Possible Boost problems

[Gman]

Hello all

I have finally got my nice yellow FD, drove it back from Scotland today, i almost soiled myself on serveral occasions some from terror and some from cheers joy.

It has an Apexi boost gauge and a power ecu with hand contoller but having not owned an fd before i\'m not sure if I\'m having problems.

Everything seemed fine on the test drive etc

On the way home today i was testing the engines performance, when i floored it the boost when up then stuttered and the car started popping from the exhaust = no power until i lifted off then increased power not so hard and it was ok.

Could anyone tell me if it is my driving or are things going to go bang (that would be a great start!!:( )

[scooby_si]

dont take it as guranateed but kinda sounds like fuel cut i used to have on me subaru when it over boosted so could be similar i guess
Si

[gregor]

On the power fc check to see what the boost is at max, if it has the standard map it should boost to .80 bar.  

If i was a gambling man i reckon when it cut\'s it will be around .925 bar or so.  If so you might want to put a smaller downpipe on the car.  You won\'t loose too much performance and will stop the cut, and keep the boost to .82 bar.  It cuts when the boost is over 0.125 bar moore than it\'s programed to do.

Check the injector duty as well it will probably be about 95% when it cut\'s.

[Gman]

My FC hand controller is locked out at the mo so it will have to wait a bit - wont damage anything will it?

[gregor]

It can be very harmful to the car, you can drive around it and have some serious fun.

I had to pull my engine and get it rebuilt due the fuel/boost cut.  Your car should not been lean tho due to it having the pfc.

Go careful with the right foot and not plant to the floor till you get it checked out.

Does it have a big downpipe?  2 change it wont cost much about £100 with a 2nd had pipe included.  Loads better that 2.5k for a rebuild.

[Gman]

Not sure bout the downpipe, i need to take it to have it checked out next weekend by a professional so they should be able to advise me.

Not lean the guys i bought it from checked when the FC was working and it is running a good amount of fuel through

[finite]

I\'ve had a similar problem to yours.  I\'m running a standard engine/ECU setup.  The CAT/pre cat has been removed and a downpipe put in their place, back box is a Blitz box.

The problem only seemed to occur when the car was at the end of the warm-up cycle.  The temperature guage was in the middle and the car had been running for about 5-10 minutes on a very cold day.  My guess was that under hard acceleration (me thinking the car had finished the warm up cycle) there was so much fuel going into the engine that there was not "enough" spark and air to get decent combustion hence the stuttering and popping (read great big flames) from the exhaust.  I have only recently had an engine rebuild (had the car three weeks before it popped), so don\'t think there is anything wrong with the block.  However I have noticed that the second turbo isn\'t boosting all the way to .75 bar, wondering if this may be adding to the problem and if anyone has any ideas what may cause this?  (at cross over the second turbo spikes to .8 then drops to about .6 and holds with very little creap).

[gregor]

To be fair, with such a derestrictive exhaust that you have, a pfc should be the next item on your shopping list.

With a standard ecu i doubt that you were getting too much fuel, more like starting to lean out.

Mine did the exact thing that you are having, the popping, flames and boost problems.

The pfc, std downpipe and some new turbo hoses sorted my car right out.

at the moment dragonperformance.co.uk have some pfc\'s on their site for sale 2nd hand (but cheap)

[Gman]

I have an aftermarket uprated ECU already i just cant check any of the settings.

[gregor]

That\'s cool but i was replying to finite the post above mine

[Gman]

Sorry my bad!

[finite]

can you recomed a PFC?  I was thinking the APEXI AFC?

[gregor]

A pfc is a Apexi Power FC.  Top ecu to get.  //www.dragonperformance.co.uk have them in stock 2nd hand but they are cheap

[Gman]

I was looking at the Apexi PFC and there as a knightsport fuel ........ box (cant remember the last word) could this have anything to do with it?

[finite]

I\'ve had a look on //www.dragonperformance.com and all I can find is the Apexi Power FC.  For £600 I\'m assuming this does more than just control the fuel map??  Took a quick look at //www.apexi.com, thus finding out that the Power FC is a complete replacement ECU and can be used to tweak just about everything (my poor brain hurts!)....

now the question is...

do i really need all this... or would something "smaller" like a piggyback fuel controller like the Apexi s-afc do the job?

ta and thanks for all the advice!