Hi,

Diren here from Australia. I thought I'd share the project I'm working on with RP Customs.

What: I want to make the best possible NA 350z for the road. The equivalent of a Porsche GT3 for a 350z.

Why: I love the NA engine and drivetrain. It is why I bought the car.

Why no Turbo?: If I wanted turbos, I'd have bought an STI. I get that there's more bang for my buck with Turbos. I do not care - for pretty much the same reason people buy the Porsche GT3 when a GT2 is more powerful.

Car: 2006 350z Track, 200,000km

Constraints:
- Needs to remain neutrally balanced to drive - I like the balance of the 350z
- Uses 98 octane or e85 flex fuel

- Keep torquey mid range (a defining characteristic of the VQ35 range)
- Completely streetable
- Aussie parts where possible
- No pointless aero or styling changes. I like the look of a normal 305z.

Current Power: 190 rwKW, 306Nm (Dynoed at Tunehouse, April 2015)

Already done previously:
- MCA suspension (Made in Australia)
- Front control arm bushes replaces
- Air Filter
- Piggy Back ECU


Mechanics Selected:
RP Customs - Excellent quality of work. They specialize in Evos. My brother in law uses them.


Parts:
To deliver the objective the following parts have been selected. In order from Intake to Exhaust/Driveline

Intake
- Jenvey Individual Throttle Bodies

Engine
- Heads worked (valve seats bored etc) (sending to Canada)
- Cams and Valves TBD (Waiting on Jim Wolf)
- Bottom End Honed (Australian Supplier)
- ID 725 Injectors

ECU:
- Link ECU (Flex Fuel) (from New Zealand)

Exhaust
- Tomei Exhaust Manifold (ceramic coated)
- Exhaust (TBD - custom made in Australia)

Driveline
- Direct (Brand) Twin Plate clutch and flywheel (Made in Australia)
- Rebuild gear box (I like the gearbox as it is - it's fun)
- Quaife Mechanical LSD

Traction - do driveline first, test, then build traction package. Below is where my current thinking is at
- Keep MCA suspension (made in Australia)
- Replace control arms (TBD)
- RPF1 rims
- Wider rear and front track to manage the power

Brakes
- Keep as is. The brembos are strong.

Progress:
- Scoped project
- Detailled build plan (Excel)
- Rough Budget
- Driveline Out
- Ordered parts, sent gearbox to be built


I'll keep posting updates as we progress. I'm in no hurry, it's not my daily anymore.

 

Track or street car

 

Sounds like a sweet project that is well thought out and organized. Not sure how Aussie's handle things like smog/inspection, but it doesn't look like you're doing anything too crazy to make it un-street-able (not pass). Potentially the cams, but usually those fly under the radar depending on how aggressive they are with your tune. Living in Commifornia, passing Smog checks is always in the back of my mind when thinking bolt-ons and other drivetrain related mods/upgrades for my Z.

You mention it's an 06? But talked about individual throttle bodies? Did the Aussie market get VQ35HRs shipped in their 06 350Zs? The dyno chart numbers you posted look like an HR's. (Edit: Nevermind! I keep forgetting to do the conversion from KW to HP).
-Icer

 

Look into a set of PPE long tubes, you can get them in RHD.

 

street. Hence we won't be going too crazy with cams.

 

smog tests aren't such a thing in Australia. Considering how old the Catalytic Converters are, I'm sure the current state isn't great - let alone post modified.

My 06 is not a HR, it's a Rev Up. 06 is a challenging year because of the cutover. It took some time to be sure, but we were able to work it out using the VIN number.

 

Yes, I looked into the PPE, unfortunately they are not street legal in Australia.

I also really liked the Tomei Exhaust Manifold. Tomei did a really detailled job testing tube lengths.

I also looked into a full custom job from engine to tip. The exhaust guy said he'd not be able to build a better solution than the Tomei. But he'll be doing everything from the manifold back.

RP Customs will get the manifold ceramic coatedto help manage heat in the engine bay.

 

Hey friend,

I'd suggest you add a lightweight flywheel to your list. Really wakes up the VQ35, turns it into a rev happy responsive beast. Love mine, and even at 13lb, I get very little chatter.

Ported DE/REVup heads are as good or better as stock HR heads, so that's good. You're going to lose some low rpm drivability with the head work and cams (and flywheel), so keep that in mind.

Are there any plans for a stroker kit? I know they're prohibitively expensive (especially if you keep it NA, $/hp ratio goes to crap) but a VQ41DE is just so... titillating.

For a street build your list is overkill in some spots, tbh... ITB's and a standalone ECU with 700+cc injectors are too much for what will be a ~330whp motor. I'd use those funds for a proper shock & spring combo and swaybars. Jenvey's + Link are nearly $5000 USD alone last I checked...

 

Hi Mate,

Excellent comments.

You are right about the Jenvey ITBs. Definitely overkill! I'm not expecting much if any kW from it. The stock intake is pretty good - The stock throttle body is so big, airflow is barely an issue. This was more of a heart than head purchase for sure - which I am aware of and am happy to wear the cost.

I agree, the flywheel is one area there's still some discussion over. JW is scoping up a light weight flywheel as part of a package, as is Direct in Australia.

Thanks for the heads up re: low rpm driveability. That is a concern that I'm a little apprehensive about. I've resolved to just cop it. I can't have everything.

There's some cash put aside for the Suspension package. I'm planning to drive the new drive train setup for a while. Get a sense of how it feels, then specc up a suspension package. I may want to increase tyre width for example. I'm very sure I want to change the rear control arms, I've had issues getting the wheel alignment right because of them. And the bushes are terrible. The rest is more about feel. I've already done coilovers. I'm happy with the MCA coilover package that I have. It's very well damped. It makes me feel confident when driving. MCA is an Australian brand from Queensland.

 

 

Thanks for the comments.

997 GT3 performance will do me fine! It's the concept of the GT3 that I'm following. That is - using the best available parts to get the most out of the engine as possible while keeping it NA and street drive-able. I want to take this this on long winding road trips.

I thought about setting a power target, but decided not to. If pure power was the game, then I'd Turbo for sure. NA is about balance and compromise. It's why speccing up the cams is taking some time. RP Customs wants to make sure we make a car that I will enjoy driving on the road - rather than a 7 second monster that works on straights only (which don;t get me wrong, is pretty cool if that's what you want!).


In regard to the intake - I agree, to get over 330 whp, it is needed. The OnPoint Dyno build proved that. It's not the best $/kW investment, but necessary to get the most power from the NA engine. It was still a heart more than a head purchase though. Considering I'm not going for the most aggressive cams, I'm really not going to get the full benefit of the ITBs. But I just want them!

I reckon the biggest restriction is the stock exhaust manifold. Compare the picture of the stock manifold to the Tomei. Air flow would be much better in the Tomei. Far less restrictions.








Tomei



Stock (not mine - from google)

 

My longtubes made a great difference in my car. Stock exhaust manifolds are *****! The intake manifold is definitely a restriction if you want to make power at high RPM, yes. I elected not to install one as my setup was made with the target of maximum power at stock RPM. Our goals are slightly different power wise, although I also am building the car with the "super OEM" goal.

Please make sure you post lots of pics of the ITB setup. Pics, review, everything. It's something I also yearn for, though can't currently afford.

 

" You are right about the Jenvey ITBs. Definitely overkill! I'm not expecting much if any kW from it. The stock intake is pretty good - The stock throttle body is so big, airflow is barely an issue. "

Stock intake and collectors blow as well as the oem t.b. Airflow IS a big issue.

 

JWT are recommending C9 intake cams/RZ1 exhaust cams. What do you think?

 

If that's what they recommend. That's the brand of cam I'd choose.
Go with a mild 2.87 pulley on a vortech or the stock option on the new hks centrifugal s.c. and you'll far surpass what you will make n.a. and for a lot less $ all the while having a similar feeling as n.a., unlike the surge from a turbo all on the stock block. Only bummer is all the added weight right up front.

 

Why such large injectors ?
I'm running standard injectors on my 350z with obx individual throttle bodies with no problems
also running a link g4 plugin ecu

 

I've been told by a local tuner shop you that you get a more granular adjustment/tuning range out of larger injectors. The reasoning behind this sounds logical, but I don't have any data to back this claim up, so take it with a grain of salt.
-Icer

 

Just going with the recommendation from RP Customs on that one.

 

Waiting on ITBs from Jenvey. Ordered nearly 6 months ago.

Engine internals finalised from JWT. Order placed, should be here in Australia in a few weeks. Should achieve an 8000rpm redline.

Stuff from JWT:
CUSTOM JE PISTONS 11.9.1 CR
WRIST PINS/LOCKS

OIL PUMP BILLET
WIDE MOUTH DE WATER PUMP HOUSING

CUSTOM C9 CAMSHAFTS/RZ71 CAMSET

LONG BOLTS/SEAL KIT
COPPER WASHERS/*** CAM HARDWARE

HEAD GASKET SET

OEM HEAD BOLT SET

SPRING SHIM SET/HI REV CAM SET SPECIFIC

PISTON RING SET

 

Awesome to see this progressing! Keep the updates rolling!