I have just fitted a Jabba FMIC to the Octy (Exhaust, DV, filter, Std Map) and the car is a completely different animal.

The turbo lag has increased, which is expected but the boost pressure has increased from 0.8 bar to 1.1bar+.

I have read by lots of people on here that the FMIC should actually reduce power but it seems to have done the opposite on my car. The car seems to be much more powerful on boost and a lot quicker.

Does anyone have any experience of this? Should I be concerned? Could the old SMIC have been blocked / damaged?

Cheers

I have the pro alloy on mine also but I'm running a custom IP map which is just over 1 bar so I'm not sure who your getting more boost on a standard map :confused:

Your not going to get much if any gains for a FMIC but it will keep the intake temps down and come the summer you will have lees heat soak

:iagree: An FMIC should not give more power unless it actually reduces intake temperature, and even then only if you increase fuelling to exploit the fact.

I am pleased to have a practical confirmation of my argument that the extra volume can cause lag though.

Extra lag is definately to be expected, but never seen one give more boost.

I fitted an HKS fmic to my Impreza, boost came in around 4-500rpm later then before fitting, and boost dropped around 0.2 bar overall.

It definately is giving more boost!

Either that or the boost gauge is not reading right!!

Could it be related to the DV adjustment?

I am seeing just under 1.1bar boost on an un mapped car - is this normal? If so could it be that the old cooler was blocked?

Maybe you have cured a boost leak by changing the IC and assossciated pipework :confused:

I am seeing just under 1.1bar boost on an un mapped car - is this normal? If so could it be that the old cooler was blocked?

Like I said mine is custom mapped by IP and I'm only getting about 1.1 spike then holding 1 bar!

I know revo and jabba can give about 1.3bar but not sure how your getting 1.1 unmapped?

Have you had the car from new?

Are you sure it's not been mapped?

1.1 bar is high for a standard car it should be around 0.8.

Car used to boost to 0.8 bar - fitted FMIC and it now boosts to 1.1 and settles to 1 bar.

Had the car for a year and bought from HSBC bank manager! pretty sure its not mapped!

Ah, if the DV has been adjusted, that could be giving you more boost before it dumps. If a FMIC makes a difference to the charge temperature, you'll get T \/ , which will lead to P\/ .

Supporting reference:- Thermodynamics - Wikipedia, the free encyclopedia

Ken,

Are you just a living, breathing book of knowledge ???

Certainly know a lot about certain subjects.

Obviously stuck in at the old Physics

Ah, if the DV has been adjusted, that could be giving you more boost before it dumps. If a FMIC makes a difference to the charge temperature, you'll get T \/ , which will lead to P\/ .

Supporting reference:- Thermodynamics - Wikipedia, the free encyclopedia

Not sure about this, the dv should always be shut when on full boost therefore should give same figures, unless its leaking but that would give less pressures. I suppose you could get a brief boost kick when you let power off quick if dv spring was too strong.

It feels like yes, or maybe I'm just bright enough to know who to ask?

Not sure about this, the dv should always be shut when on full boost therefore should give same figures, unless its leaking but that would give less pressures.

I understood that a DV was an alternative to a wastegate, in which case surely its function is to restrict maximum boost?

I understood that a DV was an alternative to a wastegate, in which case surely its function is to restrict maximum boost?

thats the n75 dv lets off when there is to much pressure, say when you let your foot off. It prevents the turbo fins bending etc. Afaik