ok, i've been reading alot about cams and talked to a few guys.. im getting new eaton lifters/lashers and crane titanuim springs and retainers. I had lifter tick really bad, and figured i would upgrade while i could. Now my question is, right now i have minor bolt ons CAI,gs-t exhaust and soon the unorthodox UDP. I am willing to p&p my intake mani, and get a new exhaust mani. I've read that most people do not notice much of a difference with #10's and had wished they went more aggressive in hind sight. People have also noted the #12's have more of a lumpy idle. Really how aggressive is the #14 cams in relation to the stock cams? And how necessary is tuning after new cams, like cam gears and afc? Really how much is involved in changing to aftermarket cams.. what is good to have and what is REQUIRED! Personally i can deal with a little bit of lump in the idle since stock i do anyway.. and what kind of gains can you expect from street cams given supporting mod's.
I have alot of questions but if i make the thread too long alot of guys won't read it... Thanks in advance


VW= The joy of driving
DSM= The frustration of fixing

What else are you doing to the motor? Are you milling the head to raise compression? If you are keeping the stock compression, Crane 10's or 12's would be a good choice, installed properly they shouldn't give you a lumpy idle.
You can get a real nice increase in power if you decided to raise the compression a bit, up to 150+hp at the wheels on a dyno with the stock computer and a few supporting simple mods like 55Mmtb, P&P manifold and a decent header.
If you want a more agressive cam , you may want to raise the compression by either milling the head or installing higher compression pistons, I gather this is a naturally aspirated motor..........

BTW Titanium retainers aren't really necessary , I would spend that money on another modification instead.
With the cams available, you won't get any real benefit from the small weight saving over the stock retainers.

well this will stay a NA for as long as i own the car. I couldn't ever afford turbo and all the things that go with that. I am looking all motor build up next year. possibly the FTY 2.2 with 10.1 compression if possible. This is not 100% but as long as i have the funds it will happen. a 2.2 with hi-comp is nothing to scoff at in terms of all motor and would post some damn good numbers. How much actual dyno tuning would we be looking at though???


VW= The joy of driving
DSM= The frustration of fixing

>well this will stay a NA for as long as i own the car. I
>couldn't ever afford turbo and all the things that go with
>that. I am looking all motor build up next year. possibly the
>FTY 2.2 with 10.1 compression if possible. This is not 100%
>but as long as i have the funds it will happen. a 2.2 with
>hi-comp is nothing to scoff at in terms of all motor and would
>post some damn good numbers. How much actual dyno tuning would
>we be looking at though???
>
>
>VW= The joy of driving
>DSM= The frustration of fixing

If the motor is built properly, not too long on the dyno, perhaps a couple of hours worth , really depends on how good the person making the adjustments is.

A well thought out combination of parts,......... header, exhaust , fuel pressure, cam timing, Tb size , etc, should , should be close to max power and should only need a little tweeking, for instance............ adjusting fuel pressure,....... cam timing, to get the most out it.

If you have to do a lot of adjusting, you might be compensating for a short coming, not enough compression, not enough fuel presssure, fuel injectors too small, too much reversion .........

I have found, when I go to a dyno , it usually takes 3 hours at the most on the dyno to get what I am looking for. ( turbo takes longer because you have much more potential for motor damage if you make a mistake)

You really want somebody knowledgable with you on the Dyno and get the most inputs as possible, definetly ask for wideband 02 readings , and try to get a datalogger so you record your run and later take it apart for instance like injector duty cycle , how hard are the injectors working?

If you are getting a stroker kit, ask the dealer for his recommendation of complimenting mods. he obviously worked with it before putting it on the market and should be able to help achieve your goals.

Did you read this thread?

http://forums.2gnt.com/dcboard.php?az=show_mesg&forum=32&topic_id=91&mesg_id=91&page=

I have lots of head work including crane#16 cams. Get the #16s trust me. My car idled kinda high before the cam install (850-1000). so mine arent that lumpy at all. But when i floor it, it moves.

Yeah, if your going to stay NA get the 16's. 14's are designed for turbo motors.

actually i did read that entire post, before i made this thread. Just the more technical discussion left me behind. I was hoping for a little more broad information, rather than cam lift duration which leaves me baffeled. Now as for the 14's being designed for turbo and the 16's for NA how does that differ?? Is the duration on the intake and exhaust that different for a turbo or NA motor? And when referring them to #'s like 10's,12's,etc.. is there a pattern that develops with higher duration per set? And are some of them overkill when it comes to an NA? Im hoping to learn alot from this thread, that's why i made it. Hopefully others can benefit also.


VW= The joy of driving
DSM= The frustration of fixing

Turbo cams have less overlap because they don't rely on exhaust gas scavenging to help fill the cylinder at higher rpms during overlap.
but they do have higher cam lifts to get as much pressurized air as possible.

N/A cams have more overlap to take advantage of the scavenging effect during overlap to help pull in the air charge as the intake valve opens up ,.............. actually creates a vacuum in the higher rpm range , as the exhaust is exiting out of the exhaust port, when that valve is about to close.

For example the way you can siphon water with an air nozzle from an air compressor.

But at lower rpms, the cylinder can fill up real fast and then actually loose some of it's charge back into the intake manifold, much like taking a large swig of Pepsi from a bottle and not closing your lips fast enough , you spill some out.

That's reversion, the valves are open too long at lower rpm's, perfectly normal and it is trade off in any N/A motor with larger cams.

That is why you usually raise the compression a bit with bigger cams.


When you lose some of the charge ( at lower rpm's) you actually fill the cylinders with a little less than normal,in effect less charge, = less compression.

Your static compression might be 9.6 to 1 but your actual dynamic compression , because of reversion in the lower rpm range ,( with a bigger cam) could drop to say anywhere from .5 to a full point of compression, depending on how big a cam is .
That's what causes the lope at idle , lower compression and reversion.

In the mid range or wherever the cam "powerband" starts , you actually get your compresssion back as the scavenging helps pull in that air charge and.......... it is possible to go a little higher than that, with a very efficient set up it is actually possible to get a 'superhcarge" effect, to be able to cram more air charge then your static compression ratio, not a lot but every little bit counts.

Raising the compression, for instance with let's say 10.5 to 1 pistons could give you back your stock compression (9.6-1 or around there) in the lower rpm range with the bigger cams, results?

Low end would feel "normal" even with the reversion that comes from a bigger cam but..........when you get in the camsahfts power band and you get that full 10.5 o 1 compression ratio, it will feel like somebody hit a nitrous switch on you ( how much depends on how big a cam )

Personally I like building an N/A motor, it is a bit less maintenance then a turbo.

^^^wow...that's a great explanation of what goes on...thanx I learned a lot there:thumbsup

totaleklipse97, I hope I didn't come off sounding like a prick when I refered you to that thread....I just thought it might have the info you needed. I know a lot of members don't venture into the advantanced tuning very often...it's kind of intimidating in there...it is for me at least...LOL

no offense taken, it is a very informative topic in advanced tuning. The only thing is it is geared toward comparing cam lift duration, and not the actual effects of how a larger cam affects the engine. I read that thread knowing very little about cams and it just got me confused. Without knowing more about cams then the duration of the cams mean very little.


VW= The joy of driving
DSM= The frustration of fixing