03GT CAM?
- Thread starter lilcgt
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boulderado
New Member
Im interested in this as well. Beyond the 500 to 600 bucks youll pay for the cams I have heard you will pay 5-6 hours of labor at your local shop, unless you can put them in yourselves. My questions are:
1. aftermarket cams pass emissions?
2. reliablility issues with cams?
3. horsepower gains?
4. you gain power at certain RPMs and lose it elsewhere?
5. recommended aftermarket cam set up on a stock 02/03 GT?
1. aftermarket cams pass emissions?
2. reliablility issues with cams?
3. horsepower gains?
4. you gain power at certain RPMs and lose it elsewhere?
5. recommended aftermarket cam set up on a stock 02/03 GT?
nickthegenius
Active Member
boulderado said:
To answer your questions:
1. Probably not. This has been asked on here and Modular Depot and the general consensus is "no". I even think one of the VT Engines guys chimed in on a response at Mod Depot and said the same thing.
2. No reliability issues other than if you don't change the valve springs and break one. VT Stage 1 cams don't require a spring change, but their Stage 2 cams and all the Comp Cams "recommend" new springs. This is one of those areas where it is "better safe than sorry". The 4.6L is an intereference motor and if you break a spring and the valve drops open even partially, there is a high chance of bending that valve and/or damaging the piston. A friend of mine and I changed my valve springs last week. The passenger side took about 4 hours. Then after we learned the process, the driver's side took 1.5 hours. Its not hard, its just tedious work.
3. Off the top of my head, the only ones I can think of with posted gains before/after are Mustang92's VT Stage I cams where he gained 22hp. Also, VT Engines posted a dyno graph on Modular Depot of a near stock (only mods were weld-in Flowmasters) '99-up Mustang that gained 29hp with their Stage 2 grind.
4. To a certain extent, yes. Most will gain more hp up top, but are still very streetable uless you get crazy.
5. For a daily driven car, I would suggest the VT Stage I cams or the Comp Cams XE262AH cams. If you can live with a rougher idle in your daily driver, then try the VT Stage II or Comp Cams XE270AH cams (thats what I have). Anything stouter than that, and you'll need ported heads. SHM has some good grinds, but I really don't know any of the specifics so you might want to look into them, too.
My other suggestions would be that if you are changing them yourself, allow yourself plenty of time to do the swap. It took us a whole week, but we just worked from 8 or 8:30 to 10pm each night. We had a total of about 12 hours doing the springs and cams.
maddogg545
Founding Member
nickthegenius said:
How would you know if you actually did that kind of damage to your engine? How would it run? Would it sound any different?
nickthegenius
Active Member
maddogg545 said:
Hmm. IF you got really lucky, you might end up with a really rough running car and depending on if it was an exhaust or intake valve, it would smoke. More than likely, it would drop enough that piston/valve contact would take place and you would definitely hear it on top of the fact that the car would run poorly.
I had it happen in a small block Chrysler once. It wasn't because of the same reason (spring breaking), but mine starting running very roughly and then locked up. It happened because of "coil bind". The factory springs had shims under them and the guy that installed the aftermarket springs left them in. Then, when the valve was at full lift, the spring was fully compressed and it actually shot the valve through the keepers and into the cylinder. It scored the walls and cracked the piston.
boulderado
New Member
nickthegenius
Active Member
boulderado said:
We don't have testing in Indiana yet. Although I haven't heard of someone doing it for cams, some guys on here with offroad pipes have mentioned slipping the guy doing the testing a few bucks to pass them. Also, knowing someone with a shop might help.
Infinity
Founding Member
There IS testing in Indiana, but only in Clark, Floyd, and one northern county (I think around South Bend). Fortunately, they're talking about doing away with the testing in Floyd/Clark altogether (sweet! I have lived in either of these counties all my life). People pass here all the time because the testing is ran by contracted individuals, and not the state. BUT, I've been pulled over and had a mirror ran under my car twice now by the DOT.
hey nick was that best time with all the listed mods excludeing the cams????
just wondering cause my best time is [email protected]
just wondering cause my best time is [email protected]
nickthegenius
Active Member
NasaGT said:Nickthegenius, do you have any kind of tune to go with your cams or are you running on the stock ECU???
Also, update your sig since the cams are installed!
Not yet. The car runs OK, but the idle is kind of funky and sometimes wants to stall at stop signs. There is a place about 30 minutes away that does tuning and has a great reputation and hope to go there in a week or two.
lilcgt said:
That pass was made last September and at the time the only mod was my Magnaflow catback, wheels, and some cosmetic stuff. All the mods in my sig have been added since then while the car was sitting during the winter.
hognutz
New Member
my .02 would be comp 270's or VT wild. I would change springs even with stage 1. I don't like taking chances. springs are not $500. I don't like saving a little money when you are risking a lot of money if something happens.
I am not sure if stage II would pass emissions. I would email the cam manufacturer.
with the correct cam you should not really lose low end but you can't have a high end and low end cam. there is always a trade off. With 281ci your best bet is always going to be low gear and high end though. there is no such thing as lots of torque at 4.6l without a power adder.
I really think this is the kind of mod you should do yourself though. the labor cost is high compared to the hp gain.
If you pay someone to do this cams is going to set you back $1500 by the time it is tuned. that is starting to get $$$$.
I am not sure if stage II would pass emissions. I would email the cam manufacturer.
with the correct cam you should not really lose low end but you can't have a high end and low end cam. there is always a trade off. With 281ci your best bet is always going to be low gear and high end though. there is no such thing as lots of torque at 4.6l without a power adder.
I really think this is the kind of mod you should do yourself though. the labor cost is high compared to the hp gain.
If you pay someone to do this cams is going to set you back $1500 by the time it is tuned. that is starting to get $$$$.
RedBullitt
New Member
scalder
Member
image said:
Dunno about the 3.73's....probably wouldn't go any less than 4.10's with the Stage II cams. Plus 4.10's are fine anyway, even on your DD.
