cheekychimp
Well-known member
Alan,
Aside from the turbo, what other mods do you have? Do you know what power your car is making compared to the one used in the AMS test? I don't think the actual figures are always that useful but in a test like this they do give an indication of the difference each type of cam makes because everything else remains as consistent as possible. I do remember however something being mentioned about new cams needing to be 'dialled in' and that if the car had been properly tuned after each set of cams was fitted, more conclusive results could have been made.
What that test suggests to me however (and anyone who has looked at that again, please correct me if I am wrong) is that on an essentially stock or lightly modified car the 264/264 and 264/272 combos seem to be the way to go. Almost 40ft/lbs of torque and an additional 25 horsepower is nothing to be sneezed at and nothing else really came close without significant off boost loss of torque.
There really isn't much to choose between the two and I would suggest which you chose out of those two would depend upon whether your car with stock cams was making around the same as the test vehicle or more at the same boost pressure. You also need to decide how far you want to go with a tune. I can understand you saying that you don't want to 'upgrade' but at the same time I think it would be silly not to liberate as much power out of your current setup as possible. If you look at 4thStroke's post above, discounting any differences created by different elevation/model of dyno etc you can see he made significantly more torque and power. Now that may well be the effect of a tuning the car properly with the 272s fitted but I would also hazard a guess that for whatever reason his car was making more power anyway and I think 264s might well have been a restriction in his car.
Bottom line here (and what I'm getting at) is that you need to have a fairly good idea of what boost pressure you want to run and what power you expect to make on the setup you intend using and decide if you need 272s or bigger to take advantage of the top end. You are going to have to try and work out what the likely offset in torque or spool is likely to be compared to what you are getting extra up top. Just using the HKS cams as an example, if I owned the car AMS did that test on I can tell you without a shadow of a doubt I'd go with the 264/264 combo. If however I had 4thStroke's car and was looking at the possibility of liberating a further 25 horsepower and nearly 20ft/lbs of torque from using the 272/272 setup, I'd go that route. AND if I discovered that spool up was slower or I was looking at less off boost power, I'd start looking at other mod's to bring spool time down like short route IC piping, better boost control, external wastegate or dual port actuator, cyclone manifold or one with longer runners and so on and so forth. Hell, if Auto-X is what is important to you, you might find changing the gearing on your car gets you where you want to be a hell of a lot easier!
Aside from the turbo, what other mods do you have? Do you know what power your car is making compared to the one used in the AMS test? I don't think the actual figures are always that useful but in a test like this they do give an indication of the difference each type of cam makes because everything else remains as consistent as possible. I do remember however something being mentioned about new cams needing to be 'dialled in' and that if the car had been properly tuned after each set of cams was fitted, more conclusive results could have been made.
What that test suggests to me however (and anyone who has looked at that again, please correct me if I am wrong) is that on an essentially stock or lightly modified car the 264/264 and 264/272 combos seem to be the way to go. Almost 40ft/lbs of torque and an additional 25 horsepower is nothing to be sneezed at and nothing else really came close without significant off boost loss of torque.
There really isn't much to choose between the two and I would suggest which you chose out of those two would depend upon whether your car with stock cams was making around the same as the test vehicle or more at the same boost pressure. You also need to decide how far you want to go with a tune. I can understand you saying that you don't want to 'upgrade' but at the same time I think it would be silly not to liberate as much power out of your current setup as possible. If you look at 4thStroke's post above, discounting any differences created by different elevation/model of dyno etc you can see he made significantly more torque and power. Now that may well be the effect of a tuning the car properly with the 272s fitted but I would also hazard a guess that for whatever reason his car was making more power anyway and I think 264s might well have been a restriction in his car.
Bottom line here (and what I'm getting at) is that you need to have a fairly good idea of what boost pressure you want to run and what power you expect to make on the setup you intend using and decide if you need 272s or bigger to take advantage of the top end. You are going to have to try and work out what the likely offset in torque or spool is likely to be compared to what you are getting extra up top. Just using the HKS cams as an example, if I owned the car AMS did that test on I can tell you without a shadow of a doubt I'd go with the 264/264 combo. If however I had 4thStroke's car and was looking at the possibility of liberating a further 25 horsepower and nearly 20ft/lbs of torque from using the 272/272 setup, I'd go that route. AND if I discovered that spool up was slower or I was looking at less off boost power, I'd start looking at other mod's to bring spool time down like short route IC piping, better boost control, external wastegate or dual port actuator, cyclone manifold or one with longer runners and so on and so forth. Hell, if Auto-X is what is important to you, you might find changing the gearing on your car gets you where you want to be a hell of a lot easier!
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