Jump to content
SAU Community

Cat And 3'' System Vs. Nocat + Genuine Exhaust''

Torques

By Torques,
in Engines & Forced Induction

 Share

Recommended Posts

Torques Mentor

Torques

Posted
Posted

I need some input on what you people think causes less restriction.

I used to have a De-Cat + the OEM standard Nissan exhaust..

That was fine and the sound was great.

I changed this to:

De-Cat + 3'' Greddy Stainless Steel PEII (http://www.nengun.com/greddy/power-extreme-ii)

The PEII is not bad but I find it noisy and I need to do something about it.

I suspect that putting the CAT back in will reduce the noise ..

However what would be more restrictive ->

De-Cat with the Nissan exhaust

or

The OEM-CAT with the PEII

I have a 3.5'' Tomei downpipe and an HKS-Dump, so there is increased volume after the turbo.

Car makes about 270kw.

hypergear Grand Master

hypergear

Posted
Posted

between a 100 cell and de-cat, the difference is 10kws at 360rwkws. On the same time it also depending on the quality of cat, as I also had a 100 cell cat which I punched out that made 120rwkws difference.

sydking Veteran

sydking

Posted
Posted

between a 100 cell and de-cat, the difference is 10kws at 360rwkws. On the same time it also depending on the quality of cat, as I also had a 100 cell cat which I punched out that made 120rwkws difference.

the problems is you can tell someone to go spend $400+ on a good CAT so they only loose on on the 10kw or so over a stocker... Or spend $0 and De cat which really, Gives the best result from a flow point of view.

Legality aside, We are all old enough to make informed choices here. End of the day nothing will beat a straight through exhaust.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

between a 100 cell and de-cat, the difference is 10kws at 360rwkws. On the same time it also depending on the quality of cat, as I also had a 100 cell cat which I punched out that made 120rwkws difference.

Hey do you want to tell us what cat that was (or PM me if you don't want to bag them publicly).
Torques Mentor

Torques

Posted
  • Author
Posted

Thanks guys,

Much appreciated ..

Anus aside ;) I am in the UK and for imported vehicles there are certain loopholes to get around the use of a CAT.

I will see if I find a higher flowing CAT and give it go ..

Torques Mentor

Torques

Posted
  • Author
Posted

How can I bolt a silencer onto the tip?

Do you mean a ristrictor by chance?

These look very silly and put a lot of back pressure into the system.

simple just get a silencer and bolt/ screw it onto the tip, if its too quiet, get a bigger hole drilled into it

Dan_J Veteran

Dan_J

Posted
Posted

yes same thing

most japanese exhausts have a hole at the bottom so u can slip them in and screw them on, and dont they look the best.......

better then what ever back pressure you were making with a decat and stock zorst

Torques Mentor

Torques

Posted
  • Author
Posted

Hey,

I am not too sure about this since I had one of these restrictors and the actual diameter of the hole in the restrictor

was about half the size of outlet area the standard zaust offered.!

So I am tempted to say that it builds up more back-pressure which is not so good.

The turbo spools up faster (due to more volume present after the turbo) but then the restrictor

stuffs the system up.

I had one of these:

http://www.raceinspired.com/p-6887-hks-inner-muffler-silencer-96mm-universal.aspx

And they look really silly with that little pigeon hole, don't you think?

Cheers. .

yes same thing

most japanese exhausts have a hole at the bottom so u can slip them in and screw them on, and dont they look the best.......

better then what ever back pressure you were making with a decat and stock zorst

Torques Mentor

Torques

Posted
  • Author
Posted

Yes,

I agree .. it's the worst possible solution.

(I removed that restrictor very quickly when I saw how tiny the diameter was)

Those silencers are not for serious use. They do exactly what you'd expect them to do. They quiet the exhaust down by strangling it. Anyone who expects otherwise needs a lesson in, well, just about everything.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Unpeeling the Orange

      By GTSBoy · Posted

      The rain is the best time to push to the edge of the grip limit. Water lubrication reduces the consumption of rubber without reducing the fun. I take pleasure in driving around the outside of numpties in Audis, WRXs, BRZs, etc, because they get all worried in the wet. They warm up faster than the engine oil does.
    • Dose Pipe Sutututu
      Unpeeling the Orange

      By Dose Pipe Sutututu · Posted

      When they're dead cold, and in the wet, they're not very fun. RE003 are alright, they do harden very quickly and turn into literally $50 Pace tyres.
    • GTSBoy
      Unpeeling the Orange

      By GTSBoy · Posted

      Yeah, I thought that Reedy's video was quite good because he compared old and new (as in, well used and quite new) AD09s, with what is generally considered to be the fast Yokohama in this category (ie, sporty road/track tyres) and a tyre that people might be able to use to extend the comparo out into the space of more expensive European tyres, being the Cup 2. No-one would ever agree that the Cup 2 is a poor tyre - many would suggest that it is close to the very top of the category. And, for them all to come out so close to each other, and for the cheaper tyre in the test to do so well against the others, in some cases being even faster, shows that (good, non-linglong) tyres are reaching a plateau in terms of how good they can get, and they're all sitting on that same plateau. Anyway, on the AD08R, AD09, RS4 that I've had on the car in recent years, I've never had a problem in the cold and wet. SA gets down to 0-10°C in winter. Not so often, but it was only 4°C when I got in the car this morning. Once the tyres are warm (ie, after about 2km), you can start to lay into them. I've never aquaplaned or suffered serious off-corner understeer or anything like that in the wet, that I would not have expected to happen with a more normal tyre. I had some RE003s, and they were shit in the dry, shit in the wet, shit everywhere. I would rate the RS4 and AD0x as being more trustworthy in the wet, once the rubber is warm. Bridgestone should be ashamed of the RE003.
    • Kinkstaah
      Unpeeling the Orange

      By Kinkstaah · Posted

      This is why I gave the disclaimer about how I drive in the wet which I feel is pretty important. I have heard people think RS4's are horrible in the rain, but I have this feeling they must be driving (or attempting to drive) anywhere close to the grip limit. I legitimately drive at the speed limit/below speed the limit 100% of the time in the rain. More than happy to just commute along at 50kmh behind a train of cars in 5th gear etc. I do agree with you with regards to the temp and the 'quality' of the tyre Dose. Most UHP tyres aren't even up to temperature on the road anyway, even when going mad initial D canyon carving. It would be interesting to see a not-up-to-temp UHP tyre compared against a mere... normal...HP tyre at these temperatures. I don't think you're (or me in this case) is actually picking up grip with an RS4/AD09 on the road relative to something like a RE003 because the RS4/AD09 is not up to temp and the RE003 is closer to it's optimal operating window.
    • Dose Pipe Sutututu
      RB20DE NEO smallbox clutch.

      By Dose Pipe Sutututu · Posted

      Either the bearing has been installed backwards OR the gearbox input shaft bearing is loosey goosey.   When in doubt, just put in a Samsonas in.
×
×
  • Create New...