Street Mild Cam?

[Shannond]

hey guys im thinking about putting a street mild cam in my car because my mate said he would do it for me and i just wanted to know abit of info about them as i do not know nothing at all about them? are they good?? worth getting? how much power i gain ?

[R34 -_-]

If you have an aftermarket exhaust say 2.5" in diameter and intake mods like a high flow panel filter and your mates doing the labor side for you then go ahead and put the cams in, if you had to pay for someone to do it most people would say its a waste of money.

Gains wise, not HUGE but definitely noticeable and probably the best mod you can do for an N/A other than the basics..

[Shannond]

If you have an aftermarket exhaust say 2.5" in diameter and intake mods like a high flow panel filter and your mates doing the labor side for you then go ahead and put the cams in, if you had to pay for someone to do it most people would say its a waste of money.

Gains wise, not HUGE but definitely noticeable and probably the best mod you can do for an N/A other than the basics..

yeah i have a 2.5" tiwn exhaust, and a pod filter, yeah hes gonna do it for like $180-$220 he rekons ill get like 40 kw outta it?

[SKiT_R31]

What are the specs of the cam, and what is your engine?

[R34 -_-]

most gains are approx 20kw on an NA car, but those are usually cars with aftermarket ecu's with a good tune

Edited August 3, 2010 by R34 -_-

[floody]

most gains are between 20-30kw on an NA car, but those are usually cars with aftermarket ecu's with a good tune

You are dreaming if you think there is 20kw in a mild street cam for a NA late model skyline mate.

Edited August 3, 2010 by floody

[R34 -_-]

Its been done before.

*edit: oh yea sorry i forgot it was mild, i was thinking along the lines of something more aggressive.

lol at least my estimate wasn't 40kw like his mate said

Edited August 3, 2010 by R34 -_-

[Shannond]

i got no idea the specs of the cam and my engine is RB25DE 2.5 L....whats the best cam out there? to get the most out of it ? man i dont even know what im talking about here LOL i know nothing at all about cams and also can u notice them under the hood? is it something that cops would notice

[R34 -_-]

Impossible to tell you have to them if your looking at the engine, aggressive cams change the engine sound a bit so are noticeable if someones looking at your engine while its turned on.

Camshaft Basics

The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.

To understand why this is the case, imagine that we are running an engine extremely slowly -- at just 10 or 20 revolutions per minute (RPM) -- so that it takes the piston a couple of seconds to complete a cycle. It would be impossible to actually run a normal engine this slowly, but let's imagine that we could. At this slow speed, we would want cam lobes shaped so that:

* Just as the piston starts moving downward in the intake stroke (called top dead center, or TDC), the intake valve would open. The intake valve would close right as the piston bottoms out.

* The exhaust valve would open right as the piston bottoms out (called bottom dead center, or BDC) at the end of the combustion stroke, and would close as the piston completes the exhaust stroke.

This setup would work really well for the engine as long as it ran at this very slow speed. But what happens if you increase the RPM? Let's find out.

When you increase the RPM, the 10 to 20 RPM configuration for the camshaft does not work well. If the engine is running at 4,000 RPM, the valves are opening and closing 2,000 times every minute, or 33 times every second. At these speeds, the piston is moving very quickly, so the air/fuel mixture rushing into the cylinder is moving very quickly as well.

When the intake valve opens and the piston starts its intake stroke, the air/fuel mixture in the intake runner starts to accelerate into the cylinder. By the time the piston reaches the bottom of its intake stroke, the air/fuel is moving at a pretty high speed. If we were to slam the intake valve shut, all of that air/fuel would come to a stop and not enter the cylinder. By leaving the intake valve open a little longer, the momentum of the fast-moving air/fuel continues to force air/fuel into the cylinder as the piston starts its compression stroke. So the faster the engine goes, the faster the air/fuel moves, and the longer we want the intake valve to stay open. We also want the valve to open wider at higher speeds -- this parameter, called valve lift, is governed by the cam lobe profile.

Any given camshaft will be perfect only at one engine speed. At every other engine speed, the engine won't perform to its full potential. A fixed camshaft is, therefore, always a compromise. This is why car makers have developed schemes to vary the cam profile as the engine speed changes.

factory cams are very conservative so they sacrifice effeciency for better drive ability.

After markets cams are more aggresive and work the other way around.

They increase lift and duration and make the combustion cycle more effecient by letting more air in and out faster and make better use of the combustion pressure on the piston (lift and duration).

Drive-ability gets worse because aftermarket cams are made for certain RPMS, at this certain rpm the camshafts are working at optimum speeds and every engine part is working in sync (valves/pistons etc), outside this rpm zone driving becomes rougher i.e accelerating is not smooth until your near the optimum rpm.

Mild cams are one step better than factory and the compromise in drive-ability is very little, but gains are still good.

I'm sure someone can explain this better, i just found the first part on the net cause im lazy and cbf explaining it all lol.

Also, are you getting cam gears or camshafts??

Edited August 4, 2010 by R34 -_-

[Shannond]

Impossible to tell you have to them if your looking at the engine, aggressive cams change the engine sound a bit so are noticeable if someones looking at your engine while its turned on.

Camshaft Basics

The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.

To understand why this is the case, imagine that we are running an engine extremely slowly -- at just 10 or 20 revolutions per minute (RPM) -- so that it takes the piston a couple of seconds to complete a cycle. It would be impossible to actually run a normal engine this slowly, but let's imagine that we could. At this slow speed, we would want cam lobes shaped so that:

* Just as the piston starts moving downward in the intake stroke (called top dead center, or TDC), the intake valve would open. The intake valve would close right as the piston bottoms out.

* The exhaust valve would open right as the piston bottoms out (called bottom dead center, or BDC) at the end of the combustion stroke, and would close as the piston completes the exhaust stroke.

This setup would work really well for the engine as long as it ran at this very slow speed. But what happens if you increase the RPM? Let's find out.

When you increase the RPM, the 10 to 20 RPM configuration for the camshaft does not work well. If the engine is running at 4,000 RPM, the valves are opening and closing 2,000 times every minute, or 33 times every second. At these speeds, the piston is moving very quickly, so the air/fuel mixture rushing into the cylinder is moving very quickly as well.

When the intake valve opens and the piston starts its intake stroke, the air/fuel mixture in the intake runner starts to accelerate into the cylinder. By the time the piston reaches the bottom of its intake stroke, the air/fuel is moving at a pretty high speed. If we were to slam the intake valve shut, all of that air/fuel would come to a stop and not enter the cylinder. By leaving the intake valve open a little longer, the momentum of the fast-moving air/fuel continues to force air/fuel into the cylinder as the piston starts its compression stroke. So the faster the engine goes, the faster the air/fuel moves, and the longer we want the intake valve to stay open. We also want the valve to open wider at higher speeds -- this parameter, called valve lift, is governed by the cam lobe profile.

Any given camshaft will be perfect only at one engine speed. At every other engine speed, the engine won't perform to its full potential. A fixed camshaft is, therefore, always a compromise. This is why car makers have developed schemes to vary the cam profile as the engine speed changes.

factory cams are very conservative so they sacrifice effeciency for better drive ability.

After markets cams are more aggresive and work the other way around.

They increase lift and duration and make the combustion cycle more effecient by letting more air in and out faster and make better use of the combustion pressure on the piston (lift and duration).

Drive-ability gets worse because aftermarket cams are made for certain RPMS, at this certain rpm the camshafts are working at optimum speeds and every engine part is working in sync (valves/pistons etc), outside this rpm zone driving becomes rougher i.e accelerating is not smooth until your near the optimum rpm.

Mild cams are one step better than factory and the compromise in drive-ability is very little, but gains are still good.

I'm sure someone can explain this better, i just found the first part on the net cause im lazy and cbf explaining it all lol.

Also, are you getting cam gears or camshafts??

hahah thanks for that ummm i dont even know what cam gears and cam shafts are? LOL

[Jezza-gtR]

hey guys im thinking about putting a street mild cam in my car because my mate said he would do it for me and i just wanted to know abit of info about them as i do not know nothing at all about them? are they good?? worth getting? how much power i gain ?

Cost VS Gain it's not really worth doing unless your going to do it properly. Sure you can put some drop in cams and you may notice a little difference but it will be nothing special. Also you have to work out what you want the engine to do. Do you want to make more low down torque or top end HP?

To do it properly:

*Pick cams for your application

*Port the head

*Larger valves

*Springs

*May need lifters

*Cam gears if you want to change the torque/power cruve

*Tune

Note: You may also need other supporting mods.. eg. Larger fuel pump.

^.. But doing all that is ALOT of money for not alot of gain. Up to yourself. Hope this helps.

[mad082]

ok, no the cams can't be seen by the cops. this picture indicates where they are in the engine

then once you pull those covers off it looks like this. the arrows point to the 2 cams

and here is how a cam shaft works http://www.howstuffworks.com/camshaft.htm

[Shannond]

aw ok thanks heaps guys lol im still confused and not sure what i should do now hmm.. tuff decsion

[TwoCents]

Ive looked into Cams for a 33 GTS and the best option is to go with these http://www.nengun.com/tomei/pon-camshafts

They will keep the VCT enabled and you can use them in a rb25det if you wish to in the future. Also get an adjustable camgear for the exhaust side (as intake is already has VCT) for better tuning/use. Buy that from nengun and its $1088.86 of the camshafts and gear. Then you want a tune.. you will want to buy a z32 ecu and put a nistune chip in it that will set you back about another $1000.

A different option ive been told is to get some rb26 cam shafts and get them machined to your application, in doing this you loose the VCT tho.

I was about to buy all this, was just 1 click away from it being all ordered but decided screw it and bought a brake upgrade (get me on the track quicker/safer), 5 stud all round, r33 turbo calipers, new master cylinder,slotted rotors, stainless steel brake lines some street/track pads and an Apexi AFC Neo for some fun.

[Jezza-gtR]

There is never a ''best option'' when picking something such as cams. Also those cams are for turbo application. He would be better off getting a custom profile with a re-grind.

[Shannond]

i spoke to my mate about it yeah he said hes putting a street mild cam in so i dont need to change everything and that his mate that works at a tuning place is gonna dyno, tune it and power run it all for me

[zebra]

i spoke to my mate about it yeah he said hes putting a street mild cam in so i dont need to change everything and that his mate that works at a tuning place is gonna dyno, tune it and power run it all for me

Ummmm...how is he going to tune it...and if he says mild cam.....well there are 2 of them for a start, and what cams?

I guess you have no aftermarket ecu to tune with...sounds like your mate is a bogan that knows nothing about Twin cam Rbs

[zebra]

Ive looked into Cams for a 33 GTS and the best option is to go with these http://www.nengun.com/tomei/pon-camshafts

A different option ive been told is to get some rb26 cam shafts and get them machined to your application, in doing this you loose the VCT tho.

Turbo cams run totally different lobe ramp rates to what a small capacity NA needs.

Without boost and using large cams designed for use with turbos will result in bugger all mid range and maybe gain some in the top end.

anyway my 2c lol

[TwoCents]

Turbo cams run totally different lobe ramp rates to what a small capacity NA needs.

Without boost and using large cams designed for use with turbos will result in bugger all mid range and maybe gain some in the top end.

anyway my 2c lol

Only reason is because they can retain the VCT which i wouldn't want to loose on an NA car. And i was going to chuck them into a turbo engine when i was off my P's anyway.

I guess you could do something with the stock cams to make them more suitable to whatever your doing?

[XRATED]

Don't let your 'mate' anywhere near your car!

... the NA thread is allways good for a laugh.