New guy ? about cam swap and idle characteristics

[Indiana]

I've been looking at a lot of dyno charts and cam specs. I see that the majority of cams list an operating range of 1400-6500, 1600-6500....

Does that mean you have to set your idle that high, or that it just doesn't make any power under that range?

 

[Red2000GT]

It just means that's where they will start to make power. You won't have to adjust your idle from factory unless you get a really big lumpy cam,which is a bad idea unless you have a really big lumpy motor for it to go in. Don't forget to change the valve springs with any new cam.

 

[Indiana]

Thanks.

No plans for big lumpiness here (except for the big lump of cash!).

 

[4.6_02_Black_GT]

Indinia,

Seem cams are on everyone's mind lately we are all running out of bolts on to add. Anyway I too am swapping cam soon. I have narrowed down my choice. Heres a little info, I have found. Hopefully this will set up on the path.

Your Stang is 02 like mine so we have both have PI heads(Comp makes PI and NPI cams Romeo engines). Some dyno runs have shown cams can provide 20-25 HP to our motors. Some a little more(have seen 30hp quoted..but I question that high a number) based on intake and exhaust mods. 20 seems a fair expectation. Both company cams are roughly $500 plus $180 for springs. Wheter or not you need tune seems to be based on preference. The cam swap will give you greater power in the range that is stated on the cam card. Typcially cams are going to help you out above the 1800-2000 rpm range and up, with the stiffer springs and better breathing at high rpm you can possibly push you motor up a few hundred rpms as well and gain some power up high.

Lots of people on Stang Net are favoring the Comp cam xe270(me too ). The Stage 2 VT cams seem to have a big following over on Modular Depot. They have good reviews there as well.

The only drawback to concern you should be the cam swap is straight forward but requires attention to detail to avoid f@@#$$ your timing up, that would be bad(4 more hours to pull the timing cover and reset it). The valve springs will take a day to install and requires patience(keepers are slippy and small). You will need a few speciality tools you might not have a cool little valve spring compressor($50) and cylinder leak down tester($80) and possibly and timing chain locking tool(or a spare set of hands). .

Some people have had some clearance issues with aftermarket heads and aftermarket flat-top pistons. Some people have complained that the Stage 2 Comp grind caused some piston to valve contact even with stock pistons and heads(do a search for details) It is a fact the Comp Stage 2 is really really aggressive and is very close to the maximum duration for our stock setup. Notice how the VT Stage is has slight less duration on int/exh and havent seen anyone with proven ptv contact yet.

That being said I'm still leaning toward the Comp x270 cam. There are as many people with the 270 grind that have NO problems as people with issues. I have seen no dyno comparisoin between the Stage 2 VT and Comp Stage 2. So there no hard facts as to which one would make the most power. But they will both be close in power. Stage 1...are just not worth the effort to use if you keeping the engine in the car. Stage 2 is the way to go... You pick a company either would should make you happy. You might also check out Crowder and SeanHyland they make cams too.

hope this helps

Comp Cam
Stage 1 xe262 226/230 @.050 with .550 lift (1400-5400 rpm)
Stage 2 xe270 234/238 @.050 with .550 lift (1800-5800 rpm)

VT Engines
Stage 1 N/A 224/226 @ .050 (total lift no stated) (rpm not given)
Stage 2 N/A 225/235@ .050 (total lift no stated) (rpm not given)

 

[nickthegenius]

Well said, 4.6_02_Black_GT. The Comp 270s, VT Stage I, and VT Stage II cams have proven to be very popular on here and ModularDepot. There was a post on ModularDepot where they took a '99-up GT with nothing more than Flowmasters welded into the catback and added VT Engines Stage II cams and picked up 29hp. Mustang92 is one of the first to have VT Stage I cams and gained 22hp with non-ported heads.

I personally have the XE270AHs from CompCams, but I never had a "before" dyno to compare my numbers with but I think the final product is fine. I'd like to go back when I have 10-15k miles to see if I gain any as the motor loosens up as it ages since the cams were installed at 5k miles.

 

[Indiana]

Thanks for the input guys,

I don't really have a plan yet, I'm just educating myself. I'm looking to set this car up for road courses. i.e. Mid Ohio, Putnam Park etc., so I think I'm going to want to favor mid-range torque. I'm trying to decide between cams, porting, intake, or Supercharger, or all. Which will put me in an area where forged innards would probably be a good idea. (and where I'll need a part-time job )

Finding charts on cams seems to be a little difficult. Some of the best info is comming from people here. I'm also reading a few books, the best of which so far is Four-Stroke Performance Tuning by A.G. Bell. I still need to find a shop that can due the tuning. I'm pretty close to Kenny Brown, so I'm in good shape as far as suspension tuning goes.

4.6- I'm looking forward to seeing some before and after numbers.

Nick- You're avatars are the greatest. I'm going to be unloading some R/C stuff too. I have one plane, that should pay for the S.C. That is if I don't smash it first! I hate to give it up, but I can only afford one expensive hobby....

 

[96SOHC]

Indinia,

Seem cams are on everyone's mind lately we are all running out of bolts on to add. Anyway I too am swapping cam soon. I have narrowed down my choice. Heres a little info, I have found. Hopefully this will set up on the path.

Your Stang is 02 like mine so we have both have PI heads(Comp makes PI and NPI cams Romeo engines). Some dyno runs have shown cams can provide 20-25 HP to our motors. Some a little more(have seen 30hp quoted..but I question that high a number) based on intake and exhaust mods. 20 seems a fair expectation. Both company cams are roughly $500 plus $180 for springs. Wheter or not you need tune seems to be based on preference. The cam swap will give you greater power in the range that is stated on the cam card. Typcially cams are going to help you out above the 1800-2000 rpm range and up, with the stiffer springs and better breathing at high rpm you can possibly push you motor up a few hundred rpms as well and gain some power up high.

Lots of people on Stang Net are favoring the Comp cam xe270(me too ). The Stage 2 VT cams seem to have a big following over on Modular Depot. They have good reviews there as well.

The only drawback to concern you should be the cam swap is straight forward but requires attention to detail to avoid f@@#$$ your timing up, that would be bad(4 more hours to pull the timing cover and reset it). The valve springs will take a day to install and requires patience(keepers are slippy and small). You will need a few speciality tools you might not have a cool little valve spring compressor($50) and cylinder leak down tester($80) and possibly and timing chain locking tool(or a spare set of hands). .

Some people have had some clearance issues with aftermarket heads and aftermarket flat-top pistons. Some people have complained that the Stage 2 Comp grind caused some piston to valve contact even with stock pistons and heads(do a search for details) It is a fact the Comp Stage 2 is really really aggressive and is very close to the maximum duration for our stock setup. Notice how the VT Stage is has slight less duration on int/exh and havent seen anyone with proven ptv contact yet.

That being said I'm still leaning toward the Comp x270 cam. There are as many people with the 270 grind that have NO problems as people with issues. I have seen no dyno comparisoin between the Stage 2 VT and Comp Stage 2. So there no hard facts as to which one would make the most power. But they will both be close in power. Stage 1...are just not worth the effort to use if you keeping the engine in the car. Stage 2 is the way to go... You pick a company either would should make you happy. You might also check out Crowder and SeanHyland they make cams too.

hope this helps

Comp Cam
Stage 1 xe262 226/230 @.050 with .550 lift (1400-5400 rpm)
Stage 2 xe270 234/238 @.050 with .550 lift (1800-5800 rpm)

VT Engines
Stage 1 N/A 224/226 @ .050 (total lift no stated) (rpm not given)
Stage 2 N/A 225/235@ .050 (total lift no stated) (rpm not given)

Just to add to the VT cam specs: Stage 1 lift is 540/550 with a C/L of 110. Stage 2 lift is 560/575 with a C/L of 108. Not sure of the RPM ranges for either.

 

[VTEngines]

Just to add to the VT cam specs: Stage 1 lift is 540/550 with a C/L of 110. Stage 2 lift is 560/575 with a C/L of 108. Not sure of the RPM ranges for either.

RPM range also depends on what the head flow is. On a stock head, the rpm range will be 3000-6500...about 500rpn higher with the Stage 2's. I just posted some Stage 1 results with stock heads over on Modular depot. They gained 33rwhp peak to peak and about 50rwhp at 6000rpm. Stage 2's will see similar results with stock heads...but really shine with some addition head airflow.

Hope this helps....

 

[Purebred]

RPM range also depends on what the head flow is. On a stock head, the rpm range will be 3000-6500...about 500rpn higher with the Stage 2's. I just posted some Stage 1 results with stock heads over on Modular depot. They gained 33rwhp peak to peak and about 50rwhp at 6000rpm. Stage 2's will see similar results with stock heads...but really shine with some addition head airflow.

Hope this helps....

Would the Stage 1s be smog legal in MD? How much of a detriment to gas mileage would they be?

Edit: I'm looking at a blower down the road - are the Stage 1s blower friendly?

 

[DrK MrK iV]

If VT stage 1's make about 20 HP without changing springs, and VT stage 2's make about 25-30 with changing the springs... That is about another 400 bucks in labor that can be used elsewhere. Are stage 1's worth it on a mild motor? As in every bolt on and cams?

 

[4.6_02_Black_GT]

Drk Mark...

Although Nicks is gonna be disappointed, I just didnt have the stomach for the Comp 270 cams, just too many risks involved in my opionion(my opionion..no flames please). I ordered the VT Stage 2's today .560 lift 225/235 int/exh. Just a touch milder than the Comp270 grind. So I'm very happy, bad news is there out of stock and grinding some more this week, so I should have my set mid week next week

Heres a dyno of cams on normal 2002 GT can do for all the cam haters out there. 31 peak hp. 11 ft/lb torque and look at what those puppies do in above 4500 to 6000 gains are in the 50 hp range at 5500 rpm that is AWESOME.... so with good cam an intake plenum and good x pipe 285hp is no problem. I getting mine GT baselined this weekend so I will have before and after dyno for everyone, I will keep you posted on how the cam swap goes.

original thread

http://forums.modulardepot.com/showthread.php?s=&threadid=29097

Heres the dyno(courtesy of Modular Depot peps

 

[Indiana]

That is a great looking chart. I really like the HP curve after 5k, when you can really feel the drop in power, or at least the lack of increase. It also looks like it left the bottom end alone!

 

[DrK MrK iV]

Damn 4.6! We're deffinatly going to have to meet up! I want to hear the stage 2's. Where in charlotte are you? North or South?

 

[4.6_02_Black_GT]

Hey DRk Mark

I stay near the Speedway.

These guys are putting in my 4.10s and aluminum drive shaft this Saturday. We are gonna put my car on the dyno to get a good baseline. So when I install the cams next week we will have the gains to post here.

Heres their link they are on South Pit road on the backside of the track near Petty's shop.

http://www.gofastfords.com/frames.html

 

[Indiana]

4.6_02_Black_GT: Got cams?