Hey guys,

 

I know alot of people do it but as i have had both turbos replaced already I'm quite cautious and like to make sure everything's cool. I just wanted to know if decatting a TT has any negative effects for the turbos? I.e wear them out quicker or not good for them etc.

 

Thanks

 

Sav

Hey guys,

 

I know alot of people do it but as i have had both turbos replaced already I'm quite cautious and like to make sure everything's cool. I just wanted to know if decatting a TT has any negative effects for the turbos? I.e wear them out quicker or not good for them etc.

 

Thanks

 

Sav

 

This subject will give you 100 different opinions..mine from experience of all my zeds being decatted is no difference at all. :)

Thanks for the reply. Youve got a wealth of experience on the forum so that sounds good to me!

Decatting will only reveil a problem with an old turbo that was previously hidden, if the turbos good it won't cause an issue.

^^^ this is true, but whilst the problem is hidden, its not a problem if you understand.

Fact is that some people do fit decat pipes to find the turbo/s start to smoke due to lack of back pressure. The sudden lack of back pressure allows a poorly turbo seal to pass and smoke. You might find this embarrassing, it might effect MOT emission testing, causing you to spend money that wasn't needed at THAT time. True, your already poorly turbo may have started to smoke soon enough anyway, but it might have done several more thousand miles without as well which to some Zed owners is years of ownership!

My experience with an Astra mk4 turbo was the opposite to Znuts, within minutes of fitting a decat and cat back exhaust the dam thing started to smoke, only at idle mind, the difference being the engine didn't require removing to replace the dam thing and there was only one turbo.

End of the day, fit a decat, if it smokes try replacing the PCV's, failing that, if replacing the tubs is out of the question, refit the cats and it will probably band-aid the tubs again.

Similar story to me, except I rebuilt them fixed some other stuff and then the motor went bang. Oh the joy! The motor didn't blow because I decatted it btw, it blew for another reason.

Hmm interesting reading. Like i said ive had them both replaced in the last 2 years from zedworld, had recon tubs fitted tbf. Im just thinking about it at the moment, my exhaust is completely gone so need a new 1 and was looking at the japspeed ones, they do a dcat pipe that is good quality ive been told.

It's acceptable quality yeah, I've got them. The first fit was a bit of a pain, but I've had it off twice since then without issue. It's well made and sounds lovely esp for the price.

If your tubs are that new then they should be in good order, therefore your risk will be less, as the risk is that they are damaged.

Some points to think about, if your car is auto it may be a tight fit. The auto transmission is a larger diameter I believe and people have reported fitment problems in this scenario. They used to do and possibly still do, NA decats. Have a research but I seem to remember these do fit and will bolt onto the stock turbo elbows. This helps two fold, you won't have to disturb the turbo exhaust flange which are often pesky and you will gain a silencer which should in theory help create some back pressure reducing the risk of seal failure showing up. Uk cars have a precat in one elbow and I think are a different shape two making them incompatible, you would have to research this.

http://www.zcentre.co.uk/index.php?page=shop.product_details&flypage=flypage.pbv.tpl&product_id=52&category_id=55&option=com_virtuemart&Itemid=7

There are a few companies selling them, they are the same product rebranded.

 

http://m.ebay.co.uk/sch/i.html?_nkw=300zx+decat&isNewKw=1&_pgn=1&epp=24&itemId=&isRefine=true&mfs=GOCLK&acimp=0&sqp=300zx+decat&trksid=p2056088.m2428.l1313.TR0.TRC0.X300zx+decat

Right.....i fitted decat pipes about 2months ago and the car was fine - i dont drive the car mich at all maybe 100-200miles a month or 1nce a week or so - on start up only the car smokes, only once its starting up but as i drive off after a few mins the smoke is gone - blue smoke though and defineatly oil......but my main concern now is.... The turbos before used to spool up and youd get a big surge in accelaration - there is no real spool anymore and it feels like somethings wrong - its not as fast and feels more like im driving an NA - has anyone got any ideas or maybe experienced this before?

What is the spec of your Zed? Boost controller fitted? What boost does the car produce? Did the lack of performance come at exactly the same time as fitting decats? If you're only seeing 7psi and it's in safety mode, that would explain the poor performance. It could be a coincidental issue, such as faulty knock sensor loom causing code 34 for example.

Hello mate,its a uk spec TT with the only real upgrade a zedworld ECU - no boost controller fitted ...the lack of boost didnt happen immediately, it happened after a few weeks - as for 7psi if im perfectly honest i havent even noticed what its boosting upto so ill check that tomorrow - so if it doesnt go above then knock sensor is a more than likely issue - thanks mate, ill check it tomorrow and see what happens - would make sense though as it feels like its spooling but no boost at all!

Hey, just an update - its defo in safety mode as does not boost past 7psi - whats the easiest solution? I do put low octane fuel in at times and they say that could cause an issue - could running higher octane potentially help the issue or is there another fix without removing the engine?

Hey, just an update - its defo in safety mode as does not boost past 7psi - whats the easiest solution? I do put low octane fuel in at times and they say that could cause an issue - could running higher octane potentially help the issue or is there another fix without removing the engine?

 

You need to now determine why it is in safety mode. If it is constantly in safety boost, it will likely be the loom for the knock sensor. You should have DTC code 34.

 

Fix 1: 1MΩ resistor to bypass the knock sensor. ONLY do this if you are 110% that the engine isn't knocking and the mapping is suitable & safe.

Fix 2: Remove the engine and fit a new knock sensor.

 

Never use regular unleaded, Tesco Momentum or Shell V Power Nitro.