How about some form of spring loaded valve in the manifold to release the excess pressure into the exhaust further downstream.

The high gas temps are going to be a problem, I'm sort of thinking about how gas turbines release excess compressor pressure, but in that scenario gas temps are around 250 degC.

yeah, well at the moment we ave got where the EGR valve use to be to play with, but the control is going to be the challenge.

make the path too easy to take and the turbo will not spool properly, dont take enough and the turbo becomes a restriction and the pressure goes up.

One option might be to alter the mapping of the EGR valve coupled with a narrow outlet post valve side. this could either be done via the ECU or by a seperate control method to activate the solnoid in it.

the downsides to this is either design and build a 'mini' ecu for some pre-programmed values, or cost\time to get a remapper to 'muck about' with things. and then istill need to devise a method to read the pressure while all this is being tested.

With the % increases of things i am not really sure i want to risk tapping the exhaust manifold directly at this time, so i need to be able to utilise a blanking plate of some shape still.....

An External wastegate would not cope with the gas temps so it pretty much out the question :(

It is not going to be easy i dont think....

thanks for the thoughts though :)

Ps the 'real' solution is a turbo with a bigger hot side - but VNT control has it's own problems and non vnt units are too laggy :(

Sounds like you are almost there, hope you can sort the pressure problem out.

Got to give you respect for carrying on and boosting the L series.

Will have to see it in the flesh one day.

:hooray::hooray::thumbsup::thumbsup::thumbsup:

Right have worked out my first port of call method to control this EMP and it is going to try to follow the KISS approach (keep it simple stupid)

going to decide on an external wategate that i might* purchase.
*the word might is there for a reason
Then i am going to get an adpator plate made up that will go from the EGR port, a short section of intermediate pipework and then the end plate will match the possible external wategate i might* buy.

I will get the short section tapped to fit a boost reading device - currently using a compression fit and some brake line, so happy to keep that method for now.

then get a few blanking plates made up for the wastegate end; to start with i will literally just drill a hole and see if we can lower things enough without affecting spool by following this very simple approach.

If i discover a suitable diameter hole that fits the bill i will then either:
a) mate the correct diamter pipework to the downpipe to by pass the turbo
b) feed the pipework under the car to let it vent that way.

If lag is affected too much, or not enough pressure drop occurs, then i will get the wategate that matches the adaptor plate i have had made up, and start the testing again using the pressure to manipulate the actuator\wastegate.

As wastegates are generally quite large things i will need to experiment with a restrictor again to lower the flow either pre or post wastegate or both.

If that fails then i will cry and sulk lots :laugh:

being serious though if the 2nd attempt fails then i will look at electronic boost controllers - but they are quiet pricey so want to avoid theat outlay if it is not needed.

Now just to work out which wastegate i might want and then get the adaptor made up.

Hi Pete, is a wastegate the same as the dump valve???

On my Volvo 440 I could hear that sucking and hissing away, I cant say I've noticed the same with the L series, did squirt some WD40 around the adjustment arm to see if it was stuck.

The turbo kicks in OK, just dont get the suck and wooosh noise.

Your one is much too technical for me, just about know how the derv works, but with the torque you are getting I bet it goes.

:smile2::smile2::smile2::smile2:

Not quite Peter,

On a petrol when the throttle closes and it blocks off the intake in order to dump the air to avoid stalling the turbo you vent it off to atmosphere in a 'psst noise'

Our diesels dont ever get a closed throttle plate, so we dont need a dump valve. you can bodge one up electronically, but it actually looses performance as you need to get the boost pressure back again :)

the wastegate on our turbo's is actually integral to the hot side of the exhaust itself, they are driven by the actuator. When boost pressure on the cold side is reached they open up and divert the hot gas away from the exhuast turbine therefore restricting the rpms the turbo can spool and therefore hitting you boost limit.

As a combination of the wastegate and hot side of the housing is too small for the volume and flow of gas, we are now seeing the pressure building up.

I have also realised that if my single simple plate method doesn't work, then i am going to also need another actuator to drive the wastegate, unless i get one with summit integrated into it.

I had put in a bit about the run back from the station to the farm, but discretion being the better part of valour and all that i decided to not post it, just suffice to say: it shifts ;)

Cheers for that, I can stop spraying the WD40 about. Glad its going well.

:wave::wave::wave:

Right finally got off my backside and took a few pics of the engine bay... for those randomly interested in the bodgetastic Exhuast manifold pressure reading system then take a quick peak at these :)

http://img.photobucket.com/albums/v4...d/DSC_0008.jpg

http://img.photobucket.com/albums/v4...d/DSC_0009.jpg

http://img.photobucket.com/albums/v4...d/DSC_0010.jpg
And yes i know i need to clean my air filter ;)

Id want to remove that and push it down my stairs :D

lol... took me a while to work out what you are on about....

I am afraid it has no spring, as it is brake line... the end result would be to wach it roll down :laugh:

Yer guessed it was solid but that was the first thing that came to my mind. :laugh:

well figured i ought to pop a quick post up here, car is till waiting for a slave cylinder rebuild kit to make it up to the farm - the rebuild kit for a 620Ti slave cylinder cost about ?10 rather than the close to ?100 for a new slave so waiting is def the order of the day...

I am also still fearing the worst about the fuel pump, but as the car can't make its own way around at the moment it has not been for a diagnostic session yet..... am keeping fingers crossed it is just the EML playing silly buggers, and once that is cleared it will run smoothly again!

Keep everything crossed for you, deserve a bit of luck.

:smile1::smile1::smile1:

+1 ........

this thread is a great read! hope that when its running again i get chance to see this thing shift!

Well i am hoping to bring it to down the meet in Oct - i got my AA cover up to date so if it breaks again it wont be the end of the world.... man i really should not still see the funny sidefthins now :laugh:

I hope so too, about time you had a good run with no issues.

well there are two bits of news....

first the Good news.... my repair bill did not cost me anything....

and now for the........... excellent news - nothing wass wrong with it :D

It had the slave cylinder rebuilt for peanuts and upon investigation matt thinks that it gfailed due to external contamination, so he has fitted a really beefy dust cover to it this time.

RE: the pump, there was a lot of water\crud marks from the various explosions of coolant and they had worked their way into the connectors.

Initially the pump guy could not clear them as they kept coming back, things like timing errors, pump disconnected flow rates etc, but once the connectors were all cleared and sorted no more codes :D

so all i have to do is to pick it up, hoping GF will be up for a drive to the farm tomorrow, but if not it will be Thursday night when i get back to the UK...

So back to the relief system.... and i got a couple of forum friedns to help me.

One does technical drawings, and the other is a metalworker. Both have said they will do it for beer tokens :D

*cosses fingers*

That's great news! About time you had the rub of the green! :yes:

Great stuff Pete, So not much left to do now!

I know... maybe finally getting close to completeion!

Picked it up this afternoon as the GF agreed to do the return trip, and i have to say, i missed her! the car that is not the GF.

Forgot what it was like to waft around torque filled luxury, and i worked out that my car is as quick as a 1.4 pug 206 if i use under 50% throttle and change up at 2-2.5K rpm :laugh:

Dont get tempted to use the torque, well not till we see it on the 24th!!

:yes::yes::yes::laugh::laugh:

lol yea dude steady as she goes

tell me about it...

everytime i complete a trip in it i let out a breath i had not been realising i was holding :laugh:

my new 'fear' is that the clutch is on the way out as the bite point is now rather high..... could just be due to rebuilding of the cylinder etc...... i hope!

Once your on the motorway you wont need the clutch!!!!

:devil::devil::beer2::beer2::beer2:

i know - did heathrow terminal 5 to bristol m32 without changing out of 5th last night - was even doing 35mph at one point :laugh:

Figured i would pop an update in here as it has been a month or so....

Well good news is that the clutch still hasn't gone, so the altered bite point i think is just down to the slave cylinder being rebuilt..... now i said that it will die on me next week :rofl:

I have been loosing coolant at a slow but steady rate, but just topped up with 500ml of OAT after about 1500miles, and i think i found the leak from the bottom rad hose..... here is hoping anyways.... lossened the pipe, re seated it and nipped it back up, with the engine running there was no drip this time....

my metal working friend has not been able to take my mocked up update off me yet, as either i have been out the country or he has, so it looks like the pressure relief system is still further timein the future to being resolved..... if i am lucky i might get it back inbetween Xmas and new year and can open her up agin to test stuff out :)

Have to say i am proud of the mightly L-series.. fires up with only one glow plug working, even in -2 and being buried in a snow drift for a week.... good old airport carparks....

I am hoping that when matt changed the plug (the only one working) he popped it into number 4, as that one is staying in there until the head comes off, as it is a fuel pump removal required to change it..... number 1 is tight underneath a coolant pipe too..... I will know more when i get a multimeter onto it and read the resitance of each plug.... would go out and buy one, and have done it, but it was on my Santa list so no idea if it has been bought yet.... :S

Ah well keeps me out of trouble :laugh:

Glad that things are starting to go your way bud, look forward to you posting another post with more reliable miles under your belt:)

Pete top tip to testing glow plugs, take the power lead off each plug, then get a plain bit of wire and hold one end on the + of the battery and then with the other end just touch the terminal on the plug, if it sparks then its working :)

ah cool thanks for the tip Steve..... i am 100% sure that it is running 1, just need to find out which one :)

Matt did ring me the other day and told me to drop the car off with him to sort the coolant loss out... was impressed by the offer as he could only have seen it from posts on various forums..... if the cap is good and the rad hose dont fix it, then it will be HG related i am sure..... and it is not completely unknown for a HG to to be faulty... knowing my car and my current luck that would be the case..... am hoping it is being nice to me for once tho :)

Once pressure is reduced and i can use that final 40% of throttle again i am going to be one happy bunny for sure :D

Hope the hose was the only cause of the water level dropping, think you deserve a bit of Christmas luck.

Start the New Year off with a sorted pressure relief system and your there.

:thumbsup::thumbsup::thumbsup::clap2::clap2:

right the hose is not the cause of the leak, but digging around with some virgin snow at my folks has identified it is not dripping while idle or reved without major load going through the system.....

there are crystals that are being formed on the waterpump, so a leak is happening externally... which is good, but i can't see it dripping at idle etc... frustrating but better than it going internally!

pressure pipe is being made up this week, and i hope to get my hands on it and try to get some holes drilled and sorted over Xmas period.... but it may not be done before i leave on the 23rd, so might be closer to new year....

Decided in the rework to get the pigtail of copper attached directly onto it my by mate, as it saves me trying to faff about with it and cocking it all up :laugh:

Glad its not the head gasket, all the best with it, hope 2011 lets you put the power down.

:clap::clap::clap:

Probably is the waterpump. You won't see it because it will just evaporate in that area with the heat. Just get it changed before it does do any damage.

Well it is drinking coolant at quite a rate, but nothing i am not able to keep on top off. Matt thinks that it is an issue with the new pump that was fitted, and it not making the seal properly - the old one had to be smashed out at it has fused solid :(

Just need to get it up to him to sort out before i got to the states in the 2nd week of Jan...

Well it has been a month and i have been out the uk for almost all of it....

However the coolant issue was sorted in 10mins of matt gettin it on ramps.. the hoseclip had failed but only after the system presurized and the stat had opened... it would pop open a few teeth only every time you tightened it - once it got hot.. the little ******...


However the good news kinda stops there... ther EML light is on again, and it is slow starting again - after matt fixed it with sorting the timing out.... the temp gauge has packed in, the air con is flat again.....

On the plus side tho the 'bit of pipe' for the relief system turned up.. but did not fit - looking at the pic of it, it was not as i had requested.... so Matt will butcher it and get that stuff all sorted....

had to drive a brand new corsa to gatwick the other week and it was hellish... just no poke; tho more from a 1.2 that i expected tbh!

The good and the bad mate, least the coolant leak was an easy fix and the temp guage and flat air con should be an easy sort too. No sure about the eml light but hopefully matt will get to the bottom of it. Your getting there, slowly but surely!!:)

Glad its not the head gasket, hope the rest is an easy fix.

Got some SDi injectors now, sorted the thread out on one, so I,m just deciding when and if to fit them, and then pay a visit to Yeovil and Reidy's RR.

:beer2::beer2:

yeah getting there slowly but surely.... last time the EML was on it was a stored code from the belt replacement; but this time nothing has been touched and it came on again. worst case is the fuel pump is dying and these are the early signs....

best case is stored code and the poor starting is air in the system... hopefully matt can indeed trace it to the later and not the first... new pumps are extortion and getting one reconn'd aint much better so you kinda have to trust to luck with a scrappy one!

A\C was regassed about 6 months ago, so there is a leak, hopefully the dye has not washed off yet and it can be spotted easily and it aint too expensive to fix... not that i need for any other time than 2 weeks a year :rofl:

Peter:
If your dyno trip is going to be in a few months i may plan to join you - by then the relief system will be done and i want to see how many ponies i lost getting over that backpressure. as my car has always been on that dyno it is the one i need to go back to for comparison purposes. :)

Am hoping that all will be done in time for the meet so some runs can be given :)

Sounds like she isnt letting you have it easy is she?
Still as said some of the bits are 'easy' fixes... on the Reidy rr side I would be game for a run down there to get a remap done to mine.