Hey guys,

Long story short, Ive recently installed a boost gauge, its read 0.4 so I checked all my piping and vacuum lines. The problem was cracked intercooler hose. Got that fixed. Now my car runs 0.78 bar during the day and 0.9 at night!! When it runs 0.9 bar it splutters at high rpms and boost fluctuates. Im worried the car might be run too lean. What could be causing my car to do this?

Car is Series 8

Mods, Intake, Greedy FMIC, 3.5inch cat back. (everything else is stock)

Thanks

 

You need a boost controller NOW!!! With a stock ecu, you are very unsafe. Do not acceclerate hard until you get a boost controller. You are at risk to blow your engine.

 

It's breaking up at higher rpm, get it tuned and get a HKS twinpower ignition amp, Denso pump, boost controller, and aftermarket rad.

 

Radiator to solve a boost problem?

Ignition amp to solve a boost problem?

I agree with Adam_c (as usual) just put on a boost controller, get it dialed to where it should be, and you'll quit hitting fuel cut.

 

I presume he is ALREADY hitting fuel-cut, isn't he? I mean, .9 bar is like 13.5 psi so it SHOULD be shutting down.
Right?

 

Thanks for the replies

Yes it is hitting fuel cut! bUT the question is why the hell is it? Why is it boosting up so high? I know many of you guys running more free flowing exhaust with out the boost creeping...

Could there be something faulty? Im thinking the previous owner did some unknow mods??

That sucks coz my Power FC is on order and its taking ages...

when I changed the hosing on the intercooler, there was some oil in the piping, is this normall or its something i should be worried about?

 

Every car is different and reacts differently to various mods, but there's also a good chance that there is mod (or possible turbo control issue) you don't know about on your car that's causing your car to boost so comparatively high.

 

I had overboost problems with only downpipe, catback and apexi intakes. I was hitting almost 14 psi and now it's all gone with greddy profec B.

 

Every car is different but hell they arent THAT different, I'm hitting .86bar on cool nights with a midpipe without a ported wastegate...You should not be hitting .9bar through the stock cat.....It sounds like some sort of boost control problem rather than a mod. Check hoses to the wastegate/pre-control actuators.

 

With no flow mods and stock pills my car was hitting 12/13psi when I bought it.

Fortunately the stock ECU is very conservative so I did not do any damage - but I bought a boost controller pronto.

 

The reason why you are boosting higher at night is simply because your engine is getting much colder air = more boost.

The best way to safely drive with increased boost is an aftermarket ecu or similar (power fc etc) together with a boost controller.

My own experience with boost problems came after 3" dp and cat-back together with open air filters, I was boosting 15psi (with reprogrammed ecu) and that was waaay to much even with an aftermarket ecu.

 

If you keep going WOT with the problem you're having, you won't have to worry about the wait for that PFC...

 

Got profec B and Re Amei dump pipe installed today. Got the boost back down to 0.7 bar using version 1 of the installation. Car runs good but the car misses some times and back fires alot once the secondary turbo kicks in above 5k. Checked the leads and are all on properly.

Any other ideas what could be causing this?

 

Try version 2. I'm running it and I find it alot better than version 1.

I had similar experience after I fixed a boost leak being the y cross over pipe hose cracked. First drive after that and it was spiking then settled down. I also blew my first engine on a cold night at WOT so be careful especially when the intake temperature is cold particularly at night (I didn't have a boost controller). Personally I still prefer to drive the car at night as oppose to day time.

If you haven't changed your spark plugs it will be a good idea. My car was breaking up at high rpm LIKE it was hitting fuel cut. Considering I was running exactly .79 bar I knew this couldn't be possible. Changed the plugs and problem solved.