Full Blown Turbo Kit Owners Topic

[toekneehair]

Originally Posted by Dipstik-sportech

I think unless you specifically tell LJ to put a higher psi spring in the wastegate it comes with the lowest one in it as a default.

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makes me wonder what the mechanic was thinking then.. I am glad I checked.

[Deadspool]

The BOV spring should be set to the amount of vacuum your engine has at idle. The 12psi spring will do 22-24, the 11psi spring is 20-22.

[King Tut]

The 12 psi BOV spring is the correct spring for this car. Anything less than that and the BOV can open up in high vacuum situations like letting off the throttle when coasting. If the BOV opens up it messes with the MAF sensor and can cause stalling and weird running issues with the car.

[Dipstik-sportech]

Actually I think because the bov is before the maf it won't make any difference in the way the car runs because the maf is still seeing the incoming air, its just not filtered. I was doing some spring testing on my car and put a 9psi spring in it and it was open at idle but the car ran and drove fine. I ended up with a 10psi spring in mine I'm guessing due to the lower compression.

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[Deadspool]

Originally Posted by King Tut

The 12 psi BOV spring is the correct spring for this car. Anything less than that and the BOV can open up in high vacuum situations like letting off the throttle when coasting. If the BOV opens up it messes with the MAF sensor and can cause stalling and weird running issues with the car.

Its not the correct spring rate for my car. The bov should not flutter off decel, the whole purpose for the bov is to release pressure from the charge pipe as quickly as possible so the back pressure from closing the throttle plate does not effect the turbo.

When it flutters, pressure that should have been released in a smooth timely manor is creating a pulse in the charge pipe that will effect the turbo over time.

I absolutely see what you mean by it opening under high vacuum decel, but how would it be any different from when the car was stock, not too far from the MAF was an air filter, open to atmosphere. The opening is pre maf, there shouldn't be any issues.

But then again, you did infact have problems, I remember reading your posts on it. Im just not sure why. A MAF reads the air passing by it, the BOV is not on the metered side of the MAF.

[King Tut]

Originally Posted by Deadspool

Its not the correct spring rate for my car. The bov should not flutter off decel, the whole purpose for the bov is to release pressure from the charge pipe as quickly as possible so the back pressure from closing the throttle plate does not effect the turbo.

When it flutters, pressure that should have been released in a smooth timely manor is creating a pulse in the charge pipe that will effect the turbo over time.

I absolutely see what you mean by it opening under high vacuum decel, but how would it be any different from when the car was stock, not too far from the MAF was an air filter, open to atmosphere. The opening is pre maf, there shouldn't be any issues.

But then again, you did infact have problems, I remember reading your posts on it. Im just not sure why. A MAF reads the air passing by it, the BOV is not on the metered side of the MAF.

Unless you have a vacuum leak then your car should be able to hit 22-24 in high vacuum situations like when engine braking. At normal idle an 11 psi spring should work. A MAF does read smooth flowing air as it passes. The reason that the BOV opening up messes with the car is because of the turbulent nature of the air crossing the MAF as the BOV opens and closes. The sudden changes cause the idle to fluctuate as the BOV opens and closes at idle. You are correct that this is similar to the OEM setup and you will find tons of owners of Injen intakes that thought they could just throw an intake on with no issues. You will find them experiencing stalling and issues caused by the open filter being so close to the MAF sensor and not being able to have the air smoothed enough prior to flowing past it. You can put whatever spring you want in and if your idle is good and your car doesn't stall then that is great, but I will go with what I have seen and what Tial recommends.

[Deadspool]

Having owned an injen, aside from a few CEL's that went away after two or three cycles, I had no issues.

A vacuum leak is highly unlikely, as there would also be hunting idle plaguing as well.

Im simply saying, the BOV should not flutter, that is a real problem for the turbo. The car obviously shouldn't stall because the BOV spring is too weak. There must be a solution.

[King Tut]

Originally Posted by Deadspool

Having owned an injen, aside from a few CEL's that went away after two or three cycles, I had no issues.

A vacuum leak is highly unlikely, as there would also be hunting idle plaguing as well.

Im simply saying, the BOV should not flutter, that is a real problem for the turbo. The car obviously shouldn't stall because the BOV spring is too weak. There must be a solution.

The solution is to place the BOV further away from the MAF sensor. All I can tell you is that I ran a 6 psi, 10 psi, 11 psi, and 11 psi spring with some washers and the BOV would open enough to mess with the MAF sensor on everything except my final setup of the 11 psi spring with a couple washers. If you are worried about your turbo then give the 6 psi spring a shot and report back with your results. I can tell you my car was undriveable with the 6 psi spring.

[Deadspool]

A better alternative would be speed density.

Im just having a hard time getting past how dipsticks worked, but yours was undriveable?

[King Tut]

Originally Posted by Deadspool

A better alternative would be speed density.

Im just having a hard time getting past how dipsticks worked, but yours was undriveable?

I agree that speed density does have that as an advantage. My kit actually came with a BOV meant for the S2000 turbo kits which are of course speed density. My only guess is differences in the way the vacuum line is routed and how much vacuum the car is pulling. I am utilizing the big vacuum port for the PCV and running that to a vacuum manifold and then an individual vacuum line to the BOV, wastegate, boost solenoid, boost gauge, and my EBC. He also has a built motor so perhaps he is pulling less vacuum at idle from something in the build.

[Dipstik-sportech]

I dunno but I can tell u it was open at idle but drove normally. I know on sr20's that have the bov after the maf if it opened too soon it would stall when u let off

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[Deadspool]

I could not be happier with this kit.


How are you guys holding up?

[mack4477]

Originally Posted by Deadspool

I could not be happier with this kit.


How are you guys holding up?

I put 8k miles on my kit last year. Car has been in the garage since November

Talked to LJ the other day. All set up to take the car back to them in March for my build. Rods, 10:1, radiator, oil cooler, catch can

[Dipstik-sportech]

Still haven't managed to kill anything on my kit. Just ordered my new turbo and I'm gonna pray for 11's

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