Differences between Comp 306 and extreme 230/236?
Registered User
Joined: Jan 2003
Posts: 408
From: West Coast
When you look at the advertised (0.006" lift) duration numbers for the two cams, the difference shows up. The 230/236 XE cam has advertised duration of 282/288, while the 306 (230/244 @0.050" lift) has advertised numbers of 290/307.
So, the XE crams the same amount of intake duration at 0.050" lift into 8 degrees less total duration than the 306 (282 for the XE vs. 290 for the 306).
Total duration (and overlap) is what causes the driveability problems associated with bigger cams. By opening the valves faster, you get a cam that behaves more like a big cam on the top end, and a cam that acts more like a small cam at low RPM (To a point at least...).
The faster opening and closing rates of the XE cams put extra stress on the valvetrain and require stiffer springs. Also, because of the more severe profiles used on the XE cams, you may run into valve float sooner. So, you may wind up with a cam that drops off after a certain RPM (as many of the XE grinds seem to do). Especially on a stock bottom end, this isn't really too big a problem, since many people don't want to rev too high anyway.
So in summary, the 306 is an all-out race cam, while the XE230/236 is more of a compromise for better direveability and low-end torque. Not that the 230/236 is bad at all (see the sig).
BRAD
So, the XE crams the same amount of intake duration at 0.050" lift into 8 degrees less total duration than the 306 (282 for the XE vs. 290 for the 306).
Total duration (and overlap) is what causes the driveability problems associated with bigger cams. By opening the valves faster, you get a cam that behaves more like a big cam on the top end, and a cam that acts more like a small cam at low RPM (To a point at least...).
The faster opening and closing rates of the XE cams put extra stress on the valvetrain and require stiffer springs. Also, because of the more severe profiles used on the XE cams, you may run into valve float sooner. So, you may wind up with a cam that drops off after a certain RPM (as many of the XE grinds seem to do). Especially on a stock bottom end, this isn't really too big a problem, since many people don't want to rev too high anyway.
So in summary, the 306 is an all-out race cam, while the XE230/236 is more of a compromise for better direveability and low-end torque. Not that the 230/236 is bad at all (see the sig).
BRAD
Registered User
Joined: Jun 2003
Posts: 2,626
From: Baylor University - TX
Originally posted by Kreinmc
The 306 will beat a 230/236 at the track any day.
The 306 will beat a 230/236 at the track any day.
Are ya sure about that? It all depends on whether or not you have your heads ported, what else is done to the car, conditions, etc
You win the BIGGEST GENERALIZATION OF THE DAY award
Registered User
Joined: Jan 2003
Posts: 408
From: West Coast
The 306 will beat a 230/236 at the track any day.
BRAD
Last edited by llafro; Dec 5, 2003 at 05:21 PM.
Registered User
Joined: Feb 2001
Posts: 622
From: Mesa, Az
Originally posted by FacelessZ
Are ya sure about that? It all depends on whether or not you have your heads ported, what else is done to the car, conditions, etc
You win the BIGGEST GENERALIZATION OF THE DAY award
Are ya sure about that? It all depends on whether or not you have your heads ported, what else is done to the car, conditions, etc
You win the BIGGEST GENERALIZATION OF THE DAY award
Registered User
Joined: Oct 2003
Posts: 537
From: Was TX, now in Portland, OR
Yeah I have the 305 (220/230 and .544/.544) and it is a good cam. A good daily driver and makes good power.
But anyway, the 306 is a proven performer. It's a bigger cam, but it has been proven to make good power time and time again. And I think that guy meant with the exact same setup between a 306 and a XE230 , same drivers, etc, the 306 will be quicker.
But anyway, the 306 is a proven performer. It's a bigger cam, but it has been proven to make good power time and time again. And I think that guy meant with the exact same setup between a 306 and a XE230 , same drivers, etc, the 306 will be quicker.
Registered User
Joined: Jun 2001
Posts: 239
From: WhiteSalmon, Wa. USA
Here are some numbers for you....
Originally posted by Kreinmc
I really haven't seen any good numbers from XE cams besides dyno #'s. Even the 305 seems to be a better cam. jmho though
I really haven't seen any good numbers from XE cams besides dyno #'s. Even the 305 seems to be a better cam. jmho though
Ken
Texas Moderator (1998-2009)
Joined: Dec 1998
Posts: 1,301
From: DFdubya, Tx.
I've had both the CC306 and now my current 230/236 - but on a 110lsa. The 306 made a lot less torque than the EX down low ~ and across the rest of the powerband, but both peak numbers are about the same. But the CC306 did hold it's peak power a couple hundred RPM higher and I've actually run a better ET at the track w/ the 306 than I have yet w/ the EX cam. Comparably, the 306 got me a 12.02@115mph, while the EX was a 12.14@114mph. Although now I have a rollbar and and few other items adding a little weight to the car.
But now I get to hit the track sometime this winter to go for a new best.
But now I get to hit the track sometime this winter to go for a new best.
Thread Starter
Registered User
Joined: Mar 2000
Posts: 407
From: Lemont IL, usa
Ok, then whats the next step up from a 306? A custom grind? How do you think my car will act with a 306, LTs, Borla, and 80,000 for mods? I had a older T/A with a bored over 350 and a 280H series cam in it, so I'm kinda understandin how the 306 will feel. Although I always felt like the 280H was too huge for the engine, but that car also had 2.41 for gears so, it never even got going til after 4700 rpm. Then it ****in roared.
