Help me understand why I keep getting spec'd such rowdy cams?
11-03-2015, 08:48 PM
#1
Help me understand why I keep getting spec'd such rowdy cams? I've spent the last month trying to find a new cam for my motor after mine was found to be damaged while swapping heads and lifters. I had a LSL/LSL 227/235 .614/.620 113+2. It's a stock bottom LS1 with 63cc 243 heads, .660 lift btr springs, ls6 intake, 42lb injectors, 1 7/8 headers, and 2.5" catted duals. M6 with 3.42 gears.
I contacted several vendors asking for recommendations for a new grind. The car is street driven, but not a daily, just a weekend toy. I'm not at all interested in drag racing. In fact I'm kind of interested in road racing. I like driving curvy highways and back country roads. My suspension is all handling stuff (konis, bmr springs, tubular controls arms, stiffer sway bars, etc..). I like roadtrips (70mph in 6th with ac and cruise on). The only thing I didn't care much about my current cam was the idle and the valve train noise. After installing cats it wasn't very choppy (5* overlap) and the exhaust valves slamming shut was pretty audible inside and out. I did state I didn't want a smaller cam, just something a little more choppy and maybe a quieter valve train if possible. I preferred a nice wide torque curve, not something high strung.
The recommendations I received thus far are:
TSP - 231/234 .629/.615 111 (10.5 overlap)
Tick - 231/235 .630/.610 111+2 (11 overlap)
BTR - 230/239 .609/.610 111+2 (12.5 overlap)
CM - 225/232 .612/.595 114+4 (0.5 overlap out of left field)
I understand that I mentioned I would like a bit more aggressive of an idle but I feel like I'm missing something. From what I've researched, cams with overlap over 8-10* tend to start suffering drive-ability at low rpms and having a narrower powerband lower in the rpm range and lose fuel economy quite significantly. I know overall overlap isn't the be all end all and there are other factors like seat to seat overlap, efficiency of the heads and exhaust, valve events, etc... which are probably part of the mystery of the recommendations.
I'm concerned these cams (not the Cam Motion cam of course as it's the complete opposite of the others) will have poor street and highway cruise manners (including hwy mpg) and be difficult for my tuner to straighten out. I'm also not sure if these would be ideal cams for a car that I might take to a road course some day.
I haven't said anything back to any of the vendors because I didn't feel intelligent enough about their recommendation to say otherwise and didn't want to waste their time with my ignorance. I figure they surely have to have a reason behind their recommendations so I've been trying to cram as much cam knowledge as I can but it's a lot to take in and I'm getting more confused.
From what I've researched and what other people have had recommended I'm surprised I didn't get rec'd something more along the lines of a 227/235 .6xx/.6xx on a 112 lsa or a 229/236 .6xx/.5xx on a 113. These would both have similar valve events but a little more overlap to break up the idle and bring the power in a little sooner (at least with the lower 112 lsa on the first cam).
If you've stuck around this far, can you help save me from myself and help me understand the reasonings for these recs and what cam I should be going after for my intended use? I'm half tempted to just say eff it and rebuy the same cam I already have so I can drive my car again since I know it was pretty decent.
I contacted several vendors asking for recommendations for a new grind. The car is street driven, but not a daily, just a weekend toy. I'm not at all interested in drag racing. In fact I'm kind of interested in road racing. I like driving curvy highways and back country roads. My suspension is all handling stuff (konis, bmr springs, tubular controls arms, stiffer sway bars, etc..). I like roadtrips (70mph in 6th with ac and cruise on). The only thing I didn't care much about my current cam was the idle and the valve train noise. After installing cats it wasn't very choppy (5* overlap) and the exhaust valves slamming shut was pretty audible inside and out. I did state I didn't want a smaller cam, just something a little more choppy and maybe a quieter valve train if possible. I preferred a nice wide torque curve, not something high strung.
The recommendations I received thus far are:
TSP - 231/234 .629/.615 111 (10.5 overlap)
Tick - 231/235 .630/.610 111+2 (11 overlap)
BTR - 230/239 .609/.610 111+2 (12.5 overlap)
CM - 225/232 .612/.595 114+4 (0.5 overlap out of left field)
I understand that I mentioned I would like a bit more aggressive of an idle but I feel like I'm missing something. From what I've researched, cams with overlap over 8-10* tend to start suffering drive-ability at low rpms and having a narrower powerband lower in the rpm range and lose fuel economy quite significantly. I know overall overlap isn't the be all end all and there are other factors like seat to seat overlap, efficiency of the heads and exhaust, valve events, etc... which are probably part of the mystery of the recommendations.
I'm concerned these cams (not the Cam Motion cam of course as it's the complete opposite of the others) will have poor street and highway cruise manners (including hwy mpg) and be difficult for my tuner to straighten out. I'm also not sure if these would be ideal cams for a car that I might take to a road course some day.
I haven't said anything back to any of the vendors because I didn't feel intelligent enough about their recommendation to say otherwise and didn't want to waste their time with my ignorance. I figure they surely have to have a reason behind their recommendations so I've been trying to cram as much cam knowledge as I can but it's a lot to take in and I'm getting more confused.
From what I've researched and what other people have had recommended I'm surprised I didn't get rec'd something more along the lines of a 227/235 .6xx/.6xx on a 112 lsa or a 229/236 .6xx/.5xx on a 113. These would both have similar valve events but a little more overlap to break up the idle and bring the power in a little sooner (at least with the lower 112 lsa on the first cam).
If you've stuck around this far, can you help save me from myself and help me understand the reasonings for these recs and what cam I should be going after for my intended use? I'm half tempted to just say eff it and rebuy the same cam I already have so I can drive my car again since I know it was pretty decent.
Last edited by RebelExtrm02; 11-03-2015 at 10:37 PM.
11-03-2015, 09:19 PM
#2
Their reasoning is quite simple, under the picture of your car it says RACE CAR.....duh ????
All jokes aside, IMO the Cam Motion cam will perform the best for what you're after out of the ones which have been listed.
It would as you mentioned, tune the easiest as well as drive the smoothest at low/cruising rpms. Now that's not to say that they couldn't all be tuned correctly, but the CM one would lug down around 1100-1300 at freeway speeds and not hiccup at all. Unfortunately it also will have the smoothest non choppy idle of the bunch.
All jokes aside, IMO the Cam Motion cam will perform the best for what you're after out of the ones which have been listed.
It would as you mentioned, tune the easiest as well as drive the smoothest at low/cruising rpms. Now that's not to say that they couldn't all be tuned correctly, but the CM one would lug down around 1100-1300 at freeway speeds and not hiccup at all. Unfortunately it also will have the smoothest non choppy idle of the bunch.
11-03-2015, 09:50 PM
#3
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Try to help a bit...
The cam trait that correlates most to where the power comes in is the intake valve close event. If it closes earlier, the power will generally come on sooner, peak sooner, and fall off sooner. Generally.
Increased overlap will tend to make the power come in later and carry better past peak. Overlap is power. Also allows fuel to short circuit from intake to exhaust at low rpms. Causing reduced fuel economy.
Seems like you're asking the cam to do two things at the same time. Want chop and improved fuel economy and quieter loves and more power. Don't we all?
My advice is to not buy the cam for sound. If you want decent street manners at low RPM, then the cam you had or the cam motion cam are good. LSL lobes are aggressive. EPS also has quiet lobes. Be honest about how you want the car to drive and buy for that.
If the only reason you want overlap is chop, just retard your idle timing and idle at low rpm.
If you really want 8 to 10 degrees of overlap and a 227 duration, check out the tick torque max V2. About perfect.
The cam trait that correlates most to where the power comes in is the intake valve close event. If it closes earlier, the power will generally come on sooner, peak sooner, and fall off sooner. Generally.
Increased overlap will tend to make the power come in later and carry better past peak. Overlap is power. Also allows fuel to short circuit from intake to exhaust at low rpms. Causing reduced fuel economy.
Seems like you're asking the cam to do two things at the same time. Want chop and improved fuel economy and quieter loves and more power. Don't we all?
My advice is to not buy the cam for sound. If you want decent street manners at low RPM, then the cam you had or the cam motion cam are good. LSL lobes are aggressive. EPS also has quiet lobes. Be honest about how you want the car to drive and buy for that.
If the only reason you want overlap is chop, just retard your idle timing and idle at low rpm.
If you really want 8 to 10 degrees of overlap and a 227 duration, check out the tick torque max V2. About perfect.
11-03-2015, 10:15 PM
#4
Tick has the "Milder" lobe option on their Torquemax cams which are "quieter" and have longer spring life. I agree with Darth and would say the Torquemax stage 2 "Milder" would be a great off the shelf choice.
11-03-2015, 10:20 PM
#5
Try to help a bit...
The cam trait that correlates most to where the power comes in is the intake valve close event. If it closes earlier, the power will generally come on sooner, peak sooner, and fall off sooner. Generally.
Increased overlap will tend to make the power come in later and carry better past peak. Overlap is power. Also allows fuel to short circuit from intake to exhaust at low rpms. Causing reduced fuel economy.
Seems like you're asking the cam to do two things at the same time. Want chop and improved fuel economy and quieter loves and more power. Don't we all?
My advice is to not buy the cam for sound. If you want decent street manners at low RPM, then the cam you had or the cam motion cam are good. LSL lobes are aggressive. EPS also has quiet lobes. Be honest about how you want the car to drive and buy for that.
If the only reason you want overlap is chop, just retard your idle timing and idle at low rpm.
If you really want 8 to 10 degrees of overlap and a 227 duration, check out the tick torque max V2. About perfect.
The cam trait that correlates most to where the power comes in is the intake valve close event. If it closes earlier, the power will generally come on sooner, peak sooner, and fall off sooner. Generally.
Increased overlap will tend to make the power come in later and carry better past peak. Overlap is power. Also allows fuel to short circuit from intake to exhaust at low rpms. Causing reduced fuel economy.
Seems like you're asking the cam to do two things at the same time. Want chop and improved fuel economy and quieter loves and more power. Don't we all?
My advice is to not buy the cam for sound. If you want decent street manners at low RPM, then the cam you had or the cam motion cam are good. LSL lobes are aggressive. EPS also has quiet lobes. Be honest about how you want the car to drive and buy for that.
If the only reason you want overlap is chop, just retard your idle timing and idle at low rpm.
If you really want 8 to 10 degrees of overlap and a 227 duration, check out the tick torque max V2. About perfect.
In a nutshell I want my car to be as powerful as it was before. Be easy for a decent tuner to tune for good drive ability (no world class tuners around here). Pull hard from 2500rpms-6500rpms. Be road race, open curvy road friendly. Handle idling with the AC on. Be able to cruise at 70mph in 6th with 3.42 gears and not bounce me around. Have noticeable chop through a full exhaust. Have a quieter valve train than an lsl lobe slamming the exhaust valves shut. All pretty much that order of priority.
My thing is that I don't think I want 10 degrees of overlap because i'm told it's much harder to tune to drive well and even then doesn't drive that well at low rpms. Im not asking for perfect drive ability but I don't want to be jerked around when I'm just cruising. If there is nothing between 5 and 10 degrees that make an appreciable difference to the criteria above besides reduced drive-ability it seems I'd be better off sticking with my 5 degrees and doing as you say.
Last edited by RebelExtrm02; 11-03-2015 at 10:31 PM.
11-03-2015, 10:37 PM
#6
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If you like how your cam performs then just have TSP grind the same specs but using the new soft lobes they offer. It will perform the same but have a quiet valve train with a much longer lifespan.
11-03-2015, 10:42 PM
#7
How did you like the drive ability of your current cam? Be honest with yourself if you want to have less or more low RPM/light throttle surging/fish biting with your next cam?
As the overlap increases, so does the surging. And as mentioned, your fuel mileage decreases with increased overlap. That Cam Motion cam will still have a choppy idle at 750 RPM and will have similar power. Will drive smoother & have better MPG's.
Russ Kemp
As the overlap increases, so does the surging. And as mentioned, your fuel mileage decreases with increased overlap. That Cam Motion cam will still have a choppy idle at 750 RPM and will have similar power. Will drive smoother & have better MPG's.
Russ Kemp
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11-03-2015, 11:02 PM
#9
I'm not asking for increased fuel economy. I get that power requires fuel and air. I just don't want it to tank to where I don't want to drive my car out of town anymore (teens on the highway, current cam gets about 26-27mpg highway). That was more of a side note than criteria. Just not wanting to go off the deep end.
In a nutshell I want my car to be as powerful as it was before. Be easy for a decent tuner to tune for good drive ability (no world class tuners around here). Pull hard from 2500rpms-6500rpms. Be road race, open curvy road friendly. Handle idling with the AC on. Be able to cruise at 70mph in 6th with 3.42 gears and not bounce me around. Have noticeable chop through a full exhaust. Have a quieter valve train than an lsl lobe slamming the exhaust valves shut. All pretty much that order of priority.
My thing is that I don't think I want 10 degrees of overlap because i'm told it's much harder to tune to drive well and even then doesn't drive that well at low rpms. Im not asking for perfect drive ability but I don't want to be jerked around when I'm just cruising. If there is nothing between 5 and 10 degrees that make an appreciable difference to the criteria above besides reduced drive-ability it seems I'd be better off sticking with my 5 degrees and doing as you say.
In a nutshell I want my car to be as powerful as it was before. Be easy for a decent tuner to tune for good drive ability (no world class tuners around here). Pull hard from 2500rpms-6500rpms. Be road race, open curvy road friendly. Handle idling with the AC on. Be able to cruise at 70mph in 6th with 3.42 gears and not bounce me around. Have noticeable chop through a full exhaust. Have a quieter valve train than an lsl lobe slamming the exhaust valves shut. All pretty much that order of priority.
My thing is that I don't think I want 10 degrees of overlap because i'm told it's much harder to tune to drive well and even then doesn't drive that well at low rpms. Im not asking for perfect drive ability but I don't want to be jerked around when I'm just cruising. If there is nothing between 5 and 10 degrees that make an appreciable difference to the criteria above besides reduced drive-ability it seems I'd be better off sticking with my 5 degrees and doing as you say.
11-03-2015, 11:04 PM
#10
How did you like the drive ability of your current cam? Be honest with yourself if you want to have less or more low RPM/light throttle surging/fish biting with your next cam?
As the overlap increases, so does the surging. And as mentioned, your fuel mileage decreases with increased overlap. That Cam Motion cam will still have a choppy idle at 750 RPM and will have similar power. Will drive smoother & have better MPG's.
Russ Kemp
As the overlap increases, so does the surging. And as mentioned, your fuel mileage decreases with increased overlap. That Cam Motion cam will still have a choppy idle at 750 RPM and will have similar power. Will drive smoother & have better MPG's.
Russ Kemp
11-03-2015, 11:07 PM
#11
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Cam Motion for the Win!
Better Driveability,Tuneability and longevity of the cams listed.
As stated have the idle tuned low ~750 RPM for the Lopey
Sound you desire.
Better Driveability,Tuneability and longevity of the cams listed.
As stated have the idle tuned low ~750 RPM for the Lopey
Sound you desire.
11-05-2015, 09:12 AM
#15
What I was surprised about is the amount of overlap as well as the high intake duration everyone but cam motion recommended. It cant just be my remark about idle, out of the 30 other questions I answered, that has caused them to recommend these cams. There has to be other factors about the car and myself that they took into account.
I've already admitted my ignorance in the perceptible differences of degrees overlap, so there is no reason to chastise me there. I had originally assumed I could have a cam with just a couple more degrees of overlap for a slightly more aggressive idle and a little more midrange power without giving up much more drive-ability.
I was honestly expecting to get a recommendation close to what I have now but with a slightly lower LSA and maybe a little more advance. As I understood it at the time this would fill out the mid range a little more, where I perceive most of my driving takes place. Sort of a compromise between my existing cam and the SNS 2. In fact there is a thread not far off from this (mid range/torquey/road race cam which I've read probably 20 times now trying to understand everything everyone talked about) where a person with similar requests was spec'd just that, though he has a better flowing intake and heads that may have been factored in.
I'd imagine this has become a situation of splitting hairs. I tend to over analyze everything and desire to understand everything I can. I've always been more about the why vs the what.
11-05-2015, 09:27 AM
#18
My car's current drive-ability doesn't bother me at all. I haven't driven a car with a larger cam so I cannot say what would or wouldn't bother me in that regard. I have just read that once you hit 10* of overlap and over 230 intake duration that things start to go down hill pretty quick as far as drive-ability in a street car is concerned. Not knowing the real world difference myself is why I inquired into the professionals.
11-05-2015, 09:43 AM
#19
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It's not 10 years ago tuning has come a really long way there was a time a 230/230 cam was huge and untunable.
Now a days most decent tuners can get good street manners out of any of those cams.
The only reason I would even consider something a bit smaller is the powerband and you running 3.42 gears.
Now a days most decent tuners can get good street manners out of any of those cams.
The only reason I would even consider something a bit smaller is the powerband and you running 3.42 gears.
11-05-2015, 10:11 AM
#20
Who tuned your car OP? I see you're in Missouri like me. In the St. Louis area, there isn't any better tuner than Shane Hinds. If you're more toward the Kanas City area, you should look up LSXkilr or Justin (Justune). If you are in the Midwest, I had a local guy tune my car, and he did a hell of a job.