2006 WRX!
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look kid, u are contradicting urself. u mean wrx cannot change bigger turbo or reinforced engine parts? and besides, u can claim u weren't refering to 2 bars on a rex. but wad u said was pretty clear.Originally posted by ceecookie:read again...i did not say put 2 bar on the WRX lah....
i was saying 2 bar is only for those engine with big turbo and reinforced engine parts
isn't it ur point dat rex can tolerate 2 bars as long as it has a bigger turbo?Originally posted by ceecookie:yea...becoz the WRX is using a small turbo...
setting boost at 2 bar can only be tolerated by big turbos....
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of course no cylinders would fire off at the same time. cun imagine subaru or any other car maker allowing their engineers to design such an engine.Originally posted by shicane:i understand what you're saying. and in theory, it does make perfect sense that unequal length exhaust manifolds has its disadvantages due to the different lengths the exhaust has to travel from the cylinders.
your explaination renders me helpless with this argument. cause it is true. in theory.
but... the cylinders dont fire off @ the same time, producing the same amount of exhaust, all at the same rate though. as far as timing is concern
if anything would render the efficiency of the whole engine more then anything esle in terms of the paths of the exhaust fumes after it exits the cylinders. it would have to be the piping diameter of the exhaust manifold, bents of the manifold.. and the amount of back pressure..
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i still stand by my opinon.... you did brought up a good point in a perfect situation though...
so my response to Twin turbo's post as to whether unequal exhaust manifolds are bad? .. in theory yes... in real application .. no...
and my layman respone to this would be.. if the unequal exhaust manifolds results in the EJ running @ a lower efficiency rate, i really dont think the engineers would have it on in the first place..
but dat is besides the point. i do agree that the size of the primaries and secondaries as well as how they are shaped also has an effect on how efficiently an exhaust system works. but then again, dats also an application of a theory is it not?
i do note ur faith in the engineering expertise of subaru engineers though. if having unequal extractor lengths was anything to go by in the name of exhaust efficiency, then i think subaru are the only car makers in the world subscribing to this theory. -
13.1 CR on boost? no wonder the engine blew upOriginally posted by HENG@:orh. must be the porsche brakes WRX guy then.
mine was only around 12.5 the last time. -
wad is the average compression ratio of regular cars on the roads?Originally posted by tailslide:13.1 CR on boost? no wonder the engine blew up
mine was only around 12.5 the last time. -
hey dun 4get the tranny and drivetrains....they need to be EXTENSIVELY strengthened to take that much boost...frankly I have never seen a car running on 2 bar boost b4....a Skyline with 1.2 Bar boost can already produce 650BHP....imagine 2 bar....3 bar? dun even think abt it....that sort of car is undrivable...well 2 bar itself actually already is....Originally posted by HENG@:u really don't know what u are talking about. do u know what 1 bar is even? 2 bar boost and 1.6 is quite a big difference. U take the old WRX engine and rework it, it can take 2 bar boost as well, dun need the new WRX engine. But whatever engine u choose, u'll need to rework it pretty extensively to endure a boost of 2 bars. U want 3 bar boost, u got enuf money, also can be done. What u've said in your post is as good as telling us nothing.
U dunno your stuff dun come here n embaress yourself. -
usually 8.9 to 9.5....plus minus la....Originally posted by TwinTurbo_Supra:wad is the average compression ratio of regular cars on the roads? -
gee, i dunno. usually in the ball park of 8 plus for turboed and anywhere between 9-11 on NA depending on the performance level.Originally posted by TwinTurbo_Supra:wad is the average compression ratio of regular cars on the roads? -
u forgetting the old F1 cars? 1.5l with 3 bars of boost to make 1500 hp.Originally posted by AE86tofu:hey dun 4get the tranny and drivetrains....they need to be EXTENSIVELY strengthened to take that much boost...frankly I have never seen a car running on 2 bar boost b4....a Skyline with 1.2 Bar boost can already produce 650BHP....imagine 2 bar....3 bar? dun even think abt it....that sort of car is undrivable...well 2 bar itself actually already is.... -
CR for normal cars arnd 8.
I know S2000's CR is 11:1
btw shicane your explanation seems logical. but heng's explanation is more 'ideal' in a sense... Less trouble isn't it for an equal length extractor? -
and thats why i agree with you in terms of theory and concept... one reason noted regarding why subaru uses the unequal length exhaust manifolds though.. besides their boxer rumble.. (silly if they stuck by it just because of its exhaust tone..).. just might probably be the clearance... my friend here swapped out the OEM ones for the cusco exhaust manifolds which are equal lengths and though the fitment and such werent a prob.. some parts of them do protrude out little more in the undercarriage...Originally posted by tailslide:of course no cylinders would fire off at the same time. cun imagine subaru or any other car maker allowing their engineers to design such an engine.
but dat is besides the point. i do agree that the size of the primaries and secondaries as well as how they are shaped also has an effect on how efficiently an exhaust system works. but then again, dats also an application of a theory is it not?
i do note ur faith in the engineering expertise of subaru engineers though. if having unequal extractor lengths was anything to go by in the name of exhaust efficiency, then i think subaru are the only car makers in the world subscribing to this theory.
another reason would be the efficiency of the OEM manifolds.... on dyno.... in comparison.. the aftermarket manifolds dont yield much hp/tq at all.. there are subaru's here running 400-500 whp on race gas with the stock manifolds...
of course.. all these are still speculations... i wouldnt have a clue why subaru uses unequal length manifolds..
and towards your last point... i wouldnt have bought a car that i have no faith towards their engineering creations... ..and subaru's the only car maker right now tht dominates the rally field not in terms of WRC... but the number of homologated cars in Group N rallies and open class...
having said that... i'm getting a EVO next ...
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i really dont know... i would think it would be more trouble for them to change over to equal length exhaust manifolds right now since they have had that config for so many years already...Originally posted by storm_freaky13:CR for normal cars arnd 8.
I know S2000's CR is 11:1
btw shicane your explanation seems logical. but heng's explanation is more 'ideal' in a sense... Less trouble isn't it for an equal length extractor?
oh yeah... honda s2000 (2000 to 2003) is 11:1.... 04-06 models had their CR raised .1 to 11.1 : 1 ... -
slight difference perhaps, because of the different makes of engines, but all engines have to conform to the same rules. end result? they all sound largely the sameOriginally posted by shicane:heng,
not all wrc cars sound the same though.. similar maybe but theres still a difference.. nvm... i wouldnt be able to discuss this with you till i can a chance to hear the different WRCs @ idleing... you might be right..
if only i had went down to the Corona Rally Mexico this yr.......
they all sound a bit like a buzzing fart. -
about 10:1Originally posted by TwinTurbo_Supra:wad is the average compression ratio of regular cars on the roads? -
12.5:1 stillOriginally posted by tailslide:13.1 CR on boost? no wonder the engine blew up
mine was only around 12.5 the last time.
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yeah, i tot it might have been a clearance issue. the boxer on the rex is mounted pretty low and dat might have posed some restrictions in the design of the manifold.Originally posted by shicane:and thats why i agree with you in terms of theory and concept... one reason noted regarding why subaru uses the unequal length exhaust manifolds though.. besides their boxer rumble.. (silly if they stuck by it just because of its exhaust tone..).. just might probably be the clearance... my friend here swapped out the OEM ones for the cusco exhaust manifolds which are equal lengths and though the fitment and such werent a prob.. some parts of them do protrude out little more in the undercarriage...
another reason would be the efficiency of the OEM manifolds.... on dyno.... in comparison.. the aftermarket manifolds dont yield much hp/tq at all.. there are subaru's here running 400-500 whp on race gas with the stock manifolds...
of course.. all these are still speculations... i wouldnt have a clue why subaru uses unequal length manifolds..
and towards your last point... i wouldnt have bought a car that i have no faith towards their engineering creations... ..and subaru's the only car maker right now tht dominates the rally field not in terms of WRC... but the number of homologated cars in Group N rallies and open class...
having said that... i'm getting a EVO next ...
u from across the pond? not questioning the accuracy of ur claims, but there is a limit to wad hps a stock extractor is capable of supporting. even for NA applications, u'll find dat a seemingly good aftermarket extractor will run outta breath with a simple cam swap (cams + aftermarket extractor A only 10 hp gain. cams + aftermarket extractor B yielded 20 plus). i would say dat 300 plus hps on the stock manifold are more conservative numbers.
ah, but extractor efficiency is not the only measure of how good a car is in terms of its engineering marvel. the truth is dat the rex is overall a very well balanced car made very affordable. dats prolly the reason behind its success in motorsports.
i note with interest dat the evo seems like a natural progression for ppl who had ever owned rexes. dun think i'll ever be able 2 afford one until the 10th or 11th incarnation.
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actually, i'm working on running 13 eventually on my current rideOriginally posted by HENG@:12.5:1 still 
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don't blow up your engine!Originally posted by tailslide:actually, i'm working on running 13 eventually on my current ride -
no worries. my current tuner knows his stuff. unlike my previous one.Originally posted by storm_freaky13:don't blow up your engine! 
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I guessed. When aim for 14?Originally posted by tailslide:actually, i'm working on running 13 eventually on my current ride