Porting help please

[Bohrn]

Well, I just got a custom 3" mandrel bent 304HT stainless exaust with a matching cat and Borla muffler. Big difference, nice workmanship, but I have a huge problem with boost creep!

I can only run a vacuum hose from the turbo nipple to the wastegate nipple with no MBC. This equates to 10.5 psi at most for normal use, but when I really get on it, it will creep over 16 in 3rd or 4th gear. If I run my manual boost controller set at 15psi (or even 12), it is great for normal driving, but floored, and at high rpm the boost goes WAY too high, and I have to lift.

Yea it's ok for 5grand and up, at WOT, but any other type of driving, I have less boost than stock, and it is kinda slow.

So I figure I have to port my wastegate. This seems kinda scary to me, so any help, tips, links etc would be greatly appreciated.

Do I need new gaskets? Other stuff??

Oh and I got a new 2G manifold put on at the same time as the exaust, so the studs, nuts etc, are all new.

Please, any experience in this area would be great, as I only have the Haynes manual.

 

[90GSX]

http://www.vfaq.com/mods/porting-turbo.html

http://www.vfaq.com/mods/porting-exhman.html

http://www.vfaq.com/mods/porting-O2.html

 

[Bohrn]

thanx, saw those, good stuff, but I am looking for more on how to and what to take off the car, to make it easier to get at etc.

What parts to replace.

I am only going to port the wastegate and maybe the O2 sensor housing. I have never done this before.

I don't really want to take the whole turbo off, due to the oil and water lines.

 

[90GSX]

You're not going to do any turbine porting on that turbo with it on the car. Follow the manual for turbo removal. It's not that hard.

Definately replace the exhaust manifold to head gasket, DP gasket, and the oil line gaskets. The rest as needed.

 

[Bohrn]

ok, thanx.

The exaust mani and dp have just been off, as on tuesday, the mani was replaced with a new 2g and the whole exaust was done. I was thinking of leaving the exasust mani on the car as I don't have alot of time and only using a dremel tool. Thoughts on this??

 

[CBgst]

Originally posted by Bohrn
ok, thanx.

The exaust mani and dp have just been off, as on tuesday, the mani was replaced with a new 2g and the whole exaust was done. I was thinking of leaving the exasust mani on the car as I don't have alot of time and only using a dremel tool. Thoughts on this??

If you don't have alot of time then I would suggest finding someone with an air grinder and a carbide bit. A dremel works but it takes forever. If you're planning on porting the o2 then it will take along time and alot of dremel bits. I'm just telling you this becuase I have already tried that. A carbide bit with an air grinder is worth its weight in gold when porting.

 

[Bohrn]

I have access to a die grinder and I can buy the bits, but the thing is I have the air tool at work, and cannot get to work without my car.

 

[RippinGSX]

Port the turbine housing also. The turbo seperates and the turbine hosing comes off without removing any lines. Just loosen the band clamp in the middle and pry it apart.

 

[CBgst]

Originally posted by Bohrn
I have access to a die grinder and I can buy the bits, but the thing is I have the air tool at work, and cannot get to work without my car.

Find a ride one day and then do it while your at work

 

[Bohrn]

I can get a ride in, but I have to work while I am at work hehe, I wish I could spend multiple hours on my own projects at work.