External wastegates- I have questions...

[yoeddynz]

Hello,

I have this setup on my elford turbo 12a that's going into my HB viva.

I'm a newbie when it comes to turbos so some questions....

I will have to make a new manifold to move the turbo forwards to clear the brake servo and master. The WG that is fitted could be moved but apart from the fact its quite bulky I dont know that it is a very good design compared to the new type of poppit WG's. Where would be a good place to buy a external WG, what size and can I buy a flange to suit said WG that I can then weld to my new manifold.

What other things do I consider when building the manifold- I have been told to keep the turbo as close as possible to block. Also to site WG as close to centre of manifold- ie just under turbo in centre. The elford as standard runs at 5psi. Are there basic WG's out there that have springs set for that low a pressure? Are there WG's out there that are easily adjustable without a adjustable bleed screw ie maybe some sort of nut adjustment on the diaphragm spring?

Can I get a manifold flange for the turbo - its a garret air research T3. Where?

Edit:...

I found this in a quick search..

http://www.trademe.co.nz/Browse/Listing ... ermanent=0

It seems OK. About as cheap as I expect these things must get? I fully realise that you get what you pay for but I cant imagine one of these working worse than the old cast affair thats bolted to the existing manifold. As long as it opens at 5Psi i'm happy.

Advice please.

cheers

alex

[Testament]

yeah that is a pretty terrible wastegate mounting. if you thing about it the exhaust gasses are flowthing through the turbo and then when you want to vent them they have to go in the other direction to get out of the wastegate - it will work, but it wont be nearly as effective as if the wastegate was mounted at the same end of the manifold next to the turbo entry.

[Walker.NZ]

hey mate my old man has an hb viva that hes pretty set on putting a 12a or 13b in aswell, you should make a build thread when it starts coming together as we wouldnt mind checking it out.

Id say your best bet with the manifold would be to go down to an engineer in your area with a watercutting machine and see if they can make the flanges for you to suit your turbo etc

Ive got a turbosmart wastegate im keen on selling as well, if your interested send me a pm

[yoeddynz]

Yeah i was thinking it looked in a silly place- plus the gas coming from the rear port would come straight out and hit the gas coming from front port- slow it down/disrupt flow/generally make it unhappy.

I sent you a PM walker but I imagine you want a lot more than my budget will allow- this is mega budget viva.

I found these last night..adjustable. Any experiences out there with them?

http://www.trademe.co.nz/Browse/Listing ... =339238996

[drftnmaz]

first off make sure you use thick walled pipe to build manifold 3-5mm thick, and make sure you run a brace going down to the block somewhere

flanges just draw your own and go find a local engineer with a plasma profile cutting machine, offer beer and wait a week or two (i would normally use 12mm thick to stop warping)

wastegates, personally i hate the two-bolt ones, have always given me hassels with blowing gaskets out at the track, not so bad for general road use, can get 4 bolt which are better

but i would only fit a V band now, but there pretty pricy

http://www.trademe.co.nz/Trade-Me-Motor ... 963728.htm

lots of the older factory gates have a nut/bolt on top to adjust the pressure, but you can always trim the spring to lower the pressure as most come with at least 7psi springs

[Raizer]

this is mega budget viva

Hit up Euro wreckers, a lot of turbo Audis have a decent external gate from stock and can often be had for cheap.

[yoeddynz]

Cool- good advice! Except Blenheim doesn't have any Audis- most locals still get around via horse- the poorer people ride goats.

Would shortening the spring inside not make it stiffer and raise the pressure needed to unseat valve though ?

I think for only 5 psi on a weedy little 12a the two bolt jobbies look ok.

I might go borrow a friends gas axe and make my own flanges- just tidy them up with a file eh. I used to spend hours on a profile machine as part of my apprenticeship- if only i had the foresight....

[drftnmaz]

cutting will also change your pre-load, same way the adjustable bolt does on the end, so giving you some adjustment/reduction, but will make spring slightly firmer so if you are running a undersized gate (inside diameter) you could run into issues with it not being able to open all the way???

i've got a old Rajay 2 bolt factory euro one here with adjustable pre-load on top, i've never used it so don't know the boost setting but was off a SABB 900 which i remember mentioned something abut low-flow so should be low boost?

no flanges tho, pm me a offer if you want

[efp0wa]

Cool- good advice! Except Blenheim doesn't have any Audis...

Umm, use a phone

[Yowzer]

Phones and wastegates aren't interchangable.

[efp0wa]

Phones and wastegates aren't interchangable.

Ha fucking ha.

He was told to "Hit up Euro wreckers, a lot of turbo Audis have a decent external gate from stock and can often be had for cheap.", then basically said there arn't any Euro wreckers in Blenheim in regards to noone owning Audis. So possible, use the phone to ring national euro part wreckers and find a Audi external wgate?

[Testament]

you'll probably find if you ask a wrecker they will want moonbeams for one and a new 38mm tial would be cheaper. if you can find an audi at pick a part or something you could get one cheap but otherwise I think the chances are slim of getting a deal.

as to that link in your first post - id stay away from those noname china brand ones and pay the extra for a genuine tial one. otherwise I'd look at getting a different turbo with internal wastegate - may actually be not much different in price.

shouldn't be too hard to get a flange for a T3 try an exhaust shop - or you can order them from online shops like atpturbo.com. slowboyracing.com, nzperformance.co.nz etc. etc. etc.

- or as you say it wouldnt be too hard to make one with a drill, angle grinder and a die grinder or file.

The engine side flange may be a little trickier, but ask some exhaust shops or maybe coby in hamilton? if they make extractors for a 12a they might sell you a flange.

[mjrstar]

a new 38mm tial would be cheaper.

I'd suggest this, or possibly slightly bigger depending on positioning, you don't want to mess about with cheap/dodgy boost control, It will make the poor rotary go boom. A decent W/G is cheap insurance on a turbo build..

It may also be worh looking for a replacement internally gated turbo such as a T28 from sylvia or similar, to save on fab work?

[yoeddynz]

sweet. good advice. I might try to use the existing wg first but its fairly baulky. But its there to try...

[drftnmaz]

hmmmm... i didn't relise you were gonna run suck through carby, idlealy you want the intake track to always be running downhill, it reduces the fuel pooling in the piping/turbo, i've only done a couple of suck-through setup's tho

so i'm guessing that factory manifold puts the turbo right up where the booster is? i'm thinking it would be easier and look/work better if you fitted a reverse mount brake master cyclinder, or remote one?

[yoeddynz]

Yeah- right smack bang in the servo/booster. Its fine on an FB as the struts are further apart and enough room. Even on mry old rx3 it wouldn't fit as the engine bay was that bit narrower. Anyway- Ive started the manifold aand it gonna be sweet. Plus I can use my existing WG which is good as this a teeny tiny budget conversion. I wouldnt want to move the master/servo etc as it works well where it is and the clutch master fitted in nice. I'm happy with progress now- though it took bloody ages today to make two flanges outta 10mm plate!! I have the time though...but no money!

[Colza]

If you want to run any designs past me before you build them I am more than happy to help. The image below summarises the basics of wastegate placement.

Remember you dont need to buy a ginormous wastegate, you just need to put it in the right place. Ginormous wastegates exist to prevent overboosting in poorly designed systems. Also because retards will buy anything big and shiny.

Heh, just spotted you arent going to use an external after all, picture posted anyway for future reference

[yoeddynz]

cheers for that! - i found that picture too- turbosmart?

I've built it all now and well happy with it- the Elford WG is almost bang in the middle just after the primarys meet and just before turbo. i think it should be fine but i have allowed for easy fitting of a 38mm wg if needed in future. I actually trust this oldschool flappy style one more than a cheap tial ripoff. like on internal flappy style WGs there isn't really any thing to seize under heat. i'll see how it goes. will post up a photo or two soon.