Something Weird Happening With The New Turbo..seems Like Its Stalling?!?

[WYTSKY]

Hey guys, as some of you may know, not long ago I needed some help about driving my car untuned with a new turbo, injectors, afm and fuel pump, before I was going to get a tune.

I put in the turbo so far, getting a fuel pump this week and then put the rest in over the weekend or so....

but something a little strange seems to be happening to my car at the moment, with just the new turbo in...

The car is running brilliantly at the moment... even though its untuned I can tell there is alot more power... the only concern I have is that after I hit boost ( which comes on really fast and really quick - (2,600 - 3,000 ) and let off the accelerator and go into neutral... ie rolling to the red lights... the revs drop as normal...... but they go too low... they may drop bellow 400rpm or 100rpm and the car may even stall on itself... this only happens in neutral when revs are free... not when I am rolling to the lights in a gear after hitting boost and the revs are a much slower controlled drop.

These are my assumptions: (tell me if you have any other ideas what it could be)

1. Crappy tune- especially not for this turbo and the rest of the stuff I am going to put on (but we already knew this)

2. Standard Blow off valve not doing its job correctly any more because of bigger turbo (only running about 11psi though) and some of the air it lets back into the turbo and the other goes back the other way making the cho cho cho sound and goes out through the pod making the afm read negative numbers so it drops the rpm and retards timing,etc... so it almost stalls...

3. Timing belt/actuator i don't know??!? timing belt was changed about 40,000 kms ago....

so to help this I have heard I should relocate the afm meter to around the throttle body area and/or get a new BOV but I want something legal.... so maybe like a GTR one.... but I still don't know...

Thanks for the help in advance.

Adam.

[NYTSKY]

Firstly why the hell are you boosting the car with A)A bigger turbo B)Standard fuel pump and injectors?

Your AFM will be the blame for the fluctuating revs due to the increased airflow,and going a bit crazy as its not tuned for it.

[Guilt-Toy]

Gives a totally new meaning to fixing something that aint broke... She is broke because its untuned.

Get it tuned. Fix the problems after its tuned, if there are any!

[WYTSKY]

lol... that was the first question I knew I was going to get .... just wanted to wait and see who was going to say it ! but to answer your question... it is very hard not to.... considering how quick the boost comes on... and how low it does.... I also forgot to mention I have a powerfc... but with a crappy tune.. I am not running on a stock ecu.... and thank you for confirming what I thought about the afm...but is it anything to do with the bov because it is making the woosh sound as well as the cho cho cho( so I thought some air is going around and some is coming back out the pod)

so if it is the afm... when I chuck in the z32 that I have... do I relocate it or will it do better once tuned in the same spot? I would like to keep it where it currently is...

Adam

[Guilt-Toy]

you might need to move the AFM away from the turbo. but dont do this untill the car is tuned and there is still a problem.

[WYTSKY]

Guilt-Toy I know! I need to tune asap! just need a tiny bit more cash for the fuel pump and tune!

being a uni student its not that easy!

[WYTSKY]

ok, thanks for the advice. sounds sensible.

[DECIM8]

Mate if your running lean ur going to saving for a new engine when it goes bang.. Drive off boost and shift at 2,500 .. sure its granny speed but ull be right

[WYTSKY]

thanks bud, but how do you know if i am running lean? is that a cause for some of the symptoms I described?

[Guilt-Toy]

You wont know it was running lean untill you blow it up. pull it appart and think... "maybe i should have waited to tune it before boosting it"

If your that short scrapped for cash PM me maybe i can do you a credit tune

[NYTSKY]

Its simple dude,dont boost the car at all until you get the other mods done.Especially the tune.

But you will only be getting it tuned when you get all the other mods done.Reason being is the car wont run with bigger injectors,plus you will need to change the AFM settings on the PFC once the Z32 is wired in.

[WYTSKY]

oh ok thanks for the info... and you can all rest assured and save lectures because I am not pushing the car... nothing over 3,000 rpm changes... driving like a pussy cat....

interesting guilt toy.. wot is a credit tune?

thanks

[dead32]

oh ok thanks for the info... and you can all rest assured and save lectures because I am not pushing the car... nothing over 3,000 rpm changes... driving like a pussy cat....

interesting guilt toy.. wot is a credit tune?

thanks

credit tune=tune now, pay later...

[stolen_s15]

If you can hear flutter (cho cho cho sound) the air is bouncing out of the turbo back towards the AFM, AFM tells the ECU to add more fuel, ECU adds more fuel, not enough air, car stalls.

As stated above a tune *should* fix it. But i have no experience with hypergear turbos they may suffer compressor suge, either way see how you go.

[WYTSKY]

ok, thats interesting... I don't know about the compression surge your talking about but yeh, I was hoping a tune would help the afm issue... I believe I am getting boost spikes as well..but I havent put my foot down enough to know for sure, but is that a symptom of the surge as well?

thanks,

Adam

[hypergear]

You need to move the AFM away from the turbo's mouth of as far as possible from it. Its best to put in to Intercooler piping and do a tune after.

[WYTSKY]

Thanks Tao I have been really happy with it so far... just need to get a few little bits sorted...and the tune. oh and btw, I got my brakes sorted... used a brand of pads called qfc...I dunno much about them.. but they fixed the squeal!