It does look like you would gain quite a bit by stretching the redline for 1st and 2nd gears, but for the rest there would be little to no gain unless you also did mods to improve the top end performance of the engine.

-D'oh!

 

Doh,

Thats exactly what I wanted to do. Nice job.

I didnt realize their would be zero overlap. Looks like redline is the answer. Would be even more benefit to shifting at redline with a plenum upgrade.

X

 

Not even so much the bottom end...gotta be careful of floating some valves....it's the heads that weren't made to rev so high....new valves, valve springs, retainers should help with that.

--wes

 

Yeah, I saw you talking about this, so I decided to give it a shot while my computer was crunching on an FEA analysis. Turned out pretty cool if I do say so myself.

One thing, it seems like the speeds in each gear are a bit high, I double checked the gear ratios and they seem fine, so the only thing left is the overall tire diameter. The tire calculators give a diameter of 26.6" for a 245/45-18 tire, but that gives us about 64 MPH in second gear. I was thinking we were closer to 62, which is corresponds to a 26" tire, but whatever, the differences would simply be a scaling of the curves, and they would still look the same with respect to eachother.

Later,
D'oh!

 

according to the guys at TS they sponser an endurance race team in japan with stock block vq's and they spend hours at 7300. they rod failure occurs at 7400

 

Yeah,

I was wanting to do something that read in a input dynojet file, but after seeing your results its kinda moot. I was thinking it would be nice to know where the shift points move as you make mods, but I dont think that anything you do will move the ideal point from redline, especially if you do the plenum upgrade.

I guess if you focus all your mods on the low end it might change, but thats kinda silly =).

X

 

Does the calculation take into account mounted/unmounted and rim width?

 

Not sure. Took the size straight from those online "tire calculators" Just put in 245/45-18. Comes out to 26.68 in a hand calc, and I think that was pretty close to what the tire calculators arrived at.

Either way, the tire size only affects the X-axis scale (speed) and not the torque (since I'm showing the torque @ the axle). Therefore, a change in the tire size would stretch or shrink the curves only in the X-axis, and would not change their relative positions.

-D'oh!

 

Is this true? VQ35 on Z's and G's stop making power at 5800 RPM? Nissan advertises peak HP @ 6200 RPM...

Someone call a lawyer.

 

STep on the gas and go!

See, you have to know all of this in order to beat us 5/AT's !

 

I love this thread....I want to make a list and in 3 months see who subscribed to this and said they can incrase their RPM's on a stock motor to 7300-7400...And see how many have shot rods through their hoods
The motor in stock form was NOT designed to be revved into the 7000 grand and up area...The rods wont take the RPM's which by the way the revoutions cause more stress on the rods than detonation does(the cyntriphical force is increased tenfold when you increase the RPMs..The rods are being stressed more by doing this..ps dont make fun of the spelling,I am retarted..)

...The heads arent designed for it..The berrings wont hold up to increased RPMS...Maybee you will get away with 7100 for a while but why do it to yourself....The extra RPM's arent worth it...

But be my guest and find out the HARD way.

 

Here we go again: 'the rods are weak... the rod bolts are weak... the bearings are cheap... the heads weren't designed for it' (whatever that means... Well, apparently the folks @ Technosquare think otherwise.

This question of "rev-ability" is one that is in great need of addressing by Nismo, itself. They ought to provide a technical guide to engine tuning (like you can get with many other mfgr's engines), that makes recommendations for each level of tune, say, in 500-rpm increments.

And, if this engine is so delicate that it won't turn over 7k without grenading, then it's award for being 'one of the industries best engines,' is a sham. Has Nissan taken us back to the 80's, and Honda motorcycle engines, that were just robust enough to be reliable in as-delivered tune. That would be a shame -- and I'm betting not.

 

No body is saying the engine is cheap or not a god engine...But the engine was designed by Nissan engineers that know alot more than YOU and I, and designed it to do what it does in stock form..The best engine in the world can fail under excessive rev's...In fact I think there are just as many engine failures from over revving as there are from bad tuning..
Have TS erase your rev limiter and rev the "AWARD WINNING ENGINE" to 7500rpms and let me know how it goes...And let me know if TS will pay for your engine after it fails from over revving...

 

What about HFM?

 

Absolutely not true.

This is my car stock on Mustang Dyno:

http://www.automotiveforums.com/dps/...0503-229hp.jpg

The HP kept growing until our cutting point at 6500RPM.

 

That's right, no one is saying that. What I am saying, though, is it would be a disappointment if such a nice engine -- with it's low internal inertia, oversquare bore, great cylinder heads, and state-of-the-art engine management -- were unable to be tuned to operate in the 7k+ rpm band and extract the power, and create the sounds, that are available there, without having to be completely rebuilt first.

The point is that 7300 rpm is not normally excessive for an engine as sophisticated as ours. I have owned several V6-powered cars that EASILY and reliably turned 7000+ with very little additional work.

I have no plan to have my rev limiter erased. While I, like you, will err on the side of caution; unlike you, I'm not convinced this engine is fragile. But, like I said, Nismo can answer these questions in detail, i f they choose to.

 

Why do you keep saying that peak power is at 5800rpm? Its not peak power is at 6200rpm. Torque peak is 4800rpm. You want to shift at readline in 1-3 gears. 4th gear you shift at 6200. You never ever shift below the HP peakwhen racing.

 

I think Nismo has already answered the question... by annoucing S1 engine.... to be able to rev up to 7200 rpm with the s1 engine, we gotta change the con rod bolts as they stated to withhold those extra hundreds of rpm... and also install cams to bring out the higher rpm power.... does that mean they don't think the z is strong enough to be revved up to 7200 without those bolts?!

cheers,

richie

 

All comments I made previously about rev'g up...

Geez was I wrong.

Adam (VandyZ) rev's up to 7200RPM ALL the time with the Crawford reflash and he is having ZERO probs with his motor.

WHEW that thing is fast!

 

There are tons of VQ30DE guys that are revving to 7200rpm. I have 140,000 miles on my engine and have been revving to 7000rpm for the last 30,000 miles. No problems yet. I would venture to say that a VQ35DE would have no problems either. I am within 6hp of my peak hp at 7000rpm with a different intake manifold, no cams. I think JWT said that the valves start to float at 7300rpm on a VQ30DE, but we have one guy revving to 8000rpm with no problems yet. (I am sure there will be long term)