Boost drop

Other than a change in the map (waiting to find out) or a leak (will be checking tomorrow), what could cause a 2 psi drop in boost pressure?

Know the reason its down on power, just need to find out why now.

Cheers

What reasons it down on power Rob.

Seems to have dropped 2psi of boost pressure between being mapped on the dyno and the dyno run on Sunday. Map was tweaked in between for exhaust change and removing sports cat (boost was kept the same) and saw a gain on the road, but looks to have 'lost' about 20-30bhp and lb/ft on the dyno run on Sunday.

Original printout shows 24psi, Sundays showing 22psi - just trying to find out why.

Waiting for the mapper to confirm that boostwas kept the same.

Cheers

Might be getting somewhere now, everything crossed......

Cos those rollers are hoss shite.

22psi (1,5 bar) sounds rite , you sure it was 24psi (1.65 bar) previously as that seems high for a vf43 ?

phil555 wrote:

Cos those rollers are hoss shite.

totally disagree....

all my cars have been within 5bhp ov what the mapper calculated (andy forrest) ...

unless you were referring too the local rollers ???

cos there results are hoss shite unless its a evo. then they make impossible figures ......................

Thought a std ecu wud only got to 1.55bar with a elec boost controller or bleed valve etc

Thanks for replys

Just going from the figures on the RR graphs - not sure how accurate the PSI figures are on them? But there's a deffo drop, found a possible cause but not 100% sure.

Rollers were ruled out as being the issue on Sunday bur running a car with no changes to when it was there not so long ago - results matched up.

Initial mapping for the VF43 -





From Sundays run -





Cheers

looking at the graphs i say 1/2 a psi which could just be down to printer etc its about the same


std ecu will only go to 1.55bar which is 22.48psi which i wud say is wot both graphs say near a can be

The ECU is only capable of 1.5 bar as it uses a 2.5bar map sensor, boost is limited to what the turbo is capable of delivering, that turbo would deliver 2.0 bar in the mind range on a 2.0 if you wanted to, not that you would

My advice would be get Dunc to have a look at it when he is next up, he will have the logs from both sets of settings to look through, as drew says though his logs may only have read the max output of the map sensor so didn't pick it the lower boost setting.

Cheers lads, apprectiate it.

Would a possible intake leak before and after the turbo cause the loss of power?

Is it worth getting a 3.5BAR map sensor fitted?

FINN wrote:

phil555 wrote:

Cos those rollers are hoss shite.

totally disagree....

all my cars have been within 5bhp ov what the mapper calculated (andy forrest) ...

unless you were referring too the local rollers ???

cos there results are hoss shite unless its a evo. then they make impossible figures ......................

Never had a good result yet. 3 times in the type R and never got a reading. The Fabia is 40 lbs ft lighter compared to the 3 previous dyno runs from other RR's.

Robbo_22 wrote:

Cheers lads, apprectiate it.

Would a possible intake leak before and after the turbo cause the loss of power?

Is it worth getting a 3.5BAR map sensor fitted?

You could fit a 3bar sensor but to be honest there is no need as 1.5 bar is really where you want to be with that turbo, any more and you go over the turbos efficiency causing it to blow hot air, not good with a top mount.

Jonny Gav wrote:

Robbo_22 wrote:

Cheers lads, apprectiate it.

Would a possible intake leak before and after the turbo cause the loss of power?

Is it worth getting a 3.5BAR map sensor fitted?

You could fit a 3bar sensor but to be honest there is no need as 1.5 bar is really where you want to be with that turbo, any more and you go over the turbos efficiency causing it to blow hot air, not good with a top mount.

That'll do for me then, cheers.

What about the suspected air leaks - could they be causing the problem?

Had time to have a good poke around the car - suspected intake leak is now confirmed. Intake pipe has split where it connects to the turbo, wasn't sure about it when I had a look but used the car yesterday and it's very definatley split now. Replacement pipe found and will be fitted next week so hopefully happy days and back to normal

Thanks to everyone for the replys and Drew for helping sort me head out and having the part in the bat cave