280's with 272's cams
 

im going to go the 280 exhaust and 272 intake cam way, i heard the idol is rough and a few other problems, what should i expect with this set up, any feedback from anyone who has this?

Most people who´ve mixed n' matched HKS 280´s with 272´s have done 280 intake and 272 exhaust. I am not saying this just because I happen to be running that particular combo, as I realize that my personal experiences are pretty irrelevant and insignificant due to lack of dyno or trap speed corroboration.

But, Curt Brown ran the 280i/272e combo and trapped above 125 mph with it on the stock turbo if my memory serves me well. I just don´t recall any reference to the inverse, or 272i/280e combo as being a significant power producer. Maybe someone else can chime in though. .Will you be running this cam combination with the stock turbo?

There is a guy on the forum ---Mellon--- he's a tuner that has a great rep, well anyways, he has tuned an Evo with HKS 280s that runs excellently...here's a video..
http://dsmvideo.vidiac.com/video/384...450135e6bc.htm

smoothest idling 280 cams and with the A/C running I've ever heard...it's all in the tuning, and Mellon is one of the best..check the vid out and give Mellon a shout out...

I have had HKS 280's on stock ecu for 6 months and 10k miles. No issues what so ever, rock solid idle and nothing but great power all through the rev range!

ya i was thinking 280e for good top end and 272i for good spool up, yes its a stock turbo..for now..but a 50 trimm is in the future

What's the advantage of having 280in/272out versus 272in/272out?

^curious as well

if you go 280, you will need to get new valve springs and retainers. I had 280 with no problems at all with the idle.

By having 272 in and out, will it give more mid range power compared to the higher lift 280's?

pretty sure curt brown ran jun 272/272s to get that 125 trap on the stocker.

http://cbevo.com/5.html his modlist is right there for all the world to see

i think im going to end up going with 272/272s , i talked to the fella who will be tuning my car and he said that are easier to tune

easier to tune maybe but thats why you are paying him to tune it right? a completely stock evo is easy to tune to but if he know his stuff he should be able to tune for 280s.

As far as I know HKS 272's and 280's have the same lift just different durations...

The more duration you have, the higher the RPM requirements are to achieve peak torque and horsepower. That's why I run 264/272.

It appears that a combo with longer exhaust duration will 1) make power earlier in the rpm band and 2) allow for better pulsation of exhaust gases.

Good to know, thanks for the info.