Adjusting adjustable cam gears.. 130-95?

[limbo]

Yes i would recommend that. ALso as the good sets have markings they will also allow for you to easily vary and adjust your settings. I wouldn't go more than 10 degrees either way

[Starfire]

The wheels with the multiple holes in them do allow for a vernier type adjustment and may be called a vernier wheel in some cirles, owing to the relationship between the hole spacing and the outer teeth of the wheel. This is not to be confused with a vernier scale.

A vernier scale lets one read more precisely from an evenly divided straight or circular measurement scale. It is fitted with a sliding secondary scale that is used to indicate where the measurement lies when it is in-between two of the marks on the main scale.

It was invented in its modern form in 1631 by the French mathematician Pierre Vernier (1580–1637). In some languages, this device is called a nonius, which is the latin name of the Portuguese astronomer and mathematician Pedro Nunes (1492–1578) who invented the principle.

Verniers are common on sextants, scientific instuments and machinists' measuring tools (all sorts, but especially calipers and micrometers) and on theodolites.

When a measurement is taken by mechanical means using one of the above mentioned instruments, the measure is read off a finely marked data scale (the "fixed" scale). The measure taken will usually be between two of the smallest gradations on this scale. The indicating scale (vernier) is used to provide an even finer additional level of precision without resorting to estimation.

[Jonny Rochester]

This is funny. Ever since the new forum rules started, everyone is falling over themselves to start usefull threads, and make intelligent posts in hope of earning "reputation" points. (Not a bad thing I may add), but some just copy and paste from the dictionary.

Well done Starfire, but at 25 points, we both have a long way to go before we can sell anything

[Starfire]

Yes part of my last post was a copy paste but it does explain what a vernier dial is I really only need enough points for an avatar.

[TurboRA28]

Just thought i'd mention the results of changing the cam timing on the 3sgte.

It's made a huge improvement! It hasn't been on a dyno yet, but instead of starting to make power at 6000rpm +, its really getting up to go at 4000rpm now. Pulls hard to the rev limited at 7500prm.

So im really happy with the result. Now when I can get it on the dyno I might make some small changes just to see the results but just set back to factory its 100x better.

Cheers
Joel

[Draven]

question from a vvti n00b here....
I know changing the inlet cam would be A Very Bad Thing, as this is where the variability is done, and I know changing the exhaust cam is A Good Thing... but what about putting an adjustable cam gear on the intake cam?
if it makes a difference, it's a constantly variable vvti system, not switch-type.

[Starfire]

Different cam timing at different rev ranges makes quite a difference to overall performance. As most cars aren't able to change the timing the static timing is set to provide best performance across the rev range.

VVT changes the inlet cam timing at a specific rev range. The way to determine when to do this is to perform a dyno run with it standard and then another with the cam advanced. Where the graphs cross over is when the timing should change to give the best results.

VVTi is just like VVT only in stead of being an on/off setup it is continually variable and controlled by the ECU based on load and accelerator position.

Benefits can be seen by changing both the inlet and exhaust, but inlet will net the most - thus for cost reasons most engines only have vvt on the inlet.

[Draven]

Having experience in counselling, I'm an expert at rewording and rephrasing a client's statements to reflect back to them... but even I'm impressed by how regurgitated that sounds.
the first 3 paragraphs are completely irrelevant. I was the one who just stated my vvti is a constantly variable system, why was that stated again?
All I wanted to know was effect of an adjustable cam gear on the inlet cam of a constantly variable vvti system.

</grumpy>

[Draven]

and it's based on load, tps, rpm and coolant temp

[Draven]

and here is the answer.. if anyone can find me an adjustable cam gear that looks like this I might just give them head:

[chris davey]

I thought you couldn't change the inlet cam timing because the cam sensors are there and that would effect other things as the ecu would have a different view of when TDC is.

BTW have to be a member to open link

[Starfire]

What I wrote was off of the top of my head. Fuck you if you didnt like it.

Most engines take cam timing off of the exhaust cam. Obviously if they want to adjust the cam timing on the exhaust methods will need to be in place to compensate for that.

[Draven]

sorry starfire, I'm a gumpy bugger today.
1jz-gte engines definitely take timing off the inlet cam (2 sensors on the inlet actually), and I would assume the 2j was much the same.

[Celica RA45]

my vvti gears have plus and minus so i can dial the cams in .so once i set them up on lifter rise at tdc i can see where best to suit them and also my vvti controlers dont move as much as they used to, std they are 25cam degress now they are 18degress .so at tdc and with cams in std posi i will advance inlet to see how far i can move it and also same with exhaust
so once i know where to stop i lock them off
also warning you need 2mm btw piston and valve or things can get messy
and draven mine in start up mode is off inlet that is but ex haust is on and about 1600 rpm onwards they advance all the way to 18degress and only move back to 10 degress at 8400 rpm
ex is turned off after 5000 rpm
getting back to what you wont the 5 bolts that go around if you undo these you will get about 4 degress of movement either way