External Wastegate
Author
Discussion

mneame

Original Poster:

1,484 posts

228 months

Friday 28th March 2008
quotequote all
Hi,

Does anyone have and diagrams or good pics of external wastegate setups. Thinking of going this route on my impreza and would like to do the work myself.

Thanks,

Matt.

stevieturbo

17,833 posts

264 months

Friday 28th March 2008
quotequote all
mneame said:
Hi,

Does anyone have and diagrams or good pics of external wastegate setups. Thinking of going this route on my impreza and would like to do the work myself.

Thanks,

Matt.
What do you need ? Most boost controllers etc will have diagrams of how to plumb them up....

Although, often they can be plumbed different ways too.

As far as physical fitment goes...you are kind of limited in terms of space as to where you fit them.

Trawling Scoobynet or 22b.com for pics would be a good idea.

If you need a wastegate, Ive a 38mm Tial I bought ages ago sitting here, but never did bother using.


aww999

2,069 posts

278 months

Saturday 29th March 2008
quotequote all
Surely you can only fit one if you have the appropriate exhaust manifold(s) and a suitably large turbo to make it worthwhile going through all the packaging bother? I use an HKS 50mm WG and have found it very reliable, just be careful when you are plumbing it in as its quite easy for pressure lines to melt on all the hot pipes round the wastegate and leave you with no boost control at all!

stevieturbo

17,833 posts

264 months

Saturday 29th March 2008
quotequote all
aww999 said:
Surely you can only fit one if you have the appropriate exhaust manifold(s) and a suitably large turbo to make it worthwhile going through all the packaging bother? I use an HKS 50mm WG and have found it very reliable, just be careful when you are plumbing it in as its quite easy for pressure lines to melt on all the hot pipes round the wastegate and leave you with no boost control at all!
They will work with any turbo ( as long as turbine has no other dumps..that said, Ive seen setups that use both !! lol ), but as you say, its pretty pointless until about 450-500+ on most 2.0 turbo engines, as there are plenty of internally gated units that do the job just fine.

Some people just want them....well, because they do.

50mm would be a huge wastegate on anything less than 650+, and going too big, coule end up with very erratic boost control.

Its no different with internal gates. They need to be sized to match the turbo/power you are using.

mneame

Original Poster:

1,484 posts

228 months

Monday 31st March 2008
quotequote all
i'm looking to make my own setup. my type ra will be coming off the road as of 11.59pm (tax runs out today) and i'm looking to rebuild it.

i was thinking of keeping the 2.0 but am now thinking about going for a 2.5 sti engine and looking at a t70 turbo unit with external wastegate setup.

the car will be rebuilt with hill climbs in mind.

aww999

2,069 posts

278 months

Monday 31st March 2008
quotequote all
Gate sizing: You only need a big gate if you want to run low boost on a big turbo, otherwise you get boost creep at high rpm. If you only want to run high boost, or you have a small turbo, you only need a small gate. Manifold design also plays a big part in how efficiently the gate can divert exhaust flow away from the turbine.
I can set my boost pressure anywhere between 8psi and 28psi and hold it dead flat all the way to the redline, if I had a smaller wastegate, then it would inevitably creep up to 16 psi or so above 5 or 6000rpm.

Big small low and high are all relative terms though! Find someone with a similar setup to you and see what works for them.

stevieturbo

17,833 posts

264 months

Monday 31st March 2008
quotequote all
mneame said:
i'm looking to make my own setup. my type ra will be coming off the road as of 11.59pm (tax runs out today) and i'm looking to rebuild it.

i was thinking of keeping the 2.0 but am now thinking about going for a 2.5 sti engine and looking at a t70 turbo unit with external wastegate setup.

the car will be rebuilt with hill climbs in mind.
T70 would be a very poor choice for a hillclimb car.

Wayyyyyyy too laggy.

mneame

Original Poster:

1,484 posts

228 months

Monday 31st March 2008
quotequote all
even with the anti lag that's going on there?

Marf

22,907 posts

258 months

Monday 31st March 2008
quotequote all
Whats your power target?

As said above you want something with decent spool. i.e. the time from 0 to full boost, all antilag will do is keep the turbo hovering around 0.

A T70 is drag turbo territory, hillclimbing is basically road driving so response is king.

Edited by Marf on Monday 31st March 21:40

stevieturbo

17,833 posts

264 months

Monday 31st March 2008
quotequote all
mneame said:
even with the anti lag that's going on there?
Who mentioned using Anti-lag ?

As Marf says... Hillclimbs are short, tight sections of road/track. The last thing you want is lag.

You would be far better suffering less power, a wide torque band, with great response.


mneame

Original Poster:

1,484 posts

228 months

Tuesday 1st April 2008
quotequote all
power target is as much as i can get really. with my driving skills i need all the help that i can get lol.

Marf

22,907 posts

258 months

Tuesday 1st April 2008
quotequote all
mneame said:
power target is as much as i can get really. with my driving skills i need all the help that i can get lol.
No offence mate but if your driving skills are lacking then a huge amount of power is the last thing you want, especially with a peaky delivery like a t70 would give you.

A GT2871 would support over 350hp and give you decent response, you also wouldnt need an external gate.



stevieturbo

17,833 posts

264 months

Tuesday 1st April 2008
quotequote all
You can get turbos that will be very responsive, and produce 4-450bhp with ease on a suitably built Subaru, on internal wastegate.
Even more so if you use a 2.5

The last thing you want is a large, laggy turbocharger.

Throw a 2.5 together with forged rods/pistons with a MD321T turbo from Mark at Lateral Performance along with supporting mods.
That will see an easy 400+, be reliable, and very fast for a hillclimb situation.

Start dreaming of beyond 450 ( reliably )....and you'll need a very large budget.

Check here for some Maltese Hillclimb footage in a Subaru !

http://bbs.22b.com/cgi-bin/ultimatebb.cgi?ubb=get_...

Edited by stevieturbo on Tuesday 1st April 18:25

mneame

Original Poster:

1,484 posts

228 months

Tuesday 1st April 2008
quotequote all
Marf said:
mneame said:
power target is as much as i can get really. with my driving skills i need all the help that i can get lol.
No offence mate but if your driving skills are lacking then a huge amount of power is the last thing you want, especially with a peaky delivery like a t70 would give you.

A GT2871 would support over 350hp and give you decent response, you also wouldnt need an external gate.
none taken. appreciate the advice. i am planning on plenty of tuition and preactise before my first event.

mneame

Original Poster:

1,484 posts

228 months

Tuesday 1st April 2008
quotequote all
stevieturbo said:
You can get turbos that will be very responsive, and produce 4-450bhp with ease on a suitably built Subaru, on internal wastegate.
Even more so if you use a 2.5

The last thing you want is a large, laggy turbocharger.

Throw a 2.5 together with forged rods/pistons with a MD321T turbo from Mark at Lateral Performance along with supporting mods.
That will see an easy 400+, be reliable, and very fast for a hillclimb situation.

Start dreaming of beyond 450 ( reliably )....and you'll need a very large budget.

Check here for some Maltese Hillclimb footage in a Subaru !

http://bbs.22b.com/cgi-bin/ultimatebb.cgi?ubb=get_...

Edited by stevieturbo on Tuesday 1st April 18:25
400 - 450 would be good. cheers for the info.

great footage. hill clibs are the way to go.