I have a vq35de in my garage. I've been contemplating a building the engine up. I've sourced some 11.0:1 compression Pistons (Wiseco). I'm still researching so I understand more and better but want to get some feedback into what other parts would be beneficial in high compression NA build.

I naturally assume a higher flowing fuel pump would be needed.
I will need to replace the headgasket on my spare motor. I've gotten a great tip on using the 350Z headgaskets as they are overall better than the stock Maxima HG. I Believe they are tripple layer vs double layer (Max). I need to verify the thickness between the two is the same.

Thought about JWT valve springs for the engine to rev a little higher.
Cams are another thought to add to the Mix.

I'm reading more and more to fully understand and imagine how certain upgrade will respond to others, but would like to get opinions and even ideas from others.




edit: For the Moment, I am not looking at price, I'm focusing on the build. If this project gets a green light it still will be a while before this get built. I know these parts can get very expensive.

 

Moving the powerband as high as possible is the key to big HP NA. Dont ask how this is I dont know. But a 3.5L engine that peaks at 7000 instead of 6000 is going to produce more HP with an otherwise identical engine.

That involves short runners, big cams, and of course the supporting mods you need in the block and valvetrain for you engine to handle the higher revs.

Look into the nismo heads if you want to increase your compression while keep stock piston reliability. Its basically a ported VQ35 head with VQ30 46 cc combustion chamber instead of stock 56 cc and delivers 12:1 comp. Then while upgrading your HGs you could put on sligthly thicker ones for safety and bring it back down to around 11.8:1 or so.

 

i kno this isnt the thread for it but ive never seen a seriously cammed vq minus on a race track. do we have the option of running like a seriously lopey(sp) cam that would push our power band alot higher...some that would aid greatly in a n/a build....something liek you would see in a ls1 when u try to build that for high n/a power

 

I would do a VTC swap if I were to do it. Just so I could have a good idle and aggressive cams.

 

I look into the Nismo heads and see the benefits of that. with arp head bolts and main bolts that would aide in additonal support for the block JWT valve springs for the higher revs.

Wouldnt 12.0:1 compression need a high octane gas? I would like to have a high NA build that still functions off pump gas (91 octane at the least).

I’ll read in my fsm when I get in from work but, Arent the VQ30 valve springs able to handle higher revs better than those in the 3.5? If that’s the case, I can easily get an extra set of vq30 valve springs and use the 3.5 application.

I’m researching the v-manage to see if it’s a possible solution. I remember the discussion on them before but I cant remember if the v-manage piggy backs off the ecu or if it can act as a stand alone.

 

From the limited information that is available, I do not think the v-manage will be an option for 3.5 swaps with 3.0 ecu.

The reason for this is that variable valve timing systems are very application specific. Just like with the emanage ultimate, Greddy has to program in the engine crank/cam sensor output waveforms so that it can read the cams angular position relative to the crank.

There are no factory VTC-equipped engines using the timing triggers/sensors of the VQ30DE, so I really do not see Greddy supporting it.

 

im down with your 3.5 build...but put it in something RWD!!! FTW!!

 

2001 Pathfinders have a VQ35 with 3.0 cam-crank sensors and early VTCs.

 

Still doesn't necessarily mean that Greddy will support it.

 

Couldnt he tune his stock VQ30 ECU with E-U, and something althogether different and unrelated for his VTCs...

 

Yes, but those sensors really have nothing to do with VTC operation.

For cam position feedback, the 01 Pathfinder uses an additional 2 cam position sensors that are mounted on the engine front cover that read off the VTC phasers. The output waveforms of these sensors are completely different from that of the A33B, Z33, etc which use sensors that trigger off of an integral signal plate at the other end of the cam.

In addition, the cam phase adjustment range on the R50 is only about half that of the newer A33B, Z33, etc.

 

Full standalone is an option (Hydra EMS, AEM, etc.) Pretty pricey and very time consuming though.

On the piggyback side, you may need to be a little careful trying to add VTC to an engine being controlled by an ecu that "knows" nothing about it. Remember the cam position signal is the only way an ecu knows which half of the 4 stroke cycle the engine is in.

Changing the angle by small amounts may not present any problems, but if you want to change things by 30 or 40 degrees of crank rotation, the ecu may throw a P0340 code. I do not think this puts the ecu in a failsafe mode but it may affect ignition timing.

 

The 01 pathfinder VTCs vary by 24 degrees vs 35 for the 350z and later maximas.

So varying by a small amount may help run agressive cams and make the low end more streetable with these.

Also whats the deal with cam timing vs ignition timing. If I advance cam timing by 15 degrees, by how much would I have to dial back ignition timing. And which would you rather have for mid-range & top end, advanced cam timing or advanced ignition timing.

 

The VTC phaser range in the A33B, Z33 etc. is 40 degrees. I have personally driven my own cams to that amount. I just checked the R50 FSM and it only shows a phaser positional range of about 20 degrees. Where did you get your info from?


Advanced relative to what? stock?

All else being equal, I will always take what gives me the most air for a given rpm and then adjust ignition timing to suit.

 

im in process of having my 3.5 built to throw in my 4th and would go with the nismo heads but they r pricey does anyone have them on and running?!

 

LOL I didn't know NISMO heads existed. I know people like using the 350Z Nismo cams, but are there other 350Z internals we can use? Obviously heads, but how about rods, valve springs, larger pistons, bottom ends? You get the point.

EDIT: Forgot to ask ... what kind of gains are you looking at with NISMO heads?

 

Total noob at this category, but I subscribed to learn and see what happens!!! Nice job on the ideas and good luck!

 

The nismo heads are not bolt-on-and-play. Simply installing production 3.0/3.5 cams in those heads will result in excessive valve clearance which can't be fixed by getting different lifters from nissan. You have to get custom cams ground with a larger base circle like nismo blanks. They come in two stages (284 duration with 11mm max lift possible and 312 duration and 14mm max lift possible). The cheapest prices i've seen are $889 and $1430 respectively, on top of the price of having them machined. Another thing is, the resulting compression ratio with those heads is over 12:1 which would force one to have to get custom pistons made to lower it to a more manageable 12:1 or lower, plus the cost of machining the block. These got my attention because a smaller combustion chamber with minimal piston dome is the ideal way to raise compression but with all the hassle and expense involved it just doesn't seem worth it to me.


http://www.my350z.com/forum/showthre...ighlight=heads