Jump to content
SAU Community

Recommended Posts

Hey Guys,

Ok so I'm reasonably new to the jap car seen and need some advice and please forgive the ignorance.

So when my car is under heavy acceleration I get a loud Pop/bang from my exhaust when up shifting in the higher rev ranges 5k+.

The only mods i have done engine wise is a 3inch turbo back stainless steel system with a massive jun-bl cannon on the back courtesy of Exhaust Technology and a Apexi power intake pod.

The Exhaust specs are , 3inch bell mouth dump and front pipe into a 100cell cat (unsure what brand) then to a single mid mount lukey oval muffler and then straight to the Jun-bl Cannon ( dunno actual sizing but it was the biggest one there)

O and by the way the Car is a R34 Gt-t sedan with a trip tonic auto trans. ( i know a trans conversion is on the cards but not right now).

So yeah is this normal it doesn't happen all the time just when its under load and only if i don't take my foot off for the gear change.

Please Help and thank you

Tom.

Link to comment
https://www.sau.com.au/forums/topic/369972-loud-bang-from-zorst/
Share on other sites

He said a "100 cell cat".

Anyway, an upshift backfire is not uncommon on auto Skylines, especially with a big exhaust. Not normally a really loud bang though. Usually just a sexy little pop thud. My R32 used to upshift dead on the rev limiter (while it was still auto) and the sound was the only good thing abotu the auto.

He said a "100 cell cat".

Anyway, an upshift backfire is not uncommon on auto Skylines, especially with a big exhaust. Not normally a really loud bang though. Usually just a sexy little pop thud. My R32 used to upshift dead on the rev limiter (while it was still auto) and the sound was the only good thing abotu the auto.

Yeah I was hoping it was just that I googled it before and it's came up with alsorts of stuff about transmission mounts on the way out.

Thanks man

there could be a leak in the exhaust system somewhere.. that causes bangs.

Gahh i would hope not i got it less then a month ago lol

And yeah its been there since i have had the new zorst put on But its got louder which i put it down to Carbon build up Still makes me abit nervous.

And with the Ecu that definitely sounds possible it would explain the bang probably needs a re tune soon any way I reckon i will do that After i get my FMIC put on in a week or 2.

did you re tighten them after it was warm? steel expands bud so things loosen themselves.

also ECU could sound right as when high in the revs you will get an injection pulse when you release the accelerator. i think its to cool down pistons or something but i know it does it

ECU on auto skylines retard timing on upshift to protect the gearbox

manual doesnt

retarded timing on 0 load high rpm creates the bang

so its just the ecu, nothing to stress about

anyone who has a power fc in their manual, try changing the timing advance in first row to 0, it'll do the same too, refer to paulr33's PFC FAQ

Ok so i checked it out and yes it is the ecu!

Sooo with tax time conveniently placed just around when i need a tune i think i might invest in a EBC, Nistune and have a FMIC already then i just need it all fitted.

Fingers Crossed for 180-200kw at the wheels :banana:

Thanks for the help :thanks:

ECU on auto skylines retard timing on upshift to protect the gearbox

manual doesnt

retarded timing on 0 load high rpm creates the bang

so its just the ecu, nothing to stress about

^^ this.

also ECU could sound right as when high in the revs you will get an injection pulse when you release the accelerator. i think its to cool down pistons or something but i know it does it

^^ not this.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hi...a bit a "development" on the brakes. I spoke to the guys where i get brakes from...and they are saying that 296mm EBC are for R34 GT-T. I then went to their site: https://www.ebcbrakes.com/vehicle/uk-row/NISSAN/Skyline (R34)/ and search for my car(R34 GT 1998 - it has GTT brakes) and it show me this USR1229 number and they are rly 296mm rotors... So now iam rly confused... The rotors i have now on the car are 310mm asi shown... So where is the problem? Does the whole EBC got it wrong or my calipers are just...idk know what?  
    • Oh What the hell, I used to get a "are you sure you want to reply, this thread is XX months old" message. Maybe a software update remove that. My bad.
    • This is a recipe for disaster* Note: Disaster is relative. The thing that often gets lost in threads like this is what is considered acceptable poke and compromise between what one person considers 'good' looks and what someone else does. The quoted specs would sit absurdly outside the guards with the spacers mentioned and need  REALLY thin tyres and a LOT of camber AND rolling the guards to fit. Some people love this. Some people consider this a ruined car. One thing is for certain though, rolling the guards is pretty much mandatory for any 'good' fitment (of either variety). It is often the difference between any fitment remotely close to the guards. "Not to mention the rears were like a mm from hitting the coilovers." I have a question though - This spec is VERY close to what I was planning to buy relative to the inboard suspension - I have an offset measuring tool on the way to confirm it. When you say "like a mm" do you mean literally 1mm? Or 2mm? Cause that's enough clearance for me in the rear :p I actually found the more limiting factor ISNT the coilover but the actual suspension arms. Did you take a look at how close those were?
    • @GTSBoy yeah sorry i know thery are known for colors bud those DBA are too in colors 🙂 Green will be good enough for me  
    • That's my life. Past-Duncan has a lot to answer for
×
×
  • Create New...