mbc help
 

can anyone help iv got a 2000 19t4 with a k&n induction kit with a 2 half s/s exhaust and baileys twin piston dump valve it runs 10 half psi it spiked to 14 somtimes so iv just fitted a mbc and turned it to just over 14psi it goes really well but drinks alot more fuel is this normal and safe i cant aford a chip so iv done it this way can anybody who done the same tell if their car alright the car seem fine and pulls well. and why does it hold 14psi and then drop boost around 4600 to 5000 revs in 1to 3 gear

Eh? Does this mean a 1.9L engine or have you fitted a 19T turbo???
I'll assume the former...

What this bit mean???
Do you mean it normally boosts to 10.5 psi?
If so, that's too low... 14psi is correct.

So maybe your boost control valve was knackered then?
One would expect it to use more fuel now it is boosting "correctly".
14psi is stock boost so you could go higher....

It is normal to lose boost I assume it is because of the rate the engine is sucking in air hence the pressure cannot be maintained.
But my MBC is turned up higher, and even up to nearly 6000 rpm it doesn't seem to drop below about 14psi although as I say this is below the peak.
The peak incidentally will vary very slightly due to the density of the air I presume, for a given setting, by perhaps +/- 1 psi.

This post is rather hard to decipher I have to say!!!!!
Do you mean it only does this in 1st,2nd,3rd?
I'm pretty sure if you get it up to full boost in 4th and 5th you will notice it in those gears as well.
However given that 4,600 to 5,000rpm in 4th is probably nearing 120mph, then I can see why you haven't experienced this in 4th or 5th :D

Cheers,
Pete

Saying all that, today even at high revs the boost didn't drop below 17psi. Weird? Dunno. Oh well, just thought I'd mention it.

Pete

help
 

volvo printed the psi boost for the 1.9t4 is 10half psi the 2litert4 runs 14 printed by their computors my car holding 14psi more and longer know who is wright about the boost im confused volvo told me and gave a print who wright

As you PM'd me but asked basically the same thing here, I'll answer it here...
I can assure you the phase 1 T4 will generate about 14psi as standard. Mine is phase 1 and mine did have that as stock. With the MBC I have turned it up to 1.3 bar about 18psi. You mention concerns about modifying the output and engine wear, well certainly anything done is at your own risk but plenty of others have done this and chipping the engine will I am sure raise the boost to at least these levels. You have the dump valve so no issues with the air recirc valve struggling to hold the pressure as you have presumably removed it.

Pete

i looked at old forums and they also say the stock psi is between 10 and 11 psi but spikes up to 14 psi and drop back to between 10 and 11 psi and their say it safe to run 14 psi which is 1 bar check out stock t4 boost in forum search so my one seems to be ok

Had to turn mine down a bit as it was spiking up to 1.4 bar not so good, now peaks at 1.25bar I'd say it is holds boost above 1 bar all the time. But am currently having some occasional poor response and surging issues so I might turn it down more, but these are hopefully fuelling problems due to a knackered fuel pump I am getting a new uprated pump soon hopefully sort it out. What I need to do is have someone monitor the air/fuel mixture while I give it some welly, see the mix goes weak when/if it goes wrong. Easier to have someone else do that instead of me trying to watch the computer, the boost gauge, the rev counter AND the road all at the same time :D

Pete

im going to put mine on the rolling road at interpro their good iv used them before it coast £60 for 3 runs checking everything and they tell me how the car going and what best next they give u good print out .to be on safe side turn ur boost to 1bar until u get on the rollers and get them to turn it up from there .they can turn it up safely i am when i got cash

im going to put it on rolling road in the next month il put what they say on here and the bhp and torque