I just got my car back from the motor shop after about 3.5 months!

They installed my Arias 8.6:1 pistons, my APS injectors (525cc I believe) and new cams. They mounted the turbos, but they could not get the intake pipe to fit, as I don't have the G35 supplamental kit. I am taking the car to a custom shop to have the pipe made, but I have a few questions before I get it there.

With my Procharger I had a boost reference fuel pressure regulator and it was set to roughly 30psi for my TS flash and my SC. I know this is super low, but does anyone know about where it should be? Is there a formula to calculate how much pressure I should have? The car barely idles and feels like it runs out of fuel above 2500 RPM. I had to drive it roughly five miles yesterday to get it from the shop to my house. Oh, and because my APS exhaust won't fit on my G I don't have any exhaust on the car at all, and I don't have my wideband bung welded in yet (Yes, it is safe to say my car is a freakin mess). Also, the Unichip hasn't been installed yet, and I'm running on a TS L flash. I don't plan on driving the car like this at all, but I want to have everything set to as close as it needs to be so I have less things to worry about once its all done.

My next question is about the boost regulator. If I understand how it works correctly if I do NOT reference manifold pressure with the actuators then I should be limited to only 6 psi correct? I want to run the lowest boost possible until I can get the motor broke in and get the car the 500 miles to the Unichip programmer. My Unichip was preprogrammed for 12psi on 93 octane, but I don't forsee any issues with running it at 6, does anyone else?

Thank you for your help,

 

Get that unichip installed before you go boom.The unichip controls fuel and timingand is boost bsed.Did they put in the fuel pump?You can get the supplemental kit for your G from an APS dealer.There injectors are 500 cc.

 

Like I said though, the turbos are installed but are NOT connected to my intake, so I am NOT boosting at all. I have a Walbro 255 pump installed, with a complete return fuel system. I would really like to get the car running smoothly NA before I connect the intercooler to the throttle body (at least as smoothly as a low compression car with big cams and big injectors will fun with stock maps).

 

sounds like a bad idea. you might want to contact Peter @ APS about this... since I am no expert on the physical abilities of the turbochargers themselves... however with you doing full throttle runs with no charge pipes connected, I would be concerned about possibly over-spinning the turbos to RPMs beyond their intended use. This might be completely wrong, but just something I would look into... wouldnt want to see you toast those babies.

 

I have no intentions of going past 3000 rpm. The shop the car is going to next is maybe two miles from my house. I just hate the fact that the car won't idle, and I would like it to be in better shape when I drop it off. I guess it comes down to me being embarrased that I have a $40,000 car, $20,000 in engine mods, and the car won't even run

 

Oh, and I already know exactly what Peter would say:

"that is a bad idea, tow the car to the nearest Unicheap tuner with a load based dyno and have them make it right for you."

If only it were a perfect world.....

 

well to help with your first post...

to run the lowest possible boost you want to hook up the actuators.

The actuators just have a spring and diagram in them... boost pressure compresses the spring and pushes a rod that swings open the wastegate. Without this action happening, the wastegate will stay closed and boost will be perpetual... that is until exhaust manifold pressure over-powers the spring in the actuator and opens the wastegate itself.. which happens between 9-12psi on APS TT kit, depending on a few other things.

If you run the actuator hose directly off the turbo compressor housing, that will have the wastegates opening at the lowest possible boost, as this is getting pressure before any losses in charge piping and intercooling (pressure here will be higher then by the time its in the manifold). However you will probably be stuck getting it off the manifold anyway, since I do not recall the compressor housings on this kit having any vacuum/pressure reference ports.

 

I believe the base APS fuel pressure is 56 PSI....

 

LOL... that does sound like him!

 

KP, did they consider the option of dremmeling a hole for the 350Z tube? That is what Z1 did for mine and I haven't had any problems.. I think they just moved a couple of AC lines and that was it. 4400 miles on it so far.

 

as far as the breakin..if you are not going past 3000rpms (which opens a whole other debate about proper breakin--i like the break in like you are gonna drive it--so, progressively harder/higher in the rpms...never past 1/2 throttle) you dont have to worry about the boost being set at , say 12psi..i broke in my car with the .8 wastegate springs...making my baseline around 10psi...if i was careful not to give too much gas at certain loads (going up a grade in 5th-you could reach full boost if you didnt pay attention to the throttle)...i could stay at around 5-6 psi for the entire length of my break-in (which was a one week duration, both times--remember-i've been through this twice)

my idle fuel pressure is at 52-54ish psi (my fp gauge is in bar)....this brings the injectors to about 90%duty cycle (i have 550's--may raise fp and scale down the entire tune to reduce the injector duty cycle numbers)

 

The stock fuel pressure is 53 PSI at idle and that is the base pressure. However I think APS uses a higher base pressure more like 56-59 PSI. The reasone being that the injectors will only produce the claimed 550 cc at that higher pressure...

 

Thank you all for your responses. I went ahead and raised the full pressure to around 60psi and the car started and idled! It ran a little rich, but I was only taking it about 3 miles to drop it off. With the car idling on its own I feel much better about having a new shop take over on the project.

I was only planning on keeping the the RPMs below 3,000 why I don't have the intake hooked up. There is no reason to take it above that if I am simply transporting the car. I looked on the odemeter and I put 12 miles on the car total moving it from one shop to my house to the next shop. The place that has it now should have it all together and ready to go for me by this weekend!

Thank you Charles for your explanation, I had it backwards. The mechanic at the shop told me the exact same thing, and that is our plan. I don't want to push this motor or risk hurting it like I did my last motor. I know it doesn't take long to cuase major engine damage (at least on stock components) as I broke two pistons in less then 1000 miles with my supercharger!

Tonio, I already have that hole dremeled out from my Procharger. That is the route we are going to take, and it lookes like the tube will bolt on, but I think the first shop was hesitant to hook it up since they didn't want to mess with the fuel system and piggyback. I felt much more comfortable recieving the car in NA form with the turbos mounted then them connecting all the plumbing without doing the fuel system.

This project has been a ton of headaches for me, I wish there was one shop in the Dayon, Ohio area that would have been willing to do everything, but it simply doesn't work out that way!

 

Hey wheres my thanks? Didn't I give you the fuel pressure answer?!!! Just kidding man...glad you got it running...

 

You know I was meaning to ask this cause I have the AAM system and I can't get the base pressure to even move with the adjustment screw. Well maybe a few psi. But it always stays around 60ish and under boost pretty much stays there. Any ideas? Yes the FPR is attached to the return line.

 

I just got back from the shop (they were having a dyno day) and I went over the car with the mechanic there and he found a ton of things wrong with it

For starters, apparantly while the car was sitting in the parking lot of the first shop it got hit because now there is a huge scuff mark on my rear bumper.

2nd, they can't figure out why the APS kit uses a recirculating bypass valve instead of a true blow off valve. It looks like they are going to want to swap it out to prevent warm air from going back in to the turbo.

3rd, the overfill line on my radiator was apparantly broke when they took the motor out/put the motor in. They JB Welded it but the JB melted in less then the 15 miles I put on the car.

4th, they put a hole in my hood liner. I already knew about this but brushed it off. After seeing the other crap I'm goint to ask them to reimburse me the $150 the hood liner costs. I know it costs this much because I have already replaced it once! The hood liner is ONLY on the G35, its basically a piece of insulation that is clipped to the underside of the hood

5th, they scratched the hell out of my black V5 Crawford Plenum. This too I noticed when I picked the car up, but accpeted it as 'part of it.' I figure if I'm going to call them on one thing, I might as well bring it ALL up.

6th, my front nose piece is all scratched up. I am planning on having it custom modified and repainted, but that is no excuse to not be careful with it. The front nose piece was picked up separately from the car, since I plan on having it worked on. However, I have a completely stock, primered nose piece I was planning on modifying so I always had my stock on to put back on...

7th, my air filter on the passengers side turbo came unglued!!! The filter was just bouncing around on the undermolding of the car. We got it out, and can see where the glue that holds the endcap on it was at one point. Now I am hoping that in that 13 miles I drove the car I didn't suck anything hard in to the turbo.

I think thats about it, but to say the least it has been a very depressing day. The shop that has it now is going to go over EVERYTHING to see what else was screwed up and make the car run and drive like intended. Then, it will still be up to the 3rd and final shop to tune the Unicheap piggy back system. And, when I was buying all these parts I thought the build would be fun!!!!!!!!!!!!!!!!!

 

nly 7 things wrong?!...eight is where it really starts getting intersting!

 

WRT to #2. The APS BOV is a two stage unit.

a) It re-circulates under "mild low boost off throttle" in order to keep the noise at a minimum.

b) It vents to the atmosphere "under aggressive high boost off-throttle" when it is most needed and you don't care about being mellow.

It's a good street setup IMO.

 

G3po, thanks! That makes much more sense. I will call them today with that information.

8, my passenger side power window is messed up. As soon as it gets to the top of travel it goes back down half way! I know this has nothing to do with the engine work/TT but I might as well throw that in too, as it just started doing it yesterday. I'm sure it is related to the body shop not setting the limit switch correctly when they put my new door on

 

Wow Kevin, sorry your getting such bad service from your tuner. Who is it so I'll never take my G there?!

Good luck anyway and can't wait to see your dyno. Maybe I'll bring down my G with the APS ST installed for side by side comparison.