Jump to content
View in the app

A better way to browse. Learn more.

300ZX Owners Club

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Afternoon,

 

Now i've got the bits to do the suspension and brakes i think it's time to get a bit more out of the engine. I've already got the ECU upgrade, EBC and an Apexi filter so it seem that the only things to get me up to 14psi would be on the exhaust side. I was planning on getting some divorced downpipes and a Mongoose exhaust but i can't decide what to do about the cats.

 

I've found some Hi-Flow cats on Z1 but was wondering if they're worth the money. I don't want to de-cat as the car's a 96 and it would mean sticking them back on once a year for the MOT and there's also the issue with the turbo seals. Does anyone know if Hi-Flow cats much better than the stock ones and can i buy them in the UK?

 

Cheers

 

Dave

Featured Replies

decat.

 

its only once a year, and its only a few bolts.

That's not the answer we are looking for. Why have to go to that bother at all if there is a correct answer. I hear my exhaust on my car is starting to go and would be interested to know about this.

Hi,

I was speaking to someone on here about de-cats and they have them fitted to a 96 car and it still passed the MOT? :nana2:

Hi,

I was speaking to someone on here about de-cats and they have them fitted to a 96 car and it still passed the MOT? :nana2:

 

should technically fail if the inspector notices it's decatted, but as the car's not on the database it only has to pass a standard cat emissions test... and you might be lucky!!

Afternoon,

 

Now i've got the bits to do the suspension and brakes i think it's time to get a bit more out of the engine. I've already got the ECU upgrade, EBC and an Apexi filter so it seem that the only things to get me up to 14psi would be on the exhaust side. I was planning on getting some divorced downpipes and a Mongoose exhaust but i can't decide what to do about the cats.

 

I've found some Hi-Flow cats on Z1 but was wondering if they're worth the money. I don't want to de-cat as the car's a 96 and it would mean sticking them back on once a year for the MOT and there's also the issue with the turbo seals. Does anyone know if Hi-Flow cats much better than the stock ones and can i buy them in the UK?

 

Cheers

 

Dave

 

Hi Dave,

 

I'm of the opinion that you should NOT decat the car. As you say, it's going to be a PITA at MOT time and you also risk oil seaping past the rear turbo seals and causing the exhaust to smoke due to a lack of back pressure. I have previously looked into hi-flow cats and these can be bought in the UK. They're not cheap and you would need them to be custom installed (with flanges custom welded, etc) but it is a good solution. I can't for the life of me find the suppliers that do these but I do remember they were based in the UK and did kits for various high performance cars (although the Z32 wasn't one of them at the time). I will see if I can find any of the old information I had over Christmas and get back to this thread.

 

But, in a nutshell - hi-flow cats will maintain a certain amount of back pressure (although less than stock) and they will filter the fumes to meet current emmissions standards. Win-Win situation if you ask me!

 

I'll start looking ...

 

Regards,

 

Dan

  • Author

Cheers Dan,

 

I'm afraid that the de-cat option was never really there for me anyway. Along with the highest insurance in the UK and couriers charging the earth to deliver things here, another perk to living in Northern Ireland is that our MOT stations are all run by the government in special facilities. All the equipment they use is state of the art and if your car emissions aren't up to scratch they will certainly fail you for it. Our local ferry company has a special offer to allow motorists to go across to Stranraer on a day return specifically to get their motors MOT's in Scotland at some local dial-an-MOT garage.

 

Putting it back on for an MOT might only be a couple of bolts but they're bolts underneath the car and i don't have access to a ramp or a lift and i despise working under cars that're only supported with axle stands. This plus the whole back pressure issue is enough to make my mind up.

 

If you can't find any, or it's looking like it's going to be a pain to get some made up i can just get some sent over from Z1, but i'd rather the money went to a local company.

 

Cheers

 

Dave

 

PS: The Z1 one's are by a company called Random Tech. Don't know if that helps....

Edited by hairdo2001

ok , for those of you who know what your talking about. I ran a thread some time ago about de cat pipes. This guy is asking about high flow cats. The same thing keeps coming up. If you try any of the above you shall blow the seals on the turbos. So did this engine ever exist without a cat. And if it did how diid it get from day to day without blowing the seals and possibly damaging the torbos. Maybe I'm just ignorant, but I would like someone who reallly knows to explain this to me.

 

Thank you, Stu.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Terms of Use

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.