Hey all just a quick update. My car has been tuned and my results were not as high as I wanted so they tuned the VVEL. I will get my car delivered here in the next hour or so. I will keep you posted. They even have DYNO runs before and after they played with the VVEL. They say it adds about 15whp in the mid range but at the top only 5 HP gain.

when I saw that +15whp at mid-range I was kind of quite happy with the result until I saw in your signature that you had a SC...

im wondering how much it would have been in N/A form...

anyway that +15whp at mid-range is still good ! :)

I agree with megan370z people are expecting to much from their upgrades these motors have so much potential 15 in the midrange is excellent i think to

The car feels good and I am very happy. I won't get DYNO's until Monday. Sorry you have to wait.

Subd for results!!

I don't care so much about gains as responsiveness.

I don't know how to answer that about responsiveness due to the fact I have not driven my car in 6 months then took it to the shop to get some parts put on. If anyone with an SC Z would like a ride and then they could judge.

Anyone NA have plans of doing this?

In for dyno sheets.

I do once more research is done

Talked to a local shop they have a z lined up that is NA to do some testing on! Ill let u guys know when i hear from them

Very cool.

See if you can get some details such as where valve overlap was changed and where lift was changed in the rev range.

Also, are these bolt-on modded Z's or bone stock? Breathing and exhaust mods will almost certainly make a difference.

Not quite sure what kind of z he is messing with im sure it more than stock at least. The cars that go into this shop usually are not ur average delearship cars haha but idk for certain. We shall see and i will try and get those details once he gets with me

I don't see how this could improve power on NA applications as the intake lift is already at it's maximum point (goes from 2mm to 11m lift) because of the eccentric cam being only so big on the VVEL ladder assembly and the overlap being precise as the rpms go up. I could see some very impressive gains on FI applications as everyone has already stated. Just like to give out my point of view

I seem to recall an old chart from another forum that showed there was more lift possible...

I'll see if I can find the image and post it.

EDIT:

Here...

http://www.the370z.com/members/jordo...vel-curves.jpg

So that chart is saying max is about .500" lift. But it's only using up to .450" lift. HMMMMMM You know how much duration there is?

Has anyone thought of our valvesprings? Can they handle any more lift, duration, and romp rate?

I always thought the issue with springs was the decompression side rather than the compression side (e.g. float).

Also coil bind. ;)

All empirical questions -- hopefully uprev has at least one or two motors they can risk destroying to find the limits...

That is why once VVEL cracking is finally done, the market for aftermarket parts opens wide for head work and parts. Valves, springs, retainers, manifolds, etc....

Good point!


But as with every other parameter, I'd be surprised if Nissan left nothing on the table in terms of VVEL tuning.

very likely. since IMO the vq has gone as far as it can in terms of performance. nissan has squeezed everything they can outta this engine platform

I think if Nissan wants more out of this engine package. They will have to give it a bigger bore, a shorter stroke, and a higher red line. The goal should be 100hp per liter. IMO

Direct injection, higher compression ratio, stroke it to 3.8-4.0L and it will be putting over 400 crank hp. With bolt on mods, we are getting around 400 crank hp. I just want to see evolution from design to design with a meaningful impact on performance.

100hp per liter is Honda talk because their cars are slow unless you build them for boost, even then their power range is like 6k-9k and that's it. We can get that 100 hp per liter with an exhaust, TP's/HFC's and an intake.

If they had there'd be no point in bolt-ons and tuning.

Valve timing and lift affect emissions as well as peak torque -- the NA gains may turn out to be modest, but I get they are there for the taking.

If another hr on the dyno playing with VVEL could net even another 5-7 whp at various points in the rev range, I'll take it.

I'm still fairly convinced that VVEL tuning is part of why Nismos tend to dyno a bit higher.

EDIT: ^^^^ apparently, I was completely wrong on this one! See further here http://www.the370z.com/tuning/84786-...ifference.html

Guess it was really just the exhaust -- SH0velman was correct!

Also, I can indeed confirm that the H-pipe Nismo take off exhaust makes good power and is superior to the Weldina Y-pipe Nismo cat-back.

The 100hp per liter is not Honda talk. I come from a motorcycle background, and that was what we use to shoot for. Now it's 200hp per liter. When you talk NA cars, that's another story. A stock 370z is putting 350hp at the crank. That's still 20hp short of the 100hp per liter mark. Remember we are talking about STOCK with NO add-ons. You really want a figure to shoot for? How about 180hp per liter. That's what the 1000cc BMW is putting out at the rear wheel. That would mean a 3.7 liter motor putting out 666hp. :D To get this kind of power. Big bore, short stroke, high rpm. Just like the bikes do it. :D And your power would begin at 5,000rpm, with NO bottom end. :(

Is short stroke the reason you get no power until later in the rev band?

It's one of the reasons. Cam timing, profile, overlap, etc, intake runner length and diameter, header size, etc.

Motorcycles are indeed a different story. I say Honda talk because it sounds better than it really is for them. It's kinda like steak... Steak is good, Honda's are a flat iron steak, and Ferrari's are Kobe Beef. To Honda guys, steak is steak... until you can actually afford Kobe beef. All of a sudden, that flat iron steak isn't so appetizing.

Yeah, I know where you're coming from. ;) Still would be nice to shoot for 125hp liter. That's 462hp for a NA 3.7 at the crank. :D I think the factory can do it. Then they would have to beef up the rest of the drive train $$$. Plus what about the warranty. LOL

We need to get on TVR's level.

Straight six, 4 Liter, 400 horsepower. NA. 100 hp per liter would be gold. This was stock, too!

Too bad TVR is dead.... damned smolensky.

This is good news and hopefully fairs better than BMW's valvetronic (the exact same as VVEL but on the market since 2001) for aftermarket performance tuning. The tuners over at BMW have been mucking around with this for some time now and have had decent results, nothing amazing.

It's interesting to note that both Nissan and BMW decided to not use this technology on their high performance models, M series and GTR. However I think BMW started using this on their M trim Xseries and on some future normal Ms.

I suspect we won't see it around for long.

Funny how one of the first thing on the grand-am rulesheet for allowed modifications for the z34 is the z33 HR head swap :nutswinger:

I could be wrong, but I thought I saw a VVEL video that said it's superior to the Valvetronic since there's no valve springs that will float (harmonic resonance) and drop a valve at high RPM.

Makes me wonder :rolleyes:

Yeah I read a good article a while back comparing vvel, valvetronic, and toyota's (can't remember name). A good read, but they all were a bit different. Toyota's seemed like the best approach, but that was about 30 minutes of reading on teh intarwebz, so what do I know!

vvt-i

Vtech + stickers ftw!!!

Didn't know that Toyota had something to VVEL, but after some research it's called Valvematic. However it doesn't seem like any of the Toyotas in the US has this.

VVT-I is like nissan's VTC

Bump. Anyone heard anything else on this? Gains? Dynos?