how to stop psi dropping so quickly?

[tekkie]

I was wondering if anyone else noticed this problem, I am sure you did

I just installed my Joe P MBC and my Blitz DTT, I configured the MBC to stop at 9.5 psi by using my autometer boost gauge. After when I installed my DTT it stops a 65kpa which is pefect (9.5psi) but I noticed it only stays there for a split second and then it drops down in the low 5xkpa area, (7psi ish) is there any way to keep the boost level up higher for a longer time? or is the only way to fix this by replacing the fuel management system? such a waste of power,

also found a good online calculator http://www.chaseuk.com/conversions.htm

 

[EVILSRT]

I found the same problem......what causes it??

 

[SpcyOrangeMSP03]

how long does the boost stay at 9.5 psi for, like what rpm range. Also the t25 is a pretty small turbo it just might not be able to generate that kind of boost at the higher rpm range. Just a guess. any more info? fix?

 

[tekkie]

it only stays above 9 psi usually less than 1 second, I think I managed to get about 3 out of it once but normally its less than 1 second, off hand I am not sure what the RPM's are at exactly

here is an example I am driving on a highway doing 100kmh, stomp on it and it will go to 9 for less than 1 second and then will fall back in the 7's, this is in 4th or 5th gear

also if I start off hard, switch through the gears it will still only stay in the 9 area very shortly, but it will pull in the 7's for a while

I dunno does not make alot of sense to me, before I installed my MBC I noticed it was doing the same thing, it would spike up to 7 but normally was only running in the 5 area

(rolling)

 

[Dexter]

okay i think ive noticed the same thing on my car stock but NOT SURE so dont quote me, but sometimes i look at my boost gauge and the boost will drop like right before i shift to 5psi or so. im not really sure though....sorry

 

[Turbo Matty P]

shoot, if it's going to drop that much I'm going to set my MBC to 12psi so it crusies at 10psi where I want it. Also just a side note about our turbos, we have AMAZING turbos. These things are high dollar and not cheap pieces to cut costs. This turbo doesn't even make power until around 16psi it also will flow very freely until about 19psi where it starts huffing. So asking the turbo for 10psi is not a chore it's an understatement. I think the boost creep may be a problem with either the ECU/fuel or the BOV leaking. Just my $.02

 

[JMS'sMSP]

I havent been worried about weather the turbo can handle more boost. But can the rest of our engine handle it?

 

[Turbo Matty P]

I'd be worried about the rods in our cars. I think that's really the only part overlooked when they built em. Stock rods on a boosted motor?? Who does that??

 

[LinuxRacr]

Guys,

Here is the best conversion utility I've seen (and its free!!!): http://www.esbconsult.com/esbcalc/esbunitconv.html

 

[perfworks]

I havent been worried about weather the turbo can handle more boost. But can the rest of our engine handle it?

Its your ignition timing i would worry about at higher boost levels. The pcm wasnt programmed to "see" more than 7psi.

 

[perfworks]

I was wondering if anyone else noticed this problem, I am sure you did

I just installed my Joe P MBC and my Blitz DTT, I configured the MBC to stop at 9.5 psi by using my autometer boost gauge. After when I installed my DTT it stops a 65kpa which is pefect (9.5psi) but I noticed it only stays there for a split second and then it drops down in the low 5xkpa area, (7psi ish) is there any way to keep the boost level up higher for a longer time? or is the only way to fix this by replacing the fuel management system? such a waste of power,

also found a good online calculator http://www.chaseuk.com/conversions.htm

hey tekkie ,
where is the signal coming from for the boost gauge?
where is the MBC tapped in?
do you notice any power decrease or just visual boost decreasethru the gauge?

 

[tekkie]

the gauge and MBC are installed properly I used the insturctions that other members posted in here

let me quantify the power, when you floor it you can really feel it pulling when its at 9psi, when it goes back to 7 its still pulling good but obviously not as good as when its at 9. the car is still running quite well but it would be nice to be able to keep it pulling at 9 for a longer time

 

[perfworks]

i need to ask one more thing being that i dont own a MSP sorry.
the wastegate vacuum line is mounted where?

 

[MSP Chris]

I believe the vacumm line goes from the wastegate actuator to the T where it tee's off to the DV and I guess back to the motor ( intake manifold )

 

[tekkie]

checkout this link, it shows how the MBC is setup

http://www.msprotege.com/vbb225/showthread.php?s=&threadid=17866&highlight=mbc+install

 

[tekkie]

and this one for the gauges http://church56.tripod.com/blitz.html

 

[perfworks]

no ididnt clarify myself. sorry
i would like to know on the stock set up. where is the reference line coming from for the wategate. is it also going to any type of solenoid? wires? anything?
again thanks for your patience but i dont have one to look at for myself right now

 

[perfworks]

also im curious if the pressure drop is two psi proportionatly thruout or have you only tried it at 9psi and seen it drop to 7
has anyone done what the other member stated and turned up the MBC to around 10-11 and see if it again only drops by two or does it go to seven again.