we have 3, 1 on the downpipe (no sensor), and 2 on the midpipe, I think both have sensors so you cant just take them out. Are there any HIGH flow cats that we can replace ours with? Or can we bypass them somehow with a custom exhaust? Let me know thx! Im still trying to figure out what to do with exhaust.
What to do with the cats on our mazdaspeeds?
- Thread starter BlackMSP
- Start date
OK ,first there is a seriuos mis-conception about high flow cats.There is really no such thing as a high flow cat!*here i go again putting on flame retardant suit!*(flame2) If you have ever looked at the inside of a stock cat and the inside of a high flow cat they have the same size honeycomb material inside.The biggest gain you will get from a high flow is the fact that it is a bigger pipe in and out ,that is it!Cats all have to meet certain epa requirements which limit the way they are produced .To get seriuos increase in your exhaust flow you must get rid of the resrictions of the cat.But to get some perf. increase and still pass inspections you might want to go with a high flow cat.I wouldn't waste my money on one but it is ultimately your decision.Ask some local performance shops and tuners about there thoughts on a high flow cat or even a good exhaust shop and i am willing to bet you that they will tell you what i just have.Cats are cats,no high flow just bigger piping and the same size restriction inside so its kind of a marketing ploy?just something to think about.
*AS I AWAIT THE ARRIVAL OF THE FLAME THROWERS*
Matt
*AS I AWAIT THE ARRIVAL OF THE FLAME THROWERS*
Matt
Turbo Matty P
Banned
Looking for a high-flow replacement? I'm designing and building a super highflow DP/cat-eliminator pipe as we speak. I'm using 2.5" mandrel-bent piping on my pipe and it allows for mounting in the factory location with basic handtools in under an hour for those who have to worry about emmissions. I don't have concrete HP numbers on this unit yet, bet previous work and common sense would say it is a large gain due to the fact the turbo spools up almost instantly. Also, I've noticed a large pull on the top end. If you're interested in my exhaust please contact me off-list @ SVTMATTY@BELLSOUTH.NET thanks.
ForceFed said:OK ,first there is a seriuos mis-conception about high flow cats.There is really no such thing as a high flow cat!*here i go again putting on flame retardant suit!*(flame2) If you have ever looked at the inside of a stock cat and the inside of a high flow cat they have the same size honeycomb material inside.The biggest gain you will get from a high flow is the fact that it is a bigger pipe in and out ,that is it!Cats all have to meet certain epa requirements which limit the way they are produced .To get seriuos increase in your exhaust flow you must get rid of the resrictions of the cat.But to get some perf. increase and still pass inspections you might want to go with a high flow cat.I wouldn't waste my money on one but it is ultimately your decision.Ask some local performance shops and tuners about there thoughts on a high flow cat or even a good exhaust shop and i am willing to bet you that they will tell you what i just have.Cats are cats,no high flow just bigger piping and the same size restriction inside so its kind of a marketing ploy?just something to think about.
*AS I AWAIT THE ARRIVAL OF THE FLAME THROWERS*
Matt
ok you ready!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
no J/K
your almost correct. what they mean when they market a high flow cat is they have a higher flow capacity.
Yes they have the same function as a stock cat and believe it or not the cat is not nessesarily the most restrictive part of the system. stock cats depending on diameter and placement can flow just as well but have different capacities. again placement is important for efficiency and proper lite off etc.
we could be here all day and talk about exhaust gas theory.
the fact is that a high flow cat will help but only to a certain degree. the most important thing is the proper pressure differential between the turbo manifold and the downpipe. from the DP to the cat you will want to keep velocity up with out going overboard on diameter. from that point to the tailpipe you could if you want agian increase the pressure differential and go a to a slightly larger diameter but for your wallets sake you want to keep it the same size thruout the system.
