Forge actuator update

[jardon]

I'll add pics tomorrow of my 'rebuild' as it is interesting to see how an actuator works. I have to back track slightly on my initial enthusiasm for the blue 14psi spring as it's a tyre shredder! The green 5 psi spring was hopeless and wouldn't reach target boost while the blue one was on/off - I haven't been able to modulate torque in low gears as the turbo is just trying to spool even with little pedal inputs. It was also spiking slightly but being me7 that was well controlled. I hadn't realised there was a spring choice in between but tonight I fitted a yellow 9 psi one. Thanks to Tim for talking me through how to remove and rebuild the actuator - it is fiddly. Anyway - I Tyhave my throttle pedal back and 1st/2nd are actually much more potent now that I can get the power down. I may be losing 1 psi at high rpm so I could add another half turn of pretension - I'll datalog to find out. It still does 60-100 gps in 5.6 sec (my own personal benchmark) so I don't think it's losing any oomph but the real gain is in off the line and mid corner ability to get power down. Nice.

[p fandango]

i've got a 1.2bar actuator fitted (which i haven't tried lol), but might look into the Forge one if its adjustable. Have you got a TD04 or KKK turbo?

[jardon]

It's a 19t - rebuilt by Owen Developments using Garret wheels. Ported and polished both housings and clipped turbine wheel. Have a look at T2 actuators and parts on the Forge website.

[p fandango]

It's a 19t - rebuilt by Owen Developments using Garret wheels. Ported and polished both housings and clipped turbine wheel. Have a look at T2 actuators and parts on the Forge website.
so it will fit my standard 19t fine then, many thanks

[jardon]

so it will fit my standard 19t fine then, many thanks

I think so - did 19t's ever have different housings?

[p fandango]

I think so - did 19t's ever have different housings?
no, i swopped the original 19t actuator with someone who bought the 1.2bar for his 16t but obviously ran too much boost then

[jardon]

Bought a Mityvac kit and thought I'd see what actually happens to my actuator when adding extra pretension. With no pretension (turnbuckle drops over the wastegate and just holds it shut) the actuator just starts to move at 9psi - as expected. With any any amount of increased pretension (I just kept adding it up to 3 turns) the pressure to just open only increased to 10 psi. My inference is that the spring is very linear - and adding pretension will make little difference. This is how it has felt to drive too - I won't say it didn't get a bit more savage with 3 turns of pretension but not a lot. While doing this I noticed the rod would stick at it's point of opening and "pop" rather than start to move gradually. Once popped it would open progressively so I lubed the rod and bearing with oil and copper grease and that sorted it. On Tims advice I will dismantle and check the rod/bearing for scratches etc and polish things up before lubing again. May try the blue spring again as could be that the savage behaviour was related to a sticky rod?

I can recommend a Mityvac kit for accurate diagnosis/set up of anything pressure/vac related (actuator/recirc/boost gauge etc). Just be sure to get a pressure and vac not vac only kit. My boost gauge is **** - it reads both high and low at all pressures!!!

[jardon]

Pics as promised a few weeks ago - the bearing is the blue plastic bit and I think the rod was sticking there. Any other tips?

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0039.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0038.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0035-1.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0036.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0037.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0032.jpg

http://i533.photobucket.com/albums/ee340/huwbellamy/IMAG0033.jpg

[jardon]

Just for fun I thought it might be worth trying a red spring - starts to open at 17 psi on my Mityvac. My concern was that I might bend a rod so I drove it gently for a bit to get the BCS adapted etc. I was expecting the ECU to say "no" as the map has always been written for a stock actuator opening at ~5 psi. It is a bit savage now but I've decided to stop being a pussy and accept that if I want scary fast I have to put up with it. Peak boost is still fairly well controlled but it will hit 22-23 psi in 4th and it comes in crazy hard (oooer) from just under 3000 rpm. I'm running a map with lots of advance, a 73mm MAF housing and a silly actuator spring relative to the size of my turbo so aggressive is how it's going to be I guess. I did get it to pull timing yesterday so I reckon I'm at the knock limit even with my WMI and methanol/V Power mix. It scares the §§§§ out of me but I like it.

[dtp]

I run the red spring in mine. :) good scary init. ;)

[jardon]

I run the red spring in mine.

I know - I felt left out.

[p fandango]

anyone know if the 19t actuators are on there website yet?

sounds like i need the red spring to go with it lol

[jardon]

Probably worth calling them. I have a yellow and blue spring if you want to buy an actuator with a red spring and find it's too harsh. I wonder how much "lost bhp" we have as a community due to ageing stock actuators. Definitely one of my favourite mods.