Jump to content
SAU Community

Help: External Wastegate On Stock Manifold?

217/r33

By 217/r33,
in Engines & Forced Induction

 Share

Recommended Posts

217/r33 Community Regular

217/r33

Posted
Posted

ok i've been looking around for aftermarket manifolds for the rb25 with no luck.

im looking for something that will fit the turbo in the original "side mount" position that could allow me to run an external gate. so i thought why not drill a hole in a stock one? but i've been told that the welds might crack? my budget is not so big and a custom manifold is not an option at this stage.

has anyone done this? i would like to hear from people who have tried it, any other suggestions are welcome.

:banana:

axe s Experienced

axe s

Posted
Posted
ok i've been looking around for aftermarket manifolds for the rb25 with no luck.

im looking for something that will fit the turbo in the original "side mount" position that could allow me to run an external gate. so i thought why not drill a hole in a stock one? but i've been told that the welds might crack? my budget is not so big and a custom manifold is not an option at this stage.

has anyone done this? i would like to hear from people who have tried it, any other suggestions are welcome.

:P

I've done it before...

I got my brother to do the cutting and welding for me, not that hard just get to 90 degree butweld fittings, cut the hole in the back of the manifold, scallop one 90 degree to fit on the back of the manifold, line up the other fitting and weld... make sure you bold it down when heating the manifold so u don't warp it...

post-27540-1222239654_thumb.jpg

post-27540-1222239685_thumb.jpg

post-27540-1222239727_thumb.jpg

post-27540-1222239759_thumb.jpg

217/r33 Community Regular

217/r33

Posted
  • Author
Posted
I've done it before...

I got my brother to do the cutting and welding for me, not that hard just get to 90 degree butweld fittings, cut the hole in the back of the manifold, scallop one 90 degree to fit on the back of the manifold, line up the other fitting and weld... make sure you bold it down when heating the manifold so u don't warp it...

thats great info mate, thank you. a few questions

1. how did you drill the hole?

2. do you need to heat the manifold red hot before you weld?

:P

rb26s13 Mentor

rb26s13

Posted
Posted
thats great info mate, thank you. a few questions

1. how did you drill the hole?

2. do you need to heat the manifold red hot before you weld?

:P

as for the whole.. pre heat the metal than oxy cut the whole.. than die grind the rest would be the easiest

not red hot.. just cast needs to be pre heated and post heating after welding.. around the 200degreeC mark should do it before welding to avoid cracking.. and it needs to cool down very slowly... so no dipping it in water after its been welded!

axe s Experienced

axe s

Posted
Posted

we tried an oxy first but the cast is sh)t so it was a pain in the a$$ ended up gouging it out...

we didn't preheat or post heat, just mig'ed it up.... only problem was warping which is why i said bolt it down when cutting and welding...

217/r33 Community Regular

217/r33

Posted
  • Author
Posted
as for the whole.. pre heat the metal than oxy cut the whole.. than die grind the rest would be the easiest

not red hot.. just cast needs to be pre heated and post heating after welding.. around the 200degreeC mark should do it before welding to avoid cracking.. and it needs to cool down very slowly... so no dipping it in water after its been welded!

we tried an oxy first but the cast is sh)t so it was a pain in the a$$ ended up gouging it out...

we didn't preheat or post heat, just mig'ed it up.... only problem was warping which is why i said bolt it down when cutting and welding...

ok i dont have an oxy :P how about drilling it? then get an exhaust place to weld a pipe and connect it to the dump pipe, or i can borrow a friends welder.

if not how hard will it be to make the bends in the pipe my self, im good with tools just dont know how i'd bend the pipe into the right shape.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

You cvan go 3 ways.

1. Spacer plate inbetween the manifold flange & turbo flange with a gate hole

2. Off the manifold (as shown already)

3. Off the turbine housing itself

All 3 ways have been done before, and i cant think of any disadvantages to any.

Depends on the setup your working with, size of turbo, size of gate as to what would best suit your needs as everyone is different.

Cheers

217/r33 Community Regular

217/r33

Posted
  • Author
Posted
You cvan go 3 ways.

1. Spacer plate inbetween the manifold flange & turbo flange with a gate hole

2. Off the manifold (as shown already)

3. Off the turbine housing itself

All 3 ways have been done before, and i cant think of any disadvantages to any.

Depends on the setup your working with, size of turbo, size of gate as to what would best suit your needs as everyone is different.

Cheers

thanks nismoid, i'll be definatly doing it from the manifold. do you think i'd be able to drill the manifold instead of having to do it with an oxy?

:P

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Not sure, never been involved with that myself... although there are a few different ideas so far in this thread.

spacer plate would be my choice though (if i could fit it in). Each to thier own

axe s Experienced

axe s

Posted
Posted

Putting a wategate off the exhaust housing can cause turbulence... you could drill it but it would take a long time as u'd have to use a small bit and drill about 30 holes to do the circle, also the manifold is split in the middle so 3 cylinders/runners per side, i'd mark it out and take it to a Fab or engineering shop and get them to oxy or gouge it out, also u'll need them to scallop the wastegate pipe that goes over the back of the manifold as it's not a circle it goes down the back a bit, buy the buttweld fittings from Bunnings should cost less than $15 for both...

217/r33 Community Regular

217/r33

Posted
  • Author
Posted
#3 is so ghetto

sure is, however ive seen it on a r33 years ago and the guy didnt have any issues from memory.

Putting a wategate off the exhaust housing can cause turbulence... you could drill it but it would take a long time as u'd have to use a small bit and drill about 30 holes to do the circle, also the manifold is split in the middle so 3 cylinders/runners per side, i'd mark it out and take it to a Fab or engineering shop and get them to oxy or gouge it out, also u'll need them to scallop the wastegate pipe that goes over the back of the manifold as it's not a circle it goes down the back a bit, buy the buttweld fittings from Bunnings should cost less than $15 for both...

sounds like i'll need to get the pro's on this then? any ideas of costs?

would it be a better idea just to take my manifold, turbo and dump pipe to someone who can do it in one hit? suggestions on places would be great. located in sydney.

:ninja:

axe s Experienced

axe s

Posted
Posted (edited)

Measure it all up then take your manifold wastegate flange and buttweld fittings to somewhere that can do it... wont need your turbo or dump...

after you have it all done take it to an exhaust shop to go from the wastegate to your dump (thats if your not running a screamer pipe... well you'll need them to make that for you anyway.)

an advantage to this way is that the exhaust gas is been flowing into the wastegate without restriction, as it's in the exhaust gas flow.

Edited by axe s
217/r33 Community Regular

217/r33

Posted
  • Author
Posted
Measure it all up then take your manifold wastegate flange and buttweld fittings to somewhere that can do it... wont need your turbo or dump...

after you have it all done take it to an exhaust shop to go from the wastegate to your dump (thats if your not running a screamer pipe... well you'll need them to make that for you anyway.)

an advantage to this way is that the exhaust gas is been flowing into the wastegate without restriction, as it's in the exhaust gas flow.

thanks for all your help mate, i'm now clear on what needs to be done :mellow:

what do you guys thing about ceramic coating the manifold after its all done, does it cost alot?

:rant:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kinkstaah
      Airbox for +T

      By Kinkstaah · Posted

      It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • GTSBoy
      Airbox for +T

      By GTSBoy · Posted

      By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • BuiltNotBought
      Airbox for +T

      By BuiltNotBought · Posted

      There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • BuiltNotBought
      Airbox for +T

      By BuiltNotBought · Posted

      I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • BuiltNotBought
      Airbox for +T

      By BuiltNotBought · Posted

      Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...