G35 Twin Turbo Project

[Jattus]

Hello, I'm new here but my name is Matt from Jattus Performance.
Working on twin turbocharging a 2003 Infiniti G35 Coupe, so figured I would make a topic to post pictures, progress, ideas, etc. And also to hopefully get some feedback, to see what you guys think or how it could be better.
Here is the game plan so far:

2x TD05-big16g water and oil cooled turbos
2x 38mm external wastegates
water to air intercooler system
2" charge pipes from each turbo merging into 2.5" to water intercooler, then to 2.75" to throttle body.
2.25" intakes, putting both of the cone filters in each fender well.
perfect power smt8t fuel controller used to fire a 7th injector (80lb injector)
2.5bar external map sensor paired up with smt8t

We are going to set both of the wastegates to 4psi for starters and tune like that. After that is dialed in then up to 8psi, which is where we will most likely keep the boost pressure (our goal is around 400whp).

I also want to utilize the OEM exhaust manifolds, and have the turbos bolt inbetween the OEM exhaust manifold flange, and the remaining exhaust. This will put the turbochargers a bit lower than normal, and will require an oil pump spliced in for the oil return correct? (Where is a good location for this now that we have a pump? Just oil pan?).

So far my only concerns is the space restrictions for charge piping, and oil return, but other than that it seems that it will work out pretty good.

One of the other main goals is to build a turbo kit for the car thats more easily bolted on to existing parts (e.g. bolts to exhaust manifolds), more of a universal approach to the fuel system (e.g. the 7th injector), and get reasonable power out of the kit.

[RED_DET]

So you don't plan on building the internals of the engine first?

[Jattus]

No, just planning on this turbo kit being installed on stock engine internals. From the research I've done, around the 400whp mark seems to be decent for the stock engine. Do you agree?

[RED_DET]

I agree 100%, but I also know from first hand knowledge boost is an addiction, you will want more and won't be able to have it because you are already at the limits. If you are going to spend the money and invest the time to do this, do it right the first time. Everytime you tap into wot you will be at the limits every time. If you build it now, you can do whatever you want in the long run.

[tollboothwilley]

I have seen guys running aroung 500-550 whp - but its not considered safe. You would be expecting the motor to blow at any given time. Its commonly known to have the rods as the weak link in the chain but I have also seen people that had the ring lands break.

[Jattus]

Finally got some pics of the prototype for ya, let me know what you think!

















I powdercoated the exhaust components with a high temperature black satin finish. Everything should stay pretty cool down there also considering the locations of the turbos, plus they are both oil and water cooled.
After we finish dyno tuning it next week, going to take all of the charge pipes off to powdercoat, and clean everything up a bit. But so far it runs great! I'm also pleased with how the collector came out (I'll post some pics of it when I remove the charge pipes, since its kind of hard to see).
I decided to go ahead and CAD up an oil pan spacer with a fitting for the oil return (you can see it in the first pic).
I have both of the external wastegate springs set for 4psi, I'm going to tune it like that first, then work my way up to 8psi and see how much power its making.

[Jattus]

Finished dyno tuning this morning, made 341whp and 339wtq at only 5psi! After all of the runs the cooler was still really cold to the touch, even the intake tube! Air/Fuel ratio above 4K was a nice straight 12:1. Next week I'm tuning it to 8psi.
Here is a pic of the dyno sheet:

My buddy took some video, trying to get him to send it to me.

[audtatious]

Not too shabby. More or less than you were expecting at setting?

[RED_DET]

Should be right on par on 5psi. At 8psi you should pick up another 30-40whp. 380-390 range on 8psi is about ideal for that setup. I wouldn't run anymore than 8 daily just to keep the motor within safe limits.

[Jattus]

As far as fuel goes, I'm using a big 7th injector, and also utilizing the OEM 6 injectors. This is also giving great stock like drive-ability and gas mileage off boost. I am also using a external 2bar MAP sensor to go along with the fuel controller. Dynoed the car at 8psi yesterday and was getting some good power down to the wheels! I'm also at about 60-70% duty cycle to get the flat 12:1 curve, and w/ the fuel pump, I can probably squeeze another 30-40whp out before the fuel system is topped out, so this is a good level with this kit I believe. The air intake temps were also still good like last time after all of the dyno runs.
Here are some pics and some videos...

Dyno graph showing the 5psi pull from a couple days ago, and the 8psi pull now...


Here is a video of a pull at 5psi from a couple days ago...
http://www.youtube.com/watch?v=N-1Vh2qG2jA

Here is a video of a pull at 8psi from yesterday...
http://www.youtube.com/watch?v=aWJp2ISPalk

[tollboothwilley]

looks like some solid numbers

will the kit work only on 6MT or will it work with 5AT?

will aftermarket headers work or not?

Have you set a price point for the kit?

[Jattus]

Thanks!
I don't see why it wouldn't work on the 5AT, fitment wise, is there anything that could potentially give clearance issues?
Aftermarket headers will work no problem, as long as they keep the flanges in the same location as OEM.
Not yet, but I'm going to do a couple at a discounted rate at first, probably in the vicinity of 5800?

[tollboothwilley]

5AT and 6MT trans are a little different in size. Also, the 5AT has the filler tube that sits between engine and firewall. Wiring could potentially get in the way for the 5AT as well.

I've got an idea...come install one on my car for me.