Outer Limits 4x4 Board

Have way too much boost (25psi) on my 4.2l diesel.

Thinking of installing an external gate.

The only place I could possibly mount it would be on the original exhaust manifold. There is a port there (possibly even the perfect size) for the EGR (which is disconnected), it is located between the 5th and 6th cylinder on the manifold. Would it be ok to mount there? engine is 1hz.

you can see the egr pipe in the top left of this photo..

External wastegate is supposed to be mounted about 90 degrees from the main flow of exhaust gasses (thats from Corky Bell's book). If that EGR plug is on the end of the log style factory manifold, then mounting the wastegate there might make it fairly inefficient.

My 2c.

did you check the setting of your wastegate before fitting it and what pressure wastegate did you get

did i check the wastegate.. no I don't really know how. I've been winging the whole installation from bits of info i gathered from all over the place. I'm impressed i have got this far.

coxy321 wrote:External wastegate is supposed to be mounted about 90 degrees from the main flow of exhaust gasses (thats from Corky Bell's book). If that EGR plug is on the end of the log style factory manifold, then mounting the wastegate there might make it fairly inefficient.

My 2c.

actually he says that 90 degrees is bad and that a shallower angle is better. it's on page 145

It would take some impressive EGT's to drive 25psi of boost. Have you considered dropping fuel to limit boost?
What is your current wastegate and why can't it keep up?

devo wrote:

coxy321 wrote:External wastegate is supposed to be mounted about 90 degrees from the main flow of exhaust gasses (thats from Corky Bell's book). If that EGR plug is on the end of the log style factory manifold, then mounting the wastegate there might make it fairly inefficient.

My 2c.

actually he says that 90 degrees is bad and that a shallower angle is better. it's on page 145

I'll go and have an other read - i though the "shallower angle" bit was talking about the re-entry of the exhaust gasses from the wastegate, so as not to impact on the main flow of exhaust gas flowing through the exhaust.

coxy321 wrote:

devo wrote:

coxy321 wrote:External wastegate is supposed to be mounted about 90 degrees from the main flow of exhaust gasses (thats from Corky Bell's book). If that EGR plug is on the end of the log style factory manifold, then mounting the wastegate there might make it fairly inefficient.

My 2c.

actually he says that 90 degrees is bad and that a shallower angle is better. it's on page 145

I'll go and have an other read - i though the "shallower angle" bit was talking about the re-entry of the exhaust gasses from the wastegate, so as not to impact on the main flow of exhaust gas flowing through the exhaust.

Come-on guys, get over it.
The angle the wastegate is at isn't going to make any difference. This guy has an internal wastegate that should be able to keep boost down to zero. Finding the problem with that is the real issue here.

who did you buy the turbo from, they should of told what size wastegate actuator it was. when i got my gt2871r it comes standard with a 6psi wastegate actuator so i got a 12psi actuator instead because i wanted to run around 15-16psi when done. what you need to do is pull your turbo off again and use some sort of pump with gauge to supply air to the actuator and see when the wastegate opens it only needs to open a cpl of mm. other thing is do you have the hoseing plumbed up correct.

I just had a look through some of your build threads - where abouts are you picking up the boost signal from? I can see from your pictures where it goes onto the wastegate actuator, but can't see where everything else is plumbed in.

Mate, wind your fuel down a quarter turn and your boost will reduce by about 8-10 psi. Diesels don't NEED a wastegate unless the turbo is too small.

bought it near new off ebay, spoken to the guy i bought it off and he reckons it is the standard actuator. Also reckons he had it on a 1litre engine and it was too big.

I haven't wound the fuel up yet.. still running on original setting.

the boost gauge and wastegate are plumbed into the the old egr port in the alloy intake crossover pipe.

in the pics I hadn't hooked up the wastegate or boost gauge.

I will have to find a compressor and test the actuator.
Can i just test it while it's on the turbo, its a bit hard to take off...
I should be able to see if it moves as there is no dump pipe on it yet

ledgend80 wrote:it comes standard with a 6psi wastegate actuator.

still got the original?

crunk81us wrote:I will have to find a compressor and test the actuator.
Can i just test it while it's on the turbo, its a bit hard to take off...
I should be able to see if it moves as there is no dump pipe on it yet

Bike pump and pressure guage. Remove your boost gauge and use that if you like. Yes you can do it in place if you can get to the wastegate line and disconnect it from the turbo end,

I run 15psi boost with the standard wastegate on my gt2860. I simply tightened (shortened) the actuator rod. Is this the most correct method? Will I be overstressing the actuator? (was set @6psi out of the box).

I'd say in the op's case, the previous owner has tightened the actuator rod right up to try and produce more boost (in vain by the sounds of things)

dogbreath_48 wrote:I run 15psi boost with the standard wastegate on my gt2860. I simply tightened (shortened) the actuator rod. Is this the most correct method? Will I be overstressing the actuator? (was set @6psi out of the box).

I'd say in the op's case, the previous owner has tightened the actuator rod right up to try and produce more boost (in vain by the sounds of things)

the rod was a bit tight.. but i have loosened it to the point of wastegate being slightly open from the get go.. still getting to 20 0dd psi..

crunk81us wrote:

dogbreath_48 wrote:I run 15psi boost with the standard wastegate on my gt2860. I simply tightened (shortened) the actuator rod. Is this the most correct method? Will I be overstressing the actuator? (was set @6psi out of the box).

I'd say in the op's case, the previous owner has tightened the actuator rod right up to try and produce more boost (in vain by the sounds of things)

the rod was a bit tight.. but i have loosened it to the point of wastegate being slightly open from the get go.. still getting to 20 0dd psi..

Something is really wrong. It takes a lot of fuel to deliver 20+psi boost on a diesel. Disconnect the wastegate flap and go for a drive, this should give you close to no boost.

KiwiBacon wrote:

crunk81us wrote:

dogbreath_48 wrote:I run 15psi boost with the standard wastegate on my gt2860. I simply tightened (shortened) the actuator rod. Is this the most correct method? Will I be overstressing the actuator? (was set @6psi out of the box).

I'd say in the op's case, the previous owner has tightened the actuator rod right up to try and produce more boost (in vain by the sounds of things)

the rod was a bit tight.. but i have loosened it to the point of wastegate being slightly open from the get go.. still getting to 20 0dd psi..

Something is really wrong. It takes a lot of fuel to deliver 20+psi boost on a diesel. Disconnect the wastegate flap and go for a drive, this should give you close to no boost.

without being rude.. what exactly would this prove?

I hooked up a compressor to the wastegate tonight.. opens at about 22ish psi.. new wastegate actuator required me thinks.. ??

It will tell you whether the wastegate is doing anything at all, and if there's a way to cut the boost down. If you still get pressure with the wastegate manually opened, it means there's issues with your exhaust housing or turbine wheel sizing.

Basically, manually locking the wastegate open bypasses all possible issues with actuators/signal lines/linkage, and tell you if the thing even works at all.

Test what Coxy is saying.

I agree with others, MANY diesels run a floating system and rearely if ever need a wastegate.

It does sound like the engine is getting too much fuel.

crunk81us wrote:without being rude.. what exactly would this prove?

I hooked up a compressor to the wastegate tonight.. opens at about 22ish psi.. new wastegate actuator required me thinks.. ??

As already mentioned, it will prove that your existing internal wastegate is capable of regulating boost, meaning no external wastegate is necessary.
I'm still surprised you have enough fuel to produce 20+ psi boost. Do you have an EGT gauge? If not I recommend you get one and fit it to the manifold. You could be close to meltdown.

What's your dump pipe like? Is it possible that it's completely blocking flow from the wastegate or fouling the gate itself? Have you actually observed the gate opening or just the actuator moving?

I can't say I'm too surprised the engine is capable of generating 25psi, my 2h will generate 20psi+ (albeit with a smaller compressor I think?)

I would agree, sounds like too much fuel. I had the wastegate wired shut on my 1HD-T, peak boost changed from 15psi to anything from 18psi up to 22psi just by changing fuel settings, when it was producing 22psi, EGTs would climb extremely quickly

currently there is no dump pipe.. not fouling the wastegate.
Observed the actuator working and moving the wastegate.. at 22psi
I see your point now.. if the gate can't flow enough then i will have trouble keeping boost down..
i really cannot see how it could be too much fuel.. but i will try winding it back a bit to see if that helps..
have egt gauge will be going into dump pipe when that's made..

Also thinking maybe my cheap boost gauge is reading inaccurately.. going to grab the good one from the rally car and stick it in..

crunk81us wrote:Also thinking maybe my cheap boost gauge is reading inaccurately.. going to grab the good one from the rally car and stick it in..

An EGT guage in the dump pipe is useless. Put it in the manifold or there's not much point.

80's_delirious wrote:I would agree, sounds like too much fuel. I had the wastegate wired shut on my 1HD-T, peak boost changed from 15psi to anything from 18psi up to 22psi just by changing fuel settings, when it was producing 22psi, EGTs would climb extremely quickly

So you had a waste gate issue.. not a fuel issue!

He wont be able to produce 25 psi unless there is a problem with the waste gate.. regardless of being delivered.

KiwiBacon wrote:

crunk81us wrote:Also thinking maybe my cheap boost gauge is reading inaccurately.. going to grab the good one from the rally car and stick it in..

An EGT guage in the dump pipe is useless. Put it in the manifold or there's not much point.

I know it would be better in there, but look at my manifold.. how am i supposed to put it in that?

crunk81us wrote:

KiwiBacon wrote:

crunk81us wrote:Also thinking maybe my cheap boost gauge is reading inaccurately.. going to grab the good one from the rally car and stick it in..

An EGT guage in the dump pipe is useless. Put it in the manifold or there's not much point.

I know it would be better in there, but look at my manifold.. how am i supposed to put it in that?

Shit easy! Pull of that heat shroud, find a reasonably flat area preferably near the exhaust outlet, drill and tap it, and away you go. It'll be a lot easier to do now rather than later on when everything is bolted up.

everything is bolted up.. :(

crunk81us wrote:I know it would be better in there, but look at my manifold.. how am i supposed to put it in that?

Drill a hole through the heat-sheild. A step drill gives a nice round hole in sheetmetal like that.