Euro_Z33

Hello everyone

I'd like to ask a question to the more track oriented members out here. I'm preparing my car for the track and i'm almost done. I have one problem. I've installed a 5 Zigen Pro Racer Cat Back System. I also have HFC's but i removed them because it was really freakin too loud. I participate on a driver's training and volume restriction is 100db. So i'll go with the stock cats + 5Zigen. The engine (VQ35HR) is stock, besides K&N drop in's, exhaust and a Osiris Reflash for improved response. Are the stock cat's able to take the stress on the track when performance is minorly enhanced?

Thanks for the answers. p.s. i tried the search function but did not find anything. if someone has the right link please share it with me.

thx a lott

CoobcioPL

Stock cats eats a lot of power i suggest you put HFC + good Y-pipe and live stock exhaust - will be quiet and best power gains

Euro_Z33

I know i know But with the HFC's the sound level is far more than 100db! so black flag for me :.(

CoobcioPL

On stock exhaust with HFC is to laud to ??

Euro_Z33

Mmh.. i don't know.. i would say HFC+Y-Pipe+Stock exhaust does not surpass 100db. But my question was not that. My question was, if the stock cats of a VQ35HR can endure 2 hours of track day driving? I would say yes because the car's engine HP is still original. You understand what i mean ?

Jennifer 2

Euro, in the U S car manufacturers must warranty emission systems including the catalytic converters for 10 years and 100,000 miles. Because of this, these components tend to be built pretty strong. As far as use on the track, cats will take a beating with rev limiters that use ignition cut to prevent over-revving. The Z however, uses a fuel cut-off to accomplish over rev protection and this method is very gentle on the cats.

Until you devise a setup that can utilize your HFCs and also keep the decibels down, go ahead and use the stock cats.

Euro_Z33

Hi Jennifer, thx for your reply as well. I understand what you mean. I have made some research and the result was: The Pre-Cat of the 350Z is made of ceramic, the main cat or second cat is made of metal and very reliable. Now the problem is when you run the car too rich, the unburned fuel between head and pre cat tends to burn and causes detonations. These detonations can damage the ceramic cat. Due to this damage and the resonance of the exhaust gas flow, these particles can be aspirated back to the combustion chamber and damage the cylinder walls.

So my point is, as i worked on the ECU program of the car myself i'm running AFR 12.5-12.8 so it's not running that fat. A buddie of mine is specialized on Cat replacements. To keep the decibel level decent, my strategie will be to put away the ceramic pre cat, and equip this position with a 200 cell monolith.

But for this little track event i keep the setup of the stock cats,

Later when budget is ready i'll try the setup that i mentioned.

MonkeyMagic72

iTrader: (2)

It seems like driver training event is not fun after all. If I have to change my HFCs out for my OEM cats to reduce hp and that awesome exhaust sound of the VQ revving, I have to pass. Save yourself all the hassle, join real track event, you will like it more because you get to enjoy it more.

Euro_Z33

i absolutley agree with you. 100%. Look, i love to drive, especially my Zed. I do live 3 hrs away from Monza and 5 hrs away from the legendary Nürburgring Nordschleife. My target is to go there, enjoy and bring the car back safe. I've already been on it once, but as a passenger on a 993 Carrera S and a tuned Golf 6 GTI. I have to say it's a hell of fun but that track is so dangerous. You can crash your car so fast there. That's why i want to make some training and expierience first. And yes... Nürburgring has a volume limit of 120db! There you can be sure that i'll swap the OEM's for my HFC's..

Waiz

iTrader: (57)

Your car is basically stock with a tune, your stock cats would obviously be fine with such a conservative mod list...