Hey folks, I want to rebulid my vq35 motor this summer. I need some input on what I need to build it safely and it is being used as a daily driver. i dyno at 245hp, 245tq with I/H/E and technosquare reflash. Im hoping with this build to hit 300. I would like to do pistons, rods, bearings, cams, clutch and flywheel. So homies im I missing something, or what parts would you recommend...THANKS

 

just shoot nitrous....haha....nah put higher compression pistons, rods, 6puck clutch and fidanza flywheel and nismo cams...if that doesnt work put nitrous...

 

If you really want to know, a Maxima forum isn't the best place to look. You have a better chance of getting information about the power level you're looking at (a rather hefty task) on 350Z forums. Those guys have pushed the extremes a little more than we have because they have a better platform and typically more money to work with than we do.

 

thanks for the great input guys..

 

I guided you in a better direction instead of spewing out a bunch of garbage. I'm giving you the truth. Some here will be able to give you a tiny bit of advice, but no one here actually has experience doing a high-HP all motor VQ.

 

anybody know what the difference in a beam and h beam rods is???

 

a agree with a tatanko, but one thing is for sure... Tomei cams.

As far as what specs for it, it depends on the other mods you do and how you want to shape your power curve. But withh tomie you can mix and match exhaust and intake cam specs. You are not forced to settle for a set of cams with X specs

 

I am not sure what an "A beam rod" is but the difference between H and I is that I beams are usually a little lighter and a little more expensive and H beams are cheaper but usually heavier. Both should support about the same amount of HP and the ends are identical.

 

I figure a 12:1cr VQ35 with custom ground 272 -280* cams, with head porting and a custom built headers (burns is real nice) and all supporting mods should easily get the engine to 300whp. I'd expect the power curve to look simular to the C32 in the nsx, not to mention it would have a nice lopey idle. If possible tune it to run on E85 as it would allow you to make way more power than 93 would. That is unless you plan on running race gas all the time.

 

We've been over this a million times. The stock heads really don't have much work you can do to them (as far as the physical unit itself, not including the components in the valvetrain). They flow very well stock and I doubt that even the 300 WHP mark NA would benefit from the crapload of money he would be spending to get next to nothing out of them. This is just the general consensus, though, he can do whatever he likes. A set if Nismo heads might be more beneficial.

 

The amount of power you're looking for, N/A wise, it's a tad bit hard to achieve, I'm talking about 300whp. If I were you, I'd just jump in and boost a minimum of 7psi's.

Quest for N/A power from the VQ's is expensive and time consuming, let alone the reliability of the rebuilt internals. The further away you are from the stock internals, the darker and deeper you reach into the woods, hence the more money you'll spend to fix and patch the possible trouble. The amount of money you'd put down to reach 300whp, you might as well boost it and call it a day. Yes, there's lots of custom work to be done to boost a vq35, but as long as you stay low boost, there shouldn't be issues to worry about. The reason why I'm saying this is because I personally think that our stock VQ internals are sufficient to handle low boosts, and a low boost can get you 300whp easily from the VQ35 motors. Why spend a lot to reach a possible peak power of a N/A VQ35DE (without stroker kit, of course) when you can spend relatively less to get beyond that peak but with the lowest boost input and abuse of a FI setup? Maybe I'm just biased and tired about rebuilding VQ internals, especially of what happend lately...

-Peter-

 

There is something special about a high-revving, ultra responsive, powerful n/a motor. Other people would just rather boost, but all-motor has it's charm even if the ultimate HP ceiling is much lower.

 

 

Even the VQ35 heads could benefit from having work done.
Not a bolt-on affair by any means.

 

Amen. A lot of friends and forum guys tell me I should just stick with my 4-banger and boost it and I'll make more power, etc. than a VQ swap. That may be true, but not everyone wants boost. There's something fantastic about N/A power.


3.5altman: can't remember the guy's name off the top of my head but there's a 3.5 4th gen Maxima with I/E/H/cams and JWT ECU with a few other mods making 275whp. That's pretty close. Check out my thread called "Critique my engine build", we talked about building the engine for 8000rpm, what's needed, etc. The only thing is you have to make power up there for it to be effective.

 

I'm still a newb to max's but usually a three angle valve job is a great way to go. The tightest spot in the head is where the hair has to flow around the valves. This area can be opened up nicely, and if the heads are gonna be off anyways, 3 angle valve jobs usually only cost between $8 and $10 per valve (between $192 and $240) and can be done at most any machine shop. This procedure usually produces about as much gain as a real good porting job on a rough head, and they are simple procedures that are dificult to screw up (unlike head porting).

 

Yes a valve job is just as important as the porting. It impoves low valve lift flow. Radius cut seems to be the new rage among those in the know.

 

To get a 300whp VQ it would have to make at least 225wtq @ 7000rpm. Rev limit could still be 7500 or 7700rpm if the motor could handle it. With a stock head and VK valve train all the other mods needed would be custom intake/exhaust manifolds + 12:1cr and cams ground for the high compression. If the engine kept the VTCs it would help the idle and bottom end power a lot better than if it didn't have it. All in all it would probably run someone $7-9K to build this 300whp engine.

 

A 3.5 with forged rods/pistons, valvetrain, and dynamically balanced rotating assembly can handle 8k+ daily. A properly balanced oem crank is good for 10000 RPM.
I don't understand what the obsession with the VK valvetrain is. Ferrea or supertech is the way to go for the money...
The cosworth IM would help considerably. I'm not convinced that custom headers would be necessary, however.
Tomei 280/272 or nismo spec 2.
It would do alot more than that, especially if the v-manage and nismo cam sprockets would be used. I'm fully confident that a built n/a motor with VTC will make more HP and TQ EVERYWHERE in the rev-range, not just top-end.
It could be done for 5-6k, but only if the final assembly was done by the OP himself.


I would also recommend the cosworth rod/main bearing for their superior oiling and lower friction. The rod bearings are also more robust. Might as well throw in their thrust washers to complete the package.

 

I'm aware they aren't factory-perfect. I wasn't implying it was bolt-on, either, but I came to the conclusion it had to be easier, more beneficial, and cheaper than attempting to mess with the stock heads.

 

The consensus applies only to motors with bolt-ons. When you open up a motor to build for high-rpm all-motor use, headwork (porting/polishing/valve job) is an important part of the puzzle.
So you honestly didn't think they bolted-on before my post? Hmmm....alrighty. And how did you come to this conclusion?



Anyway, let me take a post of mine from another thread explaining why they aren't worth it IMO.

IByoualreadyknewallthis

 

I honestly knew they didn't bolt-on, because I had read some of your other stuff. I guess I didn't pay close enough attention to ALL the details, though

 

Z guys have proven that 280RWHP is possible with just cams and no other internal mods. Get yourself a hardcore IM, exhaust system, ARP rod bolts, E-manage Ultimate and fairly aggressive cams combined with a 7200 rev limiter. Once tuned you should have no problem getting in the 270s+.

 

u wouldn't recommend a valve/shim kit 4 this setup also?

 

Ok the original poster was talking about 300 WHP, which will take a hardcore build. The JWT valve spring/shim kit is relatively mickey mouse...

 

sleeper hit 270's with mild cams and mild tuning theres so much more to do but it takes $$$.

i believe with the 5 speed loosing less HP and being fwd and the fact i dont think the earlier vtc helps peak HP .
IMOP i think it would be easier to get 300 whp from a 4.5 gen than from a 350z.

 

That's what I was relating to, as far as N/A. I think it's hard to push the ceiling beyond 280whp on these VQ35DE's already. I mean, going all-out on N/A mods, even headwork and intake optimization. It's really hard to get 280whp. Utilizing the intake and exhaust VTC's like HR motors in addition to massive N/A work are the only way to get there. I mean, how much money it takes is beyond me, but I call it unworthy to go through this harsh jouney for 300.

Now, if you go straight to a hardcore stroker kit, it'll be a different storyline, but that knocks out the fun of an underdog taking on big bad wolves. Where is the justification?

Jclaw brings out a fine point, internal upgrades, hi-end IM, super exhausts, and tuned by emanage ultimate; all these things together constitutes a massive dump of finances like I mentioned. But it's all internally pieced together, who is to guarantee the harmonics of thes components working altogether. Each components are sold by their mother companies to claim to have such and such abusive tolerances, but what research have shown the true reliability of the combo of all top end parts pieced together to run perfectly?

Boosting low psi's is still my resort to this objective.

-Peter-

 

There's been a 350Z that hit 295.9 WHP with just aggressive cams and headwork along with bolt-ons and tuning. With high compression i'm certain 300+ WHP would be attained. Dynojet numbers BTW.
See post #12.

 

All-motor = high RPM. Balancing the rotating assembly goes without saying when doing an all-motor build for high RPM use. A properly built n/a motor with balanced rotating assembly will be more reliable than stock AND be smoother to boot.

Balancing = bringing piston and rod weight to within 1 gram or less of one another and adding or removing weight from the crank counterweights to VERY PRECISELY offset the weight of the piston/rod assembly. Once again, a properly built and balanced motor will run smoother than stock at every RPM.

 

Got a link to said 350Z? I'd like to know what cams he used and headwork done. You guys telling me how mild the JWT cams are have gotten me thinking, I just wish cam makers all had dyno's to show where the powerband is for their cams.


I have a question that I have searched around for and never found a good answer: how high a compression can one go on pump gas? I know S2K's have, what, 11:1? What's the limit for VQ's?

 

I'm pretty sure it's a set of JWT S7 cams rarely sold for the 350Z's. Those are not mild at all. I am skeptical of the valvesprings that they must couple with those cams to work that good. Anyways, things happend lately, and I'm just not so happy with N/A internals now...

 

Theres no reason to believe that 11.0-11.5 is a problem. I know people who run 94 pump with 11.3-11.7 comp with no problems. Personally if I were doing a built VQ I would aim for 11.5ish, maybe 11.7 and no higher. Nismology is absolutely right about the nismo heads not being worth it (unless you have a 30,000$ budget for the whole car). And besides 12:1 or more seems a little too high for long term reliability.

If I were doing a build with mid 11.x comp Id do one map for the street with conservative timing and still put 94 in it and an all-out map for the track with race gas.

And since the stock rods can handle 7500 theres no reason to *** with the bottom end (other than ARP rod bolts) to get to only 300WHP. A head (shaved heads+port job+valvetrain)-cam-intake package should be enough with all the other supporting mods.

And honestly, im going to try to get to that 280RWHP cieling out of my 3.5 with just cams and ARP rod bolts inside, and then in a couple years if my financial situation allows it its VQ38HR and 400 reliable crank horsepower time.

 

Well it was on a non-revup so the S7's couldn't be used. Besides, the S7's are mild too. They're 262/262 compared to the S1's 260/260. Basically the S1's but for revup's. The cams used on that 350Z were crawford 295/265 cams. I'm forgetting the lift though...

He also got technosquare to adjust the VTC timing. That motor makes more power and torque everywhere in the rev-range compared to stock, even at low RPM. Stock compression...

 

Hey guys I haven't given up. Eventually I'll get it. I just don't get to spend much time on my car anymore. I still believe 290+whp can be had without going into the engine, aside from rod bolts and cams.

Cams alone would put me nicely in the lead again, but i just don't have them yet.

 

You'll be wasting your money if you go through all of the trouble to go inside the engine. It just needs to breath better.

 

Are you saying that a 11.5:1 or higher VQ35 wouldn't make more power mod for mod? Going from 10.3:1 to 11.5:1 added 19 WHP on it's own in Z350lover's car over on my350z. I'm convinced that 12:1 could be pulled off with an aggressive enough intake cam and proper tuning.

 

I am saying that would not be the best place to put your money. I just wouldn't invest in parts like that until I had exhausted all of the other (less expensive) options.

 

The cost of good cams >= cost of custom C/R pistons.

 

That could be done with the right piston and chamber design, and on milder cams.

 

Do these parts install themselves? If so, count me in.