de-cat with factory exhaust

[dyla350z]

Thinking about de-catting,i sure somewhere you could expect between 10-15bhp gains,is this true?I want to keep the sound close to stock,dont mind a bit more db but not loads,anybody no how much louder this set up would be?i know about the mot issue's,any imput will be app.

[Ian]

You won't gain anything like that.

 

This was mine with decats & stock exhaust

 

[dyla350z]

Hard to tell from the vid,its louder,do you notice much in the cabin?have you had it on a dyno? thanks for your input.

[Ian]

It was louder but that was 4 years ago so I can't remember exactly how much . Never had it dynoed with just that but I did with decats/y-pipe/exhaust/intake/plenum & gained a huge 8hp.

 

Don't believe everything the manufacturers tell you

[dyla350z]

I did doubt it but i got 11bhp doing it on my na supra,i got 9bhp on my z with just a plenum spacer & uprev,prob get it done as its quite a cheap mod and easy to reverse.

[Animal]

Decats will make it quite a lot louder. I noticed a significant difference in sound + volume with just HFCs.

[dyla350z]

In to minds now.

[Androo]

once you start whipping the silencers/resonators out you'll notice that you just get cheap 'orrible rasp without the right setup to accompany it. That said, above sounds quite nice imo

[dsapsfo1]

Am I not right in saying that only the plenum spacer will give any real-world gains, without an ecu re-flash? I thought the ecu would just compensate for any extra flow and therefore negate any gains. Often if it sounds louder though it will feel faster - good old psychology and all that.....

[Animal]

Often if it sounds louder though it will feel faster - good old psychology and all that.....

 

My car has at least 150 more imaginary bhp with a new exhaust fitted...

[dyla350z]

Think you need the re-flash to trick the ecu,i had the plenum done at the same time as the flash,re the de-cat i dont want to much noise,i spoke to scott at abbey & im leaving it to there reccomendations,booking it in soon i will post the dyno results.

[andlid]

Am I not right in saying that only the plenum spacer will give any real-world gains, without an ecu re-flash? I thought the ecu would just compensate for any extra flow and therefore negate any gains. Often if it sounds louder though it will feel faster - good old psychology and all that.....

Well on a JDM ECU the pure plenum spacer gave me 9HP (fly!) according to the UK ECU the puter will learn the mod and cancel it out... without a tune it's pointless IMO. Get all your mods done and then hand it in for a tune either with aftermarket EMS or using Uprev from Osiris. A Tune can give you around 10-11hp if I'm not wrong and then whatever other mods you got. I feel that you need to use well matched mods for the engine/exhaust/intake... not something I think that I've managed myself 100% (live and learn)

[Mark@Abbey m/s]

Well on a JDM ECU the pure plenum spacer gave me 9HP (fly!) according to the UK ECU the puter will learn the mod and cancel it out... without a tune it's pointless IMO.

 

ALL 350z,s will retune to the air fuel ratio that is in the template in the ECU this is what we tweak when we remap , the JDM is no different to any other 350Z I am afraid. I should know a JDM is my daily driver.

 

I tuned this car, what he hasnt said we have priced to fit decat pipes and a XYZ Y pipe with a race cat , this is the preferred route will tell customers that works and isnt to noisy.

[dyla350z]

Well on a JDM ECU the pure plenum spacer gave me 9HP (fly!) according to the UK ECU the puter will learn the mod and cancel it out... without a tune it's pointless IMO.

 

ALL 350z,s will retune to the air fuel ratio that is in the template in the ECU this is what we tweak when we remap , the JDM is no different to any other 350Z I am afraid. I should know a JDM is my daily driver.

 

I tuned this car, what he hasnt said we have priced to fit decat pipes and a XYZ Y pipe with a race cat , this is the preferred route will tell customers that works and isnt to noisy.

Mark I spoke to scott last wk & will be going with you and your reccomendations but i never forgot to mention xyz & race cat,you forgot to give me your recs and estimate i posted before the call from scott,will ring you next wk and book it in,thanks garry.

[andlid]

Well on a JDM ECU the pure plenum spacer gave me 9HP (fly!) according to the UK ECU the puter will learn the mod and cancel it out... without a tune it's pointless IMO.

 

ALL 350z,s will retune to the air fuel ratio that is in the template in the ECU this is what we tweak when we remap , the JDM is no different to any other 350Z I am afraid. I should know a JDM is my daily driver.

 

I tuned this car, what he hasnt said we have priced to fit decat pipes and a XYZ Y pipe with a race cat , this is the preferred route will tell customers that works and isnt to noisy.

mmm sweet, stand corrected. not sure how I got the number I did with my std ECU when I had a tune done... possibly it was on a "learn" at that stage

 

Out of interest Id more the likely go down the route of needing a Y pipe with race cat in it, can you PM me price and shipping to EIRE? (maybe a photo would be sweet too)