Boosting to 14psi with almost no mods?

[BlckTalon]

So a friend of mine has this beautiful white 99 gsx. He's been wanting to do things the right way the first time so He's only going with the best parts for it. Which in turn, means he can only do a few things at a time. Currently he has a 3" HKS downpipe, and a 3" HKS Carbon Titanium exhaust for it. We installed an autometer boost gauge, air/fuel ratio gauge, and a fuel pressure gauge today and took it for a drive. While under load, the boost plateaus at around 13.5-14 psi. Is this normal with as few of mods he has done to it?

 

[tstkl]

a higher flowing exhaust indirectly increases boost. no worries here

 

[talontsi01]

Yep. All normal here.

 

[GSntncT]

So a friend of mine has this beautiful white 99 gsx. He's been wanting to do things the right way the first time so He's only going with the best parts for it. Which in turn, means he can only do a few things at a time. Currently he has a 3" HKS downpipe, and a 3" HKS Carbon Titanium exhaust for it. We installed an autometer boost gauge, air/fuel ratio gauge, and a fuel pressure gauge today and took it for a drive. While under load, the boost plateaus at around 13.5-14 psi. Is this normal with as few of mods he has done to it?

Yes, especially considering stock psi is 14-15lbs.

 

[BlckTalon]

haha yeah thats what i thought, but he swore to me that stock psi was around 8 to 10 psi. I'll let him know.

 

[AL92]

Umm don't think stock boost is no 14 to 15. Think more like 10.And big downpipes and catbacks definitely cause boost creep..buddies 91 creeps past 17 with no boost controller ,other buddy blew up his 92 talon with same exhaust system before he sold it to his buddy.Also no boost controller and he was running regular fuel and no other mods.
I put apexi n1 downpipe and catback on my 92 and it also had big boost creep.I bought support mods so could handle it.So have no idea how so many guys say they get no creep from the big no cat downpipe and catback.
I have seen it first hand in three cars already now. Everyone had bad creep and not a couple pounds.The 2g might creep less with smaller turbo.
The one guy was running regular fuel and it creeped bad enough to blow his engine..I saw the destruction.
And boost controllers normally don't stop creep. Porting the wastegate hole can I hear and there is some kit out there but not sure if that works.A cat in the downpipe is likely enough to stop the creep.

 

[No_Skillz]

Stock boost is 10-12, every car is different. The stock bov also cannot hold more than this. Your friend may be reading 14-15 psi because autometer guages aren't the most accurate. For the money spent, your friend should have gotten a cheap high flowing exhaust but invested more on guages.

 

[huafist]

Stock boost is 10-12, every car is different. The stock bov also cannot hold more than this. Your friend may be reading 14-15 psi because autometer guages aren't the most accurate. For the money spent, your friend should have gotten a cheap high flowing exhaust but invested more on guages.

Where do you get autometer gauges aren't very accurate? Do you have factual data to back this up or is it a personal opinion? Tons of car enthusiasts use autometer gauges and never have a problem. Sure, they're not blingy like some of the high dollar gauges, but they're not inaccurate either.

 

[Ultimatedsm]

Stock boost pressure is 12 psi. The stock 2G BOV can see up to 13.5-14 psi max before it starts to leak. Intake gives you about 1 psi and so does an exhaust system because of less restrictions your engine can finally breathe. I bet if you put on a 1G BOV your boost would actually spike a little higher then 14 psi maybe 16 psi then it would settle down. I have had my autometer for years now without any problems, its very accurate in my opinion. When I read 15 psi, I also read that in my dsmlink logs, so I think thats pretty accurate to me. I think your friend should find himself a 14B because your almost running the limits of the T-25 .

 

[tstkl]

the limits of the t-25 were reached jan 1st, 1995 (or whatever the first day one was sold on a car was)

 

[Ryan95tsiAWD]

Out of boredom I hooked up 2 autometer boost gauges to the same place(manifold not that it matters) and they actually read different. I then reversed the lines JUST to make sure one wasnt getting a better reading, but got the same results. I have also notice with about 60% of autometer gauges that after a year or so they no longer rest on "0" anymore (if you are not tapping at a vaccum point you probably would never notice this).

I still use them because when I tune our cars I set boost at an approx level then work on getting a good timing advance with no knock. I do NOT however thing that they are as accurate as their compeditors, but they get the job done for their price.

And to the original poster... Make sure your buddy gets a wide band o2 to tune with instead of using the pretty lights of the a/f gauge he has now.