Turbo problems rb20de

[cjsewell]

I have just installed a turbo into a GTS and have a few problems I thought you guys could shed some light on. The best way I can describe the problems is when it boosts from about 5psi up it starts to miss, but it only happens in third gear and over, and from about 3000 rpm and up. When the gas is let off the blow off valve does not release the pressure equally, it sort of flutters and the boost gauge jumps up and down rapidly in time with the fluttering. The parts that I got with the turbo are a GTST AAC valve and the o2 sensor. Do I need a GTST afm as well? Any info you guys can provide would be greatly appreciated. Thanks.

[meggala]

I would crank the timing back and get the car on a dyno also your plug gap could be to big try .8 that should help.

meggala

[Squizz]

You don't need a GTSt AFM. Make sure you have the DET injectors and make sure you have spark-plugs to suit a GTSt. Remember you make more boost in thrid gear than you do in 1st or 2nd so you should make sure your timing etc is done to accomodate the extra load in the higher gears.

And if anyone tells you that you can't turbo the NA tell them to bite your ass because I did it over a year ago and that car has since been sold twice and is still a rocket.

[cjsewell]

Cheers for that, what boost were you running the ex NA at?

How do I turn down the boost on mine?

Is this flutter thing a problem I've read a bit about it on these forums but it seems know one knows if it's a harmful thing.

[Squizz]

I ran it at stock boost, but it was closer to 10psi. How long is the vacuum line from the compressor housing to the wastegate actuator?

[cjsewell]

not very long at all as short as it could be why is that, is it safe to be running that high, i think mines at 9psi

[Squizz]

ok, well other than getting a modifed actuator to be able loosen it right off there's not really a lot you can do to lower boost other than some for of restrictor as used in rally etc.

[Squizz]

Running 9~10psi of boost is no problem, I even ran the stock intercooler, it's all in the tuning. I ran the NA computer for a while too as it runs CRAZY rich to keep the engine alive long enough to get it sorted.

Remember there are two ways to turbocharge...

Low compression High Boost

High compression Low Boost

The first is good for top end, the latter for mid range punch, which is why my 32 was so quick on the street.

Tuning, Tuning, Tuning. That's the key.

Little steps at a time.

[cjsewell]

Well got my car back today unchanged, the guy said its nothing to do with the timing but it looks to be an air/fuel problem. He ran out of time to do anything about it today. On Monday he's going to do tests and stuff with his oscilloscope. I just nodded a said OK as if I knew what he was talking about.

[cjsewell]

Well I found out that the turbo may be off a cefiro which is OK and all, but where the hell do I put a BOV on it??