Got Fined

[Faid]

Ok guys it took a straight week to tune my car but i am about confident that i have reached my goal of about 600HP. (on my gtech i push in about 520HP but correctingthis value for wind resistance and rolling resistance it will ammount to about 600 WHP) enough of that, there is a little problem i experience when the T04Z is comming on boost, according to my AEM UEGO wideband datalog my AFR is steady at 14.3 idle and the moment i hit boost the fuel curve comes down to about 12.1. but as the boost builds when im changing gears and let of the throttle i get a huge backfire about 1.4m long. i got fined for frying the lens on a policecar that was onfurtunate to drive behind. this is realy starting to irritate cuz when i pick up my GF the whole neighborhood knows im comming cuz of the huge cannon i have trailing behind me. what can there be done to resolve this problem. should i lean the tune out a bit more to about 12.5 or should this be the way things are, and is this going to hurt my turbo or the exhaust side of the head in any way? the flame does not start in the muffler it starts just after.

[AzzurrA]

do you have an Atmo BOV?

if so, ditch it and get a plumb-back... will solve alot of your problems... sounds like it is overfuelling on gearchange, which an Atmo BOV will cause... this is due to it 'dumping' already metered air out of the system... the computer continues to pump in enough fuel to compensate for this already-metered air (which is no longer there) hence it runs rich.

[AzzurrA]

also... cars with cats usually won't blow flames.... unless the cat is already melted into a smouldering lump of goo...

be glad the cop didn't know this.... as it is a rather large fine

[mad082]

i dare say that he isn't running the stock ecu, so an atmo bov shouldn't change it much.

how lean is your low load tune? that may be the problem. if your low load afr's are too rich then when you lift of it is dumping in too much fuel.

also i'd say your cat is well and truly gone.

[illusiVe]

next time melt the cop car

hehe

[Sydneykid]

What ECU?

Have you got overrun fuel cut enabled?

cheers

PS, regardles of the ECU, if it runs an AFM and an atmosphere BOV it will run very rich on overrun.

[West]

Give me the T04Z and problem solve !

[Faid]

first of all i live in a country where we dont know what cats are ( at least the cops dont) hence i run a 3.5 inch full turboback exhaust (no restrictions just turbo and a pipe with a resonator in the middle and a muffler in the end). i run a PFC and after the advice of R31Nismoid i am still utilizing the stock GTR BOV's instead of going to the HKS SSQV (very pleased with my choice the dont leak shit quite surprising for a stock item) but i have vented the BOV as i dindt have time to make the piping to recirculate it. is is good if the flame is a bright blue colour?? cuz yesterday at a stopsign (around 12pm) some dude in a honda S2K tought he had a chance so the dude starts reving his engine. im at the end of my run in period (still have about 100 miles to go) so thought what the hell, revved it up to 9000 and dumped the clutch, lit up all 4 and when i changed in to second the only thing i saw in my rear view was a bright blue flame (thank god it doesnt burn the body of the car) but when i change from second to third the flame becomes a mis between yellow and blue and when hitting 4th its nearly complete yellow and 5th its yellow. so what i thing its farly lean on low load and when reaching higher load it richens up which is a good sign but the backfire bothers me

[Kozeyekan]

Any chance of a video/pix?

[MANWHORE]

no cat = flamage

[Faid]

ill provide the pics of the whole buil on a website i am constructing at the moment. but i am very busy at work lately and being a new dad to a set of twins its very hard to get some work done at home. the whole tuning process has video, pictures i even have a video where i run against a friend of mine with the same car he only has a HKS stroker and a T88H 34D turbo on its and makes about 800-900 HP but i did it to show him that he cant drive his car. and if i get this flamage with a cat isnt there a huge chance that i burn the internals of the cat to bits?? the next step for my car is work on the exterior and interior a bit cuz the car is fully stock on the outside. i have sent my valve & coil cover to be powdercoated and the car is going into the paint booth one of these days

Edited August 31, 2006 by Faid

[Sydneykid]

ill provide the pics of the whole buil on a website i am constructing at the moment. but i am very busy at work lately and being a new dad to a set of twins its very hard to get some work done at home. the whole tuning process has video, pictures i even have a video where i run against a friend of mine with the same car he only has a HKS stroker and a T88H 34D turbo on its and makes about 800-900 HP but i did it to show him that he cant drive his car. and if i get this flamage with a cat isnt there a huge chance that i burn the internals of the cat to bits?? the next step for my car is work on the exterior and interior a bit cuz the car is fully stock on the outside. i have sent my valve & coil cover to be powdercoated and the car is going into the paint booth one of these days

Vent the BOV’s back into the turbo inlet system and I bet the problem goes away. Just in case you don’t know what is happening;

1. The AFM’s measure the incoming air flow

2. The ECU squirts in the amount of fuel necessary to match that amount of air

3. The BOV’s vent the air after the AFM;s have measured it

4. So you get a whole heap of fuel with not enough air for it to be burnt in the combustion process.

5. Hence some unburnt fuel heads out of the engine into the exhaust system

6. That unburnt fuel either ignites straight away and gives a long slow reddish flame out the pipe (like a V8 Supercar on overrun)

7. Or, it sits in the exhaust until you put you foot back on the throttle and gives a nice bright ignition flash that is blue to white in colour.

Recycle the BOV’s and the problem will go away.

cheers

[khezz]

hell yeah. i know what i am doing for my next party trick he he. putting my hks ssq back on. COol oh wait i have a cat, damn it. Shame about the fine. lucky you dont live in the city. i dont know about anywhere else but in perth, something like that will grant them ability to pull your car of the road for a month.

[Cool Hand Luke]

hell yeah. i know what i am doing for my next party trick he he. putting my hks ssq back on. COol oh wait i have a cat, damn it. Shame about the fine. lucky you dont live in the city. i dont know about anywhere else but in perth, something like that will grant them ability to pull your car of the road for a month.

Or you could just do a keybanger . With the mircotech i had you had to turn off the ignition to reset the

display, and kabam! Great for surrounding motorists

[Faid]

dont live in the city, i dont even live in your country. i live far away from australia you can say on the other side of the planet. I live in the 3rd world. here we dont know nothing about emissions testing and so on and so forth. in my country when you go to the police to get your car cleared they only test your brakes . ok ive recirculated my bovs. (pain in the ass to take the IC off. but the backfire stopped. thanks

[Sydneykid]

ok ive recirculated my bovs. (pain in the ass to take the IC off. but the backfire stopped. thanks

As I said it would. Gosh I am good guesser

cheers