Turbo Cams and Duration?
11-21-2009, 05:33 PM
#1
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Turbo Cams and Duration? I see alot of cams for sale that seem to be called "turbo cams" usually around 600 lift, but the duration is what gets me, I'm talking 240-250+ durations.... Is this the norm?
I know as a rule 114+ lsa seems to be where you want to be, and I have heard a couple times not to get too crazy on the lift for sake of float (dont know if there is truth to that or not)..
Whats everyone think? Are the large duration cams where its at for FI or is 250 starting to push it? Thanks.
I know as a rule 114+ lsa seems to be where you want to be, and I have heard a couple times not to get too crazy on the lift for sake of float (dont know if there is truth to that or not)..
Whats everyone think? Are the large duration cams where its at for FI or is 250 starting to push it? Thanks.
11-21-2009, 11:57 PM
#2
For a 408 or smaller, a 250+ @.050" LSX cam is really pushing it. I'm not sure where you are seeing these 'turbo' cams with those durations, some sort of Bonneville speed site or Texas mile? Those are not specs commonly seen here for turbo LSX setups.
Jim
Jim
11-22-2009, 12:30 PM
#6
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Duration is really what makes a cam "bigger."
If you pull out a stock 204/211 duration cam (numbers are just an example) and swap in a 236/236 cam, you've significantly increased duration, or how long the the valves stay open. Take in more air, move more air.
24x/25x cams are pretty big and are pretty racey. Mild stuff would be in the 23x/23x range. Bigger cams will sometimes move up the power peak too, and the low end can also decrease.
Decide what is important to you and then work with someone to pick the cam.
If you pull out a stock 204/211 duration cam (numbers are just an example) and swap in a 236/236 cam, you've significantly increased duration, or how long the the valves stay open. Take in more air, move more air.
24x/25x cams are pretty big and are pretty racey. Mild stuff would be in the 23x/23x range. Bigger cams will sometimes move up the power peak too, and the low end can also decrease.
Decide what is important to you and then work with someone to pick the cam.
11-22-2009, 05:50 PM
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I see a lot of recommendations for a 24X, 24X @.050 for say a 427, yet a company like Lingenfelter who has been around the block recommends there GT-7 that has 208/230 @.050 for the same 427.
I understand that these two cams should have entirely different power bands the 24X higher up, but I would like a comparison on a dyno and see exactly how much the power band is moved, and which makes the most useable power with say a 7000 rpm limit.
If you never rev an engine past a given RPM say 7000, do you want it to be still making power past that RPM say 7500?
I understand that these two cams should have entirely different power bands the 24X higher up, but I would like a comparison on a dyno and see exactly how much the power band is moved, and which makes the most useable power with say a 7000 rpm limit.
If you never rev an engine past a given RPM say 7000, do you want it to be still making power past that RPM say 7500?
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11-22-2009, 07:38 PM
#8
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LPE cars tend to be mostly for the street, different demographic. A lot of the regulars in here want to be the quickest and fastest for a given combo.
Is your goal some sort of peak hp, or a certain mph at the drag strip? Those two goals are not always complimentary.
Is your goal some sort of peak hp, or a certain mph at the drag strip? Those two goals are not always complimentary.
11-23-2009, 07:08 AM
#11
I see alot of cams for sale that seem to be called "turbo cams" usually around 600 lift, but the duration is what gets me, I'm talking 240-250+ durations.... Is this the norm?
I know as a rule 114+ lsa seems to be where you want to be, and I have heard a couple times not to get too crazy on the lift for sake of float (dont know if there is truth to that or not)..
Whats everyone think? Are the large duration cams where its at for FI or is 250 starting to push it? Thanks.
I know as a rule 114+ lsa seems to be where you want to be, and I have heard a couple times not to get too crazy on the lift for sake of float (dont know if there is truth to that or not)..
Whats everyone think? Are the large duration cams where its at for FI or is 250 starting to push it? Thanks.
Lingenfelters turbocharged engine theories and concepts involve these basics, but put more emphasis on getting the exhaust out, as the intake charge is gonna get there on the intake side regardless due to the turbo. That explains the 208/230 duration of the GT-7 camshaft, shorter lift to better match the capabilities of stock cylinder heads and to compliment where the turbocharged engine makes awesome midrange torque, and the 121 LSA to keep the boost from bleeding off and maximizing it's efficiency. The cam is a good all around cam, but shines more on the street due to its awesome torque and lower peak RPM compared to 'big' cams.
My combination has the GT-7 cam and I love it. I plan on swapping to an LS6 intake and larger turbo next year, but love how the power comes on with this setup. It sees peak torque/boost at 4300rpm, and makes power to 5700rpm. I think this fall off is due to stock LS1 intake, small turbo exhaust housing (P-trim), and the stock 853 heads. It sure is a blast to drive though!
Last edited by Photochop; 11-23-2009 at 07:16 AM.
11-23-2009, 01:13 PM
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Some track visits, but mostly a street bruiser... I would like to keep the RPMs lower, say around 6200, so Im looking for something that comes in fairly early, yet doesn't fall flat before 6200 or so...
Thoughts on a minimum cam profile? Example, does a 224/224 581/581 114 start to be not enough? Its tough to draw that line...
I would like to keep the RPMs lower, say around 6200, so Im looking for something that comes in fairly early, yet doesn't fall flat before 6200 or so...Thoughts on a minimum cam profile? Example, does a 224/224 581/581 114 start to be not enough? Its tough to draw that line...
11-23-2009, 01:20 PM
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That explains the 208/230 duration of the GT-7 camshaft, shorter lift to better match the capabilities of stock cylinder heads and to compliment where the turbocharged engine makes awesome midrange torque, and the 121 LSA to keep the boost from bleeding off and maximizing it's efficiency. The cam is a good all around cam, but shines more on the street due to its awesome torque and lower peak RPM compared to 'big' cams.
My combination has the GT-7 cam and I love it. I plan on swapping to an LS6 intake and larger turbo next year, but love how the power comes on with this setup. It sees peak torque/boost at 4300rpm, and makes power to 5700rpm. I think this fall off is due to stock LS1 intake, small turbo exhaust housing (P-trim), and the stock 853 heads. It sure is a blast to drive though!
My combination has the GT-7 cam and I love it. I plan on swapping to an LS6 intake and larger turbo next year, but love how the power comes on with this setup. It sees peak torque/boost at 4300rpm, and makes power to 5700rpm. I think this fall off is due to stock LS1 intake, small turbo exhaust housing (P-trim), and the stock 853 heads. It sure is a blast to drive though!
11-23-2009, 04:32 PM
#15
I definitely wouldn't consider that the 'norm'. It all goes back to engine theory, what works best to minimize overlap to keep the boost in the cylinders and not bleed any psi off, while maximizing peak power at a given RPM. Like others said, it depends on what your goals are. If you're looking for something that doesn't come on and really make boost til quite a bit higher up in the RPMs and has a redline of 6500+ rpm, then those durations may be more attractive.
Lingenfelters turbocharged engine theories and concepts involve these basics, but put more emphasis on getting the exhaust out, as the intake charge is gonna get there on the intake side regardless due to the turbo. That explains the 208/230 duration of the GT-7 camshaft, shorter lift to better match the capabilities of stock cylinder heads and to compliment where the turbocharged engine makes awesome midrange torque, and the 121 LSA to keep the boost from bleeding off and maximizing it's efficiency. The cam is a good all around cam, but shines more on the street due to its awesome torque and lower peak RPM compared to 'big' cams.
My combination has the GT-7 cam and I love it. I plan on swapping to an LS6 intake and larger turbo next year, but love how the power comes on with this setup. It sees peak torque/boost at 4300rpm, and makes power to 5700rpm. I think this fall off is due to stock LS1 intake, small turbo exhaust housing (P-trim), and the stock 853 heads. It sure is a blast to drive though!
Lingenfelters turbocharged engine theories and concepts involve these basics, but put more emphasis on getting the exhaust out, as the intake charge is gonna get there on the intake side regardless due to the turbo. That explains the 208/230 duration of the GT-7 camshaft, shorter lift to better match the capabilities of stock cylinder heads and to compliment where the turbocharged engine makes awesome midrange torque, and the 121 LSA to keep the boost from bleeding off and maximizing it's efficiency. The cam is a good all around cam, but shines more on the street due to its awesome torque and lower peak RPM compared to 'big' cams.
My combination has the GT-7 cam and I love it. I plan on swapping to an LS6 intake and larger turbo next year, but love how the power comes on with this setup. It sees peak torque/boost at 4300rpm, and makes power to 5700rpm. I think this fall off is due to stock LS1 intake, small turbo exhaust housing (P-trim), and the stock 853 heads. It sure is a blast to drive though!
Then next season should have some dyno numbers with the gt7 as have no plans to swap it out. It is pretty much what I wanted in a cam . I wanted no noticeable lope. I dont want my 99 to sound like an old muscle car. Been there done that! I wanted no cam surge..it has none and is very very easy to tune. No fancy stuff needed playing with endless tables just to get it to idle. No drilling holes in the tb. I didn't want too much lift as did want headroom for the valve springs and yeah valve float is real with fi and I didn't want to be changing out springs every year. I went with 1.8 to get around 590 lift but may go back down to 1.7 next season. More headroom ,easier yet on the springs.
Duration seems ok range ,powerband seems good.I may have lost some bottom with the bigger afr 225 but dont really notice any problems down there. I had lots with the 3.54 gears with my stick .Fact could only hook up my nittos in middle of third and seem to have even more down there now with the 3.54 gears, 4l80 and the yank 3400 stall.
So I think the gt7 is a pretty good choice. I may got a bit bigger if went to a 427 or 454 built but then likely would go for something like 230/240, 600 max lift and 117 or 118 lsa. with 1.7 rockers. That likely would be my perfect totally streetable 427 or 454 cam.
I also want to add that my car was designed to be a street not a all out track car. So having a streetable cam is key. I have been in many cars with horrible horrible untunable cam surge at lower speeds. In my opinion that is worst thing you can have in a street car.
Here are some dyno numbers of similar engine to mine with gt7 cam.afr heads..
Good torque numbers.also aps standard turbos..no dyno graphs though..
its in a corvette..
1.606rwhp -640trq - 7.6 psi. 91 pump gas ( my wife drives the car with no problems
2.656rwhp -670trq 9.0 psi
3.707rwhp -773trq 11.6psi
4.736rwhp -812trq 13. psi
car makes 735rwhp(over 840 HP at the crank) on 13psi 812rwtrq(over 900 TRQ at the crank) ..car is a beast. will do the 1/4 LOW 10'S AND over 138+ mph.
condition is 8.5 /10 (its an 2002)
Here is the list of mods:
I just had a wideband installed- 250.00 plus install
( so the picture with the gauges has a wideband instead of the second boost gauge.)
Everything is done RIGHT - no corners cut!!
L.A.P.D did the install and they have done over 50 APS cars.
car has 35,500 miles and only aprox 2,000 miles on new Lingenfelter engine
2002 z06 red/black interior
APS twin turbos- $7995.00
LPE 255 fuel pump -$285.00
A&A return fuel system with a 340 secondary pump (can handle 900rwhp+) $1100.00
motrons 60 pound injectors -$499.00
magnavolt BAP-$220.00
Mcleod twin disc clutch rated at 1295rtq-$1301.00
eboost2 boost controller-$499.00
ALKY control methanol injection-$499.00
c5 black motorsports rims( i have the original stock rims , i will include with the car) $799.00
custom ART 3 inch exhaust with magnaflow mufflers $1400.00
SD 2 bar tune(you can drive the car anywhere) $800.00
lingenfelter output shafts on both sides - $999.00
brembo slotted front and back rotors /hawk pads- $520.00
steel braided brake lines
upgrades Steel BOV-$300.00
AFR 225CC heads with dual extreme springs-$2475.00
---------------------
from
403 lingenfelter forged (can handle 1000rwhp)-6340.00 (i have receipt)
LPE cam LS1-GT7 208 / 230 .554" / .546" 1.7 ratio 121 (idols like stock)
Clevite Tri-Armor Coated Rod & Main Bearings
GM LS2 aluminum block - 4.0050" bore
Water jacket plugs, oil galley & cam bearings
Manley forged aluminum pistons
custom turbo Seal Rings
Manley H Beam 4340 forged steel connecting rods - 6.125
Callies LS2 4340 forged steel crankshaft
Speed Pro heavy duty rod bearings
Speed Pro heavy duty main bearings
GM High Volume Oil Pump
GM Hydraulic roller lifters
Competition Cams .080 Pushrods
11-23-2009, 09:20 PM
#16
LS1Tech Co-Founder
iTrader: (34)
Some track visits, but mostly a street bruiser... I would like to keep the RPMs lower, say around 6200, so Im looking for something that comes in fairly early, yet doesn't fall flat before 6200 or so...
Thoughts on a minimum cam profile? Example, does a 224/224 581/581 114 start to be not enough? Its tough to draw that line...
I would like to keep the RPMs lower, say around 6200, so Im looking for something that comes in fairly early, yet doesn't fall flat before 6200 or so...Thoughts on a minimum cam profile? Example, does a 224/224 581/581 114 start to be not enough? Its tough to draw that line...
I'd be interested to see what Intmd8 would say. What about something like a 230/230/110?
11-23-2009, 09:35 PM
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Would the GT-7 cam be better for an Incon kit with upgraded (machined gt-30) turbos than using the '02+ LS6 cam? Or is the difference negligable?
PS....turning no more than 6,300-6,400 rpms
PS....turning no more than 6,300-6,400 rpms
11-23-2009, 09:38 PM
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Also running gt7. I have 408 cubes and afr 225 heads. I have never dynoed my car but would expect fall off anyway likely past 6000 for sure and likely mostly do to the aps standard turbos which do plan to upgrade over winter.
Then next season should have some dyno numbers with the gt7 as have no plans to swap it out. It is pretty much what I wanted in a cam . I wanted no noticeable lope. I dont want my 99 to sound like an old muscle car. Been there done that! I wanted no cam surge..it has none and is very very easy to tune. No fancy stuff needed playing with endless tables just to get it to idle. No drilling holes in the tb. I didn't want too much lift as did want headroom for the valve springs and yeah valve float is real with fi and I didn't want to be changing out springs every year. I went with 1.8 to get around 590 lift but may go back down to 1.7 next season. More headroom ,easier yet on the springs.
Duration seems ok range ,powerband seems good.I may have lost some bottom with the bigger afr 225 but dont really notice any problems down there. I had lots with the 3.54 gears with my stick .Fact could only hook up my nittos in middle of third and seem to have even more down there now with the 3.54 gears, 4l80 and the yank 3400 stall.
So I think the gt7 is a pretty good choice. I may got a bit bigger if went to a 427 or 454 built but then likely would go for something like 230/240, 600 max lift and 117 or 118 lsa. with 1.7 rockers. That likely would be my perfect totally streetable 427 or 454 cam.
I also want to add that my car was designed to be a street not a all out track car. So having a streetable cam is key. I have been in many cars with horrible horrible untunable cam surge at lower speeds. In my opinion that is worst thing you can have in a street car.
Here are some dyno numbers of similar engine to mine with gt7 cam.afr heads..
Good torque numbers.also aps standard turbos..no dyno graphs though..
its in a corvette..
1.606rwhp -640trq - 7.6 psi. 91 pump gas ( my wife drives the car with no problems
2.656rwhp -670trq 9.0 psi
3.707rwhp -773trq 11.6psi
4.736rwhp -812trq 13. psi
car makes 735rwhp(over 840 HP at the crank) on 13psi 812rwtrq(over 900 TRQ at the crank) ..car is a beast. will do the 1/4 LOW 10'S AND over 138+ mph.
condition is 8.5 /10 (its an 2002)
Here is the list of mods:
I just had a wideband installed- 250.00 plus install
( so the picture with the gauges has a wideband instead of the second boost gauge.)
Everything is done RIGHT - no corners cut!!
L.A.P.D did the install and they have done over 50 APS cars.
car has 35,500 miles and only aprox 2,000 miles on new Lingenfelter engine
2002 z06 red/black interior
APS twin turbos- $7995.00
LPE 255 fuel pump -$285.00
A&A return fuel system with a 340 secondary pump (can handle 900rwhp+) $1100.00
motrons 60 pound injectors -$499.00
magnavolt BAP-$220.00
Mcleod twin disc clutch rated at 1295rtq-$1301.00
eboost2 boost controller-$499.00
ALKY control methanol injection-$499.00
c5 black motorsports rims( i have the original stock rims , i will include with the car) $799.00
custom ART 3 inch exhaust with magnaflow mufflers $1400.00
SD 2 bar tune(you can drive the car anywhere) $800.00
lingenfelter output shafts on both sides - $999.00
brembo slotted front and back rotors /hawk pads- $520.00
steel braided brake lines
upgrades Steel BOV-$300.00
AFR 225CC heads with dual extreme springs-$2475.00
---------------------
from
403 lingenfelter forged (can handle 1000rwhp)-6340.00 (i have receipt)
LPE cam LS1-GT7 208 / 230 .554" / .546" 1.7 ratio 121 (idols like stock)
Clevite Tri-Armor Coated Rod & Main Bearings
GM LS2 aluminum block - 4.0050" bore
Water jacket plugs, oil galley & cam bearings
Manley forged aluminum pistons
custom turbo Seal Rings
Manley H Beam 4340 forged steel connecting rods - 6.125
Callies LS2 4340 forged steel crankshaft
Speed Pro heavy duty rod bearings
Speed Pro heavy duty main bearings
GM High Volume Oil Pump
GM Hydraulic roller lifters
Competition Cams .080 Pushrods
Then next season should have some dyno numbers with the gt7 as have no plans to swap it out. It is pretty much what I wanted in a cam . I wanted no noticeable lope. I dont want my 99 to sound like an old muscle car. Been there done that! I wanted no cam surge..it has none and is very very easy to tune. No fancy stuff needed playing with endless tables just to get it to idle. No drilling holes in the tb. I didn't want too much lift as did want headroom for the valve springs and yeah valve float is real with fi and I didn't want to be changing out springs every year. I went with 1.8 to get around 590 lift but may go back down to 1.7 next season. More headroom ,easier yet on the springs.
Duration seems ok range ,powerband seems good.I may have lost some bottom with the bigger afr 225 but dont really notice any problems down there. I had lots with the 3.54 gears with my stick .Fact could only hook up my nittos in middle of third and seem to have even more down there now with the 3.54 gears, 4l80 and the yank 3400 stall.
So I think the gt7 is a pretty good choice. I may got a bit bigger if went to a 427 or 454 built but then likely would go for something like 230/240, 600 max lift and 117 or 118 lsa. with 1.7 rockers. That likely would be my perfect totally streetable 427 or 454 cam.
I also want to add that my car was designed to be a street not a all out track car. So having a streetable cam is key. I have been in many cars with horrible horrible untunable cam surge at lower speeds. In my opinion that is worst thing you can have in a street car.
Here are some dyno numbers of similar engine to mine with gt7 cam.afr heads..
Good torque numbers.also aps standard turbos..no dyno graphs though..
its in a corvette..
1.606rwhp -640trq - 7.6 psi. 91 pump gas ( my wife drives the car with no problems
2.656rwhp -670trq 9.0 psi
3.707rwhp -773trq 11.6psi
4.736rwhp -812trq 13. psi
car makes 735rwhp(over 840 HP at the crank) on 13psi 812rwtrq(over 900 TRQ at the crank) ..car is a beast. will do the 1/4 LOW 10'S AND over 138+ mph.
condition is 8.5 /10 (its an 2002)
Here is the list of mods:
I just had a wideband installed- 250.00 plus install
( so the picture with the gauges has a wideband instead of the second boost gauge.)
Everything is done RIGHT - no corners cut!!
L.A.P.D did the install and they have done over 50 APS cars.
car has 35,500 miles and only aprox 2,000 miles on new Lingenfelter engine
2002 z06 red/black interior
APS twin turbos- $7995.00
LPE 255 fuel pump -$285.00
A&A return fuel system with a 340 secondary pump (can handle 900rwhp+) $1100.00
motrons 60 pound injectors -$499.00
magnavolt BAP-$220.00
Mcleod twin disc clutch rated at 1295rtq-$1301.00
eboost2 boost controller-$499.00
ALKY control methanol injection-$499.00
c5 black motorsports rims( i have the original stock rims , i will include with the car) $799.00
custom ART 3 inch exhaust with magnaflow mufflers $1400.00
SD 2 bar tune(you can drive the car anywhere) $800.00
lingenfelter output shafts on both sides - $999.00
brembo slotted front and back rotors /hawk pads- $520.00
steel braided brake lines
upgrades Steel BOV-$300.00
AFR 225CC heads with dual extreme springs-$2475.00
---------------------
from
403 lingenfelter forged (can handle 1000rwhp)-6340.00 (i have receipt)
LPE cam LS1-GT7 208 / 230 .554" / .546" 1.7 ratio 121 (idols like stock)
Clevite Tri-Armor Coated Rod & Main Bearings
GM LS2 aluminum block - 4.0050" bore
Water jacket plugs, oil galley & cam bearings
Manley forged aluminum pistons
custom turbo Seal Rings
Manley H Beam 4340 forged steel connecting rods - 6.125
Callies LS2 4340 forged steel crankshaft
Speed Pro heavy duty rod bearings
Speed Pro heavy duty main bearings
GM High Volume Oil Pump
GM Hydraulic roller lifters
Competition Cams .080 Pushrods
Last edited by morepsiz06; 11-23-2009 at 09:42 PM. Reason: !
11-23-2009, 10:38 PM
#19
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Very true... I always simply hope for someone with real world experience to give a vote for or against a cam. For instance, it seems that the GT7 is well received so far...
11-24-2009, 09:14 AM
#20
I would love to see a gm high tech performance issue with turbo cams compared.
Run some with different durations, lifts and lsas. But still many people would say that the various cams would work best with various combos of turbos, backpressure ,etc so not sure the point of the testing beyond simple curiousity.
I got my gt7 for good price used which is another reason went to it.
And interesting on that vette..so that is your car ??? Never did see a dyno graph with the gt7 don't suppose you have one??? Curious to see how the gt7 did up top but that could be of course limited by the turbos. I guess have to find out for myself how it does next spring.
Run some with different durations, lifts and lsas. But still many people would say that the various cams would work best with various combos of turbos, backpressure ,etc so not sure the point of the testing beyond simple curiousity.
I got my gt7 for good price used which is another reason went to it.
And interesting on that vette..so that is your car ??? Never did see a dyno graph with the gt7 don't suppose you have one??? Curious to see how the gt7 did up top but that could be of course limited by the turbos. I guess have to find out for myself how it does next spring.