Can the Cam?

[Banjo79]

I think you'll be talked out of a 685 before long, regardless, VCM once recommended the 15 over the 685 to me. With 4 degress less exhaust duration, they said it would be more appropriate for NA applications. I have neither so can't comment on characteristics.

 

[07GTS]

i can not stress the fact the tuner plays in any cam, ive seen logs for a US tuner with a cam in the 240-250 idling like a baby and the customer wanted more chop, there are far more tables then most tuners here use or even know actually help with cams they just dont have the extra few hours of testing to find them out, idle and the 1st gear slow speed transitions back and forth are prob the hardest to get right because of the tables they are shifting in and out of must all work with each other, an average tuner will get a small cam working well but a advanced tuner will get a larger cam working just as good but with the benefits of more power/torque

 

[blackve76]

Thanks for the responses gents.
I'm only looking for say 300/320 rwkw. Of course bigger specs will give me more top end. But, there are compromises of you go too big. I'll see what the Gentech boys recommend (excl Walkinshaw kits).

You could shave the heads a bit and port manifold a bit and end up with a good drivable car.

 

[Banjo79]

If camshaft max power increases in a linear fashion, relative to a numerical inrease in duration and possible changes to lsa and lift to keep it apples and apples, I've always considered a jump from roughly 200/208 stock L77 to 216/224, half way there to I what would think would be considered by most, a fairly large camshaft eg. 232/248, which would surely come with challenges, regardless of what the tuner can do for you. So could anyone confirm if a numerical increase, especially duration, would predictabily and in a linear fashion, increase the pro's and con's of any given bump stick? Maybe "baby" aftermarket camshafts aren't all that baby after all.

 

[426Cuda]

If camshaft max power increases in a linear fashion, relative to a numerical inrease in duration and possible changes to lsa and lift to keep it apples and apples, I've always considered a jump from roughly 200/208 stock L77 to 216/224, half way there to I what would think would be considered by most, a fairly large camshaft eg. 232/248, which would surely come with challenges, regardless of what the tuner can do for you. So could anyone confirm if a numerical increase, especially duration, would predictabily and in a linear fashion, increase the pro's and con's of any given bump stick? Maybe "baby" aftermarket camshafts aren't all that baby after all.

"Maybe "baby" aftermarket camshafts aren't all that baby after all"
My thoughts Ed Zachary.

 

[426Cuda]

i can not stress the fact the tuner plays in any cam, ive seen logs for a US tuner with a cam in the 240-250 idling like a baby and the customer wanted more chop, there are far more tables then most tuners here use or even know actually help with cams they just dont have the extra few hours of testing to find them out, idle and the 1st gear slow speed transitions back and forth are prob the hardest to get right because of the tables they are shifting in and out of must all work with each other, an average tuner will get a small cam working well but a advanced tuner will get a larger cam working just as good but with the benefits of more power/torque

So taking an extreme view. Are you saying a good tune can tune such good manners into say a 240/250 can, that it will behave well in an auto combination, even without a stally? Yes, there are many incremental changes that can be factored into a tune in these things. But, at the end of the day, it's just various combos of air, fuel and (ignition) timing. Am I correct in saying that?

 

[Smashfist]

So many variables go into cam manners - there's a few things that can affect it apart from the obvious valve duration. Even with a wider lobe separation I wouldn't put my 232/234 into an auto without a stall - at a 114 LSA it's got a much more sedate idle than the same grind at a 110 lobe sep, but I still wouldn't risk it depending on driving conditions. I would be toast trying to drive mine to work in gridlock, mine's manual and I swear I'd go through a clutch a month. If 100% unchanged street manners is a mandatory requirement then an aftermarket camshaft isn't really a good option.

 

[monty_vfssv]

If 100% unchanged street manners is a mandatory requirement then an aftermarket camshaft isn't really a good option.

I disagree.. sounds like you went too big. You can pick up say ~20kw and have near stock manners with improved power/torque everywhere. Once you start pushing for say +40kw you will start to sacrifice manners. LS3 responds very well to small/med cams.

 

[07GTS]

So taking an extreme view. Are you saying a good tune can tune such good manners into say a 240/250 can, that it will behave well in an auto combination, even without a stally? Yes, there are many incremental changes that can be factored into a tune in these things. But, at the end of the day, it's just various combos of air, fuel and (ignition) timing. Am I correct in saying that?

there is always a limit to torque with big cams u can get them to behave but it dosnt mean u will have good torque down low and still a higher stall would improve it keeping in its torque band, for low speed drivability a cam dosnt buck because it's a cam it bucks because the ecu isn't set up for the poor low speed airflow corrections and by that i mean more then just the adaptive idle tables, with my cam i had in manual vcm6 233 233 i could release clutch at 1000rpm and sit there and use throttle 1000-1500rpm range no worries even cruising 80kph 6th 1300rpm was fine could even lean into boost without issue and that cam isn't ment to work well till 2700rpm

 

[panhead]

So taking an extreme view. Are you saying a good tune can tune such good manners into say a 240/250 can, that it will behave well in an auto combination, even without a stally? Yes, there are many incremental changes that can be factored into a tune in these things. But, at the end of the day, it's just various combos of air, fuel and (ignition) timing. Am I correct in saying that?

I can’t see a 240/250 cam in an auto without a stall having stock manners regardless of the tuner, unless you want to be the Guinea Pig and pay a tuner to have your car for a year while they work with it and wear the cost if they fail.

I have a custom grind 230 with a 112 LSA and ported heads in my manual E Series Clubsport and it gets through traffic without any problems but the tune took some time to get right.

You can definitely tell the car is cammed and I couldn’t see it working in an auto without a stall.

The work was done by Sam’s Performance in Sydney.

In your case I'd want a cam around 224/232 LSA 113/114 if it was my car as it tried and tested and you may not need a stall.





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