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I think you guys are missing the cause or I am not explaining it correctly. My spring only pressure/preload is about 10 psi (solenoid control off) - the controller is properly installed and working as it should. However, the medium boost actuator can not hold more than 21 psi because the turbine housing pressure is blowing the wastegate open even at 100% WGDC (which is basically the same as disconnecting the vacuum line to the actuators). The only way to make higher than 21 psi would be to change to the high boost actuator (which is equivalent to swapping the springs on an EWG).
Edit: Have a look at the full stroke pressure and also the bottom of the chart you linked too previously
I saw that. That's the full stroke pressure when the boost pressure from the vac line gets to 20.6 psi, not the exhaust pressure capable of pulling the wastegates open against the spring though (other end of the diaphram).
I just can't see that the exhaust pressure would be high enough when generating 21 psi of boost on the compressor side to force the spring open with no boost pressure on the diaphragm. The way I read "The use with up to x pressures avoid long-term wear. By bottoming out the stroke, the diaphragm can be distressed over the course of time", is that putting more than 20.6 psi into the regulators will max out the stoke and bottom out the diaphragm, causing potential wear.
Are you sure your recirc inputs are seeing boost? They need the boost signal to remain closed until needed (the switch to vacuum on throttle closed pulls them open).
I saw that. That's the full stroke pressure when the boost pressure from the vac line gets to 20.6 psi, not the exhaust pressure capable of pulling the wastegates open against the spring though (other end of the diaphram).
I just can't see that the exhaust pressure would be high enough when generating 21 psi of boost on the compressor side to force the spring open with no boost pressure on the diaphragm. The way I read "The use with up to x pressures avoid long-term wear. By bottoming out the stroke, the diaphragm can be distressed over the course of time", is that putting more than 20.6 psi into the regulators will max out the stoke and bottom out the diaphragm, causing potential wear.
Are you sure your recirc inputs are seeing boost? They need the boost signal to remain closed until needed (the switch to vacuum on throttle closed pulls them open).
Yes I am running turbosmart dual ports which are working as expected. Beyond what I was told by AAM, if you do some Google searches there are posts around the web which also correspond to the 21psi wall I have hit. Perhaps my explanations aren't clear/correct enough for you to see, but I was just trying to share my experience with the medium actuators with you to prevent you from having to pull your motor an additional/yet another time.
I saw that. That's the full stroke pressure when the boost pressure from the vac line gets to 20.6 psi, not the exhaust pressure capable of pulling the wastegates open against the spring though (other end of the diaphram).
I just can't see that the exhaust pressure would be high enough when generating 21 psi of boost on the compressor side to force the spring open with no boost pressure on the diaphragm. The way I read "The use with up to x pressures avoid long-term wear. By bottoming out the stroke, the diaphragm can be distressed over the course of time", is that putting more than 20.6 psi into the regulators will max out the stoke and bottom out the diaphragm, causing potential wear.
Are you sure your recirc inputs are seeing boost? They need the boost signal to remain closed until needed (the switch to vacuum on throttle closed pulls them open).
Those are still small T25 turbines, and at 20psi of boost, your exhaust back pressure could easily be 50+ psi. That is more than enough to push a wastegate open.
Yes I am running turbosmart dual ports which are working as expected. Beyond what I was told by AAM, if you do some Google searches there are posts around the web which also correspond to the 21psi wall I have hit. Perhaps my explanations aren't clear/correct enough for you to see, but I was just trying to share my experience with the medium actuators with you to prevent you from having to pull your motor an additional/yet another time.
Don't get me wrong, I appreciate the information. Just misunderstood the reason for the 21 psi wall (as it where) as you were at pretty much exactly the max spring psi for the mids. I've seen many Z32's on Garret turbos set for around 10-12 psi spring boost easily hit 28-30 psi.
My problem is that I'm going to run a street fuel tune on 94 octane (best we can get, no E85 up here ). That's going to need a spring boost of around 10-12 psi. But my race fuel tune for the track/strip on VP109 or C16 is going to need > 21 psi. Based on your information and that pdf from BW, that doesn't seem possible, and that's a surprise to me, since I've seen it done on many cars. The high boot actuators will have a spring boost too high for my street tune.
Seems to me, that BW made the wastegate ports big on these, but then didn't increase the size of the diaphragms in the actuators, which would allow a stiffer spring for the same boost opening point. This would allow the now stiffer spring the ability to hold the gate closed at a higher exhaust pressure differential across the turbine. I'm looking into the actuators on the larger BW turbos to see if I can use one to solve this.
Got some info back from AAM, the very early kits (mine apparently) had the low boost actuators, which is why I remember my spring boost being 5-6psi (car's in storage right now), and why you got the mid's.
Lazy boost onset or wastegate blowing open
• Canister spring too soft (use “medium” or “high”)
• Not enough rod preload (tighten nut to add preload)
• No electronic intervention (spill valve can block pressure signal getting to WG can, hence delaying the opening)
One thing that we haven't done is adjusted the rod preload which is one of the 3 possible reasons for the wastegate blowing open. Perhaps it is something we can look into trying, my car should be on the lift again this week and I will see if we can tighten down the preload a bit more to see if that has any effect on psi. Since my current spring pressure is 9-10 psi, according to the chart, the preload could only be around 2mm.
Which leads me to wonder - if I recall correctly the rod preload was set at more than 2mm (for some reason I am thinking we set it closer to 10mm) - is there a possibility that I actually have the low boost actuators as opposed to the medium ones which Max told me I had..?
It seems the more we discuss the more confused I am starting to get.
One thing that we haven't done is adjusted the rod preload which is one of the 3 possible reasons for the wastegate blowing open. Perhaps it is something we can look into trying, my car should be on the lift again this week and I will see if we can tighten down the preload a bit more to see if that has any effect on psi. Since my current spring pressure is 9-10 psi, according to the chart, the preload could only be around 2mm.
Which leads me to wonder - if I recall correctly the rod preload was set at more than 2mm (for some reason I am thinking we set it closer to 10mm) - is there a possibility that I actually have the low boost actuators as opposed to the medium ones which Max told me I had..?
It seems the more we discuss the more confused I am starting to get.
It is possible you have the low's with the preload almost maxed out. What we do is use a regulated compressed air feed tee'd to both actuators to 'balance' them. We set a target crack open PSI, and use the regulator on the feed to repeatedly cross that psi and check that both wastegates crack open at the same level. That way we know the exact spring boost and also that both turbos are working the same.
A pic of the threaded end of the actuator on your car would tell. At 10 psi spring boost, if the nut is showing almost no preload, you've got the mids, if the nut is near the max end of preload (the 10mm), you're on the lows.
There may be a visible part number on these, don't know if you will be able to read it with them mounted.
Uses a second port on the actuator that uses boost pressure to hold the wastegates closed, and thus can hit higher boost with a lower spring. Need a new solenoid, but no big deal if these will cover my range.
Ttv36, feel free to reply if you figure out what actuators are installed on your car.
So I snapped a picture of one of the wastegate nuts, I think I can count about 10 threads. I'm guessing this means I actually have the low boost actuators instead of the medium ones that I was told that the kit would ship with?
So I snapped a picture of one of the wastegate nuts, I think I can count about 10 threads. I'm guessing this means I actually have the low boost actuators instead of the medium ones that I was told that the kit would ship with?
Mind is blown right now..
Looks like. If you want, to verify you could mark the current position, and back it off until it goes slack. The number of turns is your preload. Any chance off swapping them on car (as I recall unlikely)?
Just noticed your reply a ways back. Did you block off the efr's built in recircs for a bov?
Looks like. If you want, to verify you could mark the current position, and back it off until it goes slack. The number of turns is your preload. Any chance off swapping them on car (as I recall unlikely)?
Just noticed your reply a ways back. Did you block off the efr's built in recircs for a bov?
If possible, I'm sure swapping them out would probably be quite a PITA. I'll see if I can double check the preload next time it's in the air.
The recircs that came with the kit were removed and I opted for two Turbosmart Kompact Shortie Dual Ports (50% recirc and 50% VTA) instead so I could have the bov sound. The driver side has plenty of room, but we had to notch the engine bracket for the passenger side to fit.
Long story short on last summers dyno session, no passenger VTC. Did everything we could think of on the dyno, swapped the solenoid, the cam angle sensor. Ran out of time and just pulled the driver side. Suspected partial oil blockage in the rear timing cover to the VTC as I had it cleaned up and got little ceramic ***** in it (had to pull the gallery covers to clean it out). Still got 586 hp and 493 torque, but the show doesn't start until 4500 rpm or so.
After that I switched to twin 14" Spal fans that are duty cycled with an SSR from the Haltech.
I also played around with boost by gear, wheel slip boost and timing pull to generate a pretty good traction control so I can just plant it and listen to the tires squeal slightly as it pulls.
Pulled the engine, replaced the rear timing cover with a new one:
In the process found the real cause of the VTC failure:
The seal must of wedged on install and spun in the slot as it wore a grove out of one side. So ordered new cam covers and seals (plus extra seals). Didn't get them painted, not taking any chances.
And an upgrade:
Turbosmart's two port waste gate actuators for EFR's and dual 4 port solenoids. This is post having a local shop shorten the rods. The standard EFR location for these is modified by AAM to bring the actuators into the gap between the compressor and turbine housings, so I had to match.
By using these combined with the 4 port solenoid, I can use boost pressure on the bottom port and vent the top to hold the wastegate closed. This way I can run low (7psi) springs and still hold high boost levels.
Solenoids hooked up:
No way these will fit with the AAM supplied brackets, so after much mock up and three versions made from 1/8 aluminum, I finally got it to work and had another metal shop copy them into stainless:
Here's how they sit:
Put the engine, trans and drive shaft back in last weekend. Unfortunately I positioned the driver side hoses on these down so I could get to them from under the car. Looked great on the stand, but the lower port hits the steering knuckle. Got a 90 degree fitting, but still no go.
Ended up pulling the motor (again), and flipping the driver side over, no more clearance issues. But 6.5 hours of work to install one fitting. Oh well, that's what you get when you R&D stuff.
Even though the turbo smart actuators are larger, the new position helps clearance on the drivers side by mounting the actuator lower around the turbo:
The passenger side is moved up tucked more between the block and turbo.
Picked up some heat reflective gold foil and more heat sleeve. Added sleeve to the fuel return (and doubled the feed) and then wrapped the fuel lines, evap line and turbo coolant lines to keep things cooler.
Turbo outlet piping. Put the plenum and all vacuum lines back on. And mounted the rad, AC condenser. Relocated my MAP sensor to the other side of the metal between the bay and the brake master so it's better protected from heat. The 1 year old map plastic vac port broke on disassembly.
Next, finished up harness and wiring. Mounted intercooler and piping. Performed a boost leak test (no leaks first test). Filled fluids.
Fired right up after clearing fuel lines of air, sounded like crap until power steering pump got a full load of fluid.
And I've got VTC back! Verified with the Haltech on the car PC, top is cam angle targets left/right, lower is actual. We changed the cells around where it was idling to 10 degrees to force a change and heard and saw the numbers follow.
We then swapped my new clutch slave and master cylinder in, and bled, bled, bled the lines, and adjusted the pedal.
Next up, reassemble the bumper, hood, lights, fender liners, under tray and interior panels and it's drivable (if the snow melts). And I can get to putting the 485 fuel pump I'm upgrading to in.
So finished up with the lights, bumper, fenders and undersheild. Buttoned up the interior.
Dyno day isn't until mid June (ish), so I have until then to get the 485 swapped in and the driver side fuel level sensor changed.
Until then I'll be driving it (after all the snow goes) with the VTC unplugged as I'm not tuned for it right now, and the wastegate solenoids unplugged as they will react differently.
Shortly after reassembly, drove home and on the way developed a miss. While working through one coil pack at a time, car refused to turn over.
Swapped the starter with my old one, no dice. Checked battery, power draw, etc. Bought a new starter, still no dice. Finally tracked it down to a missing ground from the chassis to the block, don't know how it started on the lift and several times, but that's fixed.
Found and replaced the bad coil pack and continued to drive it to shake it down while we worked on one of the other cars we where prepping for the dyno.
A few weeks later noticed a metallic rattle from the passenger down pipe area. Pulled the down pipe and checked the turbo, all fine. It was the wastegate not being held closed. Tried to re-balance the gate and discovered that the twin port actuator is leaking air. Seems the diaphragm either blew, or became unseated.
Tried everything to pull it from under the car, but no way. Ended up having to pull the engine (again ). Decided not to risk these not reseating, and bought the mid EFR actuators. This ended up limiting my boost to 21 PSI, but I was able to max the tune on 94 octane:
Wasn't able to max out the tune on VP109.
TLDR:
680 hp / 616 ftlbs on 109 octane @ 21 psi,
567 hp / 480 ftlbs on 94 octane @ 15.5 psi.
So on the drag strip oil temps get a little hot, I'd like this to stay cooler. Here's my solution:
New dual 44 row series 1 setrab oil coolers to replace the single 34. The old one was mounted between the intercooler and AC condenser and simply didn't have enough fresh air flow, plus it covered a good percentage of the rad.
Swapped the washer fluid bottle with a much smaller one for space:
Changed to 10AN lines from 8, and made up my own lines this time:
These are tee'd together in the center with a check valve to prevent them from draining into the sump when shut down:
To get some fresh air for these, a Stillen series 2 fascia:
As my Z-Speed under shield sits a little low due to the intercooler, we had simply stretched the factory fascia down, with the splitter that wouldn't work, so I fabbed a piece of Al to mount on the bottom of the splitter to reinforce it and bridge the gap to the shield:
Then added additional spacers to the fascia and another hidden piece to make that more rigid:
Made some mesh to cover the openings:
First mock up:
Added and enlarged the air vents in the fender liners to let air out from behind the coolers, before and after:
02-22-2016, 10:35 AM
). That's going to need a spring boost of around 10-12 psi. But my race fuel tune for the track/strip on VP109 or C16 is going to need > 21 psi. Based on your information and that pdf from BW, that doesn't seem possible, and that's a surprise to me, since I've seen it done on many cars. The high boot actuators will have a spring boost too high for my street tune.
