hæ i got a 3" downpipe and a catback exhaust and i am fuelcuting alot !


this is a 2,5 STi 2006 ...its boosting like 17-18 psi

i think the fuelcut is sett to 17,5 psi ?

i am not planing to go further in mods ...bud i want to lose the fuelcut ...but be safe

what can i do ....?

Thanks

edit : and im driving on 100 oct fuel . (98 oct recomend) ... djust to be safe

 

help ?

 

When does it do it ? Gear/Revs

Is it remapped ?

Get something like a scangauge II on it and see what the fault code is. Something like a P0244 Wastegate control solenoid valve malfunction (high input).

The MY06 ECU is different to the previous ECUs and needs adjusting by a mapper to prevent overboost. I am told that the 01-05 ECUs had a boost control for each individual gear, the MY06> don't - the ECU attempts to take control itself but it often cant, hence fuel cut.

 

Mike Wood from Prodrive has said before that using a decat downpipe on a 2.5 has produced so much boost creep they couldn't control it (iirc they do not even fit the sports cat to the 2.5 Sti).... so no surprise it fuel cuts if your 3" downpipe is a decat.

Tony.

 

only in 3 and 4 gear yess it's a overboost

the car is stock ...only exhaust mods

i know theat ....but what can i do ? to controle the boost but not hurding the engine ?

fuelcut defencer ?

Apexi AFC neo ? engine management?

anything else ?

 

Remap, someone who knows what they are doing needs to change your numbers for the better.

Not only to make your car run safer with the 3" but to make better use of your current mods. I wouldn't consider a 3" system without having it remapped after.

I went to Zak at Mocom Racing and he is superb ! 2.5" system running 288/323 at the wheels and no overboost.

Mocom Racing - Performance car and trackday products

 

make shure you port the wastegate, before any remap.
because of the reduced backpressure of your 3" system the wastegate becomes to small to control the boost. No remap could cure that without a wastegate porting.

 

how is theat done ? im nott 100% sure

 

The wastegate doesn't need porting on the VF43. It appears to be a development of the old VF35 (which did need porting to stop creep), but has the wastegate already ported out by 1mm.
The remap would get the best out of your car.

Nick

 

A remap is essential for the safety of the engine - without it the boost will be all over the place and will probably kill it.

 

dosent the 06 2,5 STI have VF39 ?

 

I think it was only the US that had the VF39 and it was prone to cracking.
They seem to have also gone over to the VF43 now.

 

The 06 STi has a VF43

 

well the problem for Andri and well me too is that we dont have any mappers that are familiar with subaru's here in Iceland , I've got a classic with a 2007 wrx 2.5 engine with a 3" downpipe and 3" exhaust with 1 cat and I'm fuelcutting also, only 3-4 days since the car was finished, and today I checked for error codes in memory and I had 4 of them

P0244 Turbocharger Wastegate Solenoid A Range/Performance (High Input) - any idea why this error came?

P0123 Throttle position sensor circuit high input - Think my accelerator pedal needs adjusting because it had to be custom fitted to the car

P0118 Engine coolant temperature sensor circuit high input - this one I think is because when we started up the engine we didnt put enough coolant topped that up and all is well

P0108 Manifold Pressure Sensor Circuit Malfunction (High Input) - not sure about this error but at least it isn't there anymore

 

You need to remap the cars to get rid of the things that are causing these errors.

P0244 - caused by the boost cut - there is a table that sets this value but dont just raise it, the wastegate duty cycles need to be changed as you have de-restricted the exhaust and will hit boost much easier than standard.

P0108 - Boost spike from de-resticting the exhaust - the WGDC tables need changing to bring it back down to the target boost levels. I am guessing that you will want to raise the target boost levels too but you need to get someone experienced with this to do it as getting it wrong could be disastrous.

This is precisely why the later cars need remapping if decatting or fitting larger exhausts.

Try Main Page - OpenECU for useful pointers if there is no-one local that can map for you.