well, the past week my car had been having a hard time making the same boost it did during my tune last fall. On the street I used to make about 16.8 tapering to just under 14.5. Now, I was lucky to make over 15 and would taper to 13.6. This was on 10 lb garret actuators.

Well enough is enough, so I did some searching, asking and what-not and ordered up some new Forge actuators and springs. the install is rediculous on these so I had a local mechanic friend do most of the work on the car. Took us about 5-5.5 hrs to remove and reinstall the new actuators.

I went with the red springs which were rated at 17.5-20 psi. On the street I was hitting roughly 14.5-14.9 psi on spring pressure. Keep in mind, I am running the APS 2.5" exhaust - not the 3". In comparison, my 10 lb garretts pulled 6.5 lbs on spring pressure and I was maxing out the boost on them at ~17 tapering to ~14 at redline.

I know when I was looking at what springs to use, there wasn't much info out there, so I thought I would share my experience in case others are looking to swap theirs out.

 

good looking out zivman.

are you running an external boost controller or do you have a engine management (ie: utec, unichip) to control the boost?

i have the forge actuators with 10 psi spring, and the boost is very consistent for me at 15 psi, max boost. sometimes i get some boost spike which hits 16 psi on rare occasions during cold nights... but i think i can fine tune it a bit with the profec spec b 2 (that thing is such a pain in the **** to use).

do you have any pics of the install for future reference?

 

Glad you've got your boost back Ziv!

Long time no see!

 

So you feel the red springs are best for the APS TT application?

 

I am running the HKS Fcon Vpro with the HKS EVC V EBC. Right now, I am not running any boost controller and running strictly on spring pressure. Today with temps in the 70's, and maybe the springs seating themselves, I hitting 95-97 kPa on spring pressure.

I plan on running my boost controller this week and turning the boost up to 16-17 psi.


I would say at least get the blue springs. and if you are comfortabel with 13+ as the lowest amount of boost, go for the red ones. IMHO, over 13 lbs on spring pressure is a bit much.

Brian, you will also be running a slightly bigger exhaust with the EVOTT - I don't know if it flows better than the aps 2.5", but I would think it would. That being said, you might be better off with the blue ones. Talk to Tuan and see what he thinks

 

Thanks for sharing...boost looks about right for those springs. For those interested, just keep in mind, that you should downsize one spring, if you wanna run these pressures with the 3.5 inch test pipes, and 3 inch true dual. If you can this spring with the 3.5/3 setup, you will see close to 18psi or so.

 

+1 on Sharif's comment.

I'll be running the yellow springs from Forged which is rated at 14psi on spring pressure, I also have 3.5" downpipes and the APS 3" exhaust which should be enough to use a controller and get my desired boost setting.

 

I will eventually be putting cams in the car. Probably this winter and getting retuned on 91 octane, as a lot stations around here are dropping ot 91, and also a race gas map.
With these actuators, I might go for 18 or 19 lbs of boost depending on how confident my tuner is.


For those that are running the big exhaust, you will need to be carefull going with such a heavy spring like has been stated. I was posting this info for those of that still enjoy listening to the radio, talking to the passenger, or even hearing ourselves think and run the smaller, tamer exhausts.

After hearing the 3" in person, sorry, you guys are nuts................... or have stock in an ear plug company

 

If you say so old man.

 

I am coming up on 29 - still a kid by my defintion

 

Yeah..the 3 inch is a little loud...I just roll the windows down, and blast the music. Good stuff!

Funny thing, is the 3 inch APS is pretty mild on a G35. I guess the extra sound deadening helps. I could carry on a normal conversation in DutchBoy's G35 with the 3 inchers.

 

Yeah, I'm one of the old farts around here at 41.

 

That makes me feel even better about my EVO TT.

 

Don't worry Brian you will love the EVO TT, Its very nice and quiet, still makes power, and sounds awesome!

-George
GT Motorsports

 

Boost is back!

Got the boost controller dialed in today. I am using the HKS EVC V (limited edition black....in case you were wondering). Just needed a reset and then turn the **** until the desired boost level is reached.

I have the boost set now to 116 kPa tapering to 114 kPa. For those that only know PSI, that is 16.82 psi tapering to 16.53. My tune is good up to about 17.5 lbs. I might try to inch it up a bit, but this is good for now.

 

^^So you were at around 530whp at 14psi, I wonder where you're at now?

 

I am 35. I love my 3" exhaust. I get a kick out of it when I set off car alarms as I drive by.

 

Me and you are on the same page then.

Aaron, good to hear it worked out, I wonder how much power you're putting down now?

 

I was told in the 520's at around 14 psi on GRD's dyno. I am not really too concerned about the numbers at this point, just trying to get things dialed in the way they should be.

If I have a chance, I will run it on a local DD dyno and see what it pulls.

 

Thanks -

Like I said, if I have a chance I will run it, but not too concerned about the numbers.

If I had to guess, I would say I am at 510-530 on a dyno dynamics dyno. Keep in mind, I am running stock heads and cams