Cam Differences (Stage I & II)

[53BigDog]

ok, need some clairfications on the actual difference between stage I & stage II. (i.e diffs between duration, opp range, etc)

Some suggestions on brands and types would be great. I will be looking for daily drivability and longevitity.

 

[TweekedGT]

Start by looking on VT Engines site. They have a range of cams and will give you the lift and duration numbers. I am a VT fan and have a set of their Stage 2 N/A cams in my car. They are awesome. Just very tough to come by.

 

[03ghoststang]

yeah go to the VT web page or the comp cams web page and you'll get all the info you need as far as dur., lift, and what ranges does it work on and what upgrades are neeeded

 

[helty]

i think you need notched pistons to avoid PTV contact with the Comp Cams though. Nothing against Comp, thats just what Ive read several tims while researching this same question.

 

[TGJ]

The difference between some Stg I and Stg II cams is just more duration for the Stg II cam. Other Stg II cams from the comparable Stg I have more lift and more duration. By comparable, I mean the same company's Stg I and Stg II cams.

The problem with the Comp 270AH cams( Stg II PI ) is that people were/are installing them without degreeing them in.( Goes for almost every aftermarket cam install ) When installed properly, they safely clear Flat Top pistons. You will need to machine cut valve reliefs into the pistons if you intend to run the Comp 278AH cams( Stg III PI )

 

[hognutz]

stage I vs sage II is just different grides. I hate stage numbers they are kind of worthless.

I don't think the comp's have any issues with piston to valve contact till the 278's and those are more than stock headed car will want.

if you don't like a rough idle stay in the "stage I" teritory. If you don't mind a rough Idle and some surging possible in say lower gears go with the comp 270's or vt stage II's. they both seem to make more power even on stock heads. the have a fairly rough idle though. I would lean towards VT I think comps quality control is not so hot sometimes on off the shelf grinds. I had back to back cams with more than .007" lobe variation for a 502 I was building. what are the odds of back to back cams out of spec from them if the QC was top notch.

as for the actual cam specs go to the manufactures page for though. try to find a version of desktop dyno on the web. enter all you engine paramters, head flow, cams spec and screw around with the numbers it will give you and idea of the power curves.

 

[helty]

would VT 2's be too much for a daily driven car? I dont mind the rough idle and a little surging at all, but dont want to sacrifice too much street manner. may also see a long road trip or two once a year, any issues with that?

I dont mind going with the stage 1's, but if I can get a little extra power out of the 2's now, then why not? I'll be keeping my stock heads for the foreseeable future, maybe* some MMR stage I's down the road.

 

[imblown-ru]

hey buddy, stage 2 cams are quite streetable as far as i know. I have a friend back in VA that is running something like stage twos, and they sound sickkkk, but he seems to be fine around town, and ive got friends running pretty big HKS cams on their evos, and they are very streetable. If they are dialed in right so they dont stall when you push the clutch in, and you got a good tune you shouldnt have any problems.

 

[csledd]

would VT 2's be too much for a daily driven car? I dont mind the rough idle and a little surging at all, but dont want to sacrifice too much street manner. may also see a long road trip or two once a year, any issues with that?

I dont mind going with the stage 1's, but if I can get a little extra power out of the 2's now, then why not? I'll be keeping my stock heads for the foreseeable future, maybe* some MMR stage I's down the road.

stage 2's are very streetable, you just gotta watch it because they have a different power band than the stage 1's. you lose a lot more down low power with stage 2's but gain more up in the higher rpms. stage 2's also require valvespring upgrades

im currently on the waiting list for vt stage 2's /sigh

 

[53BigDog]

Awesome - Questions are getting answered! Thanks Guys.

My plans are to stay N/A throw in flat pistons, port, polish, and multi-angle valve job my PI heads and then I have a p&p pelnum and p&p t/b. I figured some stage II cams, a cobra crank and some forged I beams would set me nice as I try and work the highest compression.

It seems many of you drool over the vt cams. any takers on the comp? (good point hog!)

 

[helty]

stage 2's are very streetable, you just gotta watch it because they have a different power band than the stage 1's. you lose a lot more down low power with stage 2's but gain more up in the higher rpms. stage 2's also require valvespring upgrades

im currently on the waiting list for vt stage 2's /sigh

csledd, imblown, thanks for the replies

After thining about it for a while, I think Ive decided to go N/A for the foreseeable future. Not that its a bad thing, but I was really looking forward to a Novi 2000 Mongoose kit. But hey, If I can run 12's N/A, I'll be happy until I'm out of school and can afford the blower kit.

Next stop: Longtubes, Cams, and Dynospeed Racing

 

[TweekedGT]

Stage 2'sare very streetable. The only thing is that they still do stall at lights sometimes. They aren't as rough an idle as you might think either. I love mine. Too bad i'll never be able to feel them again. They are a little slower down low but the high rpm pull makes up for it. I ran my cat=r through the trapsat our 1320 @ 6500 rpm in 3rd and it was still pulling. My PI's used to fall on their face at about 5200-5300rpm.

 

[helty]

How would N/A cams work on a centrifigul blower set-up, or would they even work? and how would blower cams work on a N/A set-up? Im sure they wouldnt be ideal, but would they still produce decent power?

I really want to do cams now, but I also want to do a Novi 2000 mongoose kit in the next year or so.

 

[hotmustang331]

Stay away from VT N/A cams if your going FI. Scott @ VT is DEAD set against their stg 1 or 2 cams when using boost.

The reason is the valve overlap. Meaning both the intake and exhaust valves are open at the same time. In a N/A car the escaping exhaust helps pull in the new intake charge and thats more efficeint.

Now when your blown, the air is already being FORCED down the intake and since both valves are open, the boost goes straight through the intake and out of the exhaust for the period that both valves are open. NOT good, and you will loose a few #s of boost. = alot less power vs blower cams. IMHO even less than stock cams.

 

[01Steeda]

331 is dead on about the blower and N/A cams. It would make sense to just go with a blower cam now if you will be getting one in the near future. You wont see the same gains N/A but it will pay off big time when you get the mongoose kit.

 

[helty]

so even though my power gains wouldnt be as much, there wouldnt be any driveability/reliability issues using blower cams on a N/A car? i really dont know how long it would be for, probably a year at least. (until i get the blower set-up)

thanks guys for the help

 

[00silverstang00]

:SNSign:

 

[deftsound]

what will the idle sound like with vt stage 1's? Also would it be mandatory to get a dyno tune afterwards?

The reason i ask is i kinda wanna get new cams mostly for the idle sound, they sound sooo mean! But the added power would be nice as well...

 

[helty]

what will the idle sound like with vt stage 1's? Also would it be mandatory to get a dyno tune afterwards?

The reason i ask is i kinda wanna get new cams mostly for the idle sound, they sound sooo mean! But the added power would be nice as well...

tune isnt necessary with stage 1's (but it wouldnt hurt), idle will be slight but noticeable. the 2's are an aggressive idle, and require upgraded springs and a tune.

 

[TGJ]

I wouldn't use VT N/A cams in a blown car. The VT Stg II N/A cams are very difficult to tune( get them to idle properly ). If you are staying N/A, I would suggest you look at Cams that are biased to the intake side or are not biased at all( Similar duration and lift for intake and exhaust ). Those types of cams seem to be making more power than those that are biased to the exhaust in N/A applications.