Help me pick a mild blower cam
Originally Posted by engineermike
A long time ago, someone said that supercharger cams need less overlap, so they need to be on wide LSA's. When compared to an OPTIMAL naturally aspirated cam on a 102 - 106 LSA, a 112 - 114 LSA IS wide. Overlap is really what counts and no one has done a good job of quantifying just how much overlap is optimal. I believe that some overlap can benefit a supercharged engine because it will allow cool air to purge remaining exhaust out of the chamber.
I really wish people would quit spouting that "114 is best for superchargers and turbocharger" without knowing the context and reasoning behind it. The stock Turbo GN cam is on a 106 as are some of the aftermarket Turbo GN cams.
In your duration range, 112 is fine.
I really wish people would quit spouting that "114 is best for superchargers and turbocharger" without knowing the context and reasoning behind it. The stock Turbo GN cam is on a 106 as are some of the aftermarket Turbo GN cams.
In your duration range, 112 is fine.
The reason you run a shorter LSA on a GN is to bleed off boost down low a ward off detination.That is why you see 16-28lbs of boost on the street.Now most LS1 cams will read 112-114 duration but have a center lobe of 106-110 duration when installed.For this Vette he could run more boost by ussing a 112 duration Cam because it would bleed off torque (DCR).
Originally Posted by engineermike
A long time ago, someone said that supercharger cams need less overlap, so they need to be on wide LSA's. When compared to an OPTIMAL naturally aspirated cam on a 102 - 106 LSA, a 112 - 114 LSA IS wide. Overlap is really what counts and no one has done a good job of quantifying just how much overlap is optimal. I believe that some overlap can benefit a supercharged engine because it will allow cool air to purge remaining exhaust out of the chamber.
I really wish people would quit spouting that "114 is best for superchargers and turbocharger" without knowing the context and reasoning behind it. The stock Turbo GN cam is on a 106 as are some of the aftermarket Turbo GN cams.
In your duration range, 112 is fine.
I really wish people would quit spouting that "114 is best for superchargers and turbocharger" without knowing the context and reasoning behind it. The stock Turbo GN cam is on a 106 as are some of the aftermarket Turbo GN cams.
In your duration range, 112 is fine.
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Okay So now I'm getting confused. Let me put this another way. A stock 02 Z06 with headers and a A&A Pisc kit making no more than 9 lbs( 4.25 pulley) typically makes around 600rwhp at 6600 rpm and a tad over 500 rwtq at around 5000 rpm. If everything stayed the same but you changed the cam out for a MT1 B1 221/221 114+4 would the car make more horsepower and torque and would it make less boost? Or what about a cam like a 222/224 from comp on XE lobes on a 112+2-how would it perform? Now say off the blower the 02 Z06 with either cam should outpower the LS6 cam-so then in theory shouldn't it make more power with boost but because of the centerlines actually make more power with less boost? Then in turn wouldn't this make for a better combo as there is less chance of detonation on pump fuel (94 octane) and a safe tune (no more than 14-15 degress timing a a AFR of 11.5). Another thing is shouldn't this also narrow the powerband some from swaping out from the 117.5 centerline-so actually making more power under the curve? This thread is getting interesting guys-thanks for your input!
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From: Burlington, Ont. / North Van B.C.
Originally Posted by mdhmi
224/228 .581/.588 114 LSA.
I like the stockness of the LPE GT2-3 cam (207/220 573/.580 w 1.7 rocker 118.5 CL).
You may also want to look into the 21MC Blower cam.
Mark
I like the stockness of the LPE GT2-3 cam (207/220 573/.580 w 1.7 rocker 118.5 CL).
You may also want to look into the 21MC Blower cam.
Mark
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Originally Posted by Slowhawk
You've got alot to learn too The reason you run a shorter LSA on a GN is to bleed off boost down low a ward off detination.That is why you see 16-28lbs of boost on the street.
The reason you run a shorter LSA on a GN is to bleed off boost down low a ward off detination.That is why you see 16-28lbs of boost on the street.
Originally Posted by Slowhawk
. . . For this Vette he could run more boost by ussing a 112 duration Cam because it would bleed off torque (DCR).
Originally Posted by engineermike
You're kidding, right? A low LSA on a GN does not "bleed off boost". Ever. During overlap, the exhaust pushes into the intake port since backpressure is almos always greater than boost. On the compression stroke, a tighter LSA INCREASES DCR, thus bleeding off less pressure and increasing tendancy to detonate. And you don't see GN's running 28 psi on the street, more like 18. If they're running 28 psi, it's on C16 or Meth injection.
Again, 112, as compared to 114, would bleed off less compression and have a higher DCR, make more torque, and be more likely to detonate.
Again, 112, as compared to 114, would bleed off less compression and have a higher DCR, make more torque, and be more likely to detonate.
I've been testing this stuff for years and have plenty of data to support it.BTW-my GN ran more than 18lbs on the street on pump gas/no Meth, because the Cam I used bled off boost in the midrange which kept the DCR down.
Now,back on subject.
The 2 Cams you have listed will make more power but will probly give up midrange/low end compared to the stock LS6 Cam.
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Now I always thought the Z06 cam (02 and up) is abit lazy up to 4000 rpm. Most guys rave how the B1 has so much ***** down low and have a really fat torque curve along with other cams such as the TR224. I did some DCR calculations and this is what i cam up with. This with my 02 motor with aproximately .040 valve reliefs in both intake and exhaust and the piston sits .007 out of the hole.
LS6 204/214? 270/277 120+2.5 DCR = 8.039
B1 221/221 283 283 114+4 DCR = 7.93
222/224 275/277 112+2 = 8.21
220/220 273/273 114+4 = 8.27
So are you guys saying that up to 5000 rpm the LS6 cam will make more torque over all these cams when boost is applied? These are just all the cams that I have at my disposal-that is why I'm askin-I'm sure there are others that are way better but this is what I can choose from.
LS6 204/214? 270/277 120+2.5 DCR = 8.039
B1 221/221 283 283 114+4 DCR = 7.93
222/224 275/277 112+2 = 8.21
220/220 273/273 114+4 = 8.27
So are you guys saying that up to 5000 rpm the LS6 cam will make more torque over all these cams when boost is applied? These are just all the cams that I have at my disposal-that is why I'm askin-I'm sure there are others that are way better but this is what I can choose from.
It's hard to say because it depends on how much timing you can run in the midrange with the bigger cams/boost before detination.
I've compared a 220/224 .565/.565 on 114 Cam to a Z06 and it would take the same timing but the 220 Cam made around 25hp/20tq more across the range while keeping the stockish idle.Then I swaped to the popular 224/228 on 114 Cam and lost 40hp in the midrange but gained another 20hp up top.
I've compared a 220/224 .565/.565 on 114 Cam to a Z06 and it would take the same timing but the 220 Cam made around 25hp/20tq more across the range while keeping the stockish idle.Then I swaped to the popular 224/228 on 114 Cam and lost 40hp in the midrange but gained another 20hp up top.
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See that's what I wanted to hear. I want something with more grunt on the bottom without giving up anyhting on top. 600 rwhp is about all the stock pistons can ahndle anyway. There is a guy over at the CF forum that made over 600 rwhp and over 500 rwtq with a 04 Z06 through the factory manifolds and cats. I think he said his cam was a 218/224 on Xe lobes with 114+4. that's alot more torque throught the manifolds than the Z06 cam. I'm guessing headers would even amplify that.
so if i have a stock LS1 and im about to add a D1 would the LS6 cam be a good choice for me ?, and can i run the LS6 cam with the regular stock springs?
edit: nevermind i see the LS6 requires longer rods
edit: nevermind i see the LS6 requires longer rods
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Originally Posted by Slowhawk
Ok, Sell your LT1.Go buy a LS1 based car and start testing Cams ect and let me know what you find I've been testing this stuff for years and have plenty of data to support it.
I've been testing this stuff for years and have plenty of data to support it.Cam 1: 224/224 - 114
Cam 2: 230/230 - 111
That would yeild the same EVO and IVC, but 12 deg more overlap. Therefore, DCR would be the same and the rpm range would be roughly the same, but we could see the effects of overlap alone.
Originally Posted by Slowhawk
BTW-my GN ran more than 18lbs on the street on pump gas/no Meth, because the Cam I used bled off boost in the midrange which kept the DCR down. . .
I don't doubt that you may have gotten away with 20 or 22 psi in a GN, but it wasn't due to a "short" LSA. More likely way retarded timing.
Mike
Originally Posted by black01_WS6
why not run the LPE gt2-3 207/220 573/.580, 118.5
I have heard this is a very good cam for a F/I setup. Even though it is not the N/A cam of choice.
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Originally Posted by DrewSG
What about the Cheatr cam? I hear it makes for a nice blower cam.
Call Thunder and ask them about their results with that cam in a recent supercharged combo they built.
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The only thing I don't like about the CheatR cam is that it pushes the powerband even further out. I just dyno'd a friends car with a CheaTR cam I sold him and I will check to see where it peaks. The LS6 cam peaks at 6000 and with a blower the curve keeps going up as boost builds until you hit the rev limiter. The goal of changing the cam was to move the powerband down slightly to take advantage of making more power within ashorter rpm range, say 1500-6000 versus 1500-6600.
Interesting stuff!!!
Vortech, keep us posted on what you decide to go with and results.
Did you mill the AFR's, is that why you are getting rid of them? I was going to say why not keep the AFR's if they were unmilled.
Vortech, keep us posted on what you decide to go with and results.
Did you mill the AFR's, is that why you are getting rid of them? I was going to say why not keep the AFR's if they were unmilled.
Folks used to say that a blower would push the power peak up 500 rpms, I wonder why they used to say that.
You have to ask yourself if you are after 'chest beating" peak hp numbers or the strong power-under-the-curve cam.
Sounds like you keep focusing on what cam is gonna work great around 4000 rpms. If that is the case start looking at all the dyno sheets on here and at CorvetteForum and look at how peaky the combos are, and what are they are doing in the midrange.
Referencing GN's in here is as useful as talking about Supras. Totally different engine, cylinder heads, number of cylinders.
You have to ask yourself if you are after 'chest beating" peak hp numbers or the strong power-under-the-curve cam.
Sounds like you keep focusing on what cam is gonna work great around 4000 rpms. If that is the case start looking at all the dyno sheets on here and at CorvetteForum and look at how peaky the combos are, and what are they are doing in the midrange.
Referencing GN's in here is as useful as talking about Supras. Totally different engine, cylinder heads, number of cylinders.