Yup, we might as well get comfy with VVEL I doubt anyone will bother cracking it.

GTM UpRev, dont care who it is as long as someone does it.

Talked with Uprev today:

^^^ That is really surprising. There absolutely should be more power hiding in there with the factory cams -- especially on a car with a better flowing intake and exhaust.

That also doesn't help explain why Nismos tend to dyno higher than non-nismos with equivalent mods and tune...

I are confuzed.

Hard to believe, unless there's not much more adjustment available for the factory cams.

So a company just needs to come out with aftermarket exhaust cams to tune the vvel on the intake with? What is the stock grind on the exhaust cams?

Is the nissan system limited to timing and lift adjustment on the intake cam only?

If so I cant see the customisation of this system offering much more than a little midrange improvement.

Yes it is only on the intake. The exhaust cams are completely static, with no phasing or lift adjustments.

I'm down for a set of mild cams. Who is it gonna be??????????

Tomei was the closest to having something for the vhr, and they gave up back in 09. They said pretty much no gains to be had--the 3.7 is crammed pretty aggressive from the factory.

That sucks cause they probably could have made more power by phasing the exhaust cams instead of the intake by holding in more compression in the lower rpms (advancing the cam) and blowing more compression out on the top end (retarding the cam) giving alot wider power band with more average horsepower and torque gains. BTW you cant adjust lift because thats grinded into the cam and will always be static. Only way to gain lift is to change rocker arms on a pushrod engine. Also lift really dont make a crap anyways the things that matter most are duration and lobe seperation aka centerline. Basically the only thing the vvel does is act as an automated computer controlled cam timing gear which will only change your power band. So this being said the vvel can only give you what your stock cam can provide on both the low and top end which is a very nice thing to have, but dont expect much from someone cracking the vvel. The down side is that if someone trying to tune the vvel that does not have much experience and does not know the limitations will run a great risk of running into piston to valve clearance problems especially with aftermarket camshafts.

My interpretation of UpRev's statement is this: the ECU is pretty smart and already has full control of the available range of the stock VVEL cams, and makes good use of it when the MAF, Fuel, etc tables are set up properly for the application (intake/exhaust config, FI, etc). Therefore "cracking" VVEL probably doesn't actually allow you to gain more power through ECU tuning alone, seeing as it's already an optimally self-tuning system in realtime. But you might be able to get some gains by having a new physical VVEL cam shape/range and the ability to reprogram the relevant ECU tables to take advantage of it.

Most likely this (the capability of our ECU to self-tune VVEL to conditions) is why the car is so mod-friendly to begin with. Remember even before UpRev was available, these cars always posted unbelievably amazing gains from bolt-on exhaust and intake mods, so much that people thought others were lying about their results in the early days.

IMHO, it would probably still be nice if they put tune-ability of the tables into their product for the stock cams. It might not get you any peak dyno gain, but I bet it could open up optimization tweaks for drivability and throttle character.

You do know what VVEL stands for, right? "Variable Valve Event and Lift. It does a lot more than a lot more than a cam timing gear.

It does change lift and duration.
http://i.imgur.com/WiIV1.jpg

Oh and also the phasing is adjustable too, but that's technically the "IVT" system and not VVEL.

^The above info makes sense to me

I'm very familiar with Honda's I-VTEC system, the VVEL approach seems to have a much more limited scope in terms of adjustment.

what planet are you from??? :)

Exactly.

But, then again, if it really can self-correct both lift and overlap that much, then fair enough, but I have to say it is a little surprising.

Just a quick query, Is the black trace the full physical limit of the system and the red tace the Computer controlled limit?

So since this is a no go, is anybody up for doing the 4.5L stroker kit with a TT set up?

I'd be very interested to see what an NA 4.5L stoker could do. I think it would just be nice to see what the extra displacement brought to the table.

I think Bullitt is using this in his ongoing 1,000whp build with Sam at GTM.

From what I remember reading somewhere about this is that it will help more on the F/I aspect vs N/A. I might just do it since the price has dropped on it a little but I might just go ahead and do the TT set up with it as well.

Any idea where you read it? I'm not calling you a liar or anything, I would actually just like to read it too. There isn't a whole ton of information on stroker kits for our cars. I think part of it will depend on what kind of compression ratio you end up running with the pistons, but I'm no expert. It would be fun to see the look on peoples faces when you tell them you have a 4.5L engine and then tell them that it's a V6.

I decided a while back that if ever end up dumping loads of money into my car I want to do an NA stroker first and then add some type of forced induction later down the road. And while it's cool to be the guinea pig and do something first, it's always nice to see the results from someone else before you drop that much cash.

Doing an NA build, then going FI makes no sense. You are going to build the motor differently.

I do not understand the desire to run a huge v6 either. I would not want to be dealing with a massive, unbalanced engine, but that's just me.

Whats the Bore to stroke ratio like at 4.5L??

My understanding on the black-vs-red limits is this: if you crack open the VVEL heads, there's an adjustment that can be made in there. In the service manual it's noted as a VVEL "adjustment bolt". It's supposed to be a fine-tune adjustment done at the factory to set things "correctly", and you're never allowed to loosen it or touch it. They even say with a straight face in the SM, basically, "if you ever loosen this bolt, you must replace the entire VVEL assembly with a factory new one". But you could ignore the factory adjust specs and crank this adjustment out to the maximum limit it allows, which produces the larger black profile. God only knows if the ECU deals with it very well or not, or if it causes damage, etc. You'd have to ask someone who's actually done it.

Pic of Service Manual page that shows the adjustment bolts:

http://www.the370z.com/members/wstar...9-41-21-am.png

Almost everyone seems to be running FI kits on the stock 11:1 motors right now. So while it wouldn't necessarily be the optimal setup for FI, it should still be a feasible option.

Would balancing the engine not be something that was done when putting it together?

I mean, you can. It's just if i am dropping that much building the motor...hell, even just that time...i am gonna build it up for my end goal.


V6 motors are inherently unbalanced.

Thats pretty cool!

It seems like a case of removing the rocker cover, manually locking the arms to max lift and turning the crank over by hand to see if theres any P2V contact...

^^ Go try it and let us know :icon17:

You first :D

I would *guess* that the factory lift spec for the adjuster is so they can have reasonable mfg tolerances. e.g. some of the VVEL units mfg'd will have slightly different physical limits, but the factory spec is something that all VVEL units can be adjusted to at the factory with those bolts. You might find that some engines have more leftover room on the adjust than others (or even different on the two sides of one engine, and you really want them to match up perfectly). Still, even assuming most engines have some usable adjustment headroom on both sides and you could adjust them perfectly in sync with each other, and it doesn't cause physical contact, you're left with question marks about whether the stock ECU can deal with that safely, and/or what (possibly unknown) tuneables to tweak there to make it work right).

:iagree:

I think coping with the new angle and lift induced by manual adjustment would need another cam angle table in aftermarket software.

I'm all about P2V contact. :roflpuke2::roflpuke2::roflpuke2:

I guess the big question is how loose are things set up? If that extra potential lift that isn't being used is there to aovid problems due to potential valve float at high revs maybe it's best left alone...

It just seems really surprising to me that with better flowing intake and exhaust components that VVEL tuning wouldn't be advantageous, but data trumps theory so... :icon14:

I'd really like to know more details about what kinds of tests and adjustments were done before the conclusion "not worth it" was determined :shakes head:

I agree, providing you have piston clearance plus another table for the 'extended' cam opening in terms of fueling and ignition. I dont see how another 0.025" of lift and 5 degress of duration wouldnt make power on a bolt-on equiped Z

Looking at a bunch of I/H/E dynos generally shows everyone running out of puff around 7k RPM, unless the exhaust cam is the limiting factor thats where the additional lift should help out.

Hope this isnt a repost!

.

Not holding my breath for someone to crack VVEL but I hope someone does it. It looks like it will need both a hardware adjustment and separate ecu tuning.

Revive, but I'd like to know if anyone has messed with this adjusting screw for intake lift. Or would it not work at all?