# Forge K04 actuator testing....(pics and logs inside).



## GolfRS (Feb 4, 2006)

Well seeing that Forge has now released the K04 actuator, i thought it might be a good idea to post a few words and logs from my experience with it, as i had (and still do) the testing unit for more than 3 months now...Here is a copy paste from "the other forum"....
_Well for those of you that have been waiting for this, it's
finally here.I have no knowledge of the actual release date, but for the past month i have installed and tested one of the few existing Forge K04 actuators out there, and this thread will contain my thoughts and findings, along with (of course) graphs and numbers.I will be updating this slowly with more data and pics.
For starters, the actuator itself.It has similar appearance to the K03 actuator, but the bracket is somewhat (a lot ?) different.The mounting holes on the bracket don't line up like in the K03 version, so you definitely need this if you have a K04._
_Compared to the OEM actuator, the actual threaded part of the actuator is shorter.Having played with the nuts (the actuator's of course) the OEM actuator is pretty uselessly long, since Forge's length pretty much matches the opening range of the wastegate itself.

























Installation was indeed a b*atch, as mentioned with the K03, but maybe even more so cause of the slightly different holes.I'm pretty handy with the wrench, but still i don't regret going to a shop for it (read further down to see why..).
After talking to Forge, i was instructed to try the Blue spring first, which AFAIK is the second hardest after the Red, and one hardest than the Yellow (the spring Forge uses for the K03 version also).I had been experiencing high N75 values at redline, and my reasoning was the excessive exhaust gas volume was pushing the wastegate open.When the install was over, i set the nut at almost OEM position and went for a run, but it so proved the Blue spring is TOO HARD for this turbo, and i wasn't ever able to control boost in an orderly fashion...
That meant the next possible spring was in order, which was the Yellow one.This however posed a HUGE problem, cause i seriously didn't want to redo the whole process, so i decided to remove the spring ANOTHER WAY...Don't ask me how, but i finally did it, and i don't wish it on anyone.So if Forge sends it with the Yellow spring....you leave it at that...._


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## GolfRS (Feb 4, 2006)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*

_Going on, the whole setup needed some adjustment for it to work as it should, and having
Revo software and an SPS Plus made it a whole lot easier.
Boost needed to be adjusted to return to the OEM levels (remember we don't want to
use the actuator as a simple "wastegate tweak", its the spring that must do most of the change in how the car reacts), and i finally managed to narrow it down to a few settings
variations that do the trick.
As for the noticeable results ?Well all i can say is that its the hardest i've felt the car pull so far since i've began modding it.I can't really compare my results to the K03 ones (my car is a K04 car but it also has TONS of other mods, including cams etc), but what i mostly felt, could be felt in the low to mid revs, and not that much at the redline.
The car just pulled SO MUCH HARDER from 2000 rpm, and logs showed a +30g/s difference in the low to mid range.Now some might say that is actually the nut adjustment, and not the spring itself, but i don't think so.I had audible boost/wastegate flutter when i was hitting peak boost, and all of that is now gone.I am not hitting much higher peak boost (i actually set it up that way) but pressure now drops progressively, and not playing up and down...
Over all, i have to say this is HIGHLY recommended, but for me it is NECESSARY to be installed and fine tuned by a professional, or at least someone with a fair knowledge of how the wastegate/software works to maintain boost and have the car run at its best.
Graphs
OEM actuator_








_Forge actuator (yellow spring)_








_Graphs were made with different SPS settings to adjust for the increased boost in the low to mid range.There was not much difference in boost pressure at redline, but there was a HUGE gain in low to mid revs, WITHOUT a need to drop timing settings.You can see a difference of ~30g/s at 4000 rpm.
Somehow the OEM graph came out very "rough".Don't really know why that happened.
Both graphs are without any kind of smoothing. _


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## GolfRS (Feb 4, 2006)

*FV-QR*

Oh and just to make sure, i've sprayed some "anti-APR" spray on this thread, so i'm hoping we'll be safe....for a while at least.....
But then again, these sprays have been known to fail.....


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## crew219 (Oct 18, 2000)

Interesting . . . if you scale both graphs the same you'll see the difference more clearly. 
For instance: Timing angle/MAF/mbar
OEM @4krpms 2.5/160/2500
[email protected] 2.5/180/2550
[email protected] 2.5/185/2475
[email protected] 0/200/2550
[email protected] 7/195/2450
[email protected] 7/205/2500
[email protected],5 10/210/2375
[email protected],5 10/215/2300
[email protected] 11.5/215/2275
[email protected] 11.5/225/2175
[email protected],5k 13.75/220/2075
[email protected],5k 15/220/ 2000
From what it looks like, you have a larger boost spike (which is understandable because the wastegate has more preload on it), but your boost has actually decreased in the upper RPMs compared to the OEM wastegate. Since you adjusted the SPS, it'd hard to tell if the ECU is even requesting the same amount of boost on the forge vs oem wastegate runs. 
If you post up the raw data, I'm sure someone will graph both sets of data and set them to the same scale so it is more easily read.
Dave


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## tdotA3mike (Feb 5, 2009)

*FV-QR*

wouldn't a stage II+ HPFP software upgrade (any tuner) get you correctly calibrated ECU as well? This is on my mod list as i have said before but for my K03.


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## rhouse181 (Apr 13, 2008)

*Re: FV-QR (GolfRS)*


_Quote, originally posted by *GolfRS* »_Oh and just to make sure, i've sprayed some "anti-APR" spray on this thread, so i'm hoping we'll be safe....for a while at least.....
But then again, these sprays have been known to fail.....

http://****************.com/smile/emthup.gif 
Ohh... And the difference between those two logs is pretty spectacular


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## GolfRS (Feb 4, 2006)

*Re: (crew219)*


_Quote, originally posted by *crew219* »_Interesting . . . if you scale both graphs the same you'll see the difference more clearly. 
For instance: Timing angle/MAF/mbar
OEM @4krpms 2.5/160/2500
[email protected] 2.5/180/2550
[email protected] 2.5/185/2475
[email protected] 0/200/2550
[email protected] 7/195/2450
[email protected] 7/205/2500
[email protected],5 10/210/2375
[email protected],5 10/215/2300
[email protected] 11.5/215/2275
[email protected] 11.5/225/2175
[email protected],5k 13.75/220/2075
[email protected],5k 15/220/ 2000
From what it looks like, you have a larger boost spike (which is understandable because the wastegate has more preload on it), but your boost has actually decreased in the upper RPMs compared to the OEM wastegate. Since you adjusted the SPS, it'd hard to tell if the ECU is even requesting the same amount of boost on the forge vs oem wastegate runs. 
If you post up the raw data, I'm sure someone will graph both sets of data and set them to the same scale so it is more easily read.
Dave

SPS was adjusted for boost, actually lowering the peak boost value but keeping the requested redline value.
Somehow in my car the Forge unit showed the biggest gains in the low to mid range, making it possible to spin my wheels again after the camshaft install.I honestly couldn't have done it without it.
What was also weird AND CERTAINLY WORTH NOTING, is the fact that as you can see, with the same g/s as you noted above, and almost the same boost, i saw an actual increase in TIMING.That most definitely should mean more power....But everty car is different...
Also, in all fairness to Forge, i am now in the process of throwing codes and replacing my flap adjuster, so i can't be certain if that had any effect on the logs.I will be doing some revised logging after i do the flap motor swap.. http://****************.com/smile/emthup.gif


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## rhouse181 (Apr 13, 2008)

im not sure the discrepancy in peak numbers is more important... just look at the difference in the smoothness of the curves between stock and the forge unit. the forge wastegate controls boost levels much more consistently, which will make a huge difference in drivability. car would just pull without the tuning having to retard timing or dump boost to adjust for spikes...


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## GolfRS (Feb 4, 2006)

*Re: (rhouse181)*


_Quote, originally posted by *rhouse181* »_im not sure the discrepancy in peak numbers is more important... just look at the difference in the smoothness of the curves between stock and the forge unit. the forge wastegate controls boost levels much more consistently, which will make a huge difference in drivability. car would just pull without the tuning having to retard timing or dump boost to adjust for spikes... 


That is true, and it was something that impressed me also.At first i thought it was just "artifacting" on the OEM curve, but having a look at some older logs too, the curve was the same, full of spikes and irregularities.From a driving standpoint, the car felt more "atmospheric" and linear, and folks, lets face it, for the price Forge is selling this part, i can't think of a reason NOT to get one....
Too bad its hidden away, cause it sure is some serious engine bay jewelry too !!!


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## Joeydabomb (May 1, 2009)

I've already ordered mine, I'll make sure to post up my results in about a month or so when it gets installed.


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## acespizee (Dec 19, 2007)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*

Nice one, i've got the Forge actuator on my K03 and it definetly spools up much harder and quicker than the oem unit. I also know what your talking about when changing springs as getting the actuator in was nasty as you had two almost invisible 10mm's to undo, so you dont want to take it all out again just to change a spring, so we had to take the wheel off to get to the top of the actuator to get the spring out but getting the bolts back in was horrible, it was a horrible job. I first had the yellow spring but it was overkill on my car, holding too much boost up top or spiking hard up top. I've since had it changed to the K03 'green' spring (10 psi) and the car is much better, but that yellow spring was a beast, pulled like a mad man.
Since doing this upgrade i had a problem that i thought was because of the yellow spring but it was not, so the 'yellow' spring may go back in. My local tuner wont be happy.







Like i said it is a nasty job. but has to be done.








It is also true as you noted that the timing was much much better than before, dont know why but it was.
If done correctly this is a brilliant upgrade.







http://****************.com/smile/emthup.gif 



_Modified by acespizee at 6:47 AM 1-23-2010_


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## GolfRS (Feb 4, 2006)

*Re: Forge K04 actuator testing....(pics and logs inside). (acespizee)*


_Quote, originally posted by *acespizee* »_

Since doing this upgrade i had a problem that i thought was because of the yellow spring but it was not, so the 'yellow' spring may go back in. My local tuner wont be happy.







Like i said it is a nasty job. but has to be done.









Well since i was the tester for the K04 , i had to also test the blue spring, and removing the whole actuator to change it was NOT an option.But since i did it myself, i devised another way to change the spring, which was also a b*tch to do, but it worked....Dunno what your problem was, but i think Forge suggests the yellow spring for the K03 also....


_Quote »_It is also true as you noted that the timing was much much better than before, dont know why but it was.


Yeah, i am now going to change my crappy flap motor and see if that changes things even more....


_Modified by acespizee at 6:47 AM 1-23-2010_[/quote]


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## 08 passat turbo (Mar 29, 2008)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*

hmmmm this is interesting...what if ur overboosting and hitting full boost at 2200rpm? this is probably not the mod u want correct?


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## Krieger (May 5, 2009)

*FV-QR*

hitting more than 18 PSI sooner than 3300 sounds good to me in my book...


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## GolfRS (Feb 4, 2006)

*Re: Forge K04 actuator testing....(pics and logs inside). (08 passat turbo)*


_Quote, originally posted by *08 passat turbo* »_hmmmm this is interesting...what if ur overboosting and hitting full boost at 2200rpm? this is probably not the mod u want correct?

The reason you need someone who knows installing and fine tuning the actuator, is to keep boost under control, and to follow the spool characteristics you want.
I find it hard to hit full boost at 2200 rpm though...


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## acespizee (Dec 19, 2007)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*


_Quote, originally posted by *GolfRS* »_
The reason you need someone who knows installing and fine tuning the actuator, is to keep boost under control, and to follow the spool characteristics you want.
I find it hard to hit full boost at 2200 rpm though...

I always hit full boost around 2200-2300 rpm aswell, until my oem actuator started going funny that is, but with the Forge unit in, 2200 rpm full boost is back in full effect.


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## acespizee (Dec 19, 2007)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*


_Quote, originally posted by *GolfRS* »_
Well since i was the tester for the K04 , i had to also test the blue spring, and removing the whole actuator to change it was NOT an option.But since i did it myself, i devised another way to change the spring, which was also a b*tch to do, but it worked....Dunno what your problem was, but i think Forge suggests the yellow spring for the K03 also....



My problem was throttle closing a couple of times over 5k rpm, but was nothing to do with the actuator. Yeah Forge does suggest yellow spring for K03 but they do a softer 10psi spring if you dont get on with or dont want the yellow spring. The 10 psi spring is still alot stiffer than stock 5psi spring on the K03.


_Modified by acespizee at 3:14 PM 1-23-2010_


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## 08 passat turbo (Mar 29, 2008)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*

2460mbar at exatcly 2200rpm


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## GolfRS (Feb 4, 2006)

*Re: Forge K04 actuator testing....(pics and logs inside). (08 passat turbo)*


_Quote, originally posted by *08 passat turbo* »_2460mbar at exatcly 2200rpm

Haha...yes...But that's *YOUR* full boost and on a K03....








Some people go a LOT more....










_Modified by GolfRS at 10:40 AM 1-24-2010_


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## acespizee (Dec 19, 2007)

*Re: Forge K04 actuator testing....(pics and logs inside). (GolfRS)*


_Quote, originally posted by *GolfRS* »_
Haha...yes...But that's *YOUR* full boost and on a K03....








Some people go a LOT more....









_Modified by GolfRS at 10:40 AM 1-24-2010_

True, True.


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## jaycheetwood (Jun 18, 2009)

I am wondering if my actuator is failing.. its started doing this after turbo/wastegate replacement under warranty. I spike out and it drops like 2 - 3 psi then reboosts back up another 3-4psi or bounces around funny and I can hear like a subtle flutter. But i know its not dv or pcv.


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## GolfRS (Feb 4, 2006)

*Re: (jaycheetwood)*


_Quote, originally posted by *jaycheetwood* »_I am wondering if my actuator is failing.. its started doing this after turbo/wastegate replacement under warranty. I spike out and it drops like 2 - 3 psi then reboosts back up another 3-4psi or bounces around funny and I can hear like a subtle flutter. But i know its not dv or pcv.

It may well be your actuator.
I was having the same issue until i switched to the Forge.
Now i only get a solid spike, and boost tapers off smoothly.
No harm in trying i guess.
The worst that could happen is that you end up with a faster car..LOL


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