low stock boost?

[Mata]

so today i got to install my autometer boost gauge; the car is pretty much stock (except for a K&N ) from what i`ve been reading the numbers that i get are wrong; i get 15 hg in vacum and 5 psi max boost (sometimes spikes to 7) i already checked for any leaks and everything is correct
any idea on whats happening?

 

[turboholic]

i get 15 hg in vacum and 5 psi max boost (sometimes spikes to 7) i already checked for any leaks and everything is correct
any idea on whats happening?

-What year is your car? do you feel the rush when the turbo kick in? what does the stock gauge read? have you try doing all the free mods in the tuning guide to see if any improvement? how old is the turbo?

 

[Mata]

the car is a 92 gsx; you can actually hear and feel the turbo when it should but still only goes up to 5ps; tue stock boost gauge reads about the same; it tps off in the 7psi mark; and i dont know the age of the turbo, my guess is that its the same turbo the car came with from the factory, but could nt tell you for sure

 

[laserspeeddemon]

I'm having the same problem, I think I might be leaking air somewhere, I will swapping out the turbo for a bigger 16G, soon. I'll let you know what happens.

 

[jdmjason]

anything? im having similar problems

 

[sexehtopper]

i feel a huge rush and jolt when turbo kicks in.. like it throws me back like a big jolt. im guessing this is normal

 

[laserspeeddemon]

The 16G is not here yet, I found a leak were I installed the T fitting on the Compressor Signal line. So I replaced it, and I hold 15 psi steadily. My guess is that you guys have a boost leak too. Find it.

sexehtopper, is your jolt kinda like a rush of acceleration or does it seem like you are getting a temporary engine shut off, if its the latter you may be hitting fuel cut!

 

[GSXanimal]

so today i got to install my autometer boost gauge; the car is pretty much stock (except for a K&N ) from what i`ve been reading the numbers that i get are wrong; i get 15 hg in vacum and 5 psi max boost (sometimes spikes to 7) i already checked for any leaks and everything is correct
any idea on whats happening?

a common problem with 1g's-cracked exhaust manifold or wastegate is probably burnt up and leaking if its a old turbo? something to check anyway,good luck

 

[Quasimondo]

a common problem with 1g's-cracked exhaust manifold or wastegate is probably burnt up and leaking if its a old turbo? something to check anyway,good luck

More than likely, your problem is the wastegate. When my 1G had a cracked manifold, it took forever and a day to get it up to 10 psi, but once it was there it held. If you're getting only 5, it looks to be the wastegage.

 

[jdmjason]

im only getting to 8psi

So, how do i test the wastegate?

Is it easily repairable? How much will another one cost?

 

[philipkrotch]

i had the same problem and it was a shitty vacuum line that was dry-rotted, replace all of ur vacuum lines with new ones and see if it helps.

 

[johnk]

I replaced my turbo today if you had an original 14b the thing is probably cracked all over my exhaust mani is also cracked leaked tons of precious exhaust I need to power the turbo. The mani crack is a hairline but I had some bad ones on the exhaust snail shell inside and out just nasty. It was coming on full by about 4-4.5k (should be at 3k) and only hitting 5-7 psi (should be 10 psi) when it did. Something else that happened was my bolts from the exhaust manifold going into the turbo losened up causeing some extra leaking. I get 20 vacuum though so maybe yours does have a boost leak somewhere. But the other stuff I listed could be why your not getting full boost out of the turbo. When your down there check for shaft play too see how messed up your old turbo is so you can laugh harder when you chuck the junk out :laugh:

Oh if your not running premium gas your BCS will open up and then you will lose a lot of boost to try and stop all the knock your making.

 

[JASON ROSARIO]

I would check for cracks in the exhaust side of the turbo. Aged turbos will have cracks everywhere. But if thats fine check the wastegate. I had this happen to me b4. So I took out the wastegate and if your looking at it if the actuator you might notice that its sucked in at the bottom. If yours is like that replace it. I was at 6 psi when my wastegate was junk. Hopefully that helps a bit.

 

[unior]

what I would do is freakin unhook the WG - go out and see how much boost i could possibly make and at what rpm - HOWEVER - i would keep my eyes glued to the boost gauge and back off the throttle at anything over 18-20lbs

just to see how bad of a problem you have

 

[jdmjason]

just unhook the line to the wastegate? And watch the boost?

 

[unior]

you could if you wanted to - but now that i think more about it - you would have to have a horrible problem

you say the car feels strong right?

no stockish dsm would feel that strong at 7psi - and you say you have 15in of vaccum - thats on the low side

check the vacuum line running to your boost gauge - see if it has any rips or tears in it - they usually rip around where i send them through the firewall

maybe you are making the correct level of boost and your gauge dosnt show it

 

[jdmjason]

my vacuum is at 20.

My boost goes to about 8 and sometimes up to 11.

when it get to 8-11 it starts to kind of hesitate.


The turbo has minimal shaft play, but a couple of the fins are bent for some reason.

 

[johnk]

Unless you put a boost controller on it the stock system stops you at 10 psi. Does it spike to 11 and drop back down that would be fine. By fine I mean your not getting boost creep from haveing too large an exhaust. 20 on the vacuum sounds good thats what I have.

 

[jdmjason]

yeah, i have 20 vacuum all day.

Sometimes it goes to 11 and and then sometimes 8. I think it has to do with what gear im in.


I thought stock boost was at 14?


I do have a boost controller. I guess its time to put it in.

 

[justincredible]

let me know how it turns out.

 

[unior]

yeah, i have 20 vacuum all day.

Sometimes it goes to 11 and and then sometimes 8. I think it has to do with what gear im in.


I thought stock boost was at 14?


I do have a boost controller. I guess its time to put it in.

yes its high time you put it in - i just bought a 92 laser awd with 82,000 miles

the first thing i did when i got home was go to my parts laser, pull my spare MBC and slap it on

tune for fuel cut

 

[justincredible]

what do you mean tune for fuel cut?


I did a leak test to 20psi and had no leaks

I installed the boost controller and now i can boost to 15 psi

Only thing is, it won't let me go and lower than that...and i already have the screw out as much as possible.

Would cutting the spring help?

I really want it to stay at 14psi .

 

[unior]

i meant crank the boost till she fuel cuts - then back off a wee bit

 

[johnk]

You shouldn't go higher than 15 PSI on the stock fuel system and rewire your fuel pump before you do so your fuel supply is more consistant.

 

[unior]

i ran around in my friends $450 awd laser with these mods:

hks air filter
hacked stock maf
exhaust cutout
intake restrictor removed
ported 2g ex manifold
MBC - set as high as full cut allowed

my friend and I drove this car for about 8 monthes in that condition - never had a problem
ran sunoco 94 octane fuel - pulled LT1s on the highway - held even with a stock EVO at 19psi

then a balance shaft belt broke....bummer