JUN High Lift Exhaust Camshafts has be released
 

Hi Guys
this is something new
Finally JUN introduced there High Lift Exhaust Cams :driving:
http://www.junauto.co.jp/gallery/val...shaft_vq37.jpg

it's Specifications are:
Duration: 68 (272) deg. / Lift: 11.0mm

Price : 50400 JPY = 623.38 USD

and this is the Link :
JUN AUTO - JUN AUTO JAPAN - HOT NEWS

anyway i asked one of my friends to make sure about it and it's HP Gain
when i have any news, i will update here :iagree:

Subd

Interested..

Kool. Don't know much about cams on the Z... hope to learn a lot from this thread and possibly attempt to make this mod if it benefits me? I know the benefits are mainly with torque which we desperately need. But I'm wondering if there are any drawbacks

I know the labor will be a real nightmare

Hahaha... yeah kiss the warranty goodbye with this mod. Lol

Useful without being able to tune VVEL???

Interesting...

I wish they had tuned power comparisons on a stock Z instead of one with 12.3:1 pistons

willing to take a chance on these, but need to know the following, what kind of labor is involved? what is needed to be done to fix those, how many hours of labor are we to expect with and experianced mechanic? And will the car need to be tuned when these are installed? if so will uprev do, please someone chime in, btw where can i order them from?

and one more thing, how difficult is this job on a scale of 10

Apparently they used different (bigger?) fuel injectors too.

Hmmm.

well ... i can't tell but believe me it needs a professional mechanic to install them perfectly
don't try install them by yourself :gtfo2:

and if you want to order them, i have a japanese friend in facebook and he is doing a good business by exporting Parts from Japan
i can give you his account if you are interested

Hmmmm .... I have an idea
you can install them and do the comparison :tup:

anyway i want to know how much HP i will gain if i install them on stock engine
maybe we have to wait till someone install them :icon17:

I think vendors especially GTM should do the independent install and dyno to increase the market of this thing

Cams installation is not that difficult as cams are the top part of the engine so accessing it is pretty straight forward. But fast cam mod is definitely something not to be DIY, best get a good mech to install it as cams install requires clocking tools. As the cam durations are different from oem cams, your exhaust note, idling will all be affected and a tune would most likely be required although you may get away without a tune but you will suffer erractic idling and even occasional stalling when you clutch in. Something to think about for those keen to install.

I'm just curious how the VVEL reacts to a different exhaust cam. Would it just stay the same or would the computer adjust to "match" the new cam?

VVEL would just laugh at you and say: "Silly modder, all your timings are belong to us."

:roflpuke2::roflpuke2::roflpuke2::roflpuke2:

will an uprev tune be enough, can uprev be used to tune these cams? and will i need to change other internals to accomidate the cams, how agressive are those cams?

you need a tune that can accomodate the change in lift/durations

Does uprev have the tune option to change lift/duration?

To those asking about install difficulty, expect 10-12 hours as a competent mechanic.


To those asking about VVEL, this is an exhaust cam.

That's the question of the hour.

If phunk's theory is right, there is cl feedback and the answer is yes, at least to some degree...though how effective the system will be at compensating remains to be seen.

If not, who knows how it will behave.

JUN said themselves, and this is common knowledge, the larger duration cam lowers static compression hence why they put in high comp pistons. What i'm wondering is, how will the motor react power wise with just the cam swap and stock pistons.

To be honest with you guys, for a measly 10~15whp, its not worth ripping apart the motor to swap cams and then retune. The price per hp ratio kinda sucks. If, I was rebuilding a block and had it apart already, then maybe I would swap the cam in.

Installing these cams will require you to remove the entire timing chain cover and a slew of other stuff. Probably better to do this mod if your already building the motor. The lowered compression could go well w/ FI. I mite look into using these when I build my motor but I'll wait for more info before pulling the trigger.

Probably looking at a good $1000 just to install. But if it makes a big difference I would be willing to fork over the money.

Hmm interesting on a FI car, NO?

:iagree: Very interesting. In theory, if these lower the compression ratio then one could run more boost and make more power without needing to build the block, no? Or is it more of a certain level of power make the engine go boom kinda thing?

Then again, as stated before, if you're ripping apart the top of the motor you might as well build the whole thing.

Static compression is lowered yes, but the added compression from burning the air/fuel mixture(timing advance) is actually greater, hence why adding larger cams makes power.... usually.

This is very interesting, it'll be cool to see what kind of gains and drivability changes these cams could yield.

That doesn't necessarily mean the ECU can adapt optimally to the new profile. They have to work in harmony.

Also, note that JUN provides their own ECU with it. Along with a spark and fuel reflash, it might also have different VVEL tuning in they were able to work with Nissan on it -- we just don't know.

Covered here:



Based on what I've seen, I'm positive there is closed loop feedback. We just need to see how good the system is at adapting.

Sub'd

So who wants to buy it and ship them to me? :D

Right... but all closed loop systems are slave to a set of known physical engine environment parameters that they trim the motor's behavior around.

For example, fuel trims aimed at keeping a target AFR that reflects a stoichiometric mixture of gasoline and air will not do a good job of adapting to a new fuel with different stoichiometrics, such as methanol, without changing the parameters. It will just run poorly as it tries desperately to tune for the wrong fuel.

As soon as you change the physical parameters without updating the ECU, it's anybody's guess.

We definitely need more info from JUN.

If i remember correctly,

Back in a while, Uprev was able to crack the cams maps in VVEL but they said that they didnt find any kind of gains and they need an aftermarket cams to test it again or something like that...

Well Uprev... you got what you ask for! :stirthepot:

^ that's news to me.

http://www.the370z.com/tuning/38796-...ng-vvel-6.html

theDreamer has a post halfway down the page that touches on this matter.

Which is exactly the same thing i said. We don't know how much effort Nissan put into testing the system with things like varied exhaust cam profiles. In all likelihood they did none/very little and the system will choke when you start changing stuff...but who knows?

Well then.