MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: Hurdy on January 28, 2010, 11:26:44 pm
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The New Forge K04 wastegate actuator went in today and what a nightmare it was to get on. There is very little room to work in on the ED30 and due to this the intercooler downpipe, R/H side driveshaft, coolant expansion bottle, intake and engine mounts all had to be dropped off/taken off to get at it. Fiddly ain't the word for it. This is a PITA job. Thanks to Steve Jr and Craig at Statllers for pouring blood and sweat to get it on. :happy2:
Why did I fit it?
Basically the OEM actuator has a weaker spring and mechanism than the Forge item and when under full load the OEM actuator can "bleed" air pressure away from the impeller on the turbo reducing ultimate power handling capability. So, this job is partly eradicating a weakness and partly a tuning modification
link to Forge website...
http://www.forgemotorsport.co.uk/content.asp?inc=search
The good thing is that the car feels more immediate in the midrange and smoother. Backside dyno can feel a difference, but when you have a large amount of power anyway it is really hard to tell for sure whether it is the road conditions that have improved recently or the true pull of the car. I'll be taking the car onto the dyno next week and use the same dyno all the time, so should get some comparative runs for you all. The run will also show boost pressure. I'll get the graphs overlaid too for direct comparison. :jumping:
Here's a linky to the golfmkv forum thread where they tested it.
http://www.golfmkv.com/forums/showthread.php?t=106245
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i looked at that a while back. alot of people seemed to think that you would need mapping to utilise it, or was that all scaremongering.
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Depends what you mean by the extent of mapping. Revo is the only mapping that really suits this development due to the end user being able to adjust boost/timing/fuelling accordingly.
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Thats right, in the US REVO users were able to take much better advantage of this that others.
Nice mod Hurdy, I was wondering when somebody on here was going to get the wastegate actuator. I think you will end up quite liking this mod :evilgrin:
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woohoo , are you the first in the uk John ?
nice mod, that from what Ive read really makes a huge difference.
(it seems that many of us run with some leakage as a matter of course!)
I cant wait to see your overlaid graphs , on your car they could be quite an eye opener... :jumping:
a mod for the truly dedicated :happy2:
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nice 1 John, can't help but think I'm gonna wish I hadn't read this though :smiley:
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Another Seed Planted nicely Mr Hurditch :happy2:
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It sounds like this mod is what might be described as 'Deep Level'.
I'm glad to see our intrepid explorer Master Hurdy has taken the plunge as I don't entirely trust many of the posts across the pond. I need to catch up and read what they have to say anyway.
So, how many hours labour to install was it, John?
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Very important note from Forge: The car must have a HPFP installed before fitting their wastegate actuator mod.
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A very good description from the US forum of what it does on a modded car : -
"Due to the greater amount of exhaust gases that flow from cylinders into exhaust manifold the stock spring of the actuator is too weak to hold the raise in pressure through the exhaust manifold. The wastegate prematurely cracks open and lets gases bypass the turbine, net result is a little lag and power loss. With the actuator from Forge, the proper spring (which firmer than stock) allows the wastegate to hold higher pressure in the manifold, but at the same let the ECU and N75 value control the boost level for any given engine load and throttle position."
I think Forge offer a K03 version but need to confirm. Wastegate Actuator plus HPFP could be on the list for 2010.
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Yes they do offer a K03 version. In fact it has been around for a while longer than the K04.
Check these threads for more info:
http://www.golfmkv.com/forums/showthread.php?t=89839&highlight=wastegate+actuator
http://www.golfmkv.com/forums/showthread.php?t=80971&highlight=wastegate+actuator
Be warned - the threads contain the usual handbags that we have come to expect on the American forums.
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as the yanks would say thats "sick". :stupid:
looking forward to the overlaid graphs. i presuming the spring in the stock actuator will get weaker with age as well,
i think there could be some good potential gains here.
Depends what you mean by the extent of mapping. Revo is the only mapping that really suits this development due to the end user being able to adjust boost/timing/fuelling accordingly.
i must admit power and delivery wise im really happy with my current map, but there are so many excellent features that REVO have. most importantly adjustability.
being able to fiddle with your settings to easily utilse other mods to their max potential, and also having the possibility of making the map more agrressive for track days or less aggressive for snow/rain etc is a real positive.
somrtimes i do wish i had gone for REVO for that pure reason
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i must admit power and delivery wise im really happy with my current map, but there are so many excellent features that REVO have. most importantly adjustability.
being able to fiddle with your settings to easily utilse other mods to their max potential, and also having the possibility of making the map more agrressive for track days or less aggressive for snow/rain etc is a real positive.
somrtimes i do wish i had gone for REVO for that pure reason
....Don't let Ben hear you say that! When I saw him recently he kept banging on about when am I going to change from Revo. It got to the point where I ignored his question.
I spent a lot of time researching before choosing Revo and I'm not saying it's the only good one out there but, as you rightly point out, the ability to adjust according to your hardware mods as they change is invaluable.
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A few answers to questions.
The actuator hasn't been fully "dialled in" with the REVO software yet. We measured the OEM bracket mounting point to nut point distance and took that as a start point, marked up the threaded rod with tippex and then turned on the pressure another few turns. The actuator is working well at this point, but I'm sure that there will be more to come when logs are done and the length altered to more/less distance.
The actuator took about 4hrs to fit, but it may be done quicker now we know what is involved as we swore profusely "experimented" with different ways to see which one was best.
Another Seed Planted nicely Mr Hurditch :happy2:
I try my best :evilgrin:
woohoo , are you the first in the uk John ?
Possibly, although there may have been some UK testers out there.
My butt dyno may have been right. I did a quick 0-100 test and my previous best was a 11.1 and today I managed 10.8 in similar conditions. :happy2:
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I have heard rumours that you can adjust the OEM actuator that will do the same thing, can't say it's true or not though :popcornsoda:
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I have heard rumours that you can adjust the OEM actuator that will do the same thing, can't say it's true or not though :popcornsoda:
Yes, you are right, but if you adjust the stock actuator then it will have less travel and more pressure on a weaker spring. Not something I would be happy to do myself for the long term reliability of the car.
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Seems like an excellent mod. The one thing that concerns me is that if it's trial-and-error to achieve the optimum setup, what about the hassle involved in access to it for adjustment each time? Or am I mistaken? I'm thinking about the installation steps I've seen posted.
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Adjustment is done from the other end of the actuator on the threaded rod and makes it easier to adjust. Fitting is a PITA though! :fighting:
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^^^^
Ah, and so I assume that the threaded end is easily accessible. :drinking:
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still fiddly to get to (knuckle scraper time :scared:), but at least you don't have to dissasemble half the car :laugh:
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when you planning on the dyno run again hurdy. if you had VCDS it would have been good have to seen logs to see how well it built up and held boost in comparison to the stock actuator
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Quick update,
Been flitting about between Revo and logging data and the actuator needs backing off slightly. At the moment the bottom to midrange is mad fast, but the top end seems like it is holding back. Spoke to Carl (big thanks!!) at Revo, who helped me analyse the data and the actuator is wound on too far keeping it open longer and then when the actual boost exceeds requested it is having to back off which is killing the top end grunt.
Also it looks like I may need to investigate my cam follower as there is a difference in requested and actual rail pressure across the board under load.
The initial "after" dyno lost me 25bhp and 9lbft :sad:
Going back once the car is set right. Already feels better at lower boost setting, but needs the actuator adjusting first.
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this is what puts me off of this. quite a few of the guys in america seem to have had the same problem. its not the waste gate being the problem. its all problem to do with the adjustment of the spring causing issues. plus you have been able to adjust your settings with your SPS, i dont have that luxury
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Yeah, I know what you mean. The only real option is to have REVO and the SPS+ if you want to get the most from the actuator. A great mod once set right, but it is one of those "finger in the air" mods for the first few attempts at setting. If you haven't got VCDS (or access ) then you're pretty much stuffed too :sad1:
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well got this fitted by jkm yesterday they removed the turbo in the end to install as i was getting some arb's fitted so lower subframe was off which i believe made it easier, not cheap but on the plus side the turbo still looks in pretty good condition they say
initial impressions was that boosty certainly came on earlier and stronger, in fact its the strongest i have ever felt it, but as hurdy mentioned it also seemed to loose some umff in the higher rev range. this was all with my pre-actuator settings B8T5F6.
managed to get out this evening and do some logs, also turned down the boost to 7 and its seems pretty good, probably needs more time to adapt but this was a pull in 4th unfortunately due to traffic it was difficult to get to higher revs -
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fu347%2Fjnewby99%2Fboost-1.png&hash=2ea95f8d038ce18697a91dec07bdf2972b0a4d4f)
still quite new all this vagcom stuff but hows it looking?
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The logs look similar to mine, but your duty cycle stays on maximum slightly further in the rev range and your "actual" boost pressure is going waaaaay over where it should be. When mine was initially set up boost pressure was sitting at a peak of over 3000mbar and the only way to bring it down was to adjust the actuator as it was beyond what the SPS+ could change. My actuator is now set about 1.5 turns after the flap closes, any more and I was getting too much overboost. Too much overboost and you'll get a really strong torquey midrange but a blunted performance at the top end. Back it off and the midrange is still very strong, but you'll get your top end urge back too.
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that looks around 27-28psi peak ! Id be careful and look to getting the actuator adjusted a bit as Hurdy says.
Im not expert , but i dont get why your N75 duty cycle hiccups just as you boost starts to overshoot, I thought it was always a smooth transition. I'll go and have a readup :happy2:
glad its gone well, I guess it really needs some setup time :happy2:
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Bump :)
Whatever happened here?
Nice vid i just found, how it applies to the gti i dont know..
As long as you have a HPFP upgrade, and either REVO or APR pump-specific software, it can provide a healthy jump in boost and power. We've seen around 20 peak whp and tq with APR software and around 40 peak whp with REVO software due to the ability to adjust various settings.
GIAC software doesn't seem to like the upgrade very much.
The higher than stock base spring pressure within our replacement units allows for the wastegate flapper to be held closed tighter and for longer against the exhaust gas pressure flowing through the turbo.
Consider that by increasing the boost pressure entering the motor on the intake side of the system, you will see a similar and corresponding increase in exhaust gas pressure that is exiting the motor into the exhaust manifold to spool the turbo. It is a common practice to upgrade the bypass valve to a stronger unit that will better support the increased boost pressure on the intake side, however, you need to also increase the spring tension of the wastegate actuator on the exhaust side to better contain/sustain these higher exhaust gas pressures as well.
With the weaker spring of the stock unit, the exhaust gas pressure can sometimes force the wastegate flapper open prematurely. When this occurs, the exhaust gas that is supposed to be spooling the turbo is dumped, which will subsequently slow the speed of the compressor wheel and limit the potential to make boost in the most efficient manner.
Tightening the stock actuator and adding preload to the stock spring will have the same effect as our replacement, as many people are finding with wastegate tweak mods, but to a much lower degree. You're still working with an altogether weaker base spring pressure to begin with. the stock FSI actuator has a cracking pressure of 4 PSI.
We can assemble our units with any one of 3 different base spring pressure ranges stiffer than stock (10-15, 14-18, 19-24) so the possibility of the exhaust gas pressure prematurely opening the flapper against this higher spring pressure is minimized, if not completely eliminated. All of the exhaust gas is then kept within the exhaust housing of the turbo to continue spooling the wheel keeping boost at it's peak potential at all times.
A boost controller, mechanical or electronic, and including the stock boost control solenoid (N75 valve) will still allow you to adjust up from the base actuator spring pressure, and it will open the actuator when the target boost pressure is reached, but with the stock unit, there is still the potential for the exhaust gas pressure to prematurely force open the wastegate BEFORE the target boost is reached and the boost controller would send the signal to open the actuator.
With our unit, the N75 valve will still function in the same way, sending the pressure signal to the actuator to open it fully when the target boost level is reached, but there is far less chance of the exhaust gas pressure opening the flapper before that occurs.
Depending upon which base spring pressure is used and how the units are adjusted, you may see changes like quicker spool, less tapering, and an overall increase in the area under the boost curve.
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Bump :)
Whatever happened here?
iirc the overall consensus was it wasn't really worth the time and hassle to install and calibrate it correctly with a k04.
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Not something I'd do again as the benefits are minor.
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Well, its not that im looking for extra performance, but rather stop the air leaking out.. which im pretty sure is what im hearing
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Well, its not that im looking for extra performance, but rather stop the air leaking out.. which im pretty sure is what im hearing
That is probably the only reason to try the Forge actuator. :happy2:
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Supposedly you can initially try tightening up the oem valve.. may be worth a try
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Not relevant to the TFSI or K04 but....
All good fun and something we spent many an hour road mapping/altering/adjusting on my old Saab 9-3 Aero coupe project, I had the stock TD04-15T unit with the Forge Actuator and 2.3 conversion which managed 300bhp and 350 LB/FT and ran a 5.5 second 60-100MPH in 4th gear. Tried both the Green and Yellow springs both with and without addition pre-tension and did a run whilst logging and made adjustments etc.
You reach the point of clutching at straws especially if you cannot custom Map or alter the duty cycle of the boost control solenoid.....Adding another turn on the actuator can alter the base boost by a few PSI which throws out the rest of the software this causing an aggresive boost built or spike. Too little pre-tension and the Airmass request cant be achieved. Balancing act indeed!
I would probably advise anyone against making any actuator adjustments on their cars without proper mapping or logging equipment, just my two penneth :)
Cheers