stillracing

First contact regarding de-cats was from mattross via a PM, so he has first reserve at the mo. Will update as and when...

Thanks Gareth - items on their way to you now.

Quickest off the mark was Gaz so he has first reserve for now! Will update as and when. While I'm at it: Item 4: Resonated de-cats bought in 2012. Never used as I didn't get round to it. These come with all fixings and gaskets. Paid £90 but I'm looking for £65+pp please. Thanks again, Rob

After a bit of experimenting with the 350's exhaust, I've decided to return it to standard. As such see the below items for sale. Item 1: Berk High Flow Catalytic Converters purchased in 2012 new from this forum. These have done less than 5k miles, and are in good condition as you can see. Looking for £275+pp for these please. Item 2: O2 Sensor spacers. Again purchased new in 2012 from this forum and fitted with the Berk HFC's - so also less than 5k miles. Looking for £12+pp please. Item 3: Exhaust Heat Wrap (10 metres long) + stainless steel 'cable' ties. Unused. Looking for £8+pp please. Thanks for looking! Rob

Looks awesome...I'm inspired now!

It all starts to make more sense once they're on a track

I would have fully agreed about the lack of passion and distinction in the styling, until seeing one in the flesh. I thought they looked a bit Korean and generic until standing in front of it, but it somehow made a lot more sense...I'm sure it would make even more sense behind the wheel!

When it hits the 155 limiter is it just an ignition cut as per a normal rev limit? But presumably it sounds soft because of the time it takes to reach 155 again!

Would like to see it if the technology behaves any time soon - been contemplating some kind of DRL project!

Having bought de-cats recently and been concerned with the possibility of running lean, I did some thinking back to my engines lectures at uni. I realised that the ECU only uses closed-loop mode (ie. adjusting fuelling based on lambda values) during steady-speed and thottle-closed events. As soon as you plant it, the ECU switches to open-loop mode to give safe acceleration enrichment and therefore uses the Nissan-set map. Hence the air-fuel ratio does not depend on the O2 sensors during hard driving. So I would say that you're safe from that point of view. This is assuming that damage won't occur from slightly lean running during closed-loop running. Hopefully it's just a case of preventing the pesky CEL coming on

I'm near Norwich most of the time. Thanks for the offer though theheff - very generous

Pretty impressive Russ! I won't feel too guilty when I hit a pot hole now then

Yeah I well imagined they're engineered properly. It was just the weight difference to stock that surprised me. It kind of begs the question what the extra 3kg per wheel is doing on the stock wheel...Although saying that it could be a weaker material.

Great link thanks trackpig. It confirms that the widely available lowering springs are much softer than standard. In terms of car performance and handling - too soft. If I do go lower I think I'll be getting custom springs made...

Evening boys. Apologies for a bit of a techy post, but I thought it was worth sharing. Having fitted Rota Torque Drifts a while back, I noticed before fitment that the Rota's are about 3kg lighter each than the standard 2004 350z 18" wheels. Pretty impressive. Intrigued about the strength of the wheel, I produced a CAD model of it and put it through my FEA software. Forces Applied I went for the absolute worst case loads, which were a simultaneous combination of: Braking Acceleration : -1.5g (gives a torque of 1703Nm) Cornering Acceleration: 1.0g (gives a lateral 'force' of 300kg) 'Kerbing' Bump Event : 5.0g applied to quarter of the car's mass (gives a vertical 'force' of 3100kg) To give a visual representation of the results (where blue is low stress, going up to red which is high): http://i1063.photobucket.com/albums/t50 ... sFront.png http://i1063.photobucket.com/albums/t50 ... esRear.png This shows that the maximum stress seen is 99MPa. The ultimate (breakage) strength of the aluminium alloy used is likely to be between 150-200MPa. So I think it's safe to say that as designed, the wheel is very safe. The horror stories of people breaking wheels probably therefore comes about either by major manufacturing defects, or misuse. Hopefully of some interest! Rob

Evening boys. So I'm considering lowering springs for my 350. However, being a motorsport engineer I have had my car on the 4 Post Rig at work (if you're unsure of what a 4PR is: http://farm5.static.flickr.com/4147/5014313747_7155f06cf7_o.jpg) The rig tells me that the OEM spring stiffnesses are: Front: 93N/mm (530lbs/in in old money) Rear : 117.5N/mm (671lbs/in in old money) Now, on Tein's UK website (http://www.tein.co.uk/installation_manual/nissan/Z33_02-.html) they list the S-Tech Lowering Springs (the ones I think people typically go for) as having stiffnesses of: Front: 386lbs/in Rear : 403lbs/in So you can see they are MUCH softer than standard. My question to those who have the springs is what does the car feel like after fitment? I think any driver worth his salt should feel a change - bearing in mind that the lowering will affect load transfer. Thanks in advance for any opinions. ps. In case there was any doubt, the standard 350z was superb on the 4PR. It scored better mechanical grip ratings than many DTM, GT and Touring Cars...

Wondering the same thing, I thought I'd do as scientific test as I could muster. I logged my fuel consumption to work (13.6miles) 10 times on Tesco 95, and after a few tanks of Tesco 99 I logged 10 journeys on that fuel too. (this journey is mostly dual carriageway so predominantly constant speed and throttle). Tesco 95 Results: Average speed of 10 journeys: 51.16mph Average fuel consumption of 10 journeys: 32.9mpg Tesco 99 Results: Average speed of 10 journeys: 51.13mph Average fuel consumption of 10 journeys: 32.6mpg So you can see that on a very good statistical sample, the difference is within experimental error. From this I would also infer that there is no (or little) power improvement. Any difference between fuels is not great enough for the ECU to significantly adjust ignition timing and run more efficiently, so power is also unlikely to increase. I'd be interested to hear if anyone's done faithful back-to-back rolling road tests and compared fuels, although rolling road tests obviously come with a pinch of salt.

Yeah I guess the side exit is causing the resonance although I can't really see why as the valve is right in the side of the mid-pipe so the volume is almost identical (when the valve is shut). Presumably standard exhaust setups don't have that resonance, but I can't remember! It isn't ideal as you say. As for the noise I would have liked a well balanced exhaust system, but I don't really think the VQ35DE is well tuned enough to make a nice noise anyway (not compared to, say an NSX ). Either way having it switch-able is pretty handy. Yes HFC's were from Tarmac. Nice items and 3kg lighter each than standard Meant to say that the side exit gave a minor gain in torque and therefore power; up ~10Nm and ~5bhp on peaks at the engine (albeit measured on a rolling road).

Afternoon chaps. Have been meaning to make a first post after having a 350 for quite a while now...This seems as good a reason as any! Follow the link to see what I'm on about. Essentially my exhaust setup includes the standard system, and a side exit. I bought another mid pipe to modify and have an electronic valve installed which is able to open or close flow to the side exit. The side exit joins the mid pipe in front of the mid silencer, so it's only cats giving restriction/noise suppression. The video is with standard cats, but I have since fitted Berk HFC's. The noise is as you might expect. Measured volume the other day and was 121dB at a distance of 1metre I've got a few other interesting things to contribute in the near future, forgive any geeky stuff as I'm a motorsport designer/vehicle dynamicist lol. Rob