This is nothing in your long line of sagas, especially after what you told me what happened after replacing the gearbox, that was

talking about the ROGUE wheel by anychance?? Lol.....
ya gotta laugh!!

nick

That wheel be the one

248 bhp.................................



at a pathetic 12psi !
still can't find remaining boost leak/leaks... So that is all that will hold!
Fleas percivearance is truly astonishing!!

nick

do a boost leak test with soapy water you will find them all

Looking good for 370 BHP+ at 1.7 bar then....

The car must be hissing like a pit of snakes - there must be a lost of air escaping....

thats still good power at 0.8 bar mate!

just shows its going to be a great car once they findthe boost leaks!!

i would just take all the pipes off and re-attach them again and double up on clips ect!

Marco, what's happening with your car mate?

well i'd be WELL chuffed with 370 nevermind the '+' bit.... Anything more would be amazing from my set up.... Lets hope the leaks are an easy fix... Fingers crossed!!

nick

Just to add to this, we have pressure tested from the turbo to the throttle body, there was one major leak, but now this part of the inlet system is fully sealed holding 2bar without issue. The dump valve has been eliminated, a couple of hoses off the inlet manifold were not done up at all so they were venting, but still there remains a major leak. The final step is to pressurise the inlet manifold and see what gives. The wastegate actuator was also very weak, so this has now been adjusted to 12psi crack pressure. However, even with the wastegate vacuum hose disconnected, max boost is 1.35bar which quickly drops to 0.85bar. Turbo spool is excellent, so the leak manifests itself only under sustained pressure i.e. expansion.

Isn't that the reverse of what should happen with a turbo operating without a wastegate? The boost should rise exponentially as turbine speed increases. i.e. once 1.35 bar boost is achieved it should (continue to) shoot up rapidly.

I'm finding it hard to imagine what part of the inlet system would hold 1.35 bar and then suddenly leak - allowing the boost to drop to 0.85 bar and then apparently the 'hole' getting progressively larger as boost from the turbo increases - and then once the 'run' is over, the 'hole' is able to seal itself again so that the boost pressure pattern can be repeated.

I sympathise with your dilema, Flea!

Yes the the wastegate disconnected i.e. always shut, should allow "infinite" boost, so it is a good test to determine boost issues.

A load based leak is more common than you would think. I used the dyno to try to determine where the leak might be (power run was simply for my own interest while strapped down), anyway held at a steady state rpm the boost would build then drop, build then drop. When I first had the car, it wouldn't give more than 0.9bar boost, so we are heading in the right direction!

Maybe you have a leak on the inlet manifold coupling hoses, these don't ages very well.

Yes maybe..... This is where we hope the leak ISN'T as it will be a pain to sort!! Fingers crossed!!

That's not correct. In fact if you disconnect the actuator hose, what will actually happen is the boost will rise until the exhaust gas pressure rises enough to overcome the spring in the actuator and force the wastegate open.

You can increase the boost by winding in the actuator spring, but that will only work so far. After the spring has reached its maximum force, you can wind it in as much as you like and all that you'll do is create bigger and bigger boost spikes. The boost will still drop to whatever the spring can hold - Until, of course, you get to the point where you've clamped the wastegate shut and then the turbo really will boost itself to death.

Basically, If you use an actuator that isn't 'man' enough for the job you'll never hold the boost you want. That's one of the actuators come in different spring pressures.

Your current problem could well be a high pressure boost leak, amongst other things. But from your description of the symptoms, it sounds like you're trying to use an inadequate actuator.

If it is that, then not to worry. It's actually surprisingly easy to remove the inlet manifold and get to the rubbers. I wrote a injector removal How-To guide , which describes removing the manifold.

well the original bog standard one will hold 1 bar plus so i doubt the spring in the one i have now will be weaker than that? If it is that then reckon you should donate your old one kj as you're now running external WG now?

nick

I doubt you'd have a boost leak that big and not hear it. It's more likely to be wastegate creep. Try holding it closed with a leaver bar or wire tie it up etc. That would be the easiest test.

If it is that, you can have it! Although, one of the reasons I changed to external wastegate was because it wouldn't hold the boost I wanted

nice one.... Weren't you using dash 31 actuator?? So in time can the springs weaken in these?? I'm guessing so as that actuator would normally be able to hold 2 bar all day let alone the 1.3 bar your running??

Yes, a -31. The spring in any actuator shouldn't weaken significantly. The boost any actuator will hold depends on many factors - the turbo, the size of the wastegate, turbine trim etc, etc.

On my setup I found that the actuator wouldn't hold more than 1.1 bar. At one point in testing I went as far as unbolting the downpipe and disconnecting the actuator hose. Still the same result but just a bigger boost spike.

I spoke to a turbo rebuilder and parts supplier just to check if what I thought was correct, but he agreed that normally if you want to significantly over 1 bar than normally you'd think about using a -34.

..and just to double back-up my own findings here's a post a found from Motorsport Developments...

http://www.fordrsforums.co.uk/viewtopic.php?f=3&t=16

Anyway, we'll see how it goes. The amount of time everybody (myself included) has spent getting that bloody car to work I'll just be glad to see it finally making some power - even if I'm not doing the work this time! Good luck

one more boost leak found and sorted but still won't hold boost.... Can get it upto 1.2 but that's it.... So trying different actuator tomorrow morn, flea reckons he can change actuator without removing turbo, fiddly i'd imagine!?
really hoping the actuator IS the culprit.... Car is testing my patience now.... Can't imagine what its doing to leightons?? ....

nick

I managed to change mine in situ...

It sounds like your car is doing what mine did.

Don't worry mate! It will be worth it!!!

Fleas fitted different actuator this afternoon... Think he's fitted a forge on with 14 psi crack pressure so should be a bit more 'manly'... testing tomorrow morn!! Due some luck i think!!

Indeed, hope it all goes well for you Nick

Where was the other boost leak then?

Fingers crossed the actuator sorts the problem out

boost leak was at throttle body.... Big 90 degree Hose that goes from tb to pipe where idle control valve is.... The samco one i've got is ever so slightly big at tb end so flea has notched it out and it apparently fits much better!? Just waiting the call of flea now to say "it works"..

there was a major issue with the position of the actuator.... It was on the piss witch was causing massive pressure on the penny inside exhaust house.... It was causing the penny to not sit right.... So obviously wasn't working right!! Flea could and prob will explain a bit better at some stage!!

basically as i chose to change exhaust housings i trusted the place that was fitting engine to swap the exhaust housings instead of my turbo guy.... You know, the place that had my cam wheels the wrong way round..... Cowboys!!

The saga continues..... New actuator fitted.... No difference!!
Flea then twigged that i'd said 'i'd' changed exhaust housing.... Not a turbo expert so he got borrascope (think that's the word?) inside the turbo to discover what he feared.... Turbine wheel is complete miss match to exhaust housing.... My turbine is stage 1 and i can only assume the exhaust housing has been machined to accomidate stage 3 turbine as there is a gap of atleast 2mm all round the wheel..... So that's where all my boost was escapeing..... Que Begbies laughter!!

so now do i bolt on original housing the tiny 48ar one or try and get 63ar one?? Flea feels that as the turbo spooled so fast as is, once bolting original housing back on it will be liable to 'surge' (don't really understand what that is??), tho my turbo guy seems to think it will be fine as he ran this exact set up on his hill climb integrale?? What do i do??

Anyone have a 63ar housing kicking about that they would like to donate to the "lets put leighton out of his misery before he sets fire to my car...Fund"

you've gotta laugh!!

nick

I'll add more later, but the pictures say it all...

Normal Turbine


Nick's Turbine

Fair play with all the perseverance shown by those involved, you must be gutted.

I’d wait and get the housing that would get you a final map that you’d be happier with, pushed on this far no point selling your work short now.

Good luck , you deserve some