i am sure the question has been rasied many many a time. but i have been searching for about 25 min and have found very good explanations on each individual set of cams...264/264 272/272 280/280. what they are best used for and so on.

My question is what is the purpose of the cam combos.....weather it 264/272 272/280, what ever you have. what are the benifits or down falls if any??
dont worry about hurting my feeling with anytype of explanation, as long as i learn something i could care less?? thanks

 

ok so maybe it was a stupid questioin....but i would at least like a smart as answer then none at all....

 

well people probly havent said anything because this topic has been covered many times and if u search u'll find the answer...but i'll help u out. The more aggressive (higher number) cam profiles you get, the higher in the rpm range you move your powerband...for instance 264/264's are great for strong torque and work well with a stock turbo. I have 264/272's because its a good mix of torque and hp for the street and works well with stock turbo. str8 272's are for higher revs and can work well with stock turbo or even a bigger one, especially if you wanna build your motor to rev higher. Bigger turbos hit full boost around 5K (like a GT35) so the higher profile cams compliment this application nicely. 280's are str8 crazy for stock turbo i think, but many will disagree.

 

Here is a thread in the engine/drivetrain forum.....

https://www.evolutionm.net/forums/sh...d.php?t=165783

you must not have searched very hard!

 

keep in mind, one of the main reasons people were using cam combo's (264in/272exh..etc) a while ago was because of idleing issues when the aem ems when it first came out!!

your best bet now would be to just get 272's or 280's depending on your goal's..

 

Just go with straight 280's, you'll be fine.

 

What type of underwear do you wear?

264's Briefs
272's Boxers
280's None

 

280's on stock ECU have been proven to work. There are a lot of myths in here about them not being compatible with stock ECU. The cam combo will change the dyno curves and boost characteristics. 272's-280's will make more peaky power but run out of boost quickly.

 

the logical response to this argument is that the 272's- 280's outflow the stock turbo, hence the loss in boost. You may make a couple more top end hp with the bigger cams and stock turbo, but think of the low and and mid range torque you give up due to excessive overlap. I don't know if you mean 272/280 combo or straight 272/272 and 280/280. But if what you posted about boost loss is fact, your making a good argument to run 264's on stock turbo.

 

I've got 264/264's on my 03, and the first and second gear pull is awsom! Better in 3rd and 4th but not as good as you'll get with 272's or 280's.

It all depends on what your looking for. I like the off the line torque. I don't do too much high end speeding so went with the 264's. Still have the stock turbo.

A combo of 264/272 was what I wanted but Buschur didn't have any 272's in stock at the time. This would have been better through out the whole power band.

 

Correct me if im wrong, but wouldnt is make sense to have a cam combo that will aid in turbo spool if you have a slightly bigger turbo than has enough steam on its own until redline?

I can understand that 272 's will help on a stock turbo car, because the stock turbo runs out of steam in the top end, but with a bigger turbo, wouldnt you want to offset the turbo size with the cam size??

Just my 2cents, I am pretty shure Al was running 272's (JUN) when he ran the high 9...

 

only if you have a huge turbo, and lag is unberable will you want to run a smaller exhuast cam. otherwise you create a ton more backpressure and loose flow in the top end. but it can drop your spool by 500+rpm if done with the right cams.

 

do you know this as fact? Or, are you speculating/repeating what you've heard? I haven't seen a dyno graph yet that supports this 264/272 argument on stock turbo setup. Yes, I've seen graphs that may make 5 more hp, but they give up much more in the low end, mid range. It's wishful thinking on stock turbo..... if 264's are good, 272's are better and 280's are bestest of all! Not hardly.

 

ok....but what was this i heeard about the 272's not passing emissions test???

 

I run 272 I and 264 E...the reason I do that is to keep the boost up at high rpm. I run the stock turbo and road race the car and this makes a great combo. If you reserch Mitsubishi
runs the factoty cams the same way. larger intake smaller exhaust. Look at my sig. I also have a Dyno sheet posted under westchester evo.