All About Valves

[WinstonWolf88]

Ok, so I couldn't find any real solid info on how valve adjustments really work and affect engine performance. So I did science and came up with some really useful info.

First off, the basics:

Valves are, appropriately, under the valve cover. They can be adjusted with the screwdriver by aiming at the little round button on the end of the rocker.
They can be adjusted with the engine running and valve cover off. Adjusting valves this way spills very little oil.

Adjusting valves:

Valves are adjusted with the mousewheel by rolling forward, or backward. The screw will turn infinitely in either direction, but the adjustment will "bottom out" after 20 clicks forward or back.
Typically, a valvetrain on a new game will be adjusted well enough to start the car if everything is assembled correctly. However, if you can't start the car, the engine is on the bench, or you seriously mucked up the valves trying to adjust them, you can get the valves in range with this method:

Wheel each valve forward 20 clicks, (which bottoms out the adjustment) and then wheel back 7 clicks.

There is a sweet spot of 7 clicks in the middle of the adjustment range, if you are outside that sweet spot, you will hear a loud tinging sound letting you know you the valve is out of adjustment.
There are five clicks forward of the sweet spot before the adjustment bottoms out.
There are seven clicks backward from the sweet spot before the adjustment bottoms out.
The above adjustment method will put you 2 clicks into the sweet spot from the forward side.

Now here's where things get interesting...

You can shift the powerband of the car by adjusting the intake and exhaust valves seperately.

You can see if a valve is intake or exhaust by checking if the valve lines up to an intake pipe, or an exhaust pipe on the side of the head.

If you have all exhaust valves adjusted forward until one more click makes it ting,
and all intake valves adjusted backward until one more click back makes it ting,
The car will have insane torque on the bottom end, the powerband is so low, you can't even get it to redline.

If you have the exhaust valves adjusted to the farthest backward position of the sweet spot,
and the intake valves adjusted to the far forward position,
you have to rev it and pop the clutch to get it to roll, but it will bounce off the rev limiter like it has a turbo.

Having all valves, intake and exhaust, adjusted full forward in the sweet spot is top heavy in the powerband, but seems to me like there's less power overall.

Conversely, with all valves adjusted as far back in the sweet spot as possible. There's low end power spread through the bottom of the range, it will redline, but it also seems like there's less power there overall.

That's about it. Go forth and tune. Armed with this knowledge, you can put your powerband wherever the hell you want it, even above redline, or below idle.

One last thing as an interesting side note: If you have the mechanic rebuild your engine because you left some pistons and mains on the highway downshifting to third at 190kph,

he will adjust all your valves to the dead center of the sweet spot. Don't ask me how I know.

[NGineus]

well i don't find the power range info in your post really accurate, i found the most powerful set for every occasion (one for all) that is like every sport car have, narrow and fast intake valve and slow and wide exhaust valve. I just set the car 1 scroll over the ticking sound for the intake and 2 for the exhaus and with an A/R of about 14.7 (warm engine) the car will make trough 200km/h and will have the best power with 3.700 final gear ratio

[WinstonWolf88]

That's the beauty of it. There really is no "best" setting. It's down to personal preference. Not everyone needs, or wants, a 200km/h car, especially after getting the rusting fast achievement. I personally like the 4.2 final gear, with intake valves back 4 clicks from ticking, and exhaust forward two clicks from ticking. Car drives best for me that way. but I spend all my time in the dirt road now.

[Aim_4_The_Neck_Cus]

what do you mean by A click?

[EloFreefall]

This is interesting stuff, thanks!

[Lyricalz]

What's the best set up for top speed (A/F, Valves, and Gearing)? Is 200kmh the highest we can get?

[opa]

This is a Pro-click post. Thank's winstonwolf. 5/5

[WinstonWolf88]

Originally posted by Strikex88:

what do you mean by A click?

As you wheel the mouse forward and back, you can feel it bump under your finger. Each bump is one unit of adjustment on the valves in-game, or, "a click"

----

Thanks wikihow dog, appreciate that. :)

[Aim_4_The_Neck_Cus]

winstonwolf thx :)

[Mikhail Reign]

If you look in the game files the exhaust/intake valves already have the exhausts open later. If you set then to the lowest setting, they are recorded as 7.5 and 8. So yeah - the game includes a degree of having them open in the right order as the default setting.

[WinstonWolf88]

Yeah, you're essentially playing with the valve overlap by adjusting intake and exhaust seperately. and moving them all the same direction is kind of a roundabout way to shift the timing (spark). Will be super cool if we get an adjustable distributor cap for timing, but i'm afraid that might be too much for some. Every new discussion here would be: "Car Won't Start"

[jerv]

Originally posted by WinstonWolf88:

Every new discussion here would be: "Car Won't Start"

Just like it was right after release

[MrR0ket0]

waaay to complicated what has worked for me the best is from it original position 25 Clicks up and 11 back which brings the valve screw to the same exact postion but obviously adjusted upwards car ras just fine with it

[WinstonWolf88]

Originally posted by MrR0ket0:

waaay to complicated what has worked for me the best is from it original position 25 Clicks up and 11 back which brings the valve screw to the same exact postion but obviously adjusted upwards car ras just fine with it

If it's too complicated for you, I'm fine with that. Some people would rather be taught how things work, instead of how to work things.

[tin]

This should be reposted as a guide instead of just a post... There are only 3 guides regarding valves, only one of which is in English, and it just describes the 18-7 method.

[Mikhail Reign]

Originally posted by WinstonWolf88:

Originally posted by MrR0ket0:

waaay to complicated what has worked for me the best is from it original position 25 Clicks up and 11 back which brings the valve screw to the same exact postion but obviously adjusted upwards car ras just fine with it

If it's too complicated for you, I'm fine with that. Some people would rather be taught how things work, instead of how to work things.

That dude is gunna need some skin grafts or something. Owch.