I was porting the wastegate on my stock turbo the other day... It is a little past the puck... did I port it too much?

 

No.
You can actually port LARGER than the flapper door.
The rule of thumb is the flapper door has to cover at least 75% of the hole.


-Ted

 

what effects does overporting have? would it hurt spool up time?

 

?????????

That's really foreign to me. I've never heard that, but I'm gonna believe you on it anyways. Could you explain why that is though? Wouldn't leaving an air gap around the puck allow air to flow out and raise the turbo lag and/or lower boost too much?

 

the lag might go up a tad. but that's better then creeping...

now that you have gone past. make sure it is a decent amount past, so the puck can't get stuck in the hole, and seal shut.

or you can get bigger pucks. I think somebody on here was using honda intake valves or something??

 

if anyone.. you'll run 2 or 3 pounds of boost at idle lol thanx ported wastegate

 

The Zenki wastegate system is pathetic.&nbsp If you stare at it long enough, the bypassed exhaust gases has to take a 90-degree bend and then ANOTHER 90-degree bend to exit with the rest of the exhaust.

Overporting the wastegate hole will slow spool-up just a tad (i.e. increase turbo lag), but if you're worried about boost creep, you've got a pretty big exhaust!&nbsp If you've got a full exhaust, you've already got a pretty fast FC...

The 75% rule comes from Corky Bell's "Maximum Boost" book...



-Ted

 

I replaced the door on my WG with an exhaust valve from a B18. I actually got **** for this last time I mentioned it.

 

Excelent reference! That book should be pretty much the bible to anyone with a turbo car or whoever wants to learn about turbos. haha, i sound like an ad for the book. oh well.

Jerry

 

Ads don't normally misspell "excellent"

 

ive heard of people welding a bigger door onto the flapper.

 

great for anyone who doesn't have a rotary any doesn't run water injection. otherwise GREAT ........

 

Wow a b18 valve. I was thinging about porting to make an oval shape on my kokui, if thats spelled right. Hmmm maybe Ill look into the valve thing might be kinda fun to do.

 

boostmotor sport ported his wastegate and used an exhaust valve off an honda h22a, last i knew it worked great

 

he just said B18

 

I have a welder... how much work is it to weld on a new door...

I will be running TID mod, cone filter, rb full turbo back, plus whatever I need in fuel enhancements to compensate. I do believe I will be creeping...

 

okay creep is when you barley press on the gass, and boost goes up crazy like right....if so that happens to me usally soon after I start my car and get the mixture stioch, theres a hill near my house that helps, I was less than half thottle going up the hill and heard my turbo spoll, then kept spolling I looked a the boost gauge it said 6psi I imediatly let off the gas.......I may look into doing this mod when I get some free time on my hand, what's a good tool to port the mani with....carbide Dremmel work?, hrmm I wonder if I could use a vavle from a VW, my dad has like 3 in the garage, I think they where the air cooled ones...................

 

It was easy to weld on the new door. I just grinded off the old one, ported the hole. Reshaped the exhaust valve and cut all but .5" of the stem off it, then my welder welded it on the "arm" for me. It took him about 30 minutes to weld it. The WG went from small enough so I could barely fit my pinky in it to now I can wiggle my thumb in it! If you are looking at the inside of the turbine housing with the back plate removed you can see that the vertical wall is the limit to the size you can port it to. I ported mine til about 1 millimeter from it. Honestly I cant remember which Honda motor the valve came from, but I dont think it matters, cuz I had to grind it a lil smaller and taper the .5" left of stem with an angle grinder anyway. My rotary has a tapered valve stem!
Die grider bits(the expensive ones) are the best to port with. I used one on a regular drill and it worked great.
With full 3" exhaust, ported TB, tid mod, and intake I experience rock solid boost. It will even stay at 5.5(ser.4)lbs if I ask it to. Who says you need a ser% turbo to rid yourself of Boost creep! Just need an open mind(and empty pockets!)

 

that should say ser 5 turbo not ser%.

 

if i were to do that, do i just take the whole turbo (or just the turbine side) to a welder? id like to port the wastegate enough to eliminate as much creep as possible.

 

Do'h

 

I like Grr. Hes cool.

 

lol, yes, yes he is

 

Good topic. Im in the process of porting my WG on a s5 turbo. My question is ive already gone almost to the full size of the flapper door and im wondering if i should go all the way. Theres probably like 1mm or less left. Im just worried about overporting also, on a s5 turbo that is. Keep in mind there are 2 wg holes on these.

 

Ok, I give up. All you turbo guys talking about this stuff is making me sick.

I am going to install a turbo on my NA.