Waste gate hole

[turbojoe1]

Bison please comment/confirm. Just to be 100% sure before i open the hole up.
Brand used turbo, lol (Bison hybrid) rebuild.

CEA 5557e with a Garrett .63 AR.
I recently deleted my pm's. I think i recall .950" port?

Thanks Joe

 

[1KWIKSIX]

Hey Joe,

Hope you don't mind me chiming in, but thought I'd share my experience with you. I was having some major over boost / spike issues when I installed my new DBB 5857SP turbo last season.

My stock wastegate hole on the precision .63A/R housing was .90".

I opened up my wastegate hole to around 1.10 to 1.15", cant' recall exactly which (you don't want to open it up too much or you could have problems building boost). You want to ensure that you leave sufficient sealing area on the exh. hsg.....aim for .125" at least.
If you're running a down pipe with an internal waste gate puck, be sure to install the DP on the turbo & mark the imprint of the puck placement before porting. This way you'll be able to see the pucks footprint & know exactly where to port it by following the marking lines. My THDP has a 1.5" Puck.
Like most your will likely be off centre too. I had mine ported on a milling machine to get it centred & right on. Be sure to blend / radius the inside edges of the enlarged hole as well.
This modification got the job done to keep my overboost / spike under control on my DBB turbo.

dave

 

[turbojoe1]

Thanks for the response Dave.

I forgot to mention i running a 3" down pipe with a 46 mm external gate.

I just measured the hole at .835ish.

The porting will be done on a Bridgeport.

Thanks Joe

 

[haywire4130]

With an external gate you dont have to worry about having a small enough hole to allow a puck to seal against. You can hypothetically match it right up to the hole in your downpipe. Only downside is if you plan on selling your turbo in the future it may reduce its value since the next guy might be running an internal gate downpipe.

 

[turbojoe1]

With an external gate you dont have to worry about having a small enough hole to allow a puck to seal against. You can hypothetically match it right up to the hole in your downpipe. Only downside is if you plan on selling your turbo in the future it may reduce its value since the next guy might be running an internal gate downpipe.

Right you are, tho i don't really think about reselling it. Just putting my learning cap on here.

I want the most i can efficiently get out of this this little turbo without high boost spikes. I'm looking at higher boost levels in my application for my desired ET. 11.0's or better

Thanks Joe

 

[TT/Ameasap]

I port mine to .110 and get great boost control down low for initial tuning. If you plan on running big boost.. Like 30+, talk to Bison first.

 

[turbojoe1]

I port mine to .110 and get great boost control down low for initial tuning. If you plan on running big boost.. Like 30+, talk to Bison first.

You mean 1.10? Big boost numbers is the only way im gonna get there with this build.

Thanks Joe

 

[turbojoe1]

I was hoping Bison would chime in by now

Thanks Joe

 

[TT/Ameasap]

I was hoping Bison would chime in by now

Thanks Joe

1.100 yes... Freakin IPad!! Lol

 

[turbojoe1]

Yea i hear ya. That and auto correct is illiterate

Thanks Joe

 

[bison]

You need to open it till it controls the boost down to where you want it and no more is necessary. You should be able to get control with the hole around 1-1.1". If you want to run it hard and get it for all its worth id leave the hole around .950" You can carbide burr the hole without removing the turbo from the car if need be. The shavings wont hurt anything and will blow out the exhaust as soon as you start it. Try running it with the gate disconnected and see what the boost is at the highest rpm you will ever reach.

 

[turbojoe1]

Ok .950 i thought thats what you said. And ya i want everything i can get out of it. I already disassembled it and have it ready to throw on the drill press. I think i saw a couple bits that are close, something like a .944, .953, and a little bigger .960 i think. It looks like conturing the housing after wards is gonna be needed. I measured the hole the .835

Very nice by the way, i must say to the builder him self. Appreciate it Brian

Thanks Joe

 

[bison]

Ok .950 i thought thats what you said. And ya i want everything i can get out of it. I already disassembled it and have it ready to throw on the drill press. I think i saw a couple bits that are close, something like a .944, .953, and a little bigger .960 i think. It looks like conturing the housing after wards is gonna be needed. I measured the hole the .835

Very nice by the way, i must say to the builder him self. Appreciate it Brian

Thanks Joe

Np. If its creeping with the .950 hole then you can easily open it a little more. In the past ive had to go to 1.25" on an unopened engine with a 6262 just to get the boost into the 26-27 range. Even at that boost the turbo was only using about 60-65% of its mass flow potential on the stock engine and is too much for a stock engine most of the time.

 

[turbojoe1]

Well i got the 208 bump stick and port matched the intake to help. After i get my heads checked out, i do a little clean up, bowl work on the intake sides. Then fix the short side on the exh with a liittle blending as well

Thanks Joe