stonemonk9

Ok, after reading the end of all cam threads......... I can think of many issues that are left un answered, I'm going to try to touch on a few things I think were left out. Please correct me if I goof somthing up, lol.

First when deciding on what cam profile to choose, you must decide how you will be driving the car. It makes absolutely no sense to install a cam that makes its power above 3500-4000 rpm when you will spend most of your time driving far below that range. The car will be very boggy and hesitant on your average trip to the bank or around town.

Now that you've decided where you want the power to be, you must find where your heads stopping improving flow. For example, the patriot s2 heads claim to flow well up to .600 lift, therefore you would not want a cam that is going to surpass that amount of lift. The extra lift would be worthless. So knowing that the stock 96-98 heads crap out around .450 lift on the exhaust side its pointless to have a cam that will surpass that, the exhaust ports will be choked up.

After determing how well your heads flow and where you want your power to be, you can then choose the cam profile that best fits your needs. Now once you have that profile there are some things you must look at to prevent future problems. Probably the most important thing to find out, espececailly on these modular motors is PISTON TO VALVE cleances (PTV). This starts to happen when you add more duration or lift to you cam profile. The longer and further the valve is open the greater chance it has of hitting the piston. This will cause valves to bend and then loss of compression resulting in decreased power. Ways to get around PTV include having valve reliefs cut into your pistons, lowering compression, or possibly with an adjustable crank gear when degreeing your cams. The other thing you need to keep in mind is valve float. This occurs when the valve is bieng open and closed sooooo quickly (HIGHER RPMS) that the valve spring is not strong enough to close the valve before its time for it to open again. This will leave the valve hang open and cause the piston to smack into it, not good. I strongly recommend degreeing your cams if you put them in your self. After not doing this twice and having PTV issues both times, this is a chance I wonnt take again.

Now a few things like having a forged bottom end are good when having a motor that spins up so high, but to benefit from a stage 2-3 cam I dont think its needed. Other things to think about are is your current intake free flowing enough not to choke the motor, and is your exhaust set up free flowing enough not to create to large of a restriction. Also when changing what RPM the car makes power at, rear end gear ratio is important to make up for that low end loss. Lastly tuning will play a great role on maximizing output of your new set up and also improve the drivability abit.

I hope I've answered some questions as well as brought up some things that where missed, hope I didnt miss anything.

code3GT

Good info...my thread didn't cover everything. People just need to realize that by putting big cams in a mild bolt on 2V, they are gonna be disappointed that they don't get the gains they expected.

code3GT

Also, do me a favor and post this info in the cams thread sticky. Thanks

stonemonk9

Yup, copy and pasted, not really sure why I didn't put it there in the first place?!

03sonicgt

Would ported and polished heads and vt stage 1's be a good idea for my daily driver? I am trying to get to 300rwhp n/a.

code3GT

An excellent idea.

03sonicgt

Would that set up be the best for the money as well?? And do new valve springs do anything for performance?? I know stage 2 require new valve springs, but with new springs, would I see any gains.?

code3GT

Not needed with Stage 1's