how much power are the factory cams good for?

[mike96]

well just like the title asks... pushing the factory cams out to their limit, what range of power can someone expect to be in? i have been digging trough the Dyno challenge page to see what people are getting with them and 16G's and it looks to be somewhere in the 280 - 290 HP range. has anyone else been able to push the factory cams past 300? there was on person there that i am not sure if he had cams or not wasn't much in his profile, i think he was pushing 325ish... if you have taken the factory cams past 300, was it with a different turbo? just curious...

 

[Boosted98gsx]

Eleventy billion.

Seriously though, we're talking about a compressible gas here. You can put more and more pressure behind the OEM cams and get XXX power from them.

the point of upgrading cams is to reduce that pressure ratio, making the turbo "more efficient" and making less heat.

 

[9!'clipseDOHC]

The point of upgrading cams is not because the stock cams will fail at a certain level. It is so that you can rev higher and get enough air into the combustion chamber at those higher RPMs.

For instance lets say you make 300 hp. You have stock cams. After about 6500 RPM's you will be losing power because of the profile of the stock cams.

Now you have the same 300 hp but with 272 cams. Now you can rev up to 8,000 RPM's and make more power on the top end because of the lift and duration of the cams.

Hope this helps!

 

[slipstream808]

Though it can be said most people pushing past 400hp has cams to take advantage of a turbo that likes the higher RPM's. It isn't a requirement at that point. But they aren't needed at that point.

 

[Boosted98gsx]

Though it can be said most people pushing past 400hp has cams to take advantage of a turbo that likes the higher RPM's. It isn't a requirement at that point. But they aren't needed at that point.

This is where the argument comes in. They aren't technically "needed" but they sure do help in increasing overall airflow and thereby power (when tuned), making it easier for your engine to breathe and causing less stress on your turbo / engine.

 

[mike96]

The point of upgrading cams is not because the stock cams will fail at a certain level. It is so that you can rev higher and get enough air into the combustion chamber at those higher RPMs.

For instance lets say you make 300 hp. You have stock cams. After about 6500 RPM's you will be losing power because of the profile of the stock cams.

Now you have the same 300 hp but with 272 cams. Now you can rev up to 8,000 RPM's and make more power on the top end because of the lift and duration of the cams.

Hope this helps!

yes i do understand this... same basic concept applies to turbochargers. just because a factory t25 can crank out 25psi doesn't mean that it will still produce more power... you have gone well beyond its effective range of airflow and all it does is flow hot air.

let me rephrase the question then because it sounds like it is being misunderstood.

at what point do it become evident that the factory cams need to be replaced... like you said the factory cams may be effective in between 5K and 6.5K rpm and less effective at 7.5K, at what point does the increase in the effective range of the cams become more noticeable and feel like the motor falls on its face above that... does that make any sense.

 

[Boosted98gsx]

at what point do it become evident that the factory cams need to be replaced... like you said the factory cams may be effective in between 5K and 6.5K rpm and less effective at 7.5K, at what point does the increase in the effective range of the cams become more noticeable and feel like the motor falls on its face above that... does that make any sense.

That's totally for you to decide. If you're making 300hp on factory cams at 25psi, and you want to be making 400hp, obviously you need more volumetric efficiency out of your engine. It may be time (ie one of the options) to upgrade cams.

 

[9!'clipseDOHC]

at what point do it become evident that the factory cams need to be replaced... like you said the factory cams may be effective in between 5K and 6.5K rpm and less effective at 7.5K, at what point does the increase in the effective range of the cams become more noticeable and feel like the motor falls on its face above that... does that make any sense.

For me it would be when my turbo is able to outlast my RPM's. For instance, while a 14b/t-25 may run out of steam before the factory cams will, a 20g will not. When I get a bigger turbo, I will get bigger cams so that I can get the most out of the bigger turbos high RPM airflow.