[v6xjinbo]

Ok i think this is what Nhwak is trying to prove. He's saying that its not so wrong to keep the cat, But it would have been better if it was located some where else. And from my knowledge, i think you guys are both right. Yeah i think maybe taking out the cat can make a better performance, But will cause the air in california to go bad. In the other hand, Having a Cat is not a bad thing and will make the air in california better. However, How would we know if it really did improve or not. Are you really going to believe what every scientist say? ok let say if you do believe them, then are you going to believe the world is going to end in 2012?? Did you believe the scientist when they said a HUGE asteroid will come and
destroy everything living creature in the earth? Scientist are always wrong, and they think they created everything. Anyways i am not trying to Fight with anyone, but just saying Both of you are right. You guys gave us a good opinion and its our choice to take it or not. BUT its stupid to judge or aim at others for their information/opinion. I like you guys both( no ****) lets keep this a family business and not do one of those going around " who's right who's wrong".

 

[invsblduck]

OP was vvvvvvvvvvvvvvvvvv:

Is anybody running richie's high flow pre cats? I'm wondering the major differences between the pre cat deletes and high flow pre cats, as far as power,smell,and sound differences. I know alot on the deletes just haven't heard much on the high flow pre cats

I haven't run PCD's yet, but I do run RV6 HFPCs. They didn't make much of a sound difference in my exhaust - just a very subtle hint of rasp. Nothing much at all. As far as smell, I don't ever smell it or notice it in daily driving (if I go WOT and blow by someone they will probably get a few more fumes than they're used to).

As far as power, I didn't dyno before & after....but apparently I wrote this in my original DA post regarding my 5AT J30:

I'm really happy with the results because there's zero lag when I press the gas pedal now. It doesn't "think" for a second and then downshift when I want to accelerate hard. It picks up and goes a lot easier. The low-end torque got a lot of help.

I'm now running the same HFPCs on a Smalser J36 with a 6MT (big up to ya Paul!), so I'm not sure what their fate will be in the long run...I'll probably just go PCDs within the next year.

As far as emissions.....well, I have to smog in a few months, so I'll let you know.

HTH,
Brett

 

[t-rd]

I noticed one huge difference between the 6th gen (one cat far away) and the 7th gen V6. My 7th gen V6 engine runs hot and the the fans would come on way more often than my 6th gen. For those of us in the states that require emission test, I'm in Chicago, I have no choice but to keep the precats because that's where the O2 sensors are. It is an IMMEDIATE failure at the testing station if I were to remove the precats. I understand there are O2 sims, but that doesn't exempt the fact that they can smell the fume at testing facilities even if the ECU is fooled. So that leaves the question "is my engine going to go out due to faulty precats with chunks of platinum flying in the cylinder heads?" It's great to talk about "how" it should be done, but another to think that it "can't be avoided."

 

[KaotikPlaya]

Well i figured there were so many more people running pcd's or hfpc, and i was trying to get more input on thoughts of them. rasp is my biggest worry. if you got em let's hear how you like them.

 

[Scottwax]

That's very interesting. I never would have thought this adversely affects the longevity of the engine.

In addition to the heat, the internals of the precats can break down and the particles get sucked back into the engine when you turn it off. Huge problem with the VQ25 engines and part of the oil burning issues in early VQ35s was partly because the precats come apart inside and end up scoring the cylinder walls. Then you have an engine that uses excessive oil which in turn slowly clogs the precats.

When I replaced the precats on the first Maxima I had, it was obvious they were coming apart, you could see where there was material missing. My 45-85 time dropped by nearly 3 seconds after putting in new cats. Thats how much clogging, deteriorating cats that close to the cylinder heads can cost you.

 

[Scottwax]

I understand there are O2 sims, but that doesn't exempt the fact that they can smell the fume at testing facilities even if the ECU is fooled.

I can't imagine if you have deleted the precats but still have the main cat there would be any issues of gas fumes. The ONLY reason for the precats at all is for the first 90 seconds or so it takes for the main cat to get hot enough to work properly. After 90 seconds, the main cat alone is sufficient to cleanse the exhaust properly.

If O2 sims or spark plug non-foulers work to keep the light off, I'm all for dumping the precats. Dealt with the problem enough with my Maxima. Here you don't go to a government run emission place, most lube and tune places can do the testing. As far as they are concerned, if you don't have any codes, you pass. They don't look too much into you car if there are no codes. Main cat on the '02/03 Maximas isn't monitored, so I removed it. Precats were still there, no codes, easy pass.

 

[The black pearl]

high flow or not, it's too close to the cylinder heads thus holds heat which results to lack of power, efficiency, and also can result in pre-mature engine failure. You are better off with Pre-cat deletes(test pipe)
I've seen stock pre-cats blow out on stock cars. Dam green emissions/ tree hugging bastards really ruin a good engine design.

NO engine will run good with a restriction design like that. That's why alot of these engines have oil consumption issues at over 100k, etc. Holding too much heat in the cylinder heads = castastrophic failure. Historically, Honda engines lasted over 200k easily. These added emissions component really put a damper in that life span.

So would high flows be better To pass emissions and still get performance?