I'm looking to get rid of my dead OEM cats and install some good HFCs. Since I'm located in central Europe, there Isn't much of a choice really. I've narrowed it down to two options: Berk or Cobra. I've read multiple threads on here but most of them are old so I figured It would make sense to make a new thread to get some new opinions. If you have one of these, let me know how you like it. I have a true dual exhaust from Xforce (x-pipe design similar to Invidia Gemini) so If anybody has one of these HFCs paired up with a similar system, I  would love to hear your experience with it. My goal Is to have a fairly civilized setup which Is not obnoxiously loud at cruise speeds.

Was told my Y sections flex pipe are in rough condition and need fixing or replacing. 

Was told it would be better looking at a new Ypipe although currently got scorpion ones unsure what to do.

Also my back box tips are uneven and too close to bumper so it's melting it abit.

They said to look at a full cat back japspeed system as the labour and materials cost would be similar to purchase and labour of the Japspeed K4?

I feel like that would be a downgrade as all reviews about Japspeed seem to be bad sound and quality especially with a HFC that I need to replace shortly.

Been thoroughly warmed and even a fuel cleaner put through.

As per title, been looking for some 370z headers for quite a while now, reading online the headers will fit but the flange between manifold and cat was different on DE and HR. 

The HR will fit the 370z. 

Going on this I found the ISR long tube headers for sale on Tarmac sportz for a reasonable rate compared to the likes of PPE but there's a note saying LHD only. 

Heres the link in question: https://www.tarmacsportz.co.uk/isr-performance-nissan-350z-z33-vq35de-hr-03-09-hgc-long-tube-headers.html?gad_source=1&gclid=Cj0KCQiA7se8BhCAARIsAKnF3ry8kei4NdoSqvDcNgRFjZ1B_8EKg9A6ymkone64omA3JZZYZ7JAAvcaAgN_EALw_wcB 

Does anyone have any hands on experience with whether or not these will fit please!!!

Thanks

I'm just after some thoughts on how people have found these.

I understand that they need to be hot to pass an MOT etc, but I've been reading stories lately that people have been having a lot of issues trying to get cars to pass at all.

So I'm just wondering,

• Those of you with sports cats, what has your experience been like?
• Are there any recommended ones to use?  Preferably bolt in replacements.

I see that Tarmac Sportz ones are shown as passing from cold but I'm sorry to say, that I can't see that being possible.

I'm looking to replace my back box and tips on my 350 - it's the original but the tips are corroding and i'm looking for a slight increase in volume - nothing horrendous, don't want to scare old ladies or have a massive increase in volume inside the cabin. I've seen older comments about the Nvidia Gemini but thats a complete exhaust and my research lead me to the Tanabe Medallion Touring.

I then came across the backbox and pipes from a company called TopGear in Bridport - https://www.topgear.co.uk/nissan-350z-rear-section-with-stainless-tips - has anyone got a video with sound that they could post so i get an idea of the increase in volume for this please?

Any other advice much appreciated.

Cheers

Thanks guys.

I took the car for it's first MOT since I've had it and it passed on everything except for emissions.

It registered a CO of 0.44% (max allowed is 0.2%)

Here are some more details:
- DE engine
- Cobra HFCs (unknown installation date)
- I added Cataclean before the test and drove it for 40 mins
- The car had 97 or 99ron only over the last year
- It first recorded CO 0.72%, but after holding it at 3k rpm for 15-20 mins, it went down to 0.44 and wouldn't go any lower.

The garage said I need new cats. I've asked around and someone suggested new spark plugs and air filter.

So, my questions are:

- are spark plugs and air filter going to make up for the difference to make it compliant? I don't know when they were last changed.

- are new cats the only way to go? From searching on the forum, even new HFCs seem to be hit and miss.

- has anyone had any experience with the ISR Performance HFCs. They are the only ones I could find that are 300 cell. https://www.tarmacsportz.co.uk/isr-performance-nissan-350z-vq35de-03-06-high-flow-cat.html

Thanks

Has anyone had experience of swapping these over? If so are there studs in the downpipe/cat sections or nut and bolt? The local garage spotted the split at the MOT (it still passed) and pointed out that the nuts are shot and I should source replacements with the pipe as Japanese thread sizes are odd?

Finally, mine is a genuine GT4 Limited and some Ebay "does it fit my car?" tables says that it won't fit a VQ35DE 291HP derivative; I thought they all looked the same? Years ago I upgraded to a stainless centre section and backbox (K2 I seem to recall) and I don't recall issues then.

All advice greatly appreciated!

Hey Ladies and gents,

Just wondering has anyone tried these japspeed sports cats? And did they pass the mot?

https://www.ebay.co.uk/itm/152192031442?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20221115143302%26meid%3Dbe0f1f0e56e54b1e856e79948cb26627%26pid%3D101613%26rk%3D1%26rkt%3D1%26mehot%3Dpp%26itm%3D152192031442%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2Mobile%26brand%3DJapspeed&_trksid=p4375194.c101613.m146925&_trkparms=parentrq%3A67fb2e4818c0a8cec1dbdbd0ffffbcf6|pageci%3Ad750ad23-9a6f-11ee-8429-f21abd8fe704|iid%3A1|vlpname%3Avlp_homepage

Perhaps I should get it replaced anyway but due to circumstances I'm looking for whatever is the cheapest solution, so OEM / basic or close to it I guess.  Something like Eurofit, Kwik-fit etc?

Michael.

Can anyone tell me if an exhaust from a 2005 coupe will fit a 2005 Roadster, mine needs replacing, and seen some 2nd hand stainless but they were not from a roadster.

Thanks

After I’ve put Gemini on my car, I started noticing a light rattle on LH side of the car. At first it was so subtle I convinced myself it’s the infamous 350Z transmission. But later on the noise became more and more apparent and louder. Eventually I went under the car, hit the Cat with my hand and it was rattling. While figuring out what to do, the miles were going by. With miles the RH side cat started to rattle. Now it is a friggin’ silverware simphony going on. And it’s the cats. It’s not the transmission, it’s not the heatshields. 
 

Now, Invidia’s Gemini was first released with flex pipe at the flange that connects to the cat. But as this flex pipes were constantly tearing and failing, they later decided they will go the slip-on route, like you can see on motorcycles and their exhausts. With doing so, the whole exhaust doesn’t have s single flex point, stress release point. The only movement is the movement let by rubber hangers. So basicly all the vibrations are translated to the cat. 
 

This leads me to believe (asumption), the exhaust is bringing a lot of pressure, vibration and stress to the cats, which are attached solidly, on mounts, twisting and pulling the car, making the lower part of the cat’s core detach and rattle. Resulting in a failing cat eventually, presenting core shatter damage risk to the rest of the car’s core, whole lenght of exhaust and maybe even the engine. 
 

at this point I would like to ask users around here if they have had this or similar issue with nissan’s oem cats? And what exhausts were installed?

I am NOT amused by having these cats rattling as I know it’s another PITA job to do, not to mention the incredible expense going OEM route (2.500 bucks for a pair of new ones) or Berk (and other) alternatives which make the engine sound even louder, raspy and essentially destroying the nice VQ sound. 
 

I will email Invidia regarding this matter to get an answer from them also, but I believe (my opinion based on ibservations) they are well aware of the decision they’ve made and technical shortcomings. They have solved the RMA cases for flex pipes. And for sure they’re not paying for new cats to the customers also …

For what it's worth I thought I'd share a few thoughts on the Invidia Gemini that I have installed on the Zed. This is full cat-back. 

Fitment - took a local mechanic who has proper car lift no longer than 90 mins to swap stock for new. No issues getting onto car whatsoever. Tips sit very nicely out of the back. Looks like a shiny version of the stock one, with slightly thicker tips with rolled edges. Looks very nice and could easily be mistaken for stock. 

Sound - very similar tone to stock, albeit about 20% louder. Sounds much deeper to about 5krpm and beyond that the noise differential seems to drop off a little (from inside cabin anyway). Basically, just what I wanted. A little more without being excessive. 

Drone - nothing significant, if at all. I drove 180 miles immediately after fitment all of which is motorway and didn't notice volume had increased in cabin. Perhaps slightly deeper tone with throttle inputs but not intrusive at all. 

Overall v pleased with the system. I can understand why some may be left wanting more. However for those more interested in slightly more and maintaining stock look and tone, I think it's spot on. 

I think it would be very beneficial to the community if we could gather some emissions test data in one place to see what works and what doesn't in general.

Please could any contributors list in the below format (feel free to contribute any other data that may be relevant)

Engine: (DE, Rev-Up, HR)

Cat type: (HFC model, decat, OEM)

How old are the catalysts?: 

MOT test HC count: 

MOT test CO % volume: 

MOT test Lambda value: 

Has the car been ECU tuned?: (No, yes - UpRev @ Abbey, Horsham, etc. and year tuned)
What other performance modifications does the car have?: (none; or headers, intake, plenums, injectors, ITB, larger TB, spacers, etc.?)

What fuel is/was used on the car during MOT test?: (UK 98 RON V-Power, UK 97 RON BP Ultimate, Tesco Momentum 99 RON, etc.)

Thanks greatly to any respondents!

I had a Scorpion Exhaust with rolled tips fitted yesterday by my local power flow exhaust specialist.

It looks and sounds lovely.

However when I got home and inspected, some of the joints are leaking water/moisture (hard to tell if gas escaping). I see exhaust paste has dripped all over the place.

I am taking it back Monday for them to rectify.

Is this normal for new slip joint exhausts?

Has anyone else had a similar issue?

Any advice for when I take the car back to the exhaust specialist?

Thanks

Colin

Sort out rattle one which was a clip missing in the boot causing an echo!

Now on to rattle two which think is the exhaust. When the car is stationary makes no or maybe a slight rattle (had camera under it but cannot see anything obvious).

When driving, particularly when coming off the throttle it rattles, hard to tell where.

Does seem to rattle a tad on bumps, but not noticable particularly when accerating either soft or hard. However, does not rattle if rev stationary maybe a little but nothing like coming off the throttle.

Probably need to book it somewhere with a ramp to get a proper look, but does it sound like exhaust simply hitting underside of the car.

Exhaust and cat are only 9 months old now.