Valveman

I enquired with Milltek on the exhaust system for the 370z and they say they have no plans to develop a system for this car I am not surprised as I don't think Nissan have sold many 370Z's. Have you seen what seen what some dealers are advertising new ones for lately - 370Z with GT pack £28995 brand new!

Mine has NO problem changing fast... it's working REAL well shifting fast actually so not sure why you see a problem there... still think it could be the flywheel thats out of balance or worn down. I can't see it's fueling in my application since I'm not using the standard ECU for that and got a full retune... If you don't have the stock ECU then you won't see this problem. I have driven about 25 Zeds leading up to buying mine and they all exhibited this problem to some degree - some more than others. I have a friend who worked for Bosch and was in charge of ECU mapping a number of UK made cars (admittedly diesel) Range Rover, Freelander, Mini and the new ford V6, and he used to tell me stories of how some manufacturers would spend an enormous amount of time getting the mapping absolutely perfect, and some manufacturers would not. He used to go all over the world in different climates testing and refining the car and fine tuning the maps. This is an extremely complicated subject as the ECU is switching in different maps and juggling settings all the time to optimise the correct fueling for the vehicle and the conditions. Here I think is the problem. Nissan have optimised the maps to make the car safe and run right assuming that 95% of drivers will be happy with the car as is. They have mapped the car for "safe" running. We "experienced" drivers (probably) represent less than 5% of drivers who would notice and complain about such things.

This is a possibility although this would normally throw up an ECU fault. I only bought my Z last November and noticed the same thing on a lot of 350Z's that I drove, mostly from main Nissan dealers. When you drive the car on a regular basis you do get used to the way the car behaves and you compensate for this yourself (you slow the gear changes down to make smooth shifts) and its not until you drive something else that the holding of the revs is noticeable. I am going to drive a 370Z very soon and will check if the same thing is apparent on that car.

Why not? The map controls everything.............. Remember there is no direct connection between your right foot (accelerator) and the butterfly in the throttle body - The butterfly is controlled electronically by a stepper motor which is controlled by the map. When you remove your foot off the accelerator pedal the engine management software (or map) is controlling the throttle - this is why the engine revs rise - the map is fueling the engine not you! It can detect when the engine is about to stall and then tries to increase the throttle opening to keep the engine running. This problem has got nothing to do with the clutch or the flywheel.

Yes - this is down to the V engine configuration and the amount of revs the engine is doing (the imbalance of the engine at low revs). You don't get this so much on a flat 6 or straight 6 cylinder engine. It is similar to riding a V twin or V4 motorcycle, if any of you have you will know what I am talking about. Once past a certain number of revs the engine smooths out and revs really cleanly. hmm my SV650S V Twin doens't suffer from that... thought that had more to do with the clutch/flywheel... All V engines vibrate especially at low revs - that is inherent in the design of the V. Take a look at a 1640cc Harley (Road King, or Dyna range) where the engine is rubber mounted and you will see it vibrate about a inch either side. This is what happens to all V engines at low revs - however the greater the number of cylinders the less the effect.

Cool keep us posted so... 1800rpm though! Mine does 1500 from cold thank god, otherwise the neighbours would KILL me... litterly... If its like mine it starts off briefly at 1800-1900rpm and then drops slightly to around 1500rpm for the rest of the warm up period. Pity Nissan didn't get to Porsche to map their engine as you wouldn't have any of these issues if they had done it, plus you would probably get another 6-8 mpg better fuel consumption. Just recently drove a Cayman S round the new Porsche test facility at Silverstone and their new 3.4ltr direct injection engine was sublime, as was the handling but some of this can be attributed to the superb PCCB brakes as these are 50% lighter then the normal steel ones. Must get to drive a 370Z one of these days

Yes - this is down to the V engine configuration and the amount of revs the engine is doing (the imbalance of the engine at low revs). You don't get this so much on a flat 6 or straight 6 cylinder engine. It is similar to riding a V twin or V4 motorcycle, if any of you have you will know what I am talking about. Once past a certain number of revs the engine smooths out and revs really cleanly.

We do all have the same problem. Its something in the engine mapping - nothing else. Its a lot better once the UpRev map is installed but its not completely perfect. It is suspected that it is something to do with the anti stall map. Mark at Abbey is going to data log my car and see if the UpRev team can find out what is going on in this area. I would also like to know why the bloody engine needs to rev so high on start up. Mine starts and runs at about 1800rpm until the engine warms up before it drops to below 1000rpm. No wonder these cars are so thirsty and why >2006 cars are in the highest road tax/emissons bracket - they appear to waste so much fuel.

Bloody hell you could get another set of seats in there! No wonder it so noisy.............

Unless you are going to race it on the track what is the point of 600hp for road use?

When you say your Z throws back quite a lot of oil - do you mean you are burning oil? No not burning... well its burning when it goes into the intake chamber down to the pistons and mixing with the air before combusting on the top of the piston. Sorry, I am still not sure what you mean when you say it throws back oil - the thread mentions the throttle body getting dirty and the comment "your Z throws back oil" was made. If it throws back oil to the throttle body then it will be burning it along with the air and fuel and you will be having to top up the oil level. The only other explanation I can see is that it is your crankcase breather is venting into the inlet manifold/plenum. Unless this is blocked or restricted in some way you should not be getting any oil in the plenum or the throttle body.

When you say your Z throws back quite a lot of oil - do you mean you are burning oil?

10hp - what a joke! I doubt you will even be able to measure the difference on a Dyno.

Yes I do. If you speak to Mark at Abbey and he will tell you what is possible and provide advise. What I can tell you is the cats, XYZ pipe and filter element (standard air box as this flows the best) made a big improvement straight away and then when I had the car remapped a week later this further refined the whole set up. The engine sounds and drives like my friends V8 M3 that I have driven a few times. All the standard Nissan V6 "roughness" has disappeared and the engine is as smooth as silk and feels more like a V8 instead of a V6. Also has a wonderful wail approaching 4000rpm. I believe there are a few on this forum advertising similar HP figures so I don't think there is anything unusual about mine. You just need to speak to someone who knows how to get the best gains for your money and what parts really work.

I would suggest going for sports/race cats instead of de-cats. Saves having to remove them every time you MOT the car and the difference in performance is quite small. The XYZ pipe also works really well. I am getting about 320hp (flywheel) with a stock exhaust, XYZ pipe, Kinetix sports cats and a HKS filter - and of course a remap done at Abbey. Bloomin 'eck 320bhp! That's a fantastic result. Do you have any other mods or is that all from the exhaust/filter? Its a 2006 car with supposedly 295HP to start with. Parts include Kinetix sports cats, XYZ pipe, HKS filter and a complete remap.

I would suggest going for sports/race cats instead of de-cats. Saves having to remove them every time you MOT the car and the difference in performance is quite small. The XYZ pipe also works really well. I am getting about 320hp (flywheel) with a stock exhaust, XYZ pipe, Kinetix sports cats and a HKS filter - and of course a remap done at Abbey.

You will probably find the 20mm spacers will be too wide for the later Zeds. I sent mine back as they pushed the tyres outside the edge of the wheel arches making the car illegal. I suspect the track on the 2006> cars are wider than the previous version. I have been told by a top tuner that 10mm on the rear and 15mm on the front is the max you can go on the later Zeds to remain legal. Exhaust wise I would suggest sports cats and a Motordyne XYZ Y pipe is all you need for improved sound. It makes a lovely sound as you approach 4000rpm and you would not believe how much better it will drive, but you will need that remap to make the difference. The standard cat back flows quite well but the main restriction is the standard cats and y pipe. Also the fuel consumption will improve with the above mods and the car still looks standard so it will keep your dealer and your warrantee happy.

Seconded!

The minute amount of dirt build up will not cause a problem, plus you can potentially do more harm than good by taking the throttle body apart. If you are getting a large amount of dirt build up then your air filter is not filtering properly or your engine internals (valves and valve guides, or pistons and rings) are worn.

I raised this as a problem on another thread. I have had the same problem on an 06 Zed with Uprev engine. Modern day cars don't produce much carbon and run extremely clean so cleaning the throttle body will be a complete waste of time. I think the problem is in the engine management software. Just had my car remapped by Abbey and the problem nowhere near as bad as it was but it if I was being fussy it is still not 100% perfect. Mark is going to datalog my car's ecu and see if there is anything that can be done about it. I also have a 3.2 Boxster S (my summer car) and the mapping on that car is superb. It runs like a dream and you can get super smooth gear changes all the time. Revs drop exactly as they should when you come off the gas. P.S. that fuel cleaner is also a waste of time and money as it won't do a thing to address this problem. If you want to clean the injectors they have to be taken out of the engine and put in a special cleaning machine. I also doubt the Nissan dealers will be able to fix this problem because they won't know how if its in the mapping. I also think (as Mark at Abbey suggested) that it is something to do with the anti stall map.

It's something like 65% throttle opening is 1st, 70% in 2nd and 80% in 3rd. 4th, 5th and 6th are all 100% but Mark at Abbey I am sure will confirm.

OK thanks - good result then.

Are you talking of flywheel HP or rear wheel HP?

Well the only thing I can think is that the 2006 models onwards may have a slightly wider track because when I fitted the 20mm spacers the tyres definitely protruded past the wheel arch and that is illegal.

No you wouldn't need arches rolled, and they are easy to get around if you are careful That only gives you about 2" of suspension travel before the tyre hits the arch. Unless you have race suspension and are driving on a race track I can't see how you can get away with this for road use without either damaging your tyre(s) or your bodywork.