ghostrider25

The light and efficient 1.5-liter twin-cam four uses variable valve timing and a spring-loaded bypass valve in the muffler to boost and spread its output. It revs with such sweet abandon that, again, it offers driving enjoyment out of all proportion to its on-paper specs. resource for research road and track.


It seems that there is a nice little spring valve in the factory muffler and the TRD specifically desighned to increase the scions engine output. I suppose this is why alot of people including me have seen tremendous tourque loss with aftermarket mufflers.

I wanted to get some pretty important inforamtion out. unless your running boost there is no aftermarket muffler or catback that will outperform the stock one or the TRD. I contacted TRD they told me they had this same valve in their mufler both mufflers are made by borla the only diffrence is the tip and the factory one has alot more packing to keep the car quiet. So if your thinking about buying a catback their just for looks until somone else incorporates this valve desighn.

I know alot of you are going to throw a fit but the facts are the facts and the valve is there for a very important purpose to the engine according to toyota/scion. I like deep sounding catbacks just like everyone else but our cars have weird ecu's they are desighned a specific way for a reason and installing a catback is actually hurting your performance in a natrually aspirated situation rather then gaining anything. Once again I have to change my modding train of thought because these new cars are going in a diffrent direction and we are all going to have to rethink how we tune cars for performance in the future. The old way of thinking has to evolve with new technology I am slowly learning this fact and I hope others will start to as well.

Reactor

So due to what feature does TRD improve HP output? Less sound packing or just larger diameter tip?

brambling

TRD only claims 1hp increase, you can assume it's just larger diameter.

ghostrider25

Spring loaded bypass valve. I know persoanlly with an aftermarket cat I've lost horsepower and tourque now I won't debate this with people because it's going to be a huge argument and alot of people here are sponsered or work for Exhaust companies.

The Engine needs the spring loaded valve in the muffler to perform at it's best I take no issue with headers but this valve was very rigoursly desighned by toyota for the ist and the bb for a reason and our super smart ecu is tuned to have it there on the car. So it's one of those take it or leave it kinda deals. I found out why my factory exhaust made more power on the dyno then my aftermarket and I posted it. Yes I assume with the TRD the Valve is a larger diameer valve but the cars need the valve to make maximum horsepower and tourque in a natrually aspirated situation. If you have a turbo or supercharger the rules change get a bigger pipe run and run the free flowing catback all day long.

Chops

I still have my stock exhaust sitting in the back yard... I'll have to see if this valve is there...

And this totally goes against everything I've learned about exhaust systems... even if you're right, I'm still sticking with my Magnaflow cat-back.

Lizard1

This all coming from a guy who seemingly slaps a bunch of stuff together and doesn't dyno in proper sequence. Sounds a little fishy...

Here's his other post. Once you call him out, in typical fashion, he hides w/o proof...

https://www.scionlife.com/forums/viewtopic.php?t=134690

Anyways, not sure how credible this guy is...

pandaslayer

He also happens to be sponsored by TRD.

I don't believe a thing about the exhaust.

Of course you lose lower end torque, because the piping is sometimes larger, and mandrel bent, with a higher flow muffler and a larger tip.

Everyone knows that when you have a free'er flowing exhaust you lose some torque, but then gain HP.

Do a complete header back exhaust with 2.25 mandrel bent tubing, and I bet you will see an improvement.

phatcyclist

Considering that the valve requires pressure to be overcome so it can open, it isn't best for horsepower. It is designed to give the engine a bit or back-pressure, so that it has the most tourqe possible in the low end. This is fine for a stock car, because the exhaust only gets somewhat louder at higher RPM, and is quiet while cruising. It is however, not the best for making peak horsepower.

I will admit that I custom fabbed up a rear section, and lost tourqe, but I plan on re-designing it. I was using too-large of tubing, and a muffler with a huge core in it, so I knew I would loose some. I will be going with 2 inch piping and muffler core, because it is a jump in size over the 1-5/8 inch tubing we have stock, but not so huge that all the tourqe will be lost (I hope).

Lizard1

And I'm sponsored by Betty Crocker. We get free cookies. Yeah, right...

If he's sponsored, cool, but he needs to chat with an engineer or an engine builder before he speaks.

He has no idea on the exhaust deal...

jct

have you taken these mufflers apart before??? i kind of would like too see the insides of factory/trd mufflers

hotbox05

neither is good.

the trd is much better than stock.

ghostrider25

ok before you go blasting me I specifically stated that I wanted to dyno a TRD muffler before posing my dyno charts I am waighting on a member to buy his new exhaust so I can buy his used one to test. I don't call that being called out or running and hiding.

secondly the valves are there to provide back pressure to the engine lizard since you have a motorcycle icon you should know this even my CBR600RR has the same type of valve in the exhaust and it is very important. The bottom line is the valve will give you more botom end tourque. Guess what our cars don't run 160mph they barely hit 115mph so low end tourque should be the goal for alot of people. Top end horsepower is overly exzgerated by every aftermarket exhaust maker for the scions period. The results are manipulated for marketing purposes. They tell you oh this part can give you up to ten whp and thats crap because your actually just trading sound and looks for a loss in tourque and low and midrange WHP and you never achieve the gains that they advertise the catbacks at period.

I think scion and TRd and Car and driver are reputable sources. I am sponsered by TRD as well as many other companies and have done alot of work to improve the scion community. I spent 3 hours oday talking to a scion Rep about finally getting some projector headlights made for the Xa. I like to waight until all my dynoing is done and I wanted to redyno a setup because the numbers seemed off to me but I posted them because thats what they were. Now as soon as the guy on here gets his new exhaust and I can get the TRD muffler then I can finish my testing of the exhausts and I have no problem posting the charts at all. But don't go blasting me for hard work and factual research when you haven't done any testing and your talking out of your ___. you don't know who I am sponsered by but I post the truth always have always will and if I make a mistake I am the first to own up to it and apologize for it. I'm sorry I didn't post what everyone wanted to hear and I am sorry the dyno doesn't give these great horsepower gains that the aftermarket companies claim I cannot control that. What I can do is post a fact that has been well researched. Do I deserve to get blasted for telling the truth I don't think so. Maybe lying is acceptable these days but I don't believe in lies and I try to post accurate information thats why I wanted to rerun some things on the dyno to make sure before I posted the charts I think that is being thourough it's my dime for all the dyno pulls to give you the information so have some respect until you dish out your cash for the betterment of this community. I get so tired of being flamed for telling the freaking truth. Are people that gulable to believe marketing hype. I'm seriously going to stop doing research and clearing things up about the pullies which I recently did. spending countless hours trying to get the projector headlights for the Xa made. Talking to Scion and TRD about bringing their header and supercharger over here. I have spent hundreds of hours working to make our cars better. If this crap keeps up I'm leaving the forums it's not right. Contact scion TRd and car and driver and then tell me I am wrong and do all the dyno testing yourself.

Chops

Yeah, our speedometer only goes up to 120mph, so 160 is definitely out of the question And by the way, 120 is more of a projected speed. Most high-end sports cars may have a max speed of 200mph, but if the driver has the *****, he could probably get it pushed a little past that, so... you're statement of 160mph has no merit.

And who cares if you've been spending countless hours trying to get projectors made for the xA. What's that got to do with the topic at hand? Hell, I'm trying to get them made as well by a friends company as well.

And how do we know you're not manipulating what you're saying to help TRDs market? Hmmmm?

Quite frankly, I believe your biggest mistake was posting this without the dyno charts. Granted you are waiting to do so, but I think having stated your research without the evidence to back it up was foolish. If a scientist makes a theory... he has to do research and testing to back it up, and during that time, fellow scientists may (or may not) mock his theory.

That and your posts just sound more like a press release than an actual telling of facts. (Unless you do write press releases, then I could see why)

So until you have the proof to back up your claims (by the way, you'll also need to test other exhaust systems on your rig to compare them to the stock/TRD muffler), get used to people bashing you/flaming/mocking/blasting whatever.

And if Scion decides to make projectors for xAs, then great.
If they make a SC for them, great.
If not... someone else will (and already has/is?).

ghostrider25

our cars are speed limmited to 115mph the ecu kicks in thats the limit unless your going down hill in nuetral thats all your supposed to be able to get.

I understand peole want charts I will be posting charts in the near future.

TRD market doesn't need manipulating it speaks for itself and unlike other manufacturers there are accurate dyno charts to back up their products.

I'm sorry my posts sound like a press release first you guys _____ that my spelling is off then you guys _____ that it's to much like a press release I can't win for losing. I think people would just rather _____ then actually do some dyno testing and reseach themselves.

What does all the countless hours I have spent have to do with anything it has to do with alot it establishes a certain amount of credibility in the fact that I really don't care what any aftermarket company claims. I seek the truth. I recently exposed the fact that people are being sold fiberglass instead of carbon fiber did anybody on the forum say hey thank you for informing us we got ripped off no they flamed.

Thats not how a helpful community should be. It's kind of pathetic actually. And my dyno testing In which I already tested two catbacks has nothing to do with the fact that there is a spring loaded valve in the stock muffler and the TRD muffler that needs to be on the car unless your running boost for maximum tourque. It's just a simple fact a simple truth a simple statement that the guys at toyota who desighned the scions weren't idiots and tuned the car very well before it left the factory. Guess what I fell victim to marketing hype too but I learned why I lost power instead of gaining power and I learned a simple well covered up fact about a spring loaded valve in the fatory and trd exhaust system that was desighned to help maximize the engine output. There have been other threads where poeple have complained about aftermarket exhaust and switched back to factory because of power loss. I'm not the only one I just found out the reason why and people criticize me for it. I thin I am going to make a personall decision real soon about wether I want to be involved in this anymore. This site is getting a bad rep all over the net and off the net not for it's info but for the conduct and language used by people and frankly I am to old to be criticized by a bunch of kids who don't know how to thank somone for good information.

Chops

No, no see... testing other cat-backs doesn't disprove there's a valve or not. It's just going to show the gains you're speaking of. If all you show is the stock/TRD muffler and nothing else, then we, the "community" have nothing to compare. Decisions and opinions are oft brought by comparison yes?

And Toyota tuned the Scion for what? Maximum reliability... not maximum potential. If all companies built their cars to their fullest potential, people like Vic Edelbrock wouldn't be famous, places like the So-Cal Speed Shop wouldn't exist and countless other men and women who invented new ways to boost a cars potential… wouldn't be the legends they are today.

And is "biscuit" slang or something? I'm not sure why you chose that word... maybe because I'm too young to have heard it?

And quite frankly, for you "age" you are acting quite immature. A mature adult wouldn't feel the need to constantly defend himself against mere "children". If you were to have been smart about this, you would have stated your facts and at the first "bashing" simply state that you would have your proof as soon as you could, the end. But no, you continued on your little crusade to cry and cry and shed them TRD enhanced crocodile tears.

And did you not read what I said? I said 120 is projected, I was in a sense defending you. It's one thing to complain about people bashing you, but why don't you try reading some ones entire post before threatening to leave.

I take great care in the words I say and the way I form my sentences to ensure I can get my point across. And I find it upsetting when someone who claims to be above us, can't even read a simple sentence that in a sense says the exact same thing he did!

I would implore you to take a moment to read my words and go over them in your head for a while. Note my use of references to automotive historical legends and points that also align with you. In my last post, I was trying to reason with you, to point out things that must be done in order for us, the "community" to trust you. For whatever reason (it was here before I joined) people have taken a negative view of your opinions and/or facts (please do not go on a tangent about this).

And yes I did read you're post on the Carbon Fiber "scam" and if you were to read the website, it does say "...woven to look just like 3k twill carbon fiber..."... I'm sure there are people who try to pass of Fiberglass with a CF overlay on it as the real deal for a cheap price; but as another poster said, it's all about common sense.

Again, I must stress for you to read over some ones post to ensure that you've understood their point, completely.

ghostrider25

pertaining to the valve in the muffler you are all wrong yes you are. I am sorry to say it. I had to tripple check it but it is the truth you can verify it with scion with a simple email. I adressed the boosted guys they obviously should run a bigger pipe and the most freeflowing exhaust possible the post was simply about the valve in the mufflers and why they are there and why we need them for the best engine perfomance output on natrually aspirated scion Xa and Xb models. Do your own research but you will find that I stumbled onto something that hasn't been brought up discussed much except by magazine experts and is obviously not being included in aftermaket exhausts. we have always been told free flowing is better but the scions have a diffrent ecu and this ecu learns and changes maps when we make changes it works against most modifications. it's been proven on the echo forums and I thought it would be comon knowledge here but nobody as ever mentioned the spring loaded valve in the mufflers. They are widely used on japanese motorcycles and if you remove them you lose tons of performance and the same is happening with these catbacks on the scions because there isn't enough backpressure. sometimes bad news and the truth is hard to swallow do your own research contact scion you will see I am right and then maybe some of you will apologize because I am at the end of my rope with people not appreciating factual research. Somone should have posted this years ago and just like the carbon fiber thing I exposed people aren't being told the truth and are buying sound and looks which is ok if you are a cruiser or want a show car but if you really want speed in turns and want to accelerate as fast as possible and maintain the best gas mileage you really should look into this becuase I am right. I just put up a post about the black box in your scion recording your driving habits nobody else has posted anything about it but it's there and it's an invasion of your privacy. just because nobody has posted about a subject before soesn't mean it doesn't exist and it doesn't mean that somone is not telling the truh. I just happened to stumble onto the truth through my own personal search for an answer that was baffling me and I decided to share it. I could have just as easily brushed it aside and said nothing but then I wouldn't be a very helpful person or an honest person. sometimes the truth is hard to swallow.

Maybe the aftermarket exhaust manufacturers didn't know the valve was in the exhaust and needed. They did rush alot out fast to the market. I will email some of the top ones and see what they have to say about it. I just posted a fact if you can prove no valve exists in the factory muffler then by all means prove it. Show me an email from scion show me pictures. I've already done the research and confirmed it is inside to cover myself . Oh and yes I am running an aftermarket exhaust on my car not TRD or stock and I don't plan on switching back becuase I am having a supercharger made in october and i will need a larger exhaust pipe to go in.

I also canot believe nobody else has changed over to the toyota celice catalytic converter it makes a diffrence like most of the mods it's not huge but it does make a diffrence.

ghostrider25

so goodnight goodbye I told the truth made my point and I'm not going to be criticized for telling everyone something that should have been adressed along time ago. I come from a well respected scion community and this flaming has gotten me so upset I just took down all the dyno numbers and I will repost them with the charts when I am done with my testing. Guess what there is a spring loaded valve in the factory muffler did I mention that and you need it for extra low and midrange power.

Lizard1

Your point about the CBR isn't the same. As in the Yamaha EXUP system and many other motorcycle exhaust systems in sportbikes. One, you CAN remove the system with the butterfly and gain TREMENDOUS performance with an aftermarket exhaust. You need to remap, but again, motorcycles do NOT have the same MAF type system found in typical car engines. If you are so in tune with TRD and don't just simply read stuff, you'd know that our cars will adjust to adding an intake, for example.

You don't need to plug in something like a Yosh Box or a Power Commander as in a motorcycle to adjust for more air intake to prevent a lean condition.

Same with exhaust...

The deal is fairly simple. Put up or shut up like many others have stated. I really don't know if you are sponsored by TRD. What your sponsorship entails is beyond me in that you obviously are not racing these machines in competition so, I suspect IF you are, it is for show stuff. So, I really doubt you are so deep within the R&D department to know a whole lot.

Plus, after reading the processes by which you added stuff and dyno'd, I really doubt you are doing it at the TRD facility which, if you were sponsored, you'd be doing all this there and be easily able to shoe proof instead of just making whitty comments...

You are obviously not understanding what the EXUP style set-up in motorcycles is all about. Completely different than car engines and not related...

Lizard1

That's some great and heartfelt wording there. Here's a simple plan, if you are sposnored by TRD, please let us know a website we can see where you are racing. Or, better yet, reveal a few events you've won or attended.

My point is this. I am sponsored as a racer. I'm not talking out of my ___ about motorcycle stuff. I also know quite a bit about engine technology as my father and many of his friends were racers and I've been around a bunch of engine tecnology. Nothing like if I were constantly down at TRD, but I'm not saying such.

You are throwing out quite a few big statements and then when people cal BS, you do the typical squid deal and say you quit and you're gonna leave.

If you are so in tune with TRD and help develope the Scions, let us know some credentials. If you are part of developement with a Japanese company, those roles are typically set for engineer types. The racing side is simply a trickle down effect and they do pull from that, but where are you in the grand scheme of things for TRD?

TRD isn't just Scion. Simply put, TRD is a broad range of product developers with a primary focus on performance - not headlight accessories and stickers. Where do you fit?

hotbox05

our vehicles are not speed limited. you sir are wrong in many ways.
i've personally hit 127 as well as many other modded car owners on this site have hit more than 115.

oh and the trd muffler is just a borla or magnaflow depending upon when and what car you buy the exhaust for. they do not have special backpressure valves inside , the stock muffler might but i KNOW the trd DOES NOT.

oh and a valve inside of a muffler which will normally fail causing a horrid rattling is not the best or only( in your opinion ) way to tune torque. piping diameter , exhaust outlet size , how many times the exhaust diameter changes , the routing of the exhaust , the header , the exhaust piping length , the intake piping length. the list goes on and on and on.