyTech moved into several other venues of racing, like NASCAR Late Model Circle track and USAC midget series. HyTech has developed the exhaust for the Esslinger Engineering Midget program which is now the dominate engine in the series. HyTech has also dominated the Cart Toyota Atlantic series for the last 3 years with its highly developed Three step anti-reversion tri-y system. HyTech has also dominated Import Drag racing series with clients like Stephan Papadakis, Brent Rau, Skunk 2, Jeremy Lookofsky, and Mark Brauning. HyTech's innovative approach to exhaust design has set us apart from the competition. With 21 years of experience in exhaust technology and the implication of anti-reversion chambers, stepped primary pipe configuration, tri-y collectors, acoustical tuning, sequential cylinder pairing and non conventional pipe shapes. We are able to forge new territory in exhaust design. It is all about acceleration or "Transient Response" as we call it. Which is how fast a particular engine will transient from its lowest rpm to its highest. And the exhaust has a major effect on how that happens. When the exhaust is designed right it will greatly influence the transient response time. then go read this.. http://www.theoldone.com/articles/Larryscivic/Larrys_Civic.htm on the proper way to build an engine.. infact read EVERYTHING at theoldone.com and then scratch your head and read it again.. 250hp daily driver naturally aspirated 2L is nothing to sneeze at.. even if it's a honda motor... and no reason our engine can't do the same thing.. except people haven't invested the time nor done the proper research.. just bolt excrement on and toss money at it in an attempt to find the magic needle in a haystack configuration of parts that might sorta work. Title: Re: Exhaust Possibilities and more Post by: JusBringIt on June 25, 2007, 03:53:39 PM stay tuned for a custom intake manifold thats already been designed...-along w/ disconnection of the egr...(response due to coalition of questions and answers prior). a constantly varying exhaust would be perfect..but...getting pipes to change size doesnt really happen. thats when u combine it with cylinder shut-off type setups. and sorry dave..i couldnt match that for the life of me.
Title: Re: Exhaust Possibilities and more Post by: Matt on June 26, 2007, 04:44:18 AM the engine and the transmission turn at an equivalent rate right? so... there's no changing between tranny and engine in 5th gear 2000 rmps turns the tranny at 45 mph so at 4000 rpms you should do 90?
Title: Re: Exhaust Possibilities and more Post by: Shiano on June 26, 2007, 05:53:28 AM Thanks Dave! Good job on the info enlightenment.
JBI...... I too am in that boat on the info part. Matt.... 2000 rpm for me is 50mph 2400 is 55mph Out of curiosity, should an Avenger be able to accelerate better than a Mercedes SL500 driven by an arrogant rich bi..... woman? Title: Re: Exhaust Possibilities and more Post by: Matt on June 26, 2007, 01:37:48 PM i was just throwing out numbers
Title: Re: Exhaust Possibilities and more Post by: Nykon on June 26, 2007, 04:33:32 PM Maybe your clutch is slipping.
Title: Re: Exhaust Possibilities and more Post by: Matt on June 27, 2007, 12:00:21 AM I doubt it would keep up with a SL500 because they came base with automatics and even an arrogant woman could put it to the floor. 315HP, they are smaller cars and i'm pretty sure they weigh less too.
Title: Re: Exhaust Possibilities and more Post by: Shiano on July 01, 2007, 10:29:50 AM I just have a problem with the Hypertech site: I didn't see anything for the 2nd Gen Eclipse [420A DOHC].
The Old One however was a good read. My eyes hurt now. Thanks Dave. lol All in all still good.
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