TADDY Posted August 10, 2009 Share Posted August 10, 2009 Just a qiuck question, im thinking of going down the decat route but wondering wether having the manifolds changed aswell will really make a worth while difference considering the awkwardness? or should i just stick to the decat? i will be having a remap aswell of cause any guidence would be greately recieved Quote Link to comment Share on other sites More sharing options...
Chris`I Posted August 11, 2009 Share Posted August 11, 2009 Not many around here have done it, not least without FI. Try searching my350z.com, much more done it on there. From what I gather it makes near to sod all difference, especially for the cost. Quote Link to comment Share on other sites More sharing options...
Dblock Posted August 11, 2009 Share Posted August 11, 2009 Not many around here have done it, not least without FI. Try searching my350z.com, much more done it on there. From what I gather it makes near to sod all difference, especially for the cost. Depends really you are right in what you are saying but you have to look into the figures. A car with plenum, ik and exhuast made 246.8 and with headers it made 247.9 so only 1bhp difference yeah? But it made that at peak. It gained 9.1bhp and some torque in the midrange. So its could be benifical if your going for lots of n/a power. Most people are put off by the 4hours fitting time and some say its worth it and some say its too much £ per bhp. I suppose they are both right but depends on what your going for. A plus would be you exhuast would sound better. Quote Link to comment Share on other sites More sharing options...
TADDY Posted August 11, 2009 Author Share Posted August 11, 2009 more noise is one thing that im after but also working towards a worth while remap if you know what i mean. are these really hard to fit then they do look difficult Quote Link to comment Share on other sites More sharing options...
Ian Posted August 11, 2009 Share Posted August 11, 2009 Not many around here have done it, not least without FI. Try searching my350z.com, much more done it on there. From what I gather it makes near to sod all difference, especially for the cost. Depends really you are right in what you are saying but you have to look into the figures. A car with plenum, ik and exhuast made 246.8 and with headers it made 247.9 so only 1bhp difference yeah? But it made that at peak. It gained 9.1bhp and some torque in the midrange. So its could be benifical if your going for lots of n/a power. Most people are put off by the 4hours fitting time and some say its worth it and some say its too much £ per bhp. I suppose they are both right but depends on what your going for. A plus would be you exhuast would sound better. Who told you 4 hours? I was quoted 10 hours for it & most people who have had them installed have said its atleast 8 hours Decats are no more difficult to fit that a set of HFCs, except of course you have to remove them MOT time (unless you have a friendly MOT tester ) I had them on my car for a year & for the noise alone they are worth it, I'm currently looking into a removeable cat option Quote Link to comment Share on other sites More sharing options...
Dblock Posted August 11, 2009 Share Posted August 11, 2009 Not many around here have done it, not least without FI. Try searching my350z.com, much more done it on there. From what I gather it makes near to sod all difference, especially for the cost. Depends really you are right in what you are saying but you have to look into the figures. A car with plenum, ik and exhuast made 246.8 and with headers it made 247.9 so only 1bhp difference yeah? But it made that at peak. It gained 9.1bhp and some torque in the midrange. So its could be benifical if your going for lots of n/a power. Most people are put off by the 4hours fitting time and some say its worth it and some say its too much £ per bhp. I suppose they are both right but depends on what your going for. A plus would be you exhuast would sound better. Who told you 4 hours? I was quoted 10 hours for it & most people who have had them installed have said its atleast 8 hours Decats are no more difficult to fit that a set of HFCs, except of course you have to remove them MOT time (unless you have a friendly MOT tester ) I had them on my car for a year & for the noise alone they are worth it, I'm currently looking into a removeable cat option 8hours!! thats put me 100% off lol, most people on the us forums said 4hours but maybe they where guessing? Quote Link to comment Share on other sites More sharing options...
Adriank Posted August 18, 2009 Share Posted August 18, 2009 I'm tempted to go for it, the stock headers are a big restriction and you will get better flow and sound with them replaced. My garage said he would be able to do them, but its a bitch of a job, still tempted to do it when im next a bit flush tho. TADDY if your going for a remap and want a bit more noise, id go for it. Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 18, 2009 Share Posted August 18, 2009 Mine took about 4 - 5 hours to do. Point is with the 350 manifolds they are all different sizes I am led to understand and the AM ones are all equal sized giving better flow. Car is now deeper in noise, one thing to remember is to get them them heatsheilded as the AM ones do give off loads more heat to the engine bay... I am thinking about putting some decats on just for a trial now... and maybe removing the single box after the y just leaving the 2 at the ends... Quote Link to comment Share on other sites More sharing options...
Adriank Posted August 18, 2009 Share Posted August 18, 2009 Dont decat it Mark, it will add too much Rasp IMO, remove the Y Pipe silencer if you want it louder, but a better bet would be to get a custom exhaust place to make up a centre pipe with no silencer, that way your not cutting up your 5Zigen one. Quote Link to comment Share on other sites More sharing options...
Ian Posted August 18, 2009 Share Posted August 18, 2009 Mine took about 4 - 5 hours to do. Point is with the 350 manifolds they are all different sizes I am led to understand and the AM ones are all equal sized giving better flow. Car is now deeper in noise, one thing to remember is to get them them heatsheilded as the AM ones do give off loads more heat to the engine bay... I am thinking about putting some decats on just for a trial now... and maybe removing the single box after the y just leaving the 2 at the ends... Doooooooooooo it. Will be uber loud I still think side exit FTW Quote Link to comment Share on other sites More sharing options...
GT4 Zed Posted August 18, 2009 Share Posted August 18, 2009 Just a qiuck question, im thinking of going down the decat route but wondering wether having the manifolds changed aswell will really make a worth while difference considering the awkwardness? or should i just stick to the decat? i will be having a remap aswell of cause any guidence would be greately recieved Personally, now that we have the availability of Uprev remap here i think this is the way to go rather than the expensive route of FI. I will go this route (Manifolds + HFC/decats) myself and also considering strongly to go for cams. Combine this with lighthenned pulleys/clutch/flywheel and 3.9+ final drive it will be one uber responsive zed:thumbs: For the ultimate NA build a stroker kit will need to come into play One should see a safe useable 350+WHP with this setup looking at the US boys but any further is into race spec engines when you have to spend big bucks and consider whether its not wotrth going FI though i think it still comes in cheaper than a full forged FI build Quote Link to comment Share on other sites More sharing options...
TADDY Posted August 18, 2009 Author Share Posted August 18, 2009 some food for thort then just not sure, as the manifolds and decats i was looking at are all in one peace so when it comes to removeing them for mot its gonna be a bitch with the sounds of it. hmmm what to do...... little question please dont laugh, whats a stroker kit? Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 18, 2009 Share Posted August 18, 2009 Dont decat it Mark, it will add too much Rasp IMO, remove the Y Pipe silencer if you want it louder, but a better bet would be to get a custom exhaust place to make up a centre pipe with no silencer, that way your not cutting up your 5Zigen one. Should only rasp if its thin piped!! I know where there is a spare set to give it a go!! GT4 Zed, go FI, you will save your self a small fortune on that lot of parts!! And then the fitting ETC!! I think one of the only people that went that way in the UK, that has posted on the forums (not this one I might add) is Giles and there is info on his build available including costs and he didnt get near 350whp.... His was built to race spec by RJN, but I dont think he went with the stroker.. Stroker kit increases the engine displacement so can take it up to 4.2 from a 3.5.. Other kit is needed when you fit them! More info here http://www.350z-tech.com/zwiki/Part:Stroker_Kits Ian, dont you knows it.... One day!! Quote Link to comment Share on other sites More sharing options...
Ian Posted August 18, 2009 Share Posted August 18, 2009 Might be sooner than you think Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted August 18, 2009 Share Posted August 18, 2009 it was one of the few things i loved on my last car i had done filter and exhaust, and sounded nice, but it was the AM manifold that really made the car sound awesome. don't know if it will do the same for the Zed though. what is exactly required for a manifold change, i'm guessing by the time frame we are talking an engine out job? Quote Link to comment Share on other sites More sharing options...
TADDY Posted August 18, 2009 Author Share Posted August 18, 2009 thanx for that 3fiddyz, with the looks of that kit it would apear that going FI would be the better way forward. tho for now decat, pulleys and a remap are on the cards Quote Link to comment Share on other sites More sharing options...
Dblock Posted August 18, 2009 Share Posted August 18, 2009 What if we got a group buy and fitting on the manifolds? Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 18, 2009 Share Posted August 18, 2009 What if we got a group buy and fitting on the manifolds? A few options and prices on the manifolds... But fitting aint gonna change unfortunatly!! Also need to find a central place for fitting I think!! Am sure Envy could sort out cat prices but then its the case of doing a deal with a few places to fit! Am sure Abbey have fitted a few, they are based south so if your based up north you may have to travel! Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 18, 2009 Share Posted August 18, 2009 it was one of the few things i loved on my last car i had done filter and exhaust, and sounded nice, but it was the AM manifold that really made the car sound awesome. don't know if it will do the same for the Zed though. what is exactly required for a manifold change, i'm guessing by the time frame we are talking an engine out job? Nope, not engine out, there just a PITA to get the bolts out!! a couple of the bolts are very hard to get too! You also need to make sure that the flanges and internal tube sizes are the same or the fitters may have to do some modifications... No use gettting 2.5" manifolds if your cats are 2.75 and then the y is 3 and then the zorst is 2.75"!! I think you need to try and get the same all the way through and 3" IIRC is well worth ging for from manifold ends to zorst tip... If its not, please feel free to correct me! Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted August 18, 2009 Share Posted August 18, 2009 i've got the Invidia true dual which if i remember rightly is 3" from tip to cats. so i suppose it would have to be new cats as well. starts getting expensive shame as i loved the popple and backfires that the manifold induced on lift off Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 18, 2009 Share Posted August 18, 2009 Yep, I get plenty of those!! I do need to take mine all off and check the internal sizes though as I think I have some differences! Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted August 18, 2009 Share Posted August 18, 2009 Yep, I get plenty of those!! I do need to take mine all off and check the internal sizes though as I think I have some differences! do you really think internal difference would really make that much difference, especially when we're talking a 1/4 of an inch. would it be no different to air flow running into silencer chambers? Quote Link to comment Share on other sites More sharing options...
Adriank Posted August 19, 2009 Share Posted August 19, 2009 Dont decat it Mark, it will add too much Rasp IMO, remove the Y Pipe silencer if you want it louder, but a better bet would be to get a custom exhaust place to make up a centre pipe with no silencer, that way your not cutting up your 5Zigen one. Should only rasp if its thin piped!! I know where there is a spare set to give it a go!! I've got my APS ones going spare if you fancy them at a reasonable price, i get rasp now with the sports CAT's in even but its a great noise. I would love to get headers to finish it off, and you can get them reasonably cheaply. Has anyone tried the japspeed ones... http://www.japspeed.co.uk/Nissan-350Z/N ... -19-1-261/ Quote Link to comment Share on other sites More sharing options...
TADDY Posted August 19, 2009 Author Share Posted August 19, 2009 how much would you be looking at adrian? pm me if you prefer Quote Link to comment Share on other sites More sharing options...
3FIDDYZ Posted August 19, 2009 Share Posted August 19, 2009 Dont decat it Mark, it will add too much Rasp IMO, remove the Y Pipe silencer if you want it louder, but a better bet would be to get a custom exhaust place to make up a centre pipe with no silencer, that way your not cutting up your 5Zigen one. Should only rasp if its thin piped!! I know where there is a spare set to give it a go!! I've got my APS ones going spare if you fancy them at a reasonable price, i get rasp now with the sports CAT's in even but its a great noise. I would love to get headers to finish it off, and you can get them reasonably cheaply. Has anyone tried the japspeed ones... http://www.japspeed.co.uk/Nissan-350Z/N ... -19-1-261/ I know that I go on about decent kit and most of the time its expensive but on the manifolds I would say go for some decent ones... Japspeed http://www.japspeed.co.uk/Nissan-350Z/N ... -19-1-261/ Fujitsubo No comparrison IMO, quality of welds, materials, bends etc look so much better on the japanese ones.... I wouldnt be putting the japspeed ones on mine to find out that after a few months they were being removed and the old ones or another set were being replaced... Unless someone else on these boards has had them and tried them and given you a good report I think it would be an expensive trial!! I also think you need to be careful about which ones you buy from the states due to the LHD / RHD differences on the Zed engine... Have a look at the DC ones, least they have been tried and tested over here.... On the Evo long term test car no less! Quote Link to comment Share on other sites More sharing options...
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