My draw through turbo

[Chip Birks]

Maybe ok in the 'Desert'? but we live where it's just too Humid

I live in a desert, still had big problems.

Will you still destroy you exhaust with wrap if its stainless?

I don't think so. The only issue i could see might be fatigue from heat. Wally might have some insight, i know he used stainless with his turbo headers, not sure if he wrapped them though.

[Piledriver]

You simply add 2 or more sheet metal straps between the tubes under the hose clamps.
(may be folded back over past the clamps or even screwed or welded)
Can be done with welded on tabs and bolts as well, you are simply adding additional lengthwise support to keep the tubes together under pressure. Works on intake and pre-turbo exhaust.
A pair of bolted together flanges is just an advanced form

[advinnie]

Hi all I'm back with another question for you turbo gods
Right I've been playing around with different strength actuator springs and have found one that starts to open the wastegate at 7psi but once I get to 7psi I start to get boost flutter (if that's what its called ) where when I get to 7psi the boost pressure start bouncing up and down. The pressure is rock solid and constant at any figure under the 7psi mark but hit 7psi and my gauge starts fluctuation form 4 to 8 psi and causes the car to jump around. Any ideas
Hope this makes sense?

[advinnie]

Last question I promise
On a draw though set up is it still ok to connect the stock crankcase breather to the carb?

[madmike]

Don't know what's up with your wastegate,,,
but if u have any oil blow by it may cause some detonation, ,which you don't want,,

[oprn]

I will start by saying that my turbo experience did not include a waste gate so what I say here is based on my experience in the industrial process control industry. It may or may not apply but I believe it may.

First off the 8 to 4 to 8 to 4psi cycle will be dictated by that spring you are using. It takes 8psi to open the waste gate and it has to drop to 4psi to fully reset it. Does the waste gate have a spring tension adjustment bolt on the top? If it does you may be able to play with other springs and get that open/closed band tightened up. I am speculating a lighter spring with more tension would do that.

Now the real problem that I think is causing the surge is that the waste gate port size it too large and as soon as it opened a bit the pressure drops right off and it closes again. If the port was sized smaller then it would have to open further and would have a better chance to control the pressure.

The other thought which is related to port size is, where is this waste gate dumping to? Is it straight to atmosphere or into the exhaust system ahead of the muffler? If there is some back pressure against the discharge of the waste gate that should slow down the gasses some and help the waste gate get better control.

Also precise pressure control can be harder to achieve at lower pressures but I respect your decision to go with a low boost mild set up for the simplicity and durability it provides!

Hope this helps.

P.S. maybe check first that the waste gate valve stem is free and not sticking from burnt on carbon deposits! That should have been at the top of this post, sorry! This may fix everything!

[advinnie]

I will start by saying that my turbo experience did not include a waste gate so what I say here is based on my experience in the industrial process control industry. It may or may not apply but I believe it may.

First off the 8 to 4 to 8 to 4psi cycle will be dictated by that spring you are using. It takes 8psi to open the waste gate and it has to drop to 4psi to fully reset it. Does the waste gate have a spring tension adjustment bolt on the top? If it does you may be able to play with other springs and get that open/closed band tightened up. I am speculating a lighter spring with more tension would do that.

Now the real problem that I think is causing the surge is that the waste gate port size it too large and as soon as it opened a bit the pressure drops right off and it closes again. If the port was sized smaller then it would have to open further and would have a better chance to control the pressure.

The other thought which is related to port size is, where is this waste gate dumping to? Is it straight to atmosphere or into the exhaust system ahead of the muffler? If there is some back pressure against the discharge of the waste gate that should slow down the gasses some and help the waste gate get better control.

Also precise pressure control can be harder to achieve at lower pressures but I respect your decision to go with a low boost mild set up for the simplicity and durability it provides!

Hope this helps.

P.S. maybe check first that the waste gate valve stem is free and not sticking from burnt on carbon deposits! That should have been at the top of this post, sorry! This may fix everything!

Nice one mate I actually enjoyed reading that
Well two things I've found are
1:- there is definitely a build up of carbon deposits on the wastegate and the waste gate was getting stiff to move so cleaned it up so it's nice and free and it's helped a little.
2:- last night I had preloaded the wastegate actuator the way they said to witch is by making the rod 2mm to short so when connected up it loads up the spring but that was causing boost bounce like I said BUT today I made the rod 5mm to short witch has increased the pressure that the wastegate opens to 9psi and now what I'm getting is a nice fast build up of boost to 9/10 psi then it dropped down to a lovely constant 8 psi. Job done

[advinnie]

Any of you lot got a timing map so I can compare it to mine to make sure I'm in the right ball park please

[Clonebug]

Timing is engine specific so my or others timing won't work for you.

You need to listen for detonation and set it up on the conservative side until you know what the engine wants.

You are also draw through which is a completely different animal than us blow through folks.

[oprn]

There you go! You were operating on the bottom end of the range for that spring. Preload it more and up your target pressure and it settles down. You would need to go to a smaller wire diameter on the spring to get smooth control at the lower pressure. Makes sense. You should be there when that happens in a natural gas process. You can get 6" pipes doing a dance in the pipe rack that will send everyone scrambling for cover!

[advinnie]

Well over the last few days I decided to change the oil feed line to the turbo. The old line had a 8mm ID and the connector on the turbo had a 5mm ID hole to a 5mm ID hose and a connector on the turbo witch only has a 2.75mm ID hole and the difference is amazing. I've gained 3 psi more engine oil pressure at idle when at operational temperature (12psi @ 900rpm) and the turbo sounds so much better and seems to spin up earlier and faster, you can even hear it when in neutral and rev th engine up.
Hopefully within the next week I will have started the data logging and will post up an ignition map

[advinnie]

Here’s my ignition map any thoughts or can anyone see any issues?

[advinnie]

Hi all slowly getting all the parts together to start the rebuild but I have a few questions I hope you lot can answer.
1- on my carb manifold (I don’t have a photo of it at the moment) there is a bolt filling a hole does anyone now what it is for?
2- water/ meth injection is it worth all the hassle?

[advinnie]

Here’s a photo of the plug in the manifold

[buguy]

I thought I read that hole was for a pre-heat. I've never had one so this is just what I thought I read somewhere.