How To Gain TQ
09-05-2007, 08:28 PM
#22
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How much torque did your dyno graph show at 2500 RPM? I almost got the same cam as you, but decided that I did not want 10 degrees of overlap and I read your post about having tuning issues. So, I came up with the cam in my sig...it has the same DCR as your cam, but 6 degrees of overlap. It put down well over 300 RWTQ at 2500 RPM.
Last edited by 01redws6ta; 09-05-2007 at 08:34 PM. Reason: adding more
09-05-2007, 09:30 PM
#23
Assuming your cam is ground correctly, and installed on a 106 Intake Centerline Angle, you should be closing the Intake Valve fairly early at 40* ABDC. An intake lobe that runs a little large, a slightly wider LSA or a variation in the timing set can contribute to later closing. A combination where all the tolerances stack against you could move your peak power up a few hundred rpms, while bleeding off precious cylinder pressure. Did you degree the cam at install? At what RPM is your HP peak number achieved?
With 66.67cc chambers and .053 GM MLS gaskets, your Dynamic Compession should come out to 8.28:1, but retarded cam timing drops that - 2 degrees later drops it to 8.15:1.
Look for a set of new or take off LS6 heads, then run a .040" head gasket. You can get the heads new pretty cheap from Gunnar @ Patriot. With 64cc chambers and a thinner gasket, you can bump your Static Compression enough to get the Dynamic Compression as high as 8.82:1, and really pump up the torque curve.
EDIT: Forgot to add, LS6 castings are generally accepted to add 20 hp with the increased air flow, so coupled with optimizing your quench, you could push over 420rwhp.
With 66.67cc chambers and .053 GM MLS gaskets, your Dynamic Compession should come out to 8.28:1, but retarded cam timing drops that - 2 degrees later drops it to 8.15:1.
Look for a set of new or take off LS6 heads, then run a .040" head gasket. You can get the heads new pretty cheap from Gunnar @ Patriot. With 64cc chambers and a thinner gasket, you can bump your Static Compression enough to get the Dynamic Compression as high as 8.82:1, and really pump up the torque curve.
EDIT: Forgot to add, LS6 castings are generally accepted to add 20 hp with the increased air flow, so coupled with optimizing your quench, you could push over 420rwhp.
Last edited by hammertime; 09-05-2007 at 10:17 PM. Reason: edit - additional info
09-06-2007, 01:43 PM
#24
Originally Posted by 01redws6ta
How much torque did your dyno graph show at 2500 RPM? I almost got the same cam as you, but decided that I did not want 10 degrees of overlap and I read your post about having tuning issues. So, I came up with the cam in my sig...it has the same DCR as your cam, but 6 degrees of overlap. It put down well over 300 RWTQ at 2500 RPM.
Here is my cam graph. Tuning was all worked out..
09-06-2007, 01:46 PM
#25
Originally Posted by hammertime
Assuming your cam is ground correctly, and installed on a 106 Intake Centerline Angle, you should be closing the Intake Valve fairly early at 40* ABDC. An intake lobe that runs a little large, a slightly wider LSA or a variation in the timing set can contribute to later closing. A combination where all the tolerances stack against you could move your peak power up a few hundred rpms, while bleeding off precious cylinder pressure. Did you degree the cam at install? At what RPM is your HP peak number achieved?
With 66.67cc chambers and .053 GM MLS gaskets, your Dynamic Compession should come out to 8.28:1, but retarded cam timing drops that - 2 degrees later drops it to 8.15:1.
Look for a set of new or take off LS6 heads, then run a .040" head gasket. You can get the heads new pretty cheap from Gunnar @ Patriot. With 64cc chambers and a thinner gasket, you can bump your Static Compression enough to get the Dynamic Compression as high as 8.82:1, and really pump up the torque curve.
EDIT: Forgot to add, LS6 castings are generally accepted to add 20 hp with the increased air flow, so coupled with optimizing your quench, you could push over 420rwhp.
With 66.67cc chambers and .053 GM MLS gaskets, your Dynamic Compession should come out to 8.28:1, but retarded cam timing drops that - 2 degrees later drops it to 8.15:1.
Look for a set of new or take off LS6 heads, then run a .040" head gasket. You can get the heads new pretty cheap from Gunnar @ Patriot. With 64cc chambers and a thinner gasket, you can bump your Static Compression enough to get the Dynamic Compression as high as 8.82:1, and really pump up the torque curve.
EDIT: Forgot to add, LS6 castings are generally accepted to add 20 hp with the increased air flow, so coupled with optimizing your quench, you could push over 420rwhp.
Yes the ICL is 106. It was installed straight up. did not degree as there 4* already grounded into the cam. See my dyno grapgh in the above post.
09-06-2007, 03:26 PM
#26
Looks like you didn't loose anything over the stock cam down low. Sounds like a perception kind of thing because it really ramps up after 4K. I have a same came but mine is 110+2. My low speed numbers are pretty much what they were before the cam change.
09-06-2007, 04:45 PM
#27
Originally Posted by Rob
Looks like you didn't loose anything over the stock cam down low. Sounds like a perception kind of thing because it really ramps up after 4K. I have a same came but mine is 110+2. My low speed numbers are pretty much what they were before the cam change.
Just feels like i have no powe under the curve
that is why i going to be doing gears, obviosuly when i do a 12 bolt
09-06-2007, 08:14 PM
#28
The only way to give you more torque is to raise DCR and SCR. Higher gears will give you the impression of higher torque though.
With your cam specified I got:
DCR: 8.03
SCR: 10.0
I'm not sure if I typed in the right numbers at .006, (277/281?), but we'll take this as a starting point and look at the gains at milling and running a thinner head gasket. Since you said you didn't want to switch heads, or cams I assume your ok with those two options?
Same mods plus 0.040 Head gaskets:
SCR: 10.36:1
DCR: 8.27:1
Same mods plus milling 0.025, given that every .005" creates 1cc less:
SCR: 10.67:1
DCR: 8.51:1
Both:
SCR: 11.0:1
DCR: 8.78:1 <----- !!!!!!!
With your cam specified I got:
DCR: 8.03
SCR: 10.0
I'm not sure if I typed in the right numbers at .006, (277/281?), but we'll take this as a starting point and look at the gains at milling and running a thinner head gasket. Since you said you didn't want to switch heads, or cams I assume your ok with those two options?
Same mods plus 0.040 Head gaskets:
SCR: 10.36:1
DCR: 8.27:1
Same mods plus milling 0.025, given that every .005" creates 1cc less:
SCR: 10.67:1
DCR: 8.51:1
Both:
SCR: 11.0:1
DCR: 8.78:1 <----- !!!!!!!
09-06-2007, 08:35 PM
#29
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I think Batmobile has it right. You are going to need an increase in cylinder pressure to create the additional force to gain TQ. At 2500-3500rpms, you only need an additional 20HP to get 40 more ft/lbs TQ. (TQ X RPM/5252).
If you find a smaller cam (on stock heads) to give you that increase in cylinder pressure down low, you'll probably lose it up top.
Compression solves that problem. Instant cylinder pressure increase and it would work well with the 10 degrees of overlap on that cam.
Personally, I think you have a very respectable dyno curve. Maybe some of the guys who have hit near 400 ft/lbs TQ on cam only can chime in, but hitting 415hp and hitting near 380 TQ is very respectable.
Unless the overlap is hurting you, or the bigger exhaust is helping more at the top end, I will defer to other members who might be running comparable set-ups.
Good luck, car looks strong to me..WeathermanShawn..
If you find a smaller cam (on stock heads) to give you that increase in cylinder pressure down low, you'll probably lose it up top.
Compression solves that problem. Instant cylinder pressure increase and it would work well with the 10 degrees of overlap on that cam.
Personally, I think you have a very respectable dyno curve. Maybe some of the guys who have hit near 400 ft/lbs TQ on cam only can chime in, but hitting 415hp and hitting near 380 TQ is very respectable.
Unless the overlap is hurting you, or the bigger exhaust is helping more at the top end, I will defer to other members who might be running comparable set-ups.
Good luck, car looks strong to me..WeathermanShawn..
09-07-2007, 06:02 PM
#30
Originally Posted by 02TransAm/Batmobile
The only way to give you more torque is to raise DCR and SCR. Higher gears will give you the impression of higher torque though.
With your cam specified I got:
DCR: 8.03
SCR: 10.0
I'm not sure if I typed in the right numbers at .006, (277/281?), but we'll take this as a starting point and look at the gains at milling and running a thinner head gasket. Since you said you didn't want to switch heads, or cams I assume your ok with those two options?
Same mods plus 0.040 Head gaskets:
SCR: 10.36:1
DCR: 8.27:1
Same mods plus milling 0.025, given that every .005" creates 1cc less:
SCR: 10.67:1
DCR: 8.51:1
Both:
SCR: 11.0:1
DCR: 8.78:1 <----- !!!!!!!
With your cam specified I got:
DCR: 8.03
SCR: 10.0
I'm not sure if I typed in the right numbers at .006, (277/281?), but we'll take this as a starting point and look at the gains at milling and running a thinner head gasket. Since you said you didn't want to switch heads, or cams I assume your ok with those two options?
Same mods plus 0.040 Head gaskets:
SCR: 10.36:1
DCR: 8.27:1
Same mods plus milling 0.025, given that every .005" creates 1cc less:
SCR: 10.67:1
DCR: 8.51:1
Both:
SCR: 11.0:1
DCR: 8.78:1 <----- !!!!!!!
Yes i wanted to prolly just get thinner head gaskets.
at .035 i got
SCR: 8.61
DCR: 10.80
at .040 i got
SCR: 8.11
DCR: 10.67
Seems jsut changing a head gasket will raise DCR.. With raised DCR, will that give me more TQ?
09-07-2007, 06:06 PM
#31
Originally Posted by WeathermanShawn
I think Batmobile has it right. You are going to need an increase in cylinder pressure to create the additional force to gain TQ. At 2500-3500rpms, you only need an additional 20HP to get 40 more ft/lbs TQ. (TQ X RPM/5252).
If you find a smaller cam (on stock heads) to give you that increase in cylinder pressure down low, you'll probably lose it up top.
Compression solves that problem. Instant cylinder pressure increase and it would work well with the 10 degrees of overlap on that cam.
Personally, I think you have a very respectable dyno curve. Maybe some of the guys who have hit near 400 ft/lbs TQ on cam only can chime in, but hitting 415hp and hitting near 380 TQ is very respectable.
Unless the overlap is hurting you, or the bigger exhaust is helping more at the top end, I will defer to other members who might be running comparable set-ups.
Good luck, car looks strong to me..WeathermanShawn..
If you find a smaller cam (on stock heads) to give you that increase in cylinder pressure down low, you'll probably lose it up top.
Compression solves that problem. Instant cylinder pressure increase and it would work well with the 10 degrees of overlap on that cam.
Personally, I think you have a very respectable dyno curve. Maybe some of the guys who have hit near 400 ft/lbs TQ on cam only can chime in, but hitting 415hp and hitting near 380 TQ is very respectable.
Unless the overlap is hurting you, or the bigger exhaust is helping more at the top end, I will defer to other members who might be running comparable set-ups.
Good luck, car looks strong to me..WeathermanShawn..
Dont get me wrong, i love the cam, i just wish that the TQ curve was a bit better. It seems once it hits 4900, it starts to fall..
And i wish that i had more TQ under 2500 RPMs.
09-08-2007, 12:41 PM
#33
Originally Posted by TORCHD 02 TA
Dont get me wrong, i love the cam, i just wish that the TQ curve was a bit better. It seems once it hits 4900, it starts to fall..
And i wish that i had more TQ under 2500 RPMs.
And i wish that i had more TQ under 2500 RPMs.
A tight LSA like your 110 often gives a more concentrated hit in the midrange, sacrificing some of the power outside that range. A cam with the same duration, but a wider LSA like a 114 would likely not achieve the peak torque that you have, but should carry it over a wider powerband.
That said, thinner gaskets are your best bet, and on a budget, LS6 heads would get your DCR right where you need it for around $650 - $700 for complete heads, gaskets and new bolts.
09-08-2007, 04:36 PM
#34
Originally Posted by 02TransAm/Batmobile
Yes, the thinner head gaskets raise DCR which, in return, raises torque. A thinner gasket along with the 4.10 gears should remedy your sickness!
Originally Posted by hammertime
The tuning of LS1/LS6 and FAST manifolds is geared toward a peak torque at 4800, and peak HP about 6300. Your cam should complement that pretty well.
A tight LSA like your 110 often gives a more concentrated hit in the midrange, sacrificing some of the power outside that range. A cam with the same duration, but a wider LSA like a 114 would likely not achieve the peak torque that you have, but should carry it over a wider powerband.
That said, thinner gaskets are your best bet, and on a budget, LS6 heads would get your DCR right where you need it for around $650 - $700 for complete heads, gaskets and new bolts.
A tight LSA like your 110 often gives a more concentrated hit in the midrange, sacrificing some of the power outside that range. A cam with the same duration, but a wider LSA like a 114 would likely not achieve the peak torque that you have, but should carry it over a wider powerband.
That said, thinner gaskets are your best bet, and on a budget, LS6 heads would get your DCR right where you need it for around $650 - $700 for complete heads, gaskets and new bolts.
thanks for the advise both of you. I am prolly going to go with the thinner head gasket then... what size? .035 or .040
09-08-2007, 08:01 PM
#35
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You are setting yourself up for disappointment if you only plan to install a thinner head gasket and reinstall your stock heads. The difference especially with your 3.42 gears is not going to be very noticeable. I'd do the gears first...just my $.02.
09-08-2007, 09:18 PM
#36
Originally Posted by 01redws6ta
You are setting yourself up for disappointment if you only plan to install a thinner head gasket and reinstall your stock heads. The difference especially with your 3.42 gears is not going to be very noticeable. I'd do the gears first...just my $.02.
well no matter what i am going to do gears.
09-09-2007, 01:37 AM
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Did you not ask this same question or a very similar one several months ago? For one, did you ever get your cam degreed? It would not be the first time, Comp did not grind a cam to match the cam card. I would check it just to make sure. Then as mentioned, get that DCR up. The best way would be going with thinner head gaskets and this would most likely make the biggest difference. That said, most people would prefer to go ahead and upgrade the heads while they are off anyway, and as mentioned you could get some budget heads that would flow better than stock and add even more to the DCR equation.
09-09-2007, 09:20 AM
#38
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i'm in on the changing heads bandwagon also. with a set of 62-64 cc heads and a set of .040 gaskets you will probably see 20-25 ftlbs of torque down low where you are wanting it. the gaskets alone will probably gain between 7-10 rwtq if i was guessing. gears will make a big difference as already mentioned. you could possibly throw in a couple more degrees of timing to see if it picks up alittle but i would watch it for spark knock.
09-09-2007, 11:48 AM
#39
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Whether you change gaskets or mill the heads or both, make sure the cam is degreed and the piston to valve clearance is checked, the 110 LSA is going to make things a little closer.
I'm going to pull my stock heads and mock everything up, then mill my new heads for as much compression as I can get.
I'm going to pull my stock heads and mock everything up, then mill my new heads for as much compression as I can get.
09-09-2007, 01:17 PM
#40
Originally Posted by BOWTIE
Did you not ask this same question or a very similar one several months ago? For one, did you ever get your cam degreed? It would not be the first time, Comp did not grind a cam to match the cam card. I would check it just to make sure. Then as mentioned, get that DCR up. The best way would be going with thinner head gaskets and this would most likely make the biggest difference. That said, most people would prefer to go ahead and upgrade the heads while they are off anyway, and as mentioned you could get some budget heads that would flow better than stock and add even more to the DCR equation.
Maybe the same question i don't remember. the cam has +4 built into it, when it was installed, it was dot to dot. (straight up) the cam card had all the specs that i wanted. So whoknows. I would do head gaskets. jsut not sure if i want .040 or .035. Would need to run them on the excel spread sheet that was created. And what 'budget' heads are all you talking about?
Thanks