Hks 280 Cam Specs
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Originally Posted by Ted B
Until someone can furnish lobe centers for cams like Tomei and JUN, there is no way to compare apples to apples.
For example, if one runs a set of HKS cams (any of them) at 0/0 setting and swaps in a set of Pipers, the engine sees the Pipers at -3/-2. Naturally, this makes a difference one will see on the dyno, and the seat of the pants as well. Of course, one isn't aware of this unless he knows the specs. This being said, if we want to see the difference between any HKS set and the Pipers, we need to retard the Piper intake cam 3 deg and retard the exhaust cam 2 deg.
This is why we cannot really compare advertised duration numbers between cam makers and even lift numbers are of limited value for comparisons unless we know where that lift occurs with one cam set with respect to another cam set.
Just FYI.
For example, if one runs a set of HKS cams (any of them) at 0/0 setting and swaps in a set of Pipers, the engine sees the Pipers at -3/-2. Naturally, this makes a difference one will see on the dyno, and the seat of the pants as well. Of course, one isn't aware of this unless he knows the specs. This being said, if we want to see the difference between any HKS set and the Pipers, we need to retard the Piper intake cam 3 deg and retard the exhaust cam 2 deg.
This is why we cannot really compare advertised duration numbers between cam makers and even lift numbers are of limited value for comparisons unless we know where that lift occurs with one cam set with respect to another cam set.
Just FYI.
Chris
FWIW, I noted a difference of 10whp just by changing the timing of the intake cam 3 deg with the same cam set.
How is this?
The single most important valve event is the point where the intake valve closes. If we take a cam set like the HKS 280, even installed at the same lobe center as the 272 set, what happens is the closing of the intake valve is delayed, which is going to benefit our higher rpm HP with no other timing changes. The tradeoff is inevitably increased overlap and low speed cylinder pressure, which will make the motor a bit more soggy off-boost (which causes the rough idle).
This also explains why installing the Pipers at the same setting will likely result in less higher rpm power and better low speed power. Why? Because the Piper cams are advanced in comparison to the HKS cams (notice I corrected my previous post to show +3/+2). Want to make the Pipers behave a bit more like the HKS? Take your HKS timing and spin the sprockets to retard the int 3 deg and the exhaust 2 deg when you install the Pipers.
In any case, if you post the cam cards, we'll be able to compare apples to apples.
How is this?
The single most important valve event is the point where the intake valve closes. If we take a cam set like the HKS 280, even installed at the same lobe center as the 272 set, what happens is the closing of the intake valve is delayed, which is going to benefit our higher rpm HP with no other timing changes. The tradeoff is inevitably increased overlap and low speed cylinder pressure, which will make the motor a bit more soggy off-boost (which causes the rough idle).
This also explains why installing the Pipers at the same setting will likely result in less higher rpm power and better low speed power. Why? Because the Piper cams are advanced in comparison to the HKS cams (notice I corrected my previous post to show +3/+2). Want to make the Pipers behave a bit more like the HKS? Take your HKS timing and spin the sprockets to retard the int 3 deg and the exhaust 2 deg when you install the Pipers.
In any case, if you post the cam cards, we'll be able to compare apples to apples.
Last edited by Ted B; Feb 18, 2005 at 10:07 AM.
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Originally Posted by Yaroslav
what is the duration of TOMEI 280?
11.5mm of lift on both intake and exhaust
I heard they are coming out with a 11.8mm lift cam though?
Chris
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Originally Posted by Z1 Performance
that is the duration.....
Chris
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From: Odessa
Originally Posted by 2k4EvoVIII
Duration is 280
11.5mm of lift on both intake and exhaust
I heard they are coming out with a 11.8mm lift cam though?
Chris
11.5mm of lift on both intake and exhaust
I heard they are coming out with a 11.8mm lift cam though?
Chris
when will you install it man?
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Originally Posted by trinydex
awww man that idle is so cute...and why is the vac higher on the tomeis... is that a better thing?
never heard that before 
. The vac is higher on the 260 tomei's because they are smaller in lift, less time for the valves to stay open hence 280's lower vac #s.
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Originally Posted by Evo_doer
Cute? never heard that before . The vac is higher on the 260 tomei's because they are smaller in lift, less time for the valves to stay open hence 280's lower vac #s.
never heard that before . The vac is higher on the 260 tomei's because they are smaller in lift, less time for the valves to stay open hence 280's lower vac #s.
Its becouse the duration is lower. The lift on the tomei's is actually higher. Chris
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Originally Posted by Yaroslav
Unbelivable!!!
when will you install it man?
when will you install it man?
Chris