I'm about to get my clutch changed as soon as the rps arrives from Smithy. I have also bought some phnw decat pipes to be fitted at the same time.

 

My Z is an import, has done 63k miles and has stock turbos.

 

I do have one leaky pcv valve that makes the drivers side pipe smoke for about 30sec on starting very very intermittantly. Other than that it has been running 14psi for a year no probs.

 

Is there a way of decatting without running as much risk, ie putting in small boxes on the pipes to give some pressure (i decatted my rover and the replacement pipe had a box built into it)? No problems with that car at all.

 

I have been told by at least 5 people that I oftern meet in the midlands that decatting is the best thing they have ever done and I should follow.

 

I have also read all the posts of turbos seals failing due to lack of backpressure so here is a poll, what should i do bearing in mind cant afford new turbos right now?

 

heres the poll to help me make up my mind!

de catting any turbo car does help quite a bit and in most cars the turbo generally is easy ish to change, if thing go wrong, but most cars are not the Zed. I would only de cat if you can afford to change the turbos. But this subject has been done to death!!

 

Mark

I know this has been done over and yeah there are loads of theads trying to find out how many peoples turbos have died and how many have not, but if im going to get a true idea then the poll seems to be a good method as will be able to view the numbers and make up my mind easier, may help others too!

my z is an import as well with approx 70000 miles on it decated about 3 month ago no probs so far , running about 14 psi boost and it gets well used.

ta for the input

I can't stress enough do not do it unless you have the spare money to replace the turbos. Ask Greg at Ztech how many Zeds have turbo seals go as soon as they decat. oh and Lahsx you are a very lucky man!

I know a lot of them do, and yours was one of them. It would be a good reason to get some T28s!

 

But really, I want to see what the poll comes out at and roughly what percentage of z's are killed as most people i have spoken to at meets highly recommend it.

Its not just the cats that can cause the seal to go. I have been decated for 3 years and NO problem with smoke on idle, rinning 15.5 psi as well. But 3 months ago I decided to repace the mid section and exits to mongoose stainless steel, and THEN it started to smoke on idle as soon as I started the car.

I think there may be some restrictors in the standard mid section, looking at it when I removed it, the pipes narrowed in places.

yeah part of my original post was asking if i can get a restrctor or extra box in somewhere. I currently have a stainless blue flame cat back system fitted.

In most cases, if you put the cats back as soon as the car starts to smoke you can still get quite a few miles out of the turbos (even more if you turn the boost down some)

It doesn't mean the problem is fixed though, but (most of) the smoke will be gone and oil leakage will be far less, so you have some more time to save up for new tubs..

Quite simply, if your thinking of a modification, and it worries you enough to need put a post up, then your answer is NO

 

if you have the 2k to replace the tubz, go for it

ok well as far as i can tell the seals fail due to a lack of back pressure. So might mod the decat pipes to give some pressure. Anyone done this?

I suppose if you have any doubts you could always replace the cats with some small silencers. I did that on mine mainly to keep the noise down on the Mongoose back end, but I'm glad I did now as I'm sure they offer a little bit of back pressure.

 

De-cated six weeks ago and no problems so far, boosting at about 0.9 bar as well and boy did I notice the difference when the new exhaust went on, the change in the cars response was very noticeable.

 

Gaz

well the phnw pipes i bought are straght through but i might get them modded by a stainless customs place before they go on. The phnw site says they have been well tested and developed but i suppose there is always room for further improvement!

Any more votes? Will need a decent number to get a true idea of everyone's thoughts

Any more votes? Will need a decent number to get a true idea of everyone's thoughts

 

Read this throws a big spanner in the works!

 

 

http://www.300zx.co.uk/forums/showthread.php?t=37089&page=1&pp=40&highlight=decatt

Yep that thread was the main reason for this poll. You had a lot of response and ideas on this subject but it was difficult to see the true numbers of people who had real problems. If everyone who posted on that thread could simply vote on the poll that would be great!

 

PS from reading that thread again im going to get the oil changed for some millers semi synthetic as it seems that using modern thinner synthetic oil is a contributing factor.

 

I have also spoken to a stainless system builder that I have used before and they are quite happy to add some small boxes into the pipes to keep the back pressure so I think this is the way to go.

jap tt decatted.......what a feckin' mistake!!!!!!!!!!!!!!!!!!!!!!!!

Jap TT Decatted - Perfect - faster, louder - No Smoke :) Woohoo

 

Old UK TT - Decatted - died very shortly thereafter.

with the luck you are having(droping on a car like that in the first place) :bow:

i would go for it

p.s

when you have finished doing all this work to it

can i have it back :)

Thought this was a 'Decall' poll to start with!

 

'Who thinks I should have great big stickers down the side of my car?...' lol

maybe you can have it back after my turbos have seized!

removed mine at about the same mileage and had no probs, 2 years on still ok, go for it.

Any more voters before it closes?