substantial power loss?

[dynasty]

hi all
here is the problem,before i swapped over to a xforce twinloop, i had a 5 zigen straight through canon, and it was pulling harder during 4500rpm -6800 rpm, but after swapping to xforce, i couldnt feel that pull anymore and the gforce is quite the same in all rpm ranges, it feels i have lost quite a lot of power, both have 2.5' inlet but the xforce was welded crappily onto a 2' pipe with no additional pipe? u noe the one that connects to both 2' outlet from exhaust and into 2.5' inlet onthe muffler. could it be the crappy welding or is xforce twinloop over rated as i heard its suppose to give the same performance as a canon.. :confused:

[Slow96GSR]

That's the one that loops back in to its self? If it is, then it’s probably because there is more restriction in that muffler. The twin loop is like going through two mufflers instead of one. I'd have to see dyno plots to tell you and look at the actual mufflers to see. I doubt it's the weld though. As long as it's not protruding into the tube and slowing the flow then it's fine. Might want to get a reducer some day.

[h22a accord]

did u rest your ecu? if not , u should. disconnect battery for 10 mins, reconnect and start your car and let it idle for 5 mins then turn off car. At no time should press the accelerator.

[VT3C]

hrm.. you are experiencing the wrath of the fake twin loops !!

not wanting to be seen as bagging out on Adam (civic type R) but when he recieved his OBX Twin Loop (NEW) and we examined it, I was impressed by the exterior quality however when I looked INSIDE the muffler from the inlet side and yeah there was smaller diameter piping internally and what appeared to be only a tack-weld or nothing at all holding the 2 "U" shaped bits of piping. there was also a ~2mm gap where the pipes didnt line up.. so basically it's a bottleneck in your system and prob has leaks from bad interior welds/joins etc.

your old muffler (cannon style) is basically not restrictive AT ALL.. cannons might as well just be regular exhaust piping with a milo tin slapped on the outside because in terms of flow (at least) they are essentially like having no muffler at all. only minimal turbulence is generated from the small holes i the tubing when passing through a cannon muffler - in fact those holes would actually reduce surface friction and create a venturi from inside the packing (like a Morey Mach 8TX or homer Simpson's 'speed holes') - thus making it free-flowing.. there's no bends, change of direction or resonance chambers like regular mufflers.

your old cannon is designed to have no or little restriction and this creates benefit in high RPM however may cause a lack of backressure and limit the 'scavenging' characteristics of your motor at low RPM.

the twin loop tries in theory to maintain a constant backpressure from 1RPM through to redline however this will reduce efficiency at high RPM but at the same time it SHOULD make more power down low in the RPM range.

[Limbo]

its the cost of having a more quite exhaust.

[Cartoon]

are you guys saying the mugen one would be the same or the flow of the mugen one is the best of both worlds due to the better work manship

[VT3C]

yeah I have examined both the OBX and Mugen twinloops in my hands and the quality of the mugen one is FAR better.. the mugen's 'pipes' are also much larger diameter than the OBX one which goes down to 2" inside the muffler I think..

plus the OBX one sounds the most 'farty' and annoyingly raspy out of any muffler i've heard.. the mugen one is pretty dang quiet till vtec and then its a smoth deep red-wine tone.

[Limbo]

You will get what you pay for but just rem that the quieter you want it there will be restrictions. May be good for low to mid power but you will loose out slightly on high end. You gotta weigh up the options. The expensive brand ones usually have a lot more R&D involved while your cheap ones usually copy off the expensive ones with cheaper materials.

[Cartoon]

i jst bought a mugen twin loop cat back for my car.
currently running a HKS Superdragger which i will sell now :)

but we see how the difference is :)

[MoonSha]

homer Simpson's 'speed holes'
I like how you managed to include this in a technical conversation :thumbsup:


Hoping for an update on wether or not the ECU reset did anything.

[dundas]

give it a few days.