Aftermarket Cams Or PI Cams

[Mustangman9812]

Hey Hey Its me again,

On a recent post I started, I am building a P&P NPI Headed Motor for my car now and on a stand I am going to building a P&P PI Headed Motor when this one goes. And I have run into a question should I spend the money on Aftermarket NON-PI Cams or Put Stock PI Cams in the P&P Non-PI heads? If there will be no difference in gains then I should put the stock PI cams in right? :idiot2:

 

[jfor441]

Don't you already have the XE274H's??

 

[Mustangman9812]

No I was about to order them but i have hit this cam selection thought here lol. I know it would be better to spend the money for later on the other motor but as far a power gain to power gain is spending $600 really going to do any better? and really I dont care to buy aftermarket cams for the other motor I am building that will be fine when i am ready for them.

edit: also bought my NOS Powerfogger Kit Back lol

O Yeh jfor441: Thanks for all the help in this post and the other you are awesome! I am just weird about things and cant ever make up my mind lol

 

[jfor441]

No I was about to order them but i have hit this cam selection thought here lol. I know it would be better to spend the money for later on the other motor but as far a power gain to power gain is spending $600 really going to do any better? and really I dont care to buy aftermarket cams for the other motor I am building that will be fine when i am ready for them.

O Yeh jfor441: Thanks for all the help in this post and the other you are awesome! I am just weird about things and cant ever make up my mind lol

No problem. If you can do a google search Project: Red headed Stepchild, it was an article MM&FF did. They were trying to squeeze every ounce of power out of an NPI motor. They used the XE274H cams and saw VERY good gains with it. Find the article and read it. The only thing different than what you are doing, is Holdner used a prototype intake he made and you will be using a PI intake. With XE274H cams you will see bigger gains than with the PI cams because you are going with heads. IMO, buy XE274H's and when you go to put in your built PI motor use the XE274H's in that motor too.

 

[Mustangman9812]

10-4 I will do it then! LOL THANKS.

 

[jfor441]

It is a great read that is for sure! Pay attention to the dyno graphs so you can see the power increase as well as the power under the curve changes.

 

[97stanger]

i think you might see maybe a 10hp increase with going aftermarket cams over stock PI cams...if thats worth it to ya then go for it! good luck with whatever you decide

 

[atrainsgt]

I've been holding off on installing my PI cams because I want the hot cam idle. The gains of something like stage II's over PI cams may not be much but the sound is worth it!

 

[jfor441]

i think you might see maybe a 10hp increase with going aftermarket cams over stock PI cams...if thats worth it to ya then go for it! good luck with whatever you decide

The cams he is looking at, Comp Cams XE274H's will be significant gain over PI cams. Especially considering he is going to Port and Polished heads and a PI intake. That combo alone I would be willing to bet would show an increase of nearly 100HP over stock.

 

[nyuk98gt]

274's will produce a lot of power BUT at very high RPM and you'll lose a lot of low end torque. You need to degree those [very aggressive] cams, too, or you'll have issues. High RPM needs a good (i.e.--built, not stock) bottom end.

If you're building a race car, built the engine and include 274's. If you want a streetable daily driver, look into Crower, HiTech, Cushman (original VT grinds), and Comp cams but NOT the most extreme versions of each make.

HTH,

Chris

 

[jfor441]

If he has the gears in the rear end then the the loss of lowend torque will be minimal.

 

[steedastang]

274's will produce a lot of power BUT at very high RPM and you'll lose a lot of low end torque. You need to degree those [very aggressive] cams, too, or you'll have issues. High RPM needs a good (i.e.--built, not stock) bottom end.

If you're building a race car, built the engine and include 274's. If you want a streetable daily driver, look into Crower, HiTech, Cushman (original VT grinds), and Comp cams but NOT the most extreme versions of each make.

HTH,

Chris

I just put Crower stage 3's in mine. It is very streetable with no issues when in heavy traffic. My peak power is at 6k rpm and my torque and power overlap at 5k. I have the stock sb with no issue's thus far. Our shortblocks can handle 6.5k in NA form. Heck i think mine has seen 8-9,000 rpm a few times from missing 3rd and going into first (wake ya up!) and i have had zero issues. Our engines have a bad reputation because many people add power adders and some reach the limits of the internals. Its pretty rare to hear of one blowing up that is still in NA form though i am sure it is possible.

 

[Brian95SVT]

I took mine out on an open road and WOT and it shifted at 5400... why? :dunno:

 

[nyuk98gt]

my96gtstang:

Shifts are controlled by MPH or RPM, depends on whichever condition is reached first. Both are adjustable in the tune (you can do it if you have a flasher or chip and the software, or, have your tuner do it for you).

HTH,

Chris

 

[Jrgunn5150]

I took mine out on an open road and WOT and it shifted at 5400... why? :dunno:

Because your poo motor is done making even a little power by then. Raising the shift point won't don anything for you but make more noise.

 

[Brian95SVT]

I need a high rev cam ahhah

 

[justinschmidt1]

I took mine out on an open road and WOT and it shifted at 5400... why? :dunno:

Because your poo motor is done making even a little power by then. Raising the shift point won't don anything for you but make more noise.

haha...he is right...my car doest pull at all after 5500....ive got mine shiftinng at 5500

 

[Brian95SVT]

I am going to hit it on the way home today and see where it shifts at WOT, I wanna make sure it does it at 5400-5500 again or if I was imagining things

Now if I get the PI cam or a crower blower cam (down the road for blower cam) will that increase where the shift point should be?

 

[justinschmidt1]

I am going to hit it on the way home today and see where it shifts at WOT, I wanna make sure it does it at 5400-5500 again or if I was imagining things

Now if I get the PI cam or a crower blower cam (down the road for blower cam) will that increase where the shift point should be?

you need a handheld tuner to adjust them...cams shouldnt change shift points

 

[Jrgunn5150]

Where it should be he asked... And yes, if you shift the power curve, you should change the shift point.