which cams produce most power: HKS 280's VS Comp Cam 280's
Jul 18, 2006, 08:07 PM
#76
Originally Posted by donmeca2020
that would be overtkill on the motor, with stock turbo. anyways i also decided on the HKS 272s they should be here friday or saturday. the following week they should be going in. i cant wait.
Please provide your dynosheet backing up claims that 445tq/404.6whp has been outperformed by lower duration cams. After all, we provided this info.
In fact anyone with an opinion should be providing concrete tangible facts on the subject. If not, its just a bunch of hot air.
Jul 18, 2006, 08:22 PM
#77
Evolving Member
Join Date: Sep 2002
Location: Florida
Posts: 383
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by MalibuJack
I have 280 cams, GT35r turbo, 1000cc injectors.. The three classic troublesome mods that can cause poor idle.. I posted a video of my car idling with the stock turbo and 280 cams, and it idled a bit lopey (as cams with overlap do) but the quality was rock solid and stable.. The trick to getting them to work right is in balancing increased idle speed, with adding a bit of fuel to compensate for the low vacuum and lean condition, and increasing the timing a small amount to increase exhaust volume.. This will give you a nearly perfect idle, and you shouldn't be getting raw fuel smell if the ECU is correctly running in closed loop.. On the AEM its more difficult, but you can run O2 feedback to maintain a 14.7 ratio and get similar results.. My Carburetor equipped Malibu has the same problem at idle, since its hard to perfectly meter fuel at idle without O2 feedback..
I really don't understand where some of the "poor idle" stuff comes from, I did a set of 272 cams straight up for a friend, and his car with the stock MAF idled rock solid after some minor adjustment in the BISS..
I have come to the conclusion that there are just alot of half-hearted attempts at doing things right, and too much bad info out there on how to do it. But I have sucessfully gotten good idle with cams using only a reflash, a Utec, an ECU+, and even an S-AFC.. In some cases the piggybacks were more difficult to get a good idle, which is understandable because of the way you need to set them up to compensate for the low engine vacuum and hence the lean condition at idle.
Whoever posts the tuning for idle thread, send me the link when you do post it, start a new thread I'll add my data to it..
FWIW I do agree that 280's are too big for the stock Turbo.. They hurt the midrange a bit where the stock turbo shines most.. I have to try the +2/0 timing when I get the car on the dyno and start tuning it with all my stuff finally installed.
I really don't understand where some of the "poor idle" stuff comes from, I did a set of 272 cams straight up for a friend, and his car with the stock MAF idled rock solid after some minor adjustment in the BISS..
I have come to the conclusion that there are just alot of half-hearted attempts at doing things right, and too much bad info out there on how to do it. But I have sucessfully gotten good idle with cams using only a reflash, a Utec, an ECU+, and even an S-AFC.. In some cases the piggybacks were more difficult to get a good idle, which is understandable because of the way you need to set them up to compensate for the low engine vacuum and hence the lean condition at idle.
Whoever posts the tuning for idle thread, send me the link when you do post it, start a new thread I'll add my data to it..
FWIW I do agree that 280's are too big for the stock Turbo.. They hurt the midrange a bit where the stock turbo shines most.. I have to try the +2/0 timing when I get the car on the dyno and start tuning it with all my stuff finally installed.
I am busting out the ecuflash now to start taking some screens.
Jul 18, 2006, 08:48 PM
#78
Evolved Member
iTrader: (52)
Join Date: Sep 2005
Location: Boston,MA
Posts: 1,522
Likes: 0
Received 0 Likes
on
0 Posts
talk about a vendor Biased thread!
I say we leave it to other members that have either comp cam 280s 0r HKS 280s. i personaly have a set of comp 280s, and i dont plan on porting my head. I bought these cause of a possible 3076r in the future. However i dont feel that these are a bad cam for the stock turbo. Esp on Meth. or alky. i've seen cars with hks 264s put higher numbers than 272s its all on the tune and the car itself, nothing more or less.
I say we leave it to other members that have either comp cam 280s 0r HKS 280s. i personaly have a set of comp 280s, and i dont plan on porting my head. I bought these cause of a possible 3076r in the future. However i dont feel that these are a bad cam for the stock turbo. Esp on Meth. or alky. i've seen cars with hks 264s put higher numbers than 272s its all on the tune and the car itself, nothing more or less.
Jul 18, 2006, 09:22 PM
#79
Evolving Member
Join Date: Sep 2002
Location: Florida
Posts: 383
Likes: 0
Received 0 Likes
on
0 Posts
Posted a thread up on tuning idle,
https://www.evolutionm.net/forums/sh....php?p=3283669
https://www.evolutionm.net/forums/sh....php?p=3283669
Jul 18, 2006, 10:54 PM
#80
Former Sponsor
iTrader: (206)
Join Date: Oct 2002
Location: Santa Ana, California
Posts: 5,762
Likes: 0
Received 3 Likes
on
3 Posts
So when is there too much duration? How about 290 or 300 camshafts?
I think we should all remember that:
1. The larger the camshaft duration the more top end power because more air-flow is allowed into the combustion chamber at high RPMs
2. At lower RPMs, the larger the duration the higher the >LOSS< in cylinder pressure because of the increased time it takes the valves to seat again.
3. The 4G63's redline is limited
4. 16G-Large at say 1.6-1.7 BAR is rated at what? 500CFM? This turbo simply cannot flow enough air to properly utilize 280 degree camshafts at redline.
5. Even the TD06-20G, which is rated at 650+ CFM(?) at 1.6-1.7 BAR cannot flow anywhere near those CFM's due to the excessive turbine back pressure
When all these factors are combined, I think it's pretty obvious that large duration 280 camshafts are in fact a mis-match for the factory turbocharger - if you can't get all that air into the engine why suffer the low end loss?
Furthermore, the EVO's stock valvetrain is limited in lift. The amount of airflow in the engine can be approximately by lift X duration. Therefore it often makes a lot more sense to run LESS DURATION for the low-end / mid-range benefits with GREATER lift - you will obtain better results.
Therefore we recommend the 272's for any of you guys not running huge power turbos. Hope that makes sense!
Cheers,
Gary
Gruppe-S
I think we should all remember that:
1. The larger the camshaft duration the more top end power because more air-flow is allowed into the combustion chamber at high RPMs
2. At lower RPMs, the larger the duration the higher the >LOSS< in cylinder pressure because of the increased time it takes the valves to seat again.
3. The 4G63's redline is limited
4. 16G-Large at say 1.6-1.7 BAR is rated at what? 500CFM? This turbo simply cannot flow enough air to properly utilize 280 degree camshafts at redline.
5. Even the TD06-20G, which is rated at 650+ CFM(?) at 1.6-1.7 BAR cannot flow anywhere near those CFM's due to the excessive turbine back pressure
When all these factors are combined, I think it's pretty obvious that large duration 280 camshafts are in fact a mis-match for the factory turbocharger - if you can't get all that air into the engine why suffer the low end loss?
Furthermore, the EVO's stock valvetrain is limited in lift. The amount of airflow in the engine can be approximately by lift X duration. Therefore it often makes a lot more sense to run LESS DURATION for the low-end / mid-range benefits with GREATER lift - you will obtain better results.
Therefore we recommend the 272's for any of you guys not running huge power turbos. Hope that makes sense!
Cheers,
Gary
Gruppe-S
Jul 18, 2006, 10:59 PM
#81
Evolved Member
iTrader: (2)
Join Date: Jul 2004
Location: in front of your car
Posts: 2,356
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by mchuang
What kind of map sensor kit is this?
www.machevo.com/gmmaairsem.html
Jul 18, 2006, 11:05 PM
#82
Evolved Member
iTrader: (2)
Join Date: Jul 2004
Location: in front of your car
Posts: 2,356
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Ang Wen Yan
WHy you always suggest overkill part???He only need Comp 280 cam,Flash and Mentahol.He will not take the advantage of im,piton and rod since he still on stock turbo.
if the guy is sticking with the STOCK turbo, then he is looking for the wrong cams. in that case i would recommend the Monster Sport 265's with 12.0mm lift. valve springs, valve guides & Ti retainers will be needed & cannot rev past 7500rpm to retain safety of head...
Jul 19, 2006, 05:21 AM
#84
Originally Posted by donmeca2020
that would be overtkill on the motor, with stock turbo. anyways i also decided on the HKS 272s they should be here friday or saturday. the following week they should be going in. i cant wait.
Jul 19, 2006, 07:54 AM
#85
Evolved Member
Originally Posted by housedj
bcuz ppl are always 1/2assing their installs & wonder why their car dsn't perform 4 months later from "lifter tick". my suggestion is to make the MOST power gains. it is not the ONLY power option. plenty of people are making power on cams but not as much as they could if they did it right. every award winning race engine out there has their cylinder head setup top to bottom similar to the way i mentioned.
if the guy is sticking with the STOCK turbo, then he is looking for the wrong cams. in that case i would recommend the Monster Sport 265's with 12.0mm lift. valve springs, valve guides & Ti retainers will be needed & cannot rev past 7500rpm to retain safety of head...
if the guy is sticking with the STOCK turbo, then he is looking for the wrong cams. in that case i would recommend the Monster Sport 265's with 12.0mm lift. valve springs, valve guides & Ti retainers will be needed & cannot rev past 7500rpm to retain safety of head...
Jul 19, 2006, 08:10 AM
#86
Originally Posted by TTP Engineering
280 280 with camgears will get you maximum torque and horsepower, period.
Question: Will it get you best torque and hp just by bolting them in?
Answer: No, probably not.
Question: If I just want to bolt in a set of cams and do some mild tuning with pump gas, have a clean idle, and 350whp (DJ) is my goal, are the HKS 280s a better choice than the HKS 272?
Answer: No, probably not.
Originally Posted by Gruppe-S
So when is there too much duration? How about 290 or 300 camshafts?
Originally Posted by Gruppe-S
2. At lower RPMs, the larger the duration the higher the >LOSS< in cylinder pressure because of the increased time it takes the valves to seat again.
4. 16G-Large at say 1.6-1.7 BAR is rated at what? 500CFM? This turbo simply cannot flow enough air to properly utilize 280 degree camshafts at redline.
4. 16G-Large at say 1.6-1.7 BAR is rated at what? 500CFM? This turbo simply cannot flow enough air to properly utilize 280 degree camshafts at redline.
Originally Posted by Gruppe-S
When all these factors are combined, I think it's pretty obvious that large duration 280 camshafts are in fact a mis-match for the factory turbocharger - if you can't get all that air into the engine why suffer the low end loss?
348whp @ 6400rpm @ 19 psi
340 ft lbs @ 4400rpm @ 25 psi
(Multiply those numbers by 1.15 to get approximate Dynojet equivalents)
- EVO8 TME
- 93 octane + methanol
- HKS 280s
- stock block/head
- stock ECU
As anyone can see, the low rpm tq and hp peak hardly illustrates a loss of low speed power. What it does prove is that longer duration cams, when properly adjusted, allow one to increase midrange rpm VE (torque), but without sacrificing high rpm power. This results because the motor responds favorably to increased overlap in the midrange, but the longer duration cam delays the closing of the intake valve, which preserves (and improves) high rpm power.
The notion that a longer duration cam profile can reduce midrange power and response only holds true for those who intend to bolt them in and go. For the rest of us who go a bit further into the 'rabbit hole' where physics and engineering are concerned, it's just another 1960s era misconception.
Last edited by Ted B; Jul 19, 2006 at 10:48 AM.
Jul 19, 2006, 10:44 AM
#87
Originally Posted by Sgt Blamo
EFIxMR,
How would you compare the 272/280 to a straight 272 combo? Did you get the best of both worlds,ie. midrange and top end? I've been thnking of that combo. Please elaborate.
How would you compare the 272/280 to a straight 272 combo? Did you get the best of both worlds,ie. midrange and top end? I've been thnking of that combo. Please elaborate.
For anyone who wants the straight 280's let me know I have a set for sale used thanks!
Jul 19, 2006, 10:47 AM
#88
Evolved Member
iTrader: (4)
Join Date: Jul 2003
Location: Effort
Posts: 1,739
Likes: 0
Received 0 Likes
on
0 Posts
From what I have seen and understand, the JUN 272's produce more horsepower than eiher, but I can definitely stand to be corrected, as I have not gotten too deep into this subject.
From my options, if I were running a stand alone I would take the Tomei 280's as they have more lift and a more aggressive nature than the HKS, Comps, Revolers etc. The JUN's are also quite nasty but require some mega tuning to make certain they function with civility.
Does anyone have Tomei 280's?
From my options, if I were running a stand alone I would take the Tomei 280's as they have more lift and a more aggressive nature than the HKS, Comps, Revolers etc. The JUN's are also quite nasty but require some mega tuning to make certain they function with civility.
Does anyone have Tomei 280's?
Jul 19, 2006, 10:51 AM
#89
The JUN 272s do NOT compare favorably with any HKS offering, simply because the JUN cam gives considerably more 'effective' duration (e.g. 235 deg @ 1mm) than any HKS offering.
Because of these discrepancies associated with advertised duration numbers, don't go about thinking that one maker's '272' is comparable to another's '272', because that number isn't really telling one anything from one maker to another.
FYI
Because of these discrepancies associated with advertised duration numbers, don't go about thinking that one maker's '272' is comparable to another's '272', because that number isn't really telling one anything from one maker to another.
FYI
Jul 19, 2006, 10:55 AM
#90
Evolved Member
Thread Starter
iTrader: (1)
Join Date: Oct 2005
Location: South Florida
Posts: 796
Likes: 0
Received 0 Likes
on
0 Posts
Ted B,
Thank you for elaborating and explaining in detail so a simplton like me can follow along.
As I clarified a post or two back, my goal is to attain a much usable TRQ & HP as possible with the supporting mods & subsequent custom re-tune by Al from Dynoflash.
At this juncture in time, I must then conclude that the best cam profile would be a 272 duration as opposed to the 280. My driving is basically as follows: occasional roadcourse, maybe a trip or two down the 1/4 and general "***** to the wall" (as we liked to say in the Army)driving around town and some "Private" road racing.
With that in mind, would the 272's, HKS or BC produce the most usable TQ & HP with my supporting mods or 280's with cam gears? I'm going to wager on the 272's!
Thank you for elaborating and explaining in detail so a simplton like me can follow along.
As I clarified a post or two back, my goal is to attain a much usable TRQ & HP as possible with the supporting mods & subsequent custom re-tune by Al from Dynoflash.
At this juncture in time, I must then conclude that the best cam profile would be a 272 duration as opposed to the 280. My driving is basically as follows: occasional roadcourse, maybe a trip or two down the 1/4 and general "***** to the wall" (as we liked to say in the Army)driving around town and some "Private" road racing.
With that in mind, would the 272's, HKS or BC produce the most usable TQ & HP with my supporting mods or 280's with cam gears? I'm going to wager on the 272's!