Ams Evo Cam Test
Nov 18, 2012, 06:08 PM
#751
Mickey,
No doubt that the S2s are great, but in comparison, the S1s must have a better low end performance (stock turbo). The following is a quote from the GSC site: "The S2 cams are designed for those with a GT35R-GT4067 Turbo. No low end power is lost vs the stock cams when used with the larger turbo."
Again, I'm looking for something that is suited for Autocross, the track is less than a mile long, rarely exceeding 90mph speeds. I don't mind 20-25hp only as extra, as long as I don't lose any at low end.
No doubt that the S2s are great, but in comparison, the S1s must have a better low end performance (stock turbo). The following is a quote from the GSC site: "The S2 cams are designed for those with a GT35R-GT4067 Turbo. No low end power is lost vs the stock cams when used with the larger turbo."
Again, I'm looking for something that is suited for Autocross, the track is less than a mile long, rarely exceeding 90mph speeds. I don't mind 20-25hp only as extra, as long as I don't lose any at low end.
Last edited by foxbat; Nov 18, 2012 at 06:12 PM.
Nov 18, 2012, 06:20 PM
#752
I know what Greg quotes on his website... On the EVO you will not loss spool or very very minimal between S1 vs S2. If you are trying to contest what I'm saying about the evo and cams then I'm done talking because you are going to make whatever decision you want regardless of what anyone else says. In autox you will remain in your powerband anyway so low end performance doesn't really matter since you should be above 5500 the entire time... I know people that autox cars with 35R turbos so you don't need to worry about a cam 
Mikey
Mikey
Last edited by Mikey@Spec-Ops; Nov 18, 2012 at 06:24 PM.
Nov 18, 2012, 06:39 PM
#753
With 15-20 corners, I'm hardly above 5500 all the time! http://www.streetfire.net/video/evo-...ion_197919.htm
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
Nov 18, 2012, 08:21 PM
#754
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First off there are a lot more variables in making power other than "lift"... Effective durration and ramp rate are exstremely important, more so than lift in most ocasions. I may agree with you on the stock head not being able to utilize the 11+mm lift but you buy the S2s for more than their lift. The S2s ramp rate is what allows you to run a larger cam without the expense of low end power.
The below graph is a HKS 272/280 combo swapped out for a custom S2. Substaintial gains with no loss in spool, nothing was changed on this combo but the cams. This cam is a 12mm lift cam and a 274* just like a std S2s. These cams are LARGER than the S2s in effective duration and make the same power as S3s but with zero loss in spool. Cam engineering is a lot more than a * and mm lift. At 8000rpm the new cams are making 150whp more and have a smaller "advertised" duration than the HKS 280s. Now that is GSC making a cam that works and works better than any other cam on the market in my opinion. You have to look at the whole cam, and lift is just a small piece of the pie, not saying you weren't just stating what I have dealt with in the past.
I'll tell you from my experiance with works products, not just their cams, you pay more and get less compared to what else is on the market. Works actually molded the 269 after the HKS line up, a combo of the 264 and 272. I have also never seen 269 cams give someone the power you are claiming, not saying that your numbers are incorrect or that you did other upgrades between the two dynos but I think the most I have ever seen 269s were 30whp and that was a 3076 car. They do tend to produce more mid range tq than HKS cams but HKS 272s usually make more power. Any cam that sounds like stock cams wont make the power plain and simple
Your dyno graphs are also 3 years apart so as far as I'm concerned I don't believe for a second you gained 95whp from a works 269. Maybe with more boost...
btw did this on my phone so the spelling may suck. damn driod
Mikey
The below graph is a HKS 272/280 combo swapped out for a custom S2. Substaintial gains with no loss in spool, nothing was changed on this combo but the cams. This cam is a 12mm lift cam and a 274* just like a std S2s. These cams are LARGER than the S2s in effective duration and make the same power as S3s but with zero loss in spool. Cam engineering is a lot more than a * and mm lift. At 8000rpm the new cams are making 150whp more and have a smaller "advertised" duration than the HKS 280s. Now that is GSC making a cam that works and works better than any other cam on the market in my opinion. You have to look at the whole cam, and lift is just a small piece of the pie, not saying you weren't just stating what I have dealt with in the past.
I'll tell you from my experiance with works products, not just their cams, you pay more and get less compared to what else is on the market. Works actually molded the 269 after the HKS line up, a combo of the 264 and 272. I have also never seen 269 cams give someone the power you are claiming, not saying that your numbers are incorrect or that you did other upgrades between the two dynos but I think the most I have ever seen 269s were 30whp and that was a 3076 car. They do tend to produce more mid range tq than HKS cams but HKS 272s usually make more power. Any cam that sounds like stock cams wont make the power plain and simple
Your dyno graphs are also 3 years apart so as far as I'm concerned I don't believe for a second you gained 95whp from a works 269. Maybe with more boost...
btw did this on my phone so the spelling may suck. damn driod
Mikey
I agree with you 100%!
Lift is not the only factor and again your right duration doesn't really tell the whole story. Cam design has many factors, and can make or break a setup. Knowing that the stock head can not support the lift, do you think that a custom set of S1's, with a higher duration, ramp rate and lower lift would benefit the stock framed turbo guys that are still on stock head? This would allow them to stick with stock V-springs and still make the power...for the budget minded enthusiast. That's not me for sure I threw the whole budget idea out the window a long time ago.
Thank you for clarifying your thoughts.
Now tell me more about these custom S2/S3 cams??
Last edited by casper980; Nov 21, 2012 at 06:39 PM.
Nov 18, 2012, 08:39 PM
#755
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With 15-20 corners, I'm hardly above 5500 all the time! http://www.streetfire.net/video/evo-...ion_197919.htm
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
Hey Mikey, it seems to me like he needs a cam that will help him spool that turbo just ridiculously fast instead of making a ton of power. Think maybe he needs to call GSC and get a custom grind done?
Nov 18, 2012, 10:03 PM
#756
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With 15-20 corners, I'm hardly above 5500 all the time! http://www.streetfire.net/video/evo-...ion_197919.htm
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
Im running on gt3076r/S2/1.45 boost/2.0L engine...mid to top end is great but just the lower end suck for me...maybe the stock compression is a bit low.
Nov 19, 2012, 09:13 AM
#757
With 15-20 corners, I'm hardly above 5500 all the time! http://www.streetfire.net/video/evo-...ion_197919.htm
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
35R turbo, such a bad idea for autox, I had swapped an E9 turbo with a smaller E6.5 (titanium turbine) & lap time improved by 1.5sec.
I'm seriously, sincerely looking for a good advice :}
With a larger turbo, the running differences between larger cam sets are less apparent at lower engine speeds, simply because the engine isn't making power in the ranges where longer effective duration compromises torque. A smaller turbo however tends to expose the differences more vividly at those same speeds, especially with respect to transient response - something that can't be measured on a static dyno sheet.
For a short track and smaller turbo, a cam with fast ramp rates and moderate effective duration is preferable. The GSC S1 delivers exactly that. The difference in duration at 1mm between an S1 and S2 is 216 and 232 degrees respectively, which is a substantial. And while the S1's 107/113 deg LCs should serve well in this application, there are timing tweaks that can generate even more midrange torque and quicker response if desired.
The problem isn't your compression, that won't make an appreciable difference. The problem appears to be your setup itself, especially if that turbo is fitted to an open T3 housing. That setup gives most of the lag of a GT35R, but with less power.
Nov 21, 2012, 09:10 AM
#759
Evolved Member
The problem isn't your compression, that won't make an appreciable difference. The problem appears to be your setup itself, especially if that turbo is fitted to an open T3 housing. That setup gives most of the lag of a GT35R, but with less power.[/QUOTE]
Thanks Ted but my problem til today ever since i upgraded to S2 cams & ATP Gt3076R T3 4bolts turbo is whenever i immediate full throttle my AFR drops til max 10afr as shown on my AEM wb which makes my car hard to accelerate.
The only way for me to catapult is to go partial throttle and re-throttle again and again.
Ive since changed back to stock 560cc injectors with the stock latencies & scaling values.
Will it be my cams overlapping problem?
Is there a better way to set my S2 cams?
Im now using latest Synapse recirculate bov and minimal boost leak.
Boosting 1.45 bars base on WG pressure.
Thanks Ted but my problem til today ever since i upgraded to S2 cams & ATP Gt3076R T3 4bolts turbo is whenever i immediate full throttle my AFR drops til max 10afr as shown on my AEM wb which makes my car hard to accelerate.
The only way for me to catapult is to go partial throttle and re-throttle again and again.
Ive since changed back to stock 560cc injectors with the stock latencies & scaling values.
Will it be my cams overlapping problem?
Is there a better way to set my S2 cams?
Im now using latest Synapse recirculate bov and minimal boost leak.
Boosting 1.45 bars base on WG pressure.
Last edited by jameswwt; Nov 21, 2012 at 09:23 AM.
Nov 21, 2012, 09:36 AM
#760
You are experiencing an unusual issue, but it shouldn't be a factor of the S2 cams or their timing. Something else is at the root of the problem. If you haven't already, you should start a separate discussion for this, which should aid in getting the issue resolved.
Nov 21, 2012, 10:02 AM
#761
The FP/Comp 280s make great mid-range and despite the 280 name, they are not anything like a real 280 cam. I think advertised duration is like 264* and the 0.05" duration is 212*. The lift on the intake is like 11.3mm and the exhaust is 10.8. 104/112 centerlines.
I'll have to double check those numbers. If I put the intake CL at 108, I pick up about 10HP peak but lose 10 ft-lbs below 5500 RPM.
There is a benefit to lift over 10.5mm though. You can't just put a square edge on the cam and have the valve open to 10.5mm and then sit there. The head flows up to about 10.5mm, but opening the valve further doesn't hurt flow. Opening to 11.5mm means you spend more time at the max flow. The extra 1mm of lift isn't for flow at that point, it's to control valve motion to avoid bad things like float and follower bounce. If you limited lift to 10.5mm, you would spend 1 degree of crank rotation at 10.5mm and a whole lot of time below 10.5mm. Lift the valve to 11.5mm though and now you spend 30* above 10.5mm maximizing flow.
I'll have to double check those numbers. If I put the intake CL at 108, I pick up about 10HP peak but lose 10 ft-lbs below 5500 RPM.
There is a benefit to lift over 10.5mm though. You can't just put a square edge on the cam and have the valve open to 10.5mm and then sit there. The head flows up to about 10.5mm, but opening the valve further doesn't hurt flow. Opening to 11.5mm means you spend more time at the max flow. The extra 1mm of lift isn't for flow at that point, it's to control valve motion to avoid bad things like float and follower bounce. If you limited lift to 10.5mm, you would spend 1 degree of crank rotation at 10.5mm and a whole lot of time below 10.5mm. Lift the valve to 11.5mm though and now you spend 30* above 10.5mm maximizing flow.
Nov 21, 2012, 10:06 AM
#762
The FP/Comp 280s make great mid-range and despite the 280 name, they are not anything like a real 280 cam. I think advertised duration is like 264* and the 0.05" duration is 212*. The lift on the intake is like 11.3mm and the exhaust is 10.8. 104/112 centerlines.
I'll have to double check those numbers. If I put the intake CL at 108, I pick up about 10HP peak but lose 10 ft-lbs below 5500 RPM.
There is a benefit to lift over 10.5mm though. You can't just put a square edge on the cam and have the valve open to 10.5mm and then sit there. The head flows up to about 10.5mm, but opening the valve further doesn't hurt flow. Opening to 11.5mm means you spend more time at the max flow. The extra 1mm of lift isn't for flow at that point, it's to control valve motion to avoid bad things like float and follower bounce. If you limited lift to 10.5mm, you would spend 1 degree of crank rotation at 10.5mm and a whole lot of time below 10.5mm. Lift the valve to 11.5mm though and now you spend 30* above 10.5mm maximizing flow.
I'll have to double check those numbers. If I put the intake CL at 108, I pick up about 10HP peak but lose 10 ft-lbs below 5500 RPM.
There is a benefit to lift over 10.5mm though. You can't just put a square edge on the cam and have the valve open to 10.5mm and then sit there. The head flows up to about 10.5mm, but opening the valve further doesn't hurt flow. Opening to 11.5mm means you spend more time at the max flow. The extra 1mm of lift isn't for flow at that point, it's to control valve motion to avoid bad things like float and follower bounce. If you limited lift to 10.5mm, you would spend 1 degree of crank rotation at 10.5mm and a whole lot of time below 10.5mm. Lift the valve to 11.5mm though and now you spend 30* above 10.5mm maximizing flow.
Nov 21, 2012, 11:52 AM
#763
Opening to 11.5mm means you spend more time at the max flow. The extra 1mm of lift isn't for flow at that point, it's to control valve motion to avoid bad things like float and follower bounce. If you limited lift to 10.5mm, you would spend 1 degree of crank rotation at 10.5mm and a whole lot of time below 10.5mm. Lift the valve to 11.5mm though and now you spend 30* above 10.5mm maximizing flow.
BTW, Comp Cams 280 specs:
Advertised Duration 264 deg Int / 265 deg Exh
Effective Duration 218 deg @ 0.05" Int / 218 deg @0.05" Exh
Lift 11.0mm Int / 10.4mm Exh
Lobe Centerlines 104 deg Int / 112 deg Exh
LSA 108 deg
Upgraded valve springs recommended
The Comp Cams 280's 104 deg intake LC makes for good street characteristics, but is a bit too far advanced for best power with a larger turbo. IIRC, we picked up a bit of power on the dyno in Drifto's car by retarding the Comp 280 intake to around 108 (2 cam degrees), and we may have retarded the exhaust cam by a degree as well. He used that setup to get 600whp with an HTA3076R, E85, and a CNC ported head - not too shabby.
Nov 21, 2012, 01:38 PM
#764
I couldn't remember if it was 212 or 218 on the duration so I went conservative but I knew it was in that area.
Agree on everything about the ramp rates being the important piece but I was taking a more practical approach. Two cams with the same duration at 0.050" and CLs but one has 11.5mm of lift and the other has 10.5mm of lift. The higher lift cam is likely going to make more power as it will be at/above 10.5mm lift for longer, taking full advantage of the head flow. But you are right, two cams identical on paper can still have different ramp rates and it will matter.
As for the Comps though, that was data from my car with a stock turbo and the chart is below. This is the average of 4 VDR runs, 2 runs in each direction on the same road. All testing done within a half hours time, no other tuning changes. Boost was at 12 psi for all runs. Difference below 3500 is likely just different average starting speed and I would bet the 0,0 timing made more power there as well.
Agree on everything about the ramp rates being the important piece but I was taking a more practical approach. Two cams with the same duration at 0.050" and CLs but one has 11.5mm of lift and the other has 10.5mm of lift. The higher lift cam is likely going to make more power as it will be at/above 10.5mm lift for longer, taking full advantage of the head flow. But you are right, two cams identical on paper can still have different ramp rates and it will matter.
As for the Comps though, that was data from my car with a stock turbo and the chart is below. This is the average of 4 VDR runs, 2 runs in each direction on the same road. All testing done within a half hours time, no other tuning changes. Boost was at 12 psi for all runs. Difference below 3500 is likely just different average starting speed and I would bet the 0,0 timing made more power there as well.
