Forge actuator spring advice please?

[officerbrooks]

Hi all,
I have a 2001 ME7 C70 T5, 16T with RICA map 3" downpipe ferrita cat and exhaust. I suspect the actuator is a little tired at 120,000 mls as with everything else checked and replaced boost isn't holding.
What should be my starting point with the following actuator spring choices and will it be the ME7 software and map that actually overides the quoted "running pressure"?

Thanks.

T2 actuator spring selection guide from Forge Motorsport.



The following is general information regarding Forge actuator spring tensions and are important considerations when making a decision on which spring you install, especially if you are running a boost controller or planning an ECU upgrade.

The 4 springs we offer are listed below under their relevant colour codes and related pressures. Running pressure is the lowest or minimum pressure the spring will operate at, which is important when considering which spring you choose. The spool up pressure relates to the vacuum pressure required to lift the spring from its static position, at which point the turbo waste-gate will start to open (spool up).

The actual rating for these springs is as follows, the lower pressure being the spool up pressure and the higher pressure being the running pressure:

RED 17 psi (spool up) - 20 psi (running pressure) our product code FMAS049R.

BLUE 14 psi (spool up) - 18 psi (running pressure) our product code FMAS049B.

YELLOW 9 psi (spool up) - 15 psi (running pressure) our product code FMAS049Y.

GREEN 5 psi (spool up) - 10 psi (running pressure) our product code FMAS049G.

The spool up can be altered to a higher pressure by adding more tension to the spring. Be careful not to add too much tension to the spring as it will become coil bound, affecting the rod travel and thus affect the waste-gates ability to open effectively. Running pressure cannot be adjusted by adding pressure to the spring.
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[M-R-P]

Standard running pressure is about 10psi so I would think, with the remap, probably the blue or possibly the red (the red may be too much tho)

[Wobbly Dave]

I wouldn't use a forge anything as far as I could throw it. If indeed your current actuator is getting on a bit - just replace it with a genuine one or depending on how much slack there is in the rod you can tighten it up 1/2 turn or even 1 full turn.

Because it is ME7, & on demand you just need to tweek it a little to get yourself back in the game. That's how I got from 14.5 to 13.9 on the quarter with Betsy.

How have you arrived at the conclusion that it is infact your actuator which is at fault? Boost may not hold for any number of reasons. ME7 is after all on demand.

[officerbrooks]

I wouldn't use a forge anything as far as I could throw it. If indeed your current actuator is getting on a bit - just replace it with a genuine one or depending on how much slack there is in the rod you can tighten it up 1/2 turn or even 1 full turn.

Because it is ME7, & on demand you just need to tweek it a little to get yourself back in the game. That's how I got from 14.5 to 13.9 on the quarter with Betsy.

How have you arrived at the conclusion that it is infact your actuator which is at fault? Boost may not hold for any number of reasons. ME7 is after all on demand.

Thanks, my self diagnosis follows after watching my Stax boost guage show 1.45bar then drop to 1.2 then hold at 1 bar on WOT, I thought it should hold higher boost until max rpm. All pipework is new and secure including the TCV and it has a Snabb intake pipe.

[M-R-P]

The 16t runs out of puff at high revs, could go some way towards explaining it..?

[p fandango]

Standard running pressure is about 10psi so I would think, with the remap, probably the blue or possibly the red (the red may be too much tho)
yes they do run 10psi standard, but that because the ECU raises the pressure via the BCS. Standard actuator pressure is very low, about 4-5psi i believe

[M-R-P]

That's always confused me - the bcs takes a feed directly from the compressor and either goes to the actuator or back to the inlet. How does the pressure get halved?

[officerbrooks]

This is all helpful info I did have more top end performance but feel its dropped off leading me to fit the boost guage to monitor. I'm looking for a larger drop in intercooler too as I suspect high AIT's play a large part in this. All advice on any of this topic is extremely welcome, thanks.

[Wobbly Dave]

If you are close to me I can test with the TORQUE app & get a full picture & data log your AITs. I would be very dubious that the ME7 RICA map would allow 1.45. It certainly will not push & hold that within that RICA map. Boost gauge is questionable.

[T5frankie]

boost tailing of as you climb the revs is normal and all cars do it

[Jamest5r]

boost tailing of as you climb the revs is normal and all cars do it

Mine dont :)

[Jamest5r]

yes they do run 10psi standard, but that because the ECU raises the pressure via the BCS. Standard actuator pressure is very low, about 4-5psi i believe

Yep thats right.


That's always confused me - the bcs takes a feed directly from the compressor and either goes to the actuator or back to the inlet. How does the pressure get halved?

Little hole in the BCS

[ROZER]

Thanks, my self diagnosis follows after watching my Stax boost guage show 1.45bar then drop to 1.2 then hold at 1 bar on WOT, I thought it should hold higher boost until max rpm. All pipework is new and secure including the TCV and it has a Snabb intake pipe.

i have a s60 t5 with all the same mods as you and mine boosts just like yours but holds 18psi.

[T5frankie]

Mine dont :)

ill enjoy beating you on sunday

[officerbrooks]

If you are close to me I can test with the TORQUE app & get a full picture & data log your AITs. I would be very dubious that the ME7 RICA map would allow 1.45. It certainly will not push & hold that within that RICA map. Boost gauge is questionable.


Thanks, think I'm a long way from you in Windsor. I get 1.45bar immediately as a peak it then settles and holds 1.2bar dropping then to 1 bar by 5-5.5krpm. Maybe this is normal for a car of my spec but it did have a little more, guess I'm at the limit of my current hardware.

[960kg]

The basic setting pressure of the actuator is 4.35psi for the B5234T3 but this is done with compressed air on the actuator diaphragm and not from the turbo when the engine is running so the operating psi is not halved at all as it has no real reference to the turbo pressures.

In my experience the 16T does not run out of puff at high revs and most standard cars don`t either, as the turbo fitted is within it`s efficiency range, hence different turbo`s on different models to suit.

It depends what exhaust you have fitted as the turbo pressure drops when a larger diameter exhaust or down pipe what ever is fitted, so then you turn up the boost to compensate and then you have not much boost left at higher revs. because you have surpassed the turbo`s efficiency that you have fitted.

I studied and read what i could find as i was getting a new exhaust and did not know what to fit and at the moment with a standard exhaust and very modified standard airbox and remap i am getting 20psi at the rev limiter.

So for me at the moment i like the boost at higher revs. i will keep the exhaust on hold until it falls off then decide what to fit, of course if the actuator has too many turns the turbo spools earlier as well so will run out earlier, but to state it does this or that all depends on your setup.

As far as Forge Actuator is concerned, ok i think they do a service as the pucker Volvo one ordered from Sweden only is £207 including VAT.

I have fitted the Forge Recirculating Valve but to be honest it`s noisy as it is a piston type and upon removal of the standard diaphragm type it was in excellent condition even after 159,0000
so really for me was a waste of effort and money. My `98 T4 held 20psi for two years and was still ok on the standard valve.

Everyone to there own.

[dtp]

I have the red spring in mine. My map is asking for 1.4bar boost. Until I changed my actuator my boost hit a peak of 1.4 then almost immediately dropped to 1.2bar then after 5,500 dropped to 1.1. I fitted a forge actuator pressured the diaphragm to 0.4bar and turned adjuster to just touch the arm. Now if I floor it I get 1.5bar peak this drops down to 1.4 bar and holds till the red line. I can only put this down to the OEM actuator being very tired and I was getting waste gate creep.

[claymore]

Mine dont :)

Nore mine

[Redbrick]

Black FTMFW :smileypul:

[officerbrooks]

I have the red spring in mine. My map is asking for 1.4bar boost. Until I changed my actuator my boost hit a peak of 1.4 then almost immediately dropped to 1.2bar then after 5,500 dropped to 1.1. I fitted a forge actuator pressured the diaphragm to 0.4bar and turned adjuster to just touch the arm. Now if I floor it I get 1.5bar peak this drops down to 1.4 bar and holds till the red line. I can only put this down to the OEM actuator being very tired and I was getting waste gate creep.

Thanks, may I ask at what rpm your boost develops with that spring and on my car would the boost control be via the ME7 and RICA regardless of the spring type? You can tell this is a steep learning curve for me!

[jardon]

I think you need advice from people who can offer a comparison.

On a stock vehicle your 16t won't drop boost but if mapped they will because it cannot sustain the peak. In my experience a tired stock actuator with as many turns as you like will let the wastegate blow open in the mid range-high rpm if you run the turbo hard - I justify this by logging boost and TCV duty with DiCE (logging TCV duty tells you what the ECU is trying to achieve relative to actual boost). I have done this with the stock actuator and 4 different Forge spring set ups but perhaps more importantly you can feel the extra oomph with a stronger spring. With my 19t the wastegate will blow slightly at high load with the blue spring so I run the red. ME7 can demand what it likes but when your wastegate blows open you will lose performance. My advice is fit the Forge actuator and be prepared to swap a few springs to "tune" it. It is relatively cheap, tunable and well made.

The stock actuator is fine for a stock car but I guarantee you are not extracting the most from a mapped vehicle with one. If yours is tired it's a no brainer on the basis of cost and performance gain.

Spring choice will depend on your turbo and mapping. I would fit the weakest you can get a way with. Yellow and green were progressive but didn't hold boost on mine. Red is bonkers aggressive but fun when I can get traction. Blue is a nice compromise and as I'm routinely getting wheelspin in 3rd with good tyres and a Gripper diff with the red I may re-fit the blue. DON'T fit a red spring first. DO fit something weaker and let the car adapt over a a progressively more aggressive drive rather than hoofing it immediately.

By fitting a red spring my car is running more boost than ME7 is requesting at part throttle - but it doesn't complain. In answer to your last question the ECU/map cannot control boost as finely with a stronger spring so in theory you remove some of the safety features ME7 has in reducing boost if required - as discussed earlier ME7 can demand low boost but a strong actuator spring will not allow it.

I have a yellow and blue spring on the shelf here if anyone wants to try before they buy - though they are not expensive.

Dave - logging boost with the Torque app is not accurate as it is calculated (estimated) not measured using the map sensor.

[Wobbly Dave]

When I asked the developers at Torque about that - they said it was measured, but perhaps that is inaccurate.

[officerbrooks]

Gents this is all great advice, thanks.
Tim

[officerbrooks]

Hi all,

I raised this question elsewhere..
http://forums.t5d5.org/topic/21404-forge-actuator-advice/

I've now fitted the forge actuator with blue spring the Volvo original had literally no tension left at all. I followed the "half moon" advice of fitting the actuator arm to the wastegate and have driven the car progessively to allow the ecu to adjust but alas apart from the occasional 1.5bar spike max boost seems to be about 0.5bar in 3rd or 4th with none at all in 2nd.
The old tired or as I thought unit gave great torque at 3Krpm and ran out of steam after 5-5500rpm when boost dropped to 1bar. What might I have got wrong??
Thanks

[smithy]

Hi all,

I raised this question elsewhere..
http://forums.t5d5.org/topic/21404-forge-actuator-advice/

I've now fitted the forge actuator with blue spring the Volvo original had literally no tension left at all. I followed the "half moon" advice of fitting the actuator arm to the wastegate and have driven the car progessively to allow the ecu to adjust but alas apart from the occasional 1.5bar spike max boost seems to be about 0.5bar in 3rd or 4th with none at all in 2nd.
The old tired or as I thought unit gave great torque at 3Krpm and ran out of steam after 5-5500rpm when boost dropped to 1bar. What might I have got wrong??
Thanks

Have you put any tension on the actuator sounds like it needs to be tightened abit

[jardon]

You should get minimum boost of ~13 psi once the turbo is spooling with a blue spring. You did fit the actuator with the "half moon" pulling the wastegate shut and not holding it open?

[officerbrooks]

Thanks all, gently tightening the actuator arm a turn at a time!

[jardon]

If the turnbuckle had to pulled 1-2mm to fit over the wastegate post you are not going to change anything by adding more turns - something else will be the cause. A blue spring is stiff and 1-2mm requires a fair yank.

[p fandango]

is the turbo in good condition, & have you checked for boost leaks lately

[jardon]

Or is the ecu taking offence and closing your throttle when boost rises faster than it has planned? Diagnostic plan should include checking for airleaks but if it will make 1.5 bar that seems unlikely. Backtracking a bit your 16t will not hold 1.5 bar and under 1 bar at the revlimiter is normal. A stage 2 map should make ~1.2-1.3 bar then drop off from 4500-5000 rpm.

[officerbrooks]

Or is the ecu taking offence and closing your throttle when boost rises faster than it has planned? Diagnostic plan should include checking for airleaks but if it will make 1.5 bar that seems unlikely. Backtracking a bit your 16t will not hold 1.5 bar and under 1 bar at the revlimiter is normal. A stage 2 map should make ~1.2-1.3 bar then drop off from 4500-5000 rpm..

Having tightened the actuator arm a little I can upon booting it hard get boost to 1.5bar which immediately drops to 0.5bar even with re-application of throttle it remains there! Reading this
"" A stage 2 map should make ~1.2-1.3 bar then drop off from 4500-5000 rpm. ""
That actually was my starting point with the old actuator I just thought that the 1.2 bar should have held longer. I'll refit old sloppy actuator and make sure the car is ok at that then perhaps a different spring in the Forge actuator thats as close to the Volvo original spec, now that'll be a guess!
Thanks

[oblark]

I had a boost problem a few weeks ago, It would boost to 1 bar in 3rd but only 0.5 bar in 4th.

The fault was pin pointed down to the wastegate sticking, sprayed some WD40 on it then some high temp grease and boost problem was sorted :)

Have you checked the wastegate arm ???

[jardon]

3 things:

1. You could reset the ECU as it will have stored TCV duty cycles that relate to your sloppy actuator. With a tired actuator the TCV runs much higher duty than with a strong spring. This is why I suggested running it gently before hoofing it to allow the ECU to learn what TCV activity is required. A reset may be what's needed to let the ECU start from scratch?

2. Your ecu is never going to adapt and you need a lower spring rate. My MTE map is very "happy" with changes in hardware - it was mapped with a stock actuator, stock MAF and stock pre-turbo piping but I am running a 17 psi actuator, larger MAF and piping without issue. I'm guessing that my map has significant margins of "error" with respect to out of spec sensor readings at a cost of potential engine damage if I get it too out of shape - having said that if I do really outlandish stuff it will pull timing or go into 5% ETM mode and stop me killing it (so far). I'm out of my depth on how your RICA map is configured but it may be that significant overboost at part throttle (which is what your stiffer actuator is doing) engages engine protection at an ECU set threshold. This would make sense to me on a stage map as it has been written for a very specific set of hardware. I would consider running a yellow spring and I have one here if you would like to try it. Changing the spring is not difficult - you just need to be careful not to over-tighten the 6 bolts holding the 2 halves of the body together as you can pinch the diaphragm seal and cause it to leak (in theory).

3. Check again that you have no other hardware issues or codes stored.

[officerbrooks]

The original volvo actuator is back on and normal boost has returned though I've a few gentle miles to do so the ECU can adapt. Pondering now to leave as is and accept that boost dies soon after 5000rpm or start again with a Forge green spring the lowest psi rated which I'm sure will be stronger than my current Volvo fitment.

[T5frankie]

The original volvo actuator is back on and normal boost has returned though I've a few gentle miles to do so the ECU can adapt. Pondering now to leave as is and accept that boost dies soon after 5000rpm or start again with a Forge green spring the lowest psi rated which I'm sure will be stronger than my current Volvo fitment.

you do know boost tails off near the redline? it does on mine

[p fandango]

you do know boost tails off near the redline? it does on mine
not with your 19t?

[jardon]

not with your 19t?

Of course. 1.1 bar max at 7000 rpm. Holds 1.2 bar to 6000. Nailing the wastegate shut would make no difference as it's a piddly turbo (though I wouldn't change it). If tuning for ~1.4 bar it will be dropping from that peak by 5000-5500 rpm as the flow limit of the exhaust housing is reached. I dare not measure my exhaust back pressure at high rpm WOT as it's probably quite nasty. EGT's are probably a bit iffy too but WMI should help keep a lid on it.

Edit: If you want boost to hold at ~1.4 bar to 7000 rpm then fit a 2871 minimum or buy a smaller engine. Although boost falls it is simple enough to keep reasonable torque with appropriate cooling and spark advance.

[jardon]

The original volvo actuator is back on and normal boost has returned though I've a few gentle miles to do so the ECU can adapt. Pondering now to leave as is and accept that boost dies soon after 5000rpm or start again with a Forge green spring the lowest psi rated which I'm sure will be stronger than my current Volvo fitment.

As before I have a yellow spring (which may still be too strong) if you'd like to try it.

[p fandango]

Of course. 1.1 bar max at 7000 rpm. Holds 1.2 bar to 6000
JT's 19t is running just over 1.2bar, revs to 6500rpm & as you can see from the boost gauge its as solid as a rock. No sign of drop off what so ever so defiantly got potential for more


http://www.youtube.com/watch?v=6dBohlkhqEs

[jardon]

Fair enough - mine boosts to 1.4 bar so does have a peakier boost profile. I'd still be surprised if that actually is a real 1.2+ bar at 6500 rpm. With 100% BCS duty and a 17 psi actuator mine won't hold that and the spring stiffness makes a big difference at high flow. Having said that we are comparing apples and oranges perhaps as my engine has a higher flowing head (ME7) and exhaust VVT - increase air flow through the engine and boost will drop off from it's peak more quickly.

Edit: In JT's dyno plots it doesn't hold anywhere near 1.2 bar at 6500 rpm so I wonder if we are looking at a rock solid 1 bar?

[officerbrooks]

As before I have a yellow spring (which may still be too strong) if you'd like to try it.

Thanks I shall try the green first as I think earlier advice was to use the weakest I can get away with. Having got a shiny new Forge actuator I need to spring it as close to Volvo original as I can in order to use it. I believe you're right, RICA maps to suit mostly standard parts and I'm maybe expecting too much so will I have to go to a 19T?

[p fandango]

Edit: In JT's dyno plots it doesn't hold anywhere near 1.2 bar at 6500 rpm so I wonder if we are looking at a rock solid 1 bar?
as always said, a dyno will never be able to recreate the air conditions of a road so wouldn't expect the boost curve to be the same as on the road. I'm sure he checked the calibration of his gauge against against there readings

[jardon]

Ok. My previous experience tells me its unlikely though. Redbricks car made 60bhp more and didn't hold that much boost on a 19t'd 850. Ditto for any td04 I've seen so jt's would be the first.

[p fandango]

Ok. My previous experience tells me its unlikely though. Redbricks car made 60bhp more and didn't hold that much boost on a 19t'd 850. Ditto for any td04 I've seen so jt's would be the first.
no offence, but "your experience" doesn't mean any think inless you've used the same mods as JT. Was Redbricks car MTE mapped as well?

[jardon]

no offence, but "your experience" doesn't mean any think inless you've used the same mods as JT. Was Redbricks car MTE mapped as well?

Apologies - we are arguing about 0.1 bar! My broader point is that these are peaky turbos if mapped for highish boost.

Edit - Andys car has a T5D5 community map using a 17psi actuator - fitted because they were losing boost with a 13 psi spring up top.

[jardon]

Much as I hate to admit being wrong here are some things to consider with regard to boost:

1. TCV's leak a bit so for a given set up an MBC will hold more boost. I don't know what JT runs but my car is mapped for 1.4 bar and will drop a bit compared to an MBC set at 1.4 bar.

2. You can get a shed load of boost but hopeless performance with incorrectly set cam timing.

3. My claim about ME7 engines consuming more air is flawed - they do but in such a way as to spin the turbine faster and make more boost.

4. A stock actuator set very tight will not hold more than 1.1 bar at 6000 - even with hose to the compressor housing detached - it will blow open and if you want to maximize what a 19t has to offer then fit a forge or similar.

5. 1.3 bar at 6500 is possible on a 19t'd 850 with stock head but that likely points to better flowing exhaust valves than inlet and not necessarily more power.

6. There are several reasons an equivalent ME7 engine makes more power than an 850 - I was under the impression it was just vvt and better flowing head but there are other factors including lighter crank and valve springs and bigger throttle.

I live and learn. Hope this helps and sorry for being stubborn.

[p fandango]

Much as I hate to admit being wrong here are some things to consider with regard to boost:

1. TCV's leak a bit so for a given set up an MBC will hold more boost. I don't know what JT runs but my car is mapped for 1.4 bar and will drop a bit compared to an MBC set at 1.4 bar.

2. You can get a shed load of boost but hopeless performance with incorrectly set cam timing.

3. My claim about ME7 engines consuming more air is flawed - they do but in such a way as to spin the turbine faster and make more boost.

4. A stock actuator set very tight will not hold more than 1.1 bar at 6000 - even with hose to the compressor housing detached - it will blow open and if you want to maximize what a 19t has to offer then fit a forge or similar.

5. 1.3 bar at 6500 is possible on a 19t'd 850 with stock head but that likely points to better flowing exhaust valves than inlet and not necessarily more power.

6. There are several reasons an equivalent ME7 engine makes more power than an 850 - I was under the impression it was just vvt and better flowing head but there are other factors including lighter crank and valve springs and bigger throttle.

I live and learn. Hope this helps and sorry for being stubborn.
some interesting stuff there that does make sense, JT's running a MBC & the lightweight flywheel must be helping alot. He was still running the standard actuator in the vid tho, but lets not start on all that again lol

[jardon]

For interests sake I just got 2 old TCV/BCS out of the garage. There is flow in this off-car state between the compressor and actuator ends but no flow through the intake end - because I guess in the de-energised state Volvo want the TCV to default to least boost. I connected the intake end to my mityvac and pressurised each in turn - the oldest one held 10 psi while the newer (not brand new) held 20 psi. I'm not sure what this tells me but something happens with age. I'm not sure if the valve is a pulsed pintle diverting all air to the actuator at 0% duty and all to the intake at 100% duty OR just an electronic bleed valve which is open continuously at 100% duty - this latter description is going to allow the actuator to see some boost pressure which is perhaps why they don't give the same maximum boost at high rpm as an MBC. Any ideas?

[jardon]

Not to be outdone and feeling suitably foolish in my claims I bought a 0.8mm boost restrictor "pill" from Owens and inserted it pre-BCS. The inlet to the bcs is ~2mm in diameter. The theory is less air pressure/volume gets to the bcs from the compressor housing so the bcs is not bleeding as much to the actuator. The upside of this is that I now hold 1.31 bar to 6900 rpm in 4th! There is a small spike in the 4000's to just under 1.5 bar which may be considered a gain or a problem depending on your point of view. This was datalogging with Softloader - AFR 11.3 at full boost, 32 degrees advance at 6900 rpm and iats never got above 19C (ambient 9C). This is an extra 0.2 bar at the redline and it feels amazing. Thanks for helping me prove myself wrong - it was totally worth it! My experience did in fact count for nothing - I live and learn.

[officerbrooks]

So a Forge green spring fitted which still felt stronger than the old Volvo original. I gave the ecu time to accept it and found 1.4 bar initial boost or rather a spike then 1.2 bar and 0.9 from 4500rpm. I changed the BCS to an IPD unit and had crazy low rpm boost but again 0.9 from 4500rpm. Car felt like a high powered diesel so all old original parts now back on and 1 bar at 5000rpm.
.
Has anyone fitted a Kalmar Union "Drop in intercooler" is it that straightforward and worthwhile?

[Loadsamiles]

There's no point whatsoever in comparing ME7 with previous systems, they just don't behave in the same way at all. There can be many many reasons why an ME7 will pull boost throttle and timing, it can even change with the weather.

As far as the BCS (TCV) is concerned I have found that (depending on use) as little as 30,000 to 50,000 miles of use is sufficient for it to degrade in performance, the air it uses is corrosive if you are using the stock crank case ventilation return. The ME7 ECU can have it cycling very frequently. What you think would just be an open state can actually be a very modulated cycle of states.

For your turbo to really be fully "on" the car needs to have all parameters correct, just one out of limits will cause truncated boost. If your intake temp or fuelling is anywhere near an unsatisfactory value the ECU will simply not allow a "full power" state to occur, boost, timing and throttle can all be limited.

I did a huge amount of data logging with VADIS / VCT2000, both on the dyno and the road.

It is certainly worth checking that the TCV is 100% functional. it may well be able to open/close a weak actuator if it is slightly leaking, but a stronger spring may well be too much to push against if the TCV is leaking.