does anyone know how much power you can squeeze out of an 18g turbo. i think the max boost you can get out of it stock is 10psi. is that true? this is for a jdm gsr motor. thank....

 

The most boost you can run on the stock MAP is ~10.5 psi, but with an aftermarket MAP, you can run more. With that turbo i would suggest getting a 3bar MAP and running 1.3-1.5bar. That'll give you great low end and enough air flow up top to continue making power through redline.

 

how much boost could i run on a stock jdm gsr motor? i dont want to blow it. i was going to get tuned for 10psi....

 

PSI doesn't dictate anything, its the power created that kills the engine. If you stay around the 300whp range, you'll be fine. I've made 315whp on 91 octane safely for a year and it was fine. Most people base goals on PSI alone when in fact you should be looking at the power created.

 

are you sure.........so i can run 18psi on a small turbo but only make 290 then i should be fine.......iam talking about on a stock b18c1...............wont it brust inside that cylinder.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by avotegra &raquo;</TD></TR><TR><TD CLASS="quote">are you sure.........so i can run 18psi on a small turbo but only make 290 then i should be fine.......iam talking about on a stock b18c1...............wont it brust inside that cylinder.....</TD></TR></TABLE>

Again, pressure doesn't mean anything. The gross air flow is what determines the power output and torque is what actually breaks parts. As long as you can keep detonation at bay (by use of a sufficient octane fuel with an efficient setup (low IATs)) then you should have no problems.

If you dont understand the concept of pressure and how it really works, you should do a little research into fluid dynamics. Most people here dont realize that pressure (PSI) is merely a measurement of restriction much like Ohms in an electrical circuit. Basically the turbo moves X amount of air and the engine has to move that (after heating and expanding it) back out through the turbine. If you have a larger turbine side, it takes longer to build pressure in the system because air flows through the turbine at such a rate that there is no backup (pressure). That's a simple run-down of how it works, but i still suggest reading up on it on your own. You can learn a lot through simple physics that will clarify how many things on cars work...

 

i'm trying to make between 250-300whp on 10psi. my last pull i made 257whp and 174tq but i wasnt able to hit the redline because it would cut out when it hit 10psi.

 

If you're trying to make nearly 300whp, you're going to have to run a larger turbo because it simply doesn't flow enough air at those pressure ratios to make that kind of power. With the addition of a new MAP sensor and a little more boost, you should be able to hit that no problem.

 

what you can also do is change the wastegate actuator to 14 or 18 psi.......then you might see 300whp........thats what iam doing............

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">If you're trying to make nearly 300whp, you're going to have to run a larger turbo because it simply doesn't flow enough air at those pressure ratios to make that kind of power. With the addition of a new MAP sensor and a little more boost, you should be able to hit that no problem. </TD></TR></TABLE> do you think it would be worth the money to get a gt30 if i'm only going to boost 8-10psi? if so will my stock jdm bottom hold up?

 

anymore info......

 

i just pushed 350 hp and 255 tq on a stock b16 with my 18g, but i went external wastegate with it and it makes all the diffence in the world

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90 JDM EF8 &raquo;</TD></TR><TR><TD CLASS="quote">i just pushed 350 hp and 255 tq on a stock b16 with my 18g, but i went external wastegate with it and it makes all the diffence in the world</TD></TR></TABLE>yeah i am starting to think that the little internal wastegate on the 18g just isnt going to cut it when i get up in the 7000+ rpm's. i guess i'm gonna have to get a gt30 internal wastegate. hopefully that will be able to cut it...

 

i just got street tuned on 10 psi with a greddy kit, stock elbow, 2.5 inch downpipe and 3" exhaust. the car moves very well. i'm using the stock wastegate and a manual boost controller. holds perfectly solid.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by I Have an STD &raquo;</TD></TR><TR><TD CLASS="quote">i just got street tuned on 10 psi with a greddy kit, stock elbow, 2.5 inch downpipe and 3" exhaust. the car moves very well. i'm using the stock wastegate and a manual boost controller. holds perfectly solid.</TD></TR></TABLE> maybe my wastgate isn't working properly. I don't know what's going on. I've been told that the 18g wastegate is just too small to get rid of all the extra exhuast gases when you get into high rpm's with a 3" dp and full exhaust/no cat. maybe I should just fork out for better turbo.

 

are you running the atp 3" v-band adapter for the 3" dp???if you are then your wastegate isnt opening enough

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90 JDM EF8 &raquo;</TD></TR><TR><TD CLASS="quote">are you running the atp 3" v-band adapter for the 3" dp???if you are then your wastegate isnt opening enough </TD></TR></TABLE> i have a custom made dp. i just ordered a turbo flange for a gt28 since its the same, then i had my tuner make me a dp. i checked for clearence already. i disconnected the actuator and the flapper isnt hitting anything but there is a bit of the flange that is sticking down in front of the wastegate that could be slowing down the exhaust gases a bit before they exit. could that little bit actually make a big diff? also, when the wastegate actuator is hooked up it doesnt open very much even if i try to move it by hand. its pretty hard to move.

 

any thoughts???????

 

you should take that flange and put your gasket up to it and trace the gasket on the flange and port it exactly to that...there is enough metal cause i did it even though i went external wg because it does open the exhaust flow even more...maybe your spring is messed up???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90 JDM EF8 &raquo;</TD></TR><TR><TD CLASS="quote"> maybe your spring is messed up???</TD></TR></TABLE> is there a way i can check to see if the spring is bad?

 

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