What does a motor with cams feel like?

[bummy]

From my experience (pre-tuned ECU, not fully tunable yet).
1. VTEC engagement can be set to your desired RPM. Consult a good tuner IMO.
2. VTEC kick...in my example is much more aggressive (just running stage 1's). If you get VTEC killer cams then it speaks for itself, but with a lumpier VTEC lobe you should notice more power, right?
3. Yes peak power shifts, generally upwards.
4. Yeah you want to aim for peak HP IMO. AFAIK you'll pretty much always hit your peak torque before peak HP, and I'd rather have the HP than the torque.
5. Uses a little more fuel (not properly tuned). Louder. Crazy VTEC crossover (I have other mods too).

vtec killer cams dont have vtec lobes.

[bummy]

Dougie,
What cams do you run?

I am confused as to the hp and torque thing. Hp is always after peak torque because of how hp is calculated (nm*rpm/5252).
And I am wondering whether it's ok to get cams that make peak hp after cutoff (ie the hp will keep going up after cut off) however peak torque is before cut off obviously.
The reason I ask, is one of my daily drivers has peak torque at 1,500-4,000rpm, and peak hp from 4,500-6,000rpm, however past 5,000rpm it has no pull at all.

make sure you take account of supporting system to achieve peak hp e.g. 4-1 header with long primaries, larger diameter. shorter, larger diameter IM.
not sure in the relation in valve overlap in terms of choosing camshafts. also, dont forget dynamic compression ratio, larger lobes will reduce static compression ratio?

Basically torque is measured rotationally, but horespower is measured linearly. Because an engine spins around the crank it is impossible to directly measure horsepower. You have to measure torque and then extrapolate the horsepower using the formula given earlier.




I disagree. Especially for tthe street, you're contradicting yourself when you chose the good street cams.

Its easier to think of it like this: torque is what gets you moving, power is what keeps you going. When you put your foot down and you get pressed back in your seat, that's torque.

Power is good when you have something light to move. Motorbikes make massive power, but no torque, likewise for Honda's. Torque is good for something heavy. a truck might only make 700hp, but it does it at 2500 rpm and makes 1500nm of torque. Even if you had a 700hp Honda motor you'd be pushing to make 500nm coz you'd be doing it at 8k rpm and it wouldn't work in a truck.

For a street car, you'd want torque over power. Most of the time you're coming from traffic lights etc, so low revs, and that's where you want the pull, and that's torque.


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street car needs torque i very much agree.

[dougie_504]

Basically torque is measured rotationally, but horespower is measured linearly. Because an engine spins around the crank it is impossible to directly measure horsepower. You have to measure torque and then extrapolate the horsepower using the formula given earlier.




I disagree. Especially for tthe street, you're contradicting yourself when you chose the good street cams.

Its easier to think of it like this: torque is what gets you moving, power is what keeps you going. When you put your foot down and you get pressed back in your seat, that's torque.

Power is good when you have something light to move. Motorbikes make massive power, but no torque, likewise for Honda's. Torque is good for something heavy. a truck might only make 700hp, but it does it at 2500 rpm and makes 1500nm of torque. Even if you had a 700hp Honda motor you'd be pushing to make 500nm coz you'd be doing it at 8k rpm and it wouldn't work in a truck.

For a street car, you'd want torque over power. Most of the time you're coming from traffic lights etc, so low revs, and that's where you want the pull, and that's torque.


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Yes true, but I didn't want anything extreme that would make my idle rough or mess up my fuel useage too much. I drive the car once a week and it gets rev'd out quite a lot, so the stage 1 cams were IMO a good choice for what I wanted out of my car.

Being a 1.6L I'm not too concerned about how much low-end power I'm getting. It revs out to 9,000RPM and there's plenty of power to be tapped into

[mocchi]

hey dougie,

what is this stage 1 cams? what makes them so called a stage 1 cam?

[trism]

Youll find the terminology of "stages" used to descibed cams in every single motor ever built.

Its just an easy way to describe how much more aggresive over stock they are. Normally they go in 3 stages.

Stage 1 is a street upgrade, basically a little bit more lift, a little bit longer duration, adds a few more HP and a bit more torque without the need for tuning, and without making it totally unstreetable and shit on fuel, a pig in traffic etc.

Stage 2 is for those who track their cars often, a weekender or once a month car, but still needs to be reasonable in traffic, and on fuel. Duration and lift are increased a bit more, generally helps to have something to tune to, and you wouldnt do it without having all the supporting mods, intake, exhaust etc

Stage 3 is generally regarded as race only. Massive lift, longer duration, moves the power well up in the rev range, results in the under lump idle, shit on fuel for daily driving. Really only useful with a complete aftermarket computer, all external mods, and internal stuff, valves, valve springs, retainers, all upgraded.

[mocchi]

Youll find the terminology of "stages" used to descibed cams in every single motor ever built.

Its just an easy way to describe how much more aggresive over stock they are. Normally they go in 3 stages.

Stage 1 is a street upgrade, basically a little bit more lift, a little bit longer duration, adds a few more HP and a bit more torque without the need for tuning, and without making it totally unstreetable and shit on fuel, a pig in traffic etc.

Stage 2 is for those who track their cars often, a weekender or once a month car, but still needs to be reasonable in traffic, and on fuel. Duration and lift are increased a bit more, generally helps to have something to tune to, and you wouldnt do it without having all the supporting mods, intake, exhaust etc

Stage 3 is generally regarded as race only. Massive lift, longer duration, moves the power well up in the rev range, results in the under lump idle, shit on fuel for daily driving. Really only useful with a complete aftermarket computer, all external mods, and internal stuff, valves, valve springs, retainers, all upgraded.

i think we should refrain from using such terms.
http://www.team-integra.net/forum/14...-get-next.html

i agree more to the link above.

spetz: check out this link http://www.team-integra.net/forum/14...-learning.html
be wary in choosing cams. make sure it suits your needs.

[trism]

i think we should refrain from using such terms.
http://www.team-integra.net/forum/14...-get-next.html

i agree more to the link above.

Sorta but not really the same. That thread is Reffering to stages of total upgrade packages. Just like what youd see in Gran Turismo or Need For Speed, especially the old underground/underground2 games.

They imply that a "stage 1" intake is say, an aftermarket panel filter, and will net you 5hp everytime, no matter what other supporting mods youve got. "Stage 2" is a pod and a CAI and will net you 10hp everytime, no matter what. etc etc.

This sort of talking about upgrades has only really been prevalent since the real upcoming of the "import" scene, say the last 10 years or so.

The idea of "stage" cams is one that has been around since hot rodders in the 50s, and simply refers to how much more intense over stock the cam is. There is no indicated amount of hp gain, and manufacturers will state they they will only produce a gain when combined with correct supporting mods.

[dougie_504]

Also remember 'stages' are different for each aftermarket company. I think Buddy Club's 'street upgrade' cam shaft is referred to as stage 3, similar to Skunk2's stage 1.

If you're looking at shafts you just have to see who has what to offer, but that's generally the case as trism stated.

[gumus89]

The BuddyClubs are Spec III.

[Jccck]

Also remember 'stages' are different for each aftermarket company. I think Buddy Club's 'street upgrade' cam shaft is referred to as stage 3, similar to Skunk2's stage 1.

If you're looking at shafts you just have to see who has what to offer, but that's generally the case as trism stated.

And don't forget Delta lists there cams as 'grinds' ie a 272 Delta
Bisimoto lists them in levels.. Level 1, Level 1.2, Level 2, etc etc.. All the way up to Level X.

Stages imo is a terrible way to describe the increase over standard that an item/process gives.

[Touge Tom]

And don't forget Delta lists there cams as 'grinds' ie a 272 Delta
Bisimoto lists them in levels.. Level 1, Level 1.2, Level 2, etc etc.. All the way up to Level X.

Stages imo is a terrible way to describe the increase over standard that an item/process gives.

i agree with you. cam manufactures should be forced to represent their spec's in ramp, lash, duration and lift. and take the time to find out the dynamic ( not static ) compression created, on a factory standard engine. just for reference for people whom have had their heads or block's milled, or weather your using higher comp piston's.

[string]

i agree with you. cam manufactures should be forced to represent their spec's in ramp, lash, duration and lift. and take the time to find out the dynamic ( not static ) compression created, on a factory standard engine. just for reference for people whom have had their heads or block's milled, or weather your using higher comp piston's.

The problem isn't the manufacturers, it's the consumers.

If everyone was informed, manufacturers who didn't give out these details wouldn't sell any parts.