NeverEnough

I am curious to see what everyone thinks is the greatest hindrance to our engines making better high rpm power. By this I mean: cams, throttle body, intake tract diameter/length, valve size, etc.

This thread is not an implication that our cars don't make power, just that this is an amazing engine, and I think it has the potential to make a lot more power at high RPM power than it does at present. If you look at the hp/liter of the BMW M3/Ferrari 360, it seems that there is a potential for much greater horsepower for our cars. So, what I propose is that everyone propose what is to blame for this lack of top end power, and if you feel obliged, you can also propose a solution to this.

Sorry this post is so long.

Lee DeVine

JDM4LIFE

iTrader: (2)

actually, i believe in the same philosophy. i'm working out a deal with a company to have high compression pistons and forged rods done for my max. that, along with a little bit of other tuning is my goal. everyone i've seen is doing boost. all motor 13's and lower can be easily attained. they will just take some effort on our behalf. i'm not sure if anyone has, i haven't seen it on any posts, gotten ahold of jg engine dynamics. supposedly, they make parts for the maxima. hopefully, it's something new. anyways, if you want more info on the pistons/rods, email me and/or go to www.raceeng.com it's the company i've contacted about it!

Adam Jenkins

Jeff92se

iTrader: (82)

Simple, it's either the heads, intake manifold, maf,tp, valves or the cams.

HoJo

Oh, is that all?

bill99gxe

iTrader: (1)

What about the flux capacitor?

NeverEnough

I bored and sleeved mine, and then ported and polished it and it only gained 3 bhp, so maybe someone in NZ makes another, better flux capacitor. We could have them shipped here for a hundred bucks or so.....

Lee DeVine

MilwaukeeMisfit

...I believe Jeff92se's post to actually be pretty close to the truth. My thinking is this: the VQ engine,gem that it is, was designed for (relatively) pedestrian duty. Thus, low-speed driveability, emissions concerns, and fuel economy were probably the primary concerns in its design. The fact that Mother Nissan was smart enough to put this motor in a ridiculously light chassis is really what lends credence to its "4DSC" image. Now how do we go about creating a certain power level within a certain RPM range? We manipulate the induction system. An L-shaped plenum with long, skinny runners, mild cams, and peanut-port heads create the world's most perfect idle and throttle response, but do nothing for a broad, flat power curve, much less high-RPM power.

Bottom line? I truly believe that the ENTIRE induction system would need to be revised in order to generate the power levels we enthusiasts know the VQ is capable of...but are we willing to sacrifice some of the characteristics that make this one of the "10 best engines?"

Let's leave the bottom end alone. Micropolishing, coatings, and notoriously Japanese blueprinting make it bulletproof enough to handle almost any NA demands we could put on it aside from boring & stroking, which is prohibitively expensive and outside the scope of most enthusiasts.

Just my two cents. Boy, what a cool thread!

guido_sst

I was actually going to do some CFD this weekend on some donated time with a warm and fuzzy RS/6000 and see what some variations to the engine would do for us, but no one could be bothered to provide me with some simple ****ing specs out of their FSM.

If you'd like to help me and everyone else that owns a Maxima out, please take a look at http://forums.maxima.org/showthread....hreadid=54327.

madmax2k

Just copy what Nissan did with the 5th gen. If you see any 5th gen dyno plot youll see that peak power is at redline, and is in fact still climbing when the engine hits the rev limiter around 6500 rpm. Ive always figured there would be another 10 hp in the engine if it just revved another 500-700 rpm.

NeverEnough

Just wondering if you ever had any luck locating the information you were searching for. If so, let me know, I'm interested in hearing what we've got.

And thanks MilwaukeeMisfit, I'm really glad someone else is as intrigued by this type of speculative conjecture. Now, if we could just find someone with a machine shop, a lot of patience, and an affinity to daydreaming, we'd be in business.

I'm also trying to develop a variable length/diameter intake system, to find a middleground between the CAI and the open filter style (low rpm torque and high rpm power). Wish me luck.

-Lee

Jeff92se

iTrader: (82)

I wonder if the 3-gen VE intake manifold would fit the 4-gens? Diff engines I know but they "look" very similar. The VE (5-sp only) features a dual stage manifold. Low rpm has part of the manifold blocked off. Then as rpms/load rises, the vacuum actuator rotates a flap that opens up the rest of the manifold.