Any idea where my powers gone ?

[V70 Graham]

Oh... I've just seen that you fitted a Forge one, even if the fault isn't the recirc valve personally I'd get a genuine one and use the Forge one as a paper weight ...

For what reason ?

[AndysR]

For what reason ?

Previous experiences with boosting issues and a Forge product....

[M-R-P]

having done extensive tampering with the forge recirc, I'm pretty happy with how it works. after all, it's closed under pressure and opens under vacuum.
I'm pretty sure it's holding boost. if it didn't open at all, it would chatter like mad and if it was blowing open, I'd imagine it would be pretty audible.

I'll be testing it all asap, if anybody can lend me a boost gauge for a week, it would be a big help

[Jim S70R]

Not that it helps but I reckon the power loss is from when you took that intercooler out of your boot lol.....sorry couldn't help myself!!

Reckon Andys hit the nail on the head with his diag about you car!! Hope you can get to the bottom of it and get her back up to running full power again.

[960kg]

I agree totaly with AndysR even as far as the Forge products are concerned!.........i do have the Forge Recirc Valve fitted but i don`t like it ......the noise is horrible, not even a nice chav noise!

The Mitsubishi valve diaphragm`s are a superb design and very strong and will last the engine out ......probably.

But along come us tuners or fiddlers and just because it`s nice and shiny pay the earth for something that makes no difference at all. .......me included.....i had 19psi for 3yrs on my `98 T4 and not a wimper from the 14T as standard.

The only thing one has to do is adjust the actuator rod as it does wear elongated and the boost will drop away so to keep on top of the boost adjust regularly to the base setting or whatever flicks your switch!

Probably AndysR is correct about the adjustable Forge Actuator perhaps it has stuck wide open somehow and the TCV has shut things down??

[V70 Graham]

I did also fit the 3" MAF intake but Martin kept an eye on the afr's Saturday and said everything looked fine, it's just strange the problem (chattering) has started since the TCV/recirc were done, we will be looking at the TCV and actuator next Monday to see if we can find the problem, if not I may have to change the recirc back to a genuine Volvo item.

[M-R-P]

I agree totaly with AndysR even as far as the Forge products are concerned!.........i do have the Forge Recirc Valve fitted but i don`t like it ......the noise is horrible, not even a nice chav noise!

The Mitsubishi valve diaphragm`s are a superb design and very strong and will last the engine out ......probably.

But along come us tuners or fiddlers and just because it`s nice and shiny pay the earth for something that makes no difference at all. .......me included.....i had 19psi for 3yrs on my `98 T4 and not a wimper from the 14T as standard.

The only thing one has to do is adjust the actuator rod as it does wear elongated and the boost will drop away so to keep on top of the boost adjust regularly to the base setting or whatever flicks your switch!

Probably AndysR is correct about the adjustable Forge Actuator perhaps it has stuck wide open somehow and the TCV has shut things down??

It's got a standard actuator on there at the moment Keith, there's talk of fitting a forge should this one be goosed. I checked the movement of the actuator a few weeks ago and it felt nice and strong and there were no notches in it's movement, but I didn't check to see if it was holding pressure - something on the list for monday.
I quite like the Forge recirc although it takes a bit of setting - up initially. The noise isn't really an issue for Graham as everything is still pretty quiet in the cabin but it did make some comical noises on the rollers. Knowing the car as well as I do, The possibility of the recirc being the route cause of the problem is way down the list, but won't be forgotten and once I rule out the obvious, I'll work my way through everything else.

[V70 Graham]

it can only be the tcv or actuator imo. I've always been suspicious of the tcv, I've never heard one that loud before. I have a nearly new one we could try and I could test the actuator to see if it's leaking or sticking.

Well after a long night with M-R-P we have discovered it's not the actuator, though the old one I had was letting air past, changed for the new forge unit and it's exactly the same.

We also tried a different TCV and guess what, still the same.

I think I'm going to have to start removing parts now and revert them to standard in the hope of finding the problem, probably try a new recirc first.

[stribo]

Well after a long night with M-R-P we have discovered it's not the actuator, though the old one I had was letting air past, changed for the new forge unit and it's exactly the same.

We also tried a different TCV and guess what, still the same.

I think I'm going to have to start removing parts now and revert them to standard in the hope of finding the problem, probably try a new recirc first.

I did say to MRP on the day it sounded like the recirc opening too early, but he assured me it was the TCV.

[oblark]

I think I'm going to have to start removing parts now and revert them to standard in the hope of finding the problem,

Looks like some cheap parts coming up for sale soon.

First dibs on the air filter

[V70 Graham]

I think I may have found the problem.....



Looks like compressor surge, not healthy for the turbo, here are a couple of articles.....

http://www.golfmkv.com/forums/showthread.php?t=24675

http://forums.hybridz.org/topic/7758...nation-within/

[V70 Graham]

Looks like some cheap parts coming up for sale soon.

First dibs on the air filter

Nope, car will simply be parked up till I can find a solution.

[T5RatherAmusin]

Looks like some cheap parts coming up for sale soon.

First dibs on the air filter

http://m.ebay.co.uk/itm/390592817886...ATCHING_ACTIVE

[partsforvolvos.com]

from the detail that may be related to your car symptoms in the article, I suspect a little fettling of the forge valve is worth trying as you have the tuning kit. also recommend to speak to sam or john at forge, john particularly is a font of knowledge and very helpful.

[stribo]

I've heard of this, I believe the cure is a bigger downpipe with sports cat, freer flowing exhaust, and a larger intercooler.

[V70 Graham]

Like has been said before your turbo is flowing too much air for the engine to ingest at your operating points. If you have surge at WOT you need to increase the amount of air your engine can flow with a certain displacement and engine speed, aka increase your volumetric efficiency/eliminate flow restrictions post compressor outlet.

Can anyone tell me what this means please, has the increased diameter maf pipe work caused this ?

http://www.partsforvolvosonline.com/...oducts_id=8344

[V70 Graham]

http://www.vpcuk.org/forums/showthre...ection!/page16

Post No : 307

TCV and intake pipe were done in Sept, recirc not till Oct....chattering started after the pipe work, I think the increased diameter pipe is pushing too much air into the turbo, just waiting for someone more knowledgeable to confirm lol

[partsforvolvos.com]

in the lines of the (very long!) explaination you linked to, it could be as your outlet size is standard, but your inlet size is increased.
this is not something I'm going to pretend to be an expert on, its too complicated for me.
take it off and try it is the only way . at least it is a simple thing to swap.

also, regarding engine management with fitting a larger maf housing as I have been thinking about this:

the engine ecu will work on the set software checksum that there is a certain amount of air volume passing the maf sensor (point a) given the oe diameter of the tube and pressure.
secondly, at whatever reading is generated by the maf sensor, the ecu expects to see a certain reading that it knows to be that of running correctly at point b - the lambdas.
so, if you change A to a larger size and do not remap, the engine is correcting the afr on the basis of the readings at point b- and the associated sensors in between before it goes out of range and turns on a warning light.
going significantly out of range without the me7 built in self adaptability back up results in what happened to Frankie, but this would also prove for me that ecu modification to suit the new maf inlet size is necessary whether the car has me7 or not.


Also, the other thing could be that this noise is generated by the forge part because of its design and not a fault with it.
the original rubber diaphragm could still be fluttering/pulsing, but you can't hear this happening as it is not a metal piston.

just my thoughts as to an explaination if it turns out it could be related to this inlet tube, but we'll see if/when it is swapped over.

[V70 Graham]

Having briefly spoken to Martin and gone over what mods I have done to the car and when it seems very likely that the increased diameter inlet pipe could be the cause, the recirc was added a month later to try and cure the problem (which it didn't)
Reading up on compressor surge I am fairly confident that this is what I have.....more air than the engine can handle, pushing it back through the turbo spinning it backwards.....not a good thing.

[M-R-P]

Right - Compressor surge then, After spending a few hours last night and a few more today (while waiting for contact from ze Germans, regarding a machine failure at work) looking into possible causes of this noise, not knowing Graham had been doing the same, we both came to the same conclusion. Time to get this sorted methinks!

I have my old OE inlet to use as a last resort (I can modify it to fit the BSR thingy) but I'm intending to fit a choke point into the inlet pipe, just before the MAF to reduce the airflow...

During the testing last night, I could hear a ringing noise that may or may not have been the aftermath of detonation. This was happening either side of the flutter which was followed very quickly by a slight drop in power. This is something I've had on my car when I was running a crap MBC and running lean (many of you remember the RR day at Uxbridge last year when my car spiked to 22psi and suffered multiple detonations etc..) so as Jamie has said above, the MAF could well be under-reading.

The choke in front of the maf should allow a correct reading while slowing the airflow enough to keep it all steady. I intend to use a length of silicone/rubber pipe, inserted into the existing DO88 pipe so as not to impact the overall "bling" of the engine bay.

If I can get my act together today, I'll be heading up to Graham and getting the bloody thing sorted. The car hates me. Seriously. Fighting me all the way last night, fitted hundreds of quids worth gear, pulled muscles I didn't know I had and achieved nothing other than diagnosing and rectifying a knackered actuator.
Gonna fix it I tells thee!