Upgraded cams without headwork??

[Sleepy1]

After some consideration, I think I have my mind made up that I will keep the car N/A and try to make the best of it. I want to do some cam work (either VT or SHM), but what kind of gain difference will there be between port/polishing the heads versus not? Will I be disappointed without the head work? Do you think I will need a custom dyno tune afterwards? Thanks for the input.

 

[Bone Racing]

get a mild cam and u will be very happy

15rwhp at least

 

[Sleepy1]

I was hoping to get a little more than that because final cost will be at least $1k.

 

[MrMorden]

Yes, you will need a tune, to get the most power. VT cams have made 25+rwhp on NA cars. I made 51rwhp with HP billet cams on my blower car, with no head work.

 

['96&'01Stang]

 

[WRXracer]

yeah

you could see like 25 HP but id get the vavles done while your at it too..

 

[Sleepy1]

Does anybody have any actual before and after dyno graphs? I know there is another thread going on about the same thing, but I am also interested in head work.

 

[WRXracer]

oh

there is something in a mag but most make 50 RWHP if you do everything..

 

[lopey4.6]

You will definetly need a tune.

 

[Yellow4.6]

A friend of mine made 298rwhp and 342rwtq w/ Fox Lake stage 2 heads and a stage 1 cam w/ just minor bolt ons. Yes you need a tune! I'd just go w/ a nice stage 1 cam. you'll be happy! If you go w/ a stage 2 then you'll have to change your springs as well.

 

[Sleepy1]

What kind of difference is there between the stage I and II? Springs are only $189 so really no big deal. After 20k miles the stock ones start to soften up anyways, so replacing them would be beneficial.

 

[Sleepy1]

On the VT website, it shows dyno graphs only making power above 4-4.5k rpm, while the Comp cams says their effective range is between 2.5-5.5k rpm. Does anyone have some info on where the SHM are effective?

 

[MrMorden]

On the VT website, it shows dyno graphs only making power above 4-4.5k rpm, while the Comp cams says their effective range is between 2.5-5.5k rpm. Does anyone have some info on where the SHM are effective?

Any time you go with a hot (Stage II) cam on a 4.6L car, it will move the power band up. Our heads only really get flowing well above 3000rpm, and that's where the cam will increase your power by adding lift and/or duration. A mild Stage I type won't move your power band up as much, but it also won't make the same power.

Go with a good Stage II cam and do the springs while you're in there. That way you can move the rev limiter to 6500-6800rpm and get more power at the top end.

 

[Sleepy1]

By moving the rev limiter up, are the stock pistons/rods going to be okay? This might be a dumb question, but I don't know. Are the chances of spinning a bearing greater? I change my oil every 1k miles (I know that is probably a little excessive), but is the motor spinning too fast at those rpms?

 

[Sleepy1]

Nobody has any info on this

 

[MissBlondie]

After some consideration, I think I have my mind made up that I will keep the car N/A and try to make the best of it. I want to do some cam work (either VT or SHM), but what kind of gain difference will there be between port/polishing the heads versus not? Will I be disappointed without the head work? Do you think I will need a custom dyno tune afterwards? Thanks for the input.

Mike... I asked a guy who builds engines for VTEngines this and here was his response...

"No prob Jill,
It's gunna be totally up to his budget, but he will see gains from just a cam swap with stock heads. Our stage 1's gained 22 rwhp peak-to-peak on stock heads and our stage 2's gained 29rwhp peak-to-peak and 50+rwhp at 6000rpm. This was on a completely stock 2000gt! Heads and cams together should get you close to 75+rwhp peak-to-peak, depending on tuneup. Cams will get you the best bang for the buck initially if funds are a concern."


HOpe that may help a little...

 

[Sleepy1]

Thank you very much. You can always count on Blondie.