Stock Boost PSI on a 199o Laser.

[Perkul8r]

So i heard somewhere, and please correct me if i am wrong. That stock boost is limited to about 10 psi on my 90 Laser. Which seems about right. The other day i added a Autometer boost/vac gauge to my car. And while i was driving, without really mashing the throttle it would go up to 11psi. Well, today i was messing around and really mashed the throttle on it. Took it close to redline, and as i was watching the gauge, it went up to about 14-15 psi. Is this normal? Or is there something not working right.

The car is stock, minus a Megan 3" downpipe and side exit 3" exhaust.

[93gtpeater]

If it holds at 10ish and starts to creep to 14 15 as you get close to redline. It would be boost creep. Stock dsms tend to boost creep. My 90 talon does it and its bone stock.

[Goat Blower]

Over time the stock wastegate flapper gums up with carbon and you get a little extra boost. The free flowing exhaust probably contributes a bit too.

[Perkul8r]

So its not really something i should worry about? Or do i need to do something to help prevent it? I was thinking about using a mbc to up the boost a little. But if its already creeping up that far i dont want to over do it.

[4g63tcrazy]

It's fine to about 15psi. Any higher then that I would start to worry. I would just run your car as-is.

[Perkul8r]

Cool. That makes me feel better. I just got it running, i don't wanna blow it up yet. lol

[TheBlizzard]

I would at least re-wire your fuel pump, or if you really wanted to get rid of it you could have someone port your wastegate a bit. Basically like Steve said your wastegate cannot bleed off the excess quite good enough because your exhaust is flowing more than stock or because your wastegate flapper might not be opening enough.

I would address it if you have time with some of the ideas mentioned here.

[Perkul8r]

So besides re-wiring the fuel pump. What would i have to do to safely turn boost up just a little.

[TheBlizzard]

Nothing really, you can turn them up to around 15psi safely with a rewire, providing all your other shit is working OK. Obviously there will be deviations from this from other people on the forum, and to be honest each car might be different.

Your best bet is to find someone with a logger and do some very basic tuning.

[Perkul8r]

Finding someone that can do data logging around my town is dam near impossible. Plus i dont think my ECU is setup for it. Seems as how i do want to mod the car, what would i need to set up the ecu for data logging? Thanks.

[TheBlizzard]

You don't need to setup the ECU for data logging, it has a port for that, do some research on DSMtuners or even on here for that, this is very basic stuff, just search and you'll find all the basics.

[Perkul8r]

Will do. Thanks again.

[CarPsyco84]

If you plan on running your car in the winter, might want to figure out the boost creep now... cause if its starting to creep now, it will creep alot more in the cold dense air. To the tune of 20+psi. 3" downpipe on a internal gated mitsu is bound to creep, easiest fix is a better O2 housing, that is less restrictive on the wastegated exhaust.

[Perkul8r]

I was looking at going to the O2 housing with the external dump. Not sure if it would be good for a DD but a buddy has one that he isn't using anymore so i can get it cheap

[CarPsyco84]

Those help a bit, but they can get really annoying really fast unless your a hill-billy and like annoying everyone else around you. It just depends on how you drive it, and how much you like loud annoying exhaust...

[Perkul8r]

Well, i already have 3 inch Side exit exhaust. lol. So it probably wouldn't be much more annoying. But I was planning on changing the exhaust sometime before winter.

[TheBlizzard]

If you take the turbo off and port the wastegate a bit it will get rid of the creep, and external dump is an option, but a last resort in my opinion with your setup.

[Perkul8r]

Hmm, well looks like i got a couple options. I do beleive the external dump would be my last option. BUt it seems like i should upgrade my O2 housing. I mean with the 3 inch exhaust and all. I was looking at doing the FP EVO 3 housing from MAP. I mean they are fairly cheap and if it helps than i will be happy.

[ThEwAy2b]

Them external wastegates don't do anything, I'm running a external dump with the 14b on my 2g. Still internallygated with a 3" dp and 3" exhaust. After 5 grand of rpm it jumps to 20 psi and will keep rising. I had it at 24 psi at 125 in 5th gear, no fuel cut on stock fuel. There a possible chance there can be a vaccume leake from where the boost source goes to the wastegate leake making the wastegate not open all the way? Because the actuater needs pressure to operate.

[Perkul8r]

I would have to check the vacuum lines, I started replacing them all cause they were rotted pretty good