Think a top end cam destroys your torque curve? Check out this comparison.
02-05-2007, 08:43 PM
#1
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Think a top end cam destroys your torque curve? Check out this comparison. Farting around today before going to the gym I found my dynograph from my buddy's shop Performance Auto Sport this past fall. Check out the differences compared to my graph from Abacus on Saturday w/ the G5-X2 cam.
PAS graph w/ bolt-ons only
G5-X2 114lsa
From 2000-3000 rpms I'm down about 20 ft/lbs of torque, but by 3500 the post-cam graph is at 325 and the pre-cam graph is at 330... catching up fast!
The real kicker is the amount of the curve that's over 350 rwtq... the post-cam car is >350 from 3800 all the way to 6200 The pre-cam car is over >350 from 3900 to 5600. Plus the peak torque on the cam'd car is 9 to 4 ft/lbs higher depending on which pull you compare to.
Pretty
PAS graph w/ bolt-ons only
G5-X2 114lsa
From 2000-3000 rpms I'm down about 20 ft/lbs of torque, but by 3500 the post-cam graph is at 325 and the pre-cam graph is at 330... catching up fast!
The real kicker is the amount of the curve that's over 350 rwtq... the post-cam car is >350 from 3800 all the way to 6200 The pre-cam car is over >350 from 3900 to 5600. Plus the peak torque on the cam'd car is 9 to 4 ft/lbs higher depending on which pull you compare to.
Pretty
02-06-2007, 01:10 AM
#4
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No one ever said it destroys it, but it shifts from 300ftlbs@2000 to 300ftlbs@ 3000, so you've lost down low as is normal.
Remember your car is light and with M22 steep gears so you woul'nt really notice.
You gained 48rwhp and 4ftlbs trq (peak) good power gain but weak trq (typical of a traditional split on a 114 {higher lsa})
It is looking good for roll races.
Remember your car is light and with M22 steep gears so you woul'nt really notice.
You gained 48rwhp and 4ftlbs trq (peak) good power gain but weak trq (typical of a traditional split on a 114 {higher lsa})
It is looking good for roll races.
02-06-2007, 09:15 AM
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^ Yep... stock heads.
Vortex Rammer intake
Kooks 1 3/4ths headers w/ cats
Corsa Indys
Also has an ATI super damer 10% underdrive, Yella Terra rockers (new lighter design), and a Fidanza aluminum flywheel.
Should haul *** on the road course now.
Vortex Rammer intake
Kooks 1 3/4ths headers w/ cats
Corsa Indys
Also has an ATI super damer 10% underdrive, Yella Terra rockers (new lighter design), and a Fidanza aluminum flywheel.
Should haul *** on the road course now.
Certainly looks to me like you lost down low. That torque is really slacking. Trending Topics
02-06-2007, 07:25 PM
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For lowend grunt I like a mild cam with heads with strong mid lift numbers with a good DCR. My setup makes 350rwtq @ 3000rpms. 325rwtq @ 2500rpms. Hell but with a light Z06 you don't need torque to get moving. A stock Z is a perfect example of this.
02-06-2007, 09:36 PM
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^ I only lost torque from 2000-3000 rpms... and only 20 ft/lbs at that. The car is 3000 lbs, has the mn12 trans w/ more agressive gearing, and an aluminum flywheel. The car now has more torque and a wider range at over 350... so my area under the curve has increased substantially, hence a better torque curve.
I never stated the car didnt' loose some low end torque, however it's not substantially down and overally the curve is far better.
The car is a monster from 3000-7000 rpms.
Why do I need torque farting around under 3000 rpms? I'll just dump it in 2nd and it blows the tires off. Maybe if I was trying to tow a boat, but not in a Z06.
I never stated the car didnt' loose some low end torque, however it's not substantially down and overally the curve is far better.
The car is a monster from 3000-7000 rpms.
Why do I need torque farting around under 3000 rpms? I'll just dump it in 2nd and it blows the tires off. Maybe if I was trying to tow a boat, but not in a Z06.
02-06-2007, 10:40 PM
#13
Originally Posted by Cobra4B
^ I only lost torque from 2000-3000 rpms... and only 20 ft/lbs at that. The car is 3000 lbs, has the mn12 trans w/ more agressive gearing, and an aluminum flywheel. The car now has more torque and a wider range at over 350... so my area under the curve has increased substantially, hence a better torque curve.
I never stated the car didnt' loose some low end torque, however it's not substantially down and overally the curve is far better.
The car is a monster from 3000-7000 rpms.
Why do I need torque farting around under 3000 rpms? I'll just dump it in 2nd and it blows the tires off. Maybe if I was trying to tow a boat, but not in a Z06.
I never stated the car didnt' loose some low end torque, however it's not substantially down and overally the curve is far better.
The car is a monster from 3000-7000 rpms.
Why do I need torque farting around under 3000 rpms? I'll just dump it in 2nd and it blows the tires off. Maybe if I was trying to tow a boat, but not in a Z06.
Your thread titled included "Think a top end cam destroys your torque curve?" You were implying that it didn't, but you contradicted yourself in your very first post by showing how much torque you lost under 3000 RPMs. Maybe a more appropriate title would have been "Think a top end cam destroys your torque curve from 3000 RPMs on up?" Then I'd agree...
My point is that most of the cars equipped with an LS1 don't live above 3000 RPMs. For a road racing application like yours, it certainly does (otherwise, you probably aren't driving it hard enough). Sure, you can downshift into your powerband any time you want, but that kinda becomes a nuissance around town when you are just trying to go get some ice cream. I've driven a top end cam around town (granted it was an F-body, and only had 3.73s out back), and it wasn't a great deal of fun to drive to tell you the truth. It pulled like there was no tomorrow, but was a slug just cruising around. It definitely isn't for everyone...not for me at least. And CERTAINLY not in a heavy F-body like mine.
02-06-2007, 10:53 PM
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Im curious how is the car driving around on the street at low rpms? Is it a turd down there? I didn't notice if this was your dd, because mine is and so I think that I would want a lot more torque even in the light, steep geared z06, its just more fun for everyday driving to have power at 2000 rpm. Nice numbers though, bet it hauls *** with just cam and few bolt ons 
02-07-2007, 08:11 AM
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^ The car has only lost 20 ftlbs down low... it's still making 300 ft/lbs rwtq... it's no slug at all... feels no different.
The car lights the tires up in 1st gear, 2nd gear, and rolls them over in 3rd gear. This is with 295 Kumho Ecsta MXs out back.
How can it be "a slug" when it can still obliterate the tires from a 5mph roll in 2nd?
Maybe it's a drastic difference from a mn6 camaro to a mn12 Z06. The car feels no differnet cruising arond town. Also, it's not like I'm trying to pull 100 in 2nd gear, the car went 66mph at the stock redline of 6500.
My car "lives" in the 1500-2500 range when cruising along... and it feels no different. Accelerating onto the highway in 6th is no different.
I'm confused by the argument that you need massive torque from 1000-3000 rpms... like I said, maybe it's far less aparent w/ the lighter car and the steeper gearing.
The car lights the tires up in 1st gear, 2nd gear, and rolls them over in 3rd gear. This is with 295 Kumho Ecsta MXs out back.
How can it be "a slug" when it can still obliterate the tires from a 5mph roll in 2nd?
Maybe it's a drastic difference from a mn6 camaro to a mn12 Z06. The car feels no differnet cruising arond town. Also, it's not like I'm trying to pull 100 in 2nd gear, the car went 66mph at the stock redline of 6500.
My car "lives" in the 1500-2500 range when cruising along... and it feels no different. Accelerating onto the highway in 6th is no different.
I'm confused by the argument that you need massive torque from 1000-3000 rpms... like I said, maybe it's far less aparent w/ the lighter car and the steeper gearing.
02-07-2007, 09:02 AM
#16
Just to be sure, I'm not knocking your cam choice and it sure sounds like it is well matched to driving style, but to help you understand the resistance you are getting:
That it feels no different, means there was nothing gained. A cam with a less of a top end focus might have improved throttle response and highway acceleration.
If you daily drive a heavier f-body in stop and go traffic, having improved throttle response and better torque available from 1500 - 2500 rpm really helps. A lot of people shift by 2500 rpm and sometimes you want that quick response to slice through an opening or pull out around someone stopping to make a left turn, etc. I generally don't use WOT in those situations so the benefits don't necessarily show up on a dyno graph, but you can certainly feel it in the SOTP. I don't want to shift at 3000 in traffic because of increased gas and oil consumption, and it draws attention to the car, both from law enforcement and from other motorist who don't want you sliding into their ahead of them.
Originally Posted by Cobra4B
My car "lives" in the 1500-2500 range when cruising along... and it feels no different. Accelerating onto the highway in 6th is no different.
I'm confused by the argument that you need massive torque from 1000-3000 rpms... like I said, maybe it's far less aparent w/ the lighter car and the steeper gearing.
02-07-2007, 09:45 AM
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Originally Posted by Ragtop 99
If you daily drive a heavier f-body in stop and go traffic, having improved throttle response and better torque available from 1500 - 2500 rpm really helps. A lot of people shift by 2500 rpm and sometimes you want that quick response to slice through an opening or pull out around someone stopping to make a left turn, etc. I generally don't use WOT in those situations so the benefits don't necessarily show up on a dyno graph, but you can certainly feel it in the SOTP. I don't want to shift at 3000 in traffic because of increased gas and oil consumption, and it draws attention to the car, both from law enforcement and from other motorist who don't want you sliding into their ahead of them.
We'll see what I can squeeze out of her at MIR in mid-march at our track rental.
02-07-2007, 11:11 AM
#18
Originally Posted by Ragtop 99
I don't want to shift at 3000 in traffic because of increased gas and oil consumption, and it draws attention to the car, both from law enforcement and from other motorist who don't want you sliding into their ahead of them.
Yeah, I know, defensive driving. In my toys I don't like to do that, because people are looking for a reason to race/run into you it seems. But, I drive my truck more than any of my toys, and in something that big, you can muscle your way into any lane (also, it's the loudest vehicle I have). Moreover, the throttle response in the Titan is insane compared to the LS1s. It's like an L98 with even more power (too bad the truck weighs so much, though). It's great to just tip in the throttle and snap your head back. Cams like the G5X2 don't give you that.
02-07-2007, 12:16 PM
#19
Originally Posted by Cobra4B
I'm confused by the argument that you need massive torque from 1000-3000 rpms... like I said, maybe it's far less aparent w/ the lighter car and the steeper gearing.
02-07-2007, 12:24 PM
#20
Originally Posted by MeentSS02
I think you'd realize it more if you added a few hundred pounds (like 500 or so) and got rid of the gearing advantage...that's one of the reasons why you see a lot of people with larger cams change their rear end gearing out for a higher (numerically) gear, especially in an F-body. These heavy bitches can be a pain to get started up a steep hill, etc. even with a stock cam and a sticky clutch.
