R33 gtst bogging/ misfiring? when losing traction.

[vxsr33]

Hi SAUers

 

Firstly i do not condone irresponsible driving on the street.

 

I'm having an issue whenever i do a burnout or donut (done on private property) the car will start to bog and lose power within a few seconds (I'm not limiter bashing or anything), almost as if the ecu is dumping in heaps of fuel. This is the only time this issue happens, other than the motor runs well never misfiring, bogging or hesitating under load. I'm running a power fc and the car has been tuned by Chequered Tuning with no changes after the tune.

 

Any ideas? I had a search but couldn't find anything similiar to the issue im having.

 

Thanks for any help or suggestions.

[GTSBoy]

Spray some silicone lube on the tyres before starting?

[iruvyouskyrine]

More right foot

[Super Drager]

Afm maxing out?

[vxsr33]

It's not lack of throttle thats causing the bogging and i don't think silicon lube will help in this case. AFM is a z32 and car is pushing just under 260rwkw so i assume the AFM should be no problem. I want to do a beginners drift day hence why i want to fix the issue. The odd thing is it happens only after a few seconds of losing traction so it's not as if the motor is being abused and overheated. Could it be something to do with the tune? Should i contact chequeredtuning and tell them the problem or no point?

[GTSBoy]

Set something up to log the ECU then get it spinning.  See what falls out.

[CEF33Y]

Fuel surge/Loose baffle in the tank?

Whats the fuel level been when its happened?

[vxsr33]

GTSboy what do you mean by get something to log the ecu? I don't have access to any tools like that.

CEF33Y fuel level has been around half way or a bit over. Ive never had any fuel surging issues. Pump is a walbro 255 wired up to a relay.

[GTSBoy]

1 hour ago, vxsr33 said:

GTSboy what do you mean by get something to log the ecu? I don't have access to any tools like that.

Assuming it's a tunable ECU, then whatever laptop + software is required to talk to the ECU and log its operation, is what I meant.

[Trex]

On 11/10/2017 at 6:26 PM, GTSBoy said:

Assuming it's a tunable ECU, then whatever laptop + software is required to talk to the ECU and log its operation, is what I meant.

This.

[89CAL]

Talk to Chequered Tuning about it, they seem to be good from what I see and you never know, they might pull up your tune and be able to see what is wrong without even having the car there.

Otherwise, as above. Get someone to watch what it is doing when it happens. If you have a hand controller and someone who has half an idea you may even be able to pin point it off there. They may have put a large amount of safety in some cells when they tuned it, and its not in a cell you normally hit day to day driving but when there's a different load (i.e. Burnouts) then it just touches these cells

I'm just guessing. If you have a hand controller log injector duty and timing then see if it spikes or drops when the fault happens. You can log airflow as well but I think something like injector duty or ignition timing will give you more of an idea

[vxsr33]

Spoke to chequered tuning about it a while ago (still haven't fixed issue) and they said the only way to fix the issue is to relocate the z32 maf to the cold side of the intake piping, between the intercooler and the throttle body.

Has anyone had to do this? [emoji53]
Would assume the maf wouldn't last long under boost pressures.
I'm still thinking it's an issue with the tune

[thebe]

How is your afm currently located?

[Dose Pipe Sutututu]

1 hour ago, vxsr33 said:

Spoke to chequered tuning about it a while ago (still haven't fixed issue) and they said the only way to fix the issue is to relocate the z32 maf to the cold side of the intake piping, between the intercooler and the throttle body.

Has anyone had to do this?
Would assume the maf wouldn't last long under boost pressures.
I'm still thinking it's an issue with the tune

Use a HPX MAF or a R35 MAF/AFM on the cold side

Then change the K constant to suit, works very well.

[GTSBoy]

1 hour ago, Dose Pipe Sutututu said:

Use a HPX MAF or a R35 MAF/AFM on the cold side

Then change the K constant to suit, works very well.

This.  The smart way, and Chequered should be able to handle it.  It's not as easy on PowerFC as on Nistune, but still doable.

*edit* I somewhat missed the fact that it was a PFC when I responded the first time this thread came up.  But it's there.

Edited August 17, 2018 by GTSBoy

[vxsr33]

How is your afm currently located?

It's located in the stock position before the turbo

[Dose Pipe Sutututu]

Could also be your throttle enrichment at higher RPM, it's so rich it is causing it to bog.

There's a table on the PowerFC to correct that, much needed trial and error with a wideband to get it right.

I generally aim for a 0.5 AFR dip