JS

iTrader: (4)

If I have a cam thats on a 113LSA and I install it in straight up 113ICL,Then I advanced that SAME cam 2 degree's to 111ICL what would happen to my peak HP/TQ numbers from 111ICL to 113ICL?

How much do u guys think I'd gain or lose?

Also what is opening a transverse single exhaust worth in your option on a very good breathing motor. (8 to 10RW or even alittle more?)

What is the !PS mod worth in terms of RW?

And lastly what will u lose going from a 10 bolt 3.73 to a 4.10 12 bolt in terms of RW?

Please help,I need some SOLID KNOWLEDGABLE INFO..
I'm crossing Tee's and dotting eyes and might be going in another direction with my car for personal reasons...

JS
NOT HAPPY

Scott Turvey

Your peak is going to move down the RPM scale, though the specific numbers are impossible to know as this is dependent on the engine breathing (intake and exhaust systems). Sorry if this is obvious.

Again, the same as above, but additionally, the valvetrain's ability to go high enough can affect it.

No clue here (probably what you may think of the first two answers)

Given you can equal the weight of a 10 bolt with the right parts in a 12 bolt, none. Unless you count the $$ you spend on the 12 bolt conversion.

Not trying to be a wise-*** here, just trying to point out you would need to understand the flow characteristics of the engine, plus the valvetrain's (particularily the springs) ability to handle the RPM change to answer these questions with a knowledgeable answer. Not know this, plus the other specs of the cam makes this impossible to answer accurately. In my best estimation, it will definitely kill some upper-end.

JS

iTrader: (4)

Scott there has to be some kind of loss..
U figure going from a CUTOUT to a CLOSED EXHAUST (I figure 10RW on a better breathing motor)

Also comparing a STOCK GM 3.73 10 bolt to a MOSER 33 Spline 800lb Eaton 12 Bolt I would figure it to be at least 10RW loss here too.

PS okay maybe 3RW tops...

And as far as the cam being adv and dropping power I agree but how much do u think it would drop?I thought an AUTO drag race car would like alittle more under the curve?

gomer

iTrader: (13)

I'll help where I can, On my car the cutout is worth 15rwhp over running thru the muffler ( B&B Tri-flow ), pulling the PS belt isn't worth anything noticeable on the dyno... BUT, running an electric wp and pulling the entire belt is worth 10 to 12rwhp. I've seen two cars dyno after adding a 12 bolt, one was a bolt on car.. stock H/C.. it lost about 7rwhp. The other car was a mild 224 cam'd stage 1.5 headed car and it lost about 10 to 12 rwhp.

99 Black Bird T/A

iTrader: (4)

Cut out was worth 10rwhp and ~10rwtq for my car.

Does you cam have any advance ground in?

Advancing the cam will tend to bring the power on quicker and help area under the curve. You should gain area under the curve. It will also pulled the power band down a little and probably lose some peak. The only real way to know would be to advance the cam, dyno and compare to a dyno with cam when it was straight up.

JS

iTrader: (4)

Thanks guys so I can realistically be loosing 15RW from the exhaust,maybe 2 or 3 RW from the PS and 7 to 10 from the 12-bolt.

Thats encouraging....
I might have a dead cyl according to Cartek but I'm gonna check it myself too
I'm **** that way,Julio also thinks my engine builder put the cam in 2 degrees adv and I agree with him too.The car only peaked at 6100 and it should be more like 6400.I might be loosing 5 to 7 RW peak there too?

I could be loosing 30RW and thats exactly what I thought..
Looks like I'll check the motor out this week and if Daves right then I'm screwed but if its good I'll redyno with the cutout open and possible check where my cam was installed and then redyno

Thanks....

Damian

iTrader: (89)

Advancing a cam is not going to "drop" your power level, it's going to move it.....down.

Are you saying that your cam was a 113+2, and then you advanced it again? That would put it below 110 ICL...

JS

iTrader: (4)

No the cam is 113LSA no adv. ground into it.
Cartek told me with my heads it should be put in straight up,NOT advanced.

It makes sense,U figure my power is dropping like a rock at 6100..
Julio said the cam is in wrong and needs to be in straight up,I am losing peak which is where my car is setup for----->4500 to 7000rpm..

IMO it all makes sense.
I might have to pull the timing cover and check to see where its at so I know for sure and then redyno.If I get 10RW from that and 12 to 15 from the cutout that would put me at 420RW and that would be fine by me especailly threw a 4.10/12-bolt...

Beast96Z

iTrader: (21)

In terms of advancing or retarding a cam, you are not going to gain or loose any power. Your just moving the power band. If your cam is +2 right now and peaks at 6100, installing it straight up will move the same peak power up about 1.5-200 rpms. This will also take some away from your area under the curve. So in theory, by installing the cam straight up, you will have the same peak power, just closer to 6300 rpm's. Your power could also be falling from a weak valve train. It's always good to check the pressures on a couple of springs to make sure there still in check. And like Gomer said, removing the PS is not going to show you much of anything on the dyno. No gain, no loss. The 12-bolt however can kill various ranges of power, 10-20 rw in some cases, depending on how it is set-up.

JS

iTrader: (4)

I still believe by taking the area under the curve back up I might see a few hp up top.
Julio told me the valvetrain is working flawleslly and I looked at the graph it was nice a smooth with no dips or squiggles.

I guess after I leak it down I'll need to check the cam and see if its too far adv.
I might eve go to a different cam or sell the car...

Thanks....