How to get more torque?
05-31-2011, 02:41 PM
#21
Le Mans Master
I've seen lots of "blower cams" with specs very similar to yours. I don't think that's your problem. Agree with the others about doing what you can to bring the boost in earlier. Also, don't compare your two cars too closely. The dyno from your '09 is WAY out of whack. An LS3 at 495rwhp without a pretty stout cam just isn't happening.
05-31-2011, 03:35 PM
#22
I layman's terms it was explained to me that due to the nature of a Centrifugal supercharger it is best to have a cam with fairly low intake duration(224) and about 4-8 degrees more exhaust duration(230). Lift would depend on how drivable you would want the car to be. Under .600 lift with +10:1cr will give you a great DD with no parking lot surging below 1500rpms, givin your duration is around 224/230 @ .050.
Then there is overlap.........
Your problem is the overlap.
Then there is overlap.........
Your problem is the overlap.
Last edited by APSGTO; 05-31-2011 at 03:39 PM.
05-31-2011, 03:37 PM
#23
I layman's terms it was explained to me that due to the nature of a Centrifugal supercharger it is best to have a cam with fairly low intake duration(224) and about 6-10 degrees more exhaust duration(230). Lift would depend on how drivable you would want the car to be. Under .600 lift with +10:1cr will give you a great DD with no parking lot surging below 1500rpms givin your duration is around 224/230 @ .050.
Then there is overlap.........
Then there is overlap.........
Cam 215/247 .629/.656 121LSA
05-31-2011, 03:40 PM
#24
Also you are using LS3 heads? Do you think the 102LSXR made the difference for your setup?
Last edited by APSGTO; 05-31-2011 at 03:48 PM.
05-31-2011, 04:22 PM
#26
Burning Brakes
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I've seen lots of "blower cams" with specs very similar to yours. I don't think that's your problem. Agree with the others about doing what you can to bring the boost in earlier. Also, don't compare your two cars too closely. The dyno from your '09 is WAY out of whack. An LS3 at 495rwhp without a pretty stout cam just isn't happening.
Last edited by trapp; 05-31-2011 at 04:37 PM.
05-31-2011, 04:29 PM
#27
Le Mans Master
I layman's terms it was explained to me that due to the nature of a Centrifugal supercharger it is best to have a cam with fairly low intake duration(224) and about 4-8 degrees more exhaust duration(230). Lift would depend on how drivable you would want the car to be. Under .600 lift with +10:1cr will give you a great DD with no parking lot surging below 1500rpms, givin your duration is around 224/230 @ .050.
Then there is overlap.........
Your problem is the overlap.
Then there is overlap.........
Your problem is the overlap.
05-31-2011, 04:36 PM
#29
You should have got a PD S/C.
I'm not switching SC but thanks for the thought
06-01-2011, 01:35 AM
#31
Le Mans Master
I've seen lots of "blower cams" with specs very similar to yours. I don't think that's your problem. Agree with the others about doing what you can to bring the boost in earlier. Also, don't compare your two cars too closely. The dyno from your '09 is WAY out of whack. An LS3 at 495rwhp without a pretty stout cam just isn't happening.
06-01-2011, 02:20 AM
#32
Racer
Those are the same specs as the Lingenfelter GT9 LS9 ZR1 Supercharger camshaft. They are using it in several of their supercharger packages (ZR1, LS2, LS3, CTS-V, etc.)
06-01-2011, 08:26 AM
#33
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St. Jude Donor '08-'09
that looks like a good cam, the 117 lsa is hurting your dcr which would drop your tq, but your still making 3psi at peak tq, so with that said. i got 20 bucks on that cam being installed a tooth off.
06-01-2011, 05:41 PM
#35
06-01-2011, 10:30 PM
#36
Team Owner
At 6psi you are seeing less than 2psi at 3000rpms and 3psi tops at your torque peak. Because of the nature of the boost the centrifugal makes and the large intake runner of your LS3 heads I could see the lower torque and higher HP from the same pulley/blower setup. At lower boost levels the boost dosn't really start to kit in until the torque peak of the stock cam has passed. Hence the wide gap between HP and torque. It is not uncommon to see a 90-110 rwhp-rwtq gap on centri S/C's.
Definatly talk to ECS about pulley down and using a restrictor plate, should help big time. Be prepaired to run meth injection due to the extra heat the restrictor plate creates.
Definatly talk to ECS about pulley down and using a restrictor plate, should help big time. Be prepaired to run meth injection due to the extra heat the restrictor plate creates.
besides not making alot of sence. Your/his boost is more than 3 psi at the tq peak. My number ratio hp/tq is closer and is useally closer than
your saying. His cam is hurting his boost/tq numbers.
06-02-2011, 10:06 AM
#37
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I agree, and have a very similar LS3 setup. My cam is a 224/236, but on a 114+2. It was chosen by a very experienced engine builder/sponsor as a dual purpose NA/FI cam for me. Ran strong and made good power in NA form, and ran great with the blower too. Most great NA cams work very well with a centri blower.
The 117 LSA is bleeding off some DCR at lower speeds, but that's not why he is down 70+ lb/ft. Something else is wrong....
06-02-2011, 01:37 PM
#38
My numbers were 572/530 and 599/580.on two cars with a centri kit. I haven't dyno'd my new blower but it is stronger for sure. I don't agree with your opinion here.
besides not making alot of sence. Your/his boost is more than 3 psi at the tq peak. My number ratio hp/tq is closer and is useally closer than
your saying. His cam is hurting his boost/tq numbers.
besides not making alot of sence. Your/his boost is more than 3 psi at the tq peak. My number ratio hp/tq is closer and is useally closer than
your saying. His cam is hurting his boost/tq numbers.
If you look at a dyno graph of a centrifugal supercharged car, how much boost is it making at peak torque vs at peak HP? Usually at peak torque you will only see about half of your peak boost. Generally at peak power you will see it is making ~ peak boost.
The split between HP and torque is more like 50-100. If you use a restrictor plate they will be much closer. Your results are the exception and not the rule. I suspect your dyno is off. I've seen alot of fluffy torque readings from dyno's before. Were these numbers created on the same dyno or 2 separate dyno's? What kind of dyno's? Were you using a restrictor plate?
Last edited by APSGTO; 06-02-2011 at 01:41 PM.
06-02-2011, 06:47 PM
#39
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Most of the cars we do here do not leave with meth injection (at first) and the IAT's are not any higher then any other centri package with the same boost, and much less then a PD blower.
Well I cant say I agree with you Ben, (just personal preference) but if he had an ECS kit on the car his HP and TQ would be very close to each other right from the start.
06-02-2011, 08:43 PM
#40
here you go.. my car.. same dyno.. first is my P1 at 7.5lbs... with a NA cam, much like yours.. second one is with a D1 and a blower cam.. NA cam + blower ='s HP, not tq..
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Last edited by TrenAman; 06-02-2011 at 08:45 PM.