Camshaft in a week, your guess at dyno numbers

[4RD H8R]

I agree with everyone that headers WILL improve the power and performance after the cam, especialy with a larger cam like I am installing. It might choke things down so much that it doesn't make much more power. I understand what Ted is saying. He has definitley built bigger, badder engines than I have. I have however built and raced a lot of cars. With that being said, I still want to give it a try if for nothing else that to see for myself. My gut just tells me that it will be ok. The other obstacle is I just dont have the extra money laying around to buy headers right now. In a perfect world I would also be installing a underdrive pulley and a few other things all at the same time but like most people I have a limited budget. The good thing is that with the install and tuning from the shop, they will retune for additional mods for 12 months at no charge. So other than not reaching it's full potential, it really isn't going to hurt anything and we will all get to see a before and after dyno of untuned vs tuned with cam. And when I go back later, we are really going to see just how bad the manifolds are. But I still think thay are close to shorty headers.

[JANNETTYRACING]

Originally Posted by 4RD H8R

I agree with everyone that headers WILL improve the power and performance after the cam, especialy with a larger cam like I am installing. It might choke things down so much that it doesn't make much more power. I understand what Ted is saying. He has definitley built bigger, badder engines than I have. I have however built and raced a lot of cars. With that being said, I still want to give it a try if for nothing else that to see for myself. My gut just tells me that it will be ok. The other obstacle is I just dont have the extra money laying around to buy headers right now. In a perfect world I would also be installing a underdrive pulley and a few other things all at the same time but like most people I have a limited budget. The good thing is that with the install and tuning from the shop, they will retune for additional mods for 12 months at no charge. So other than not reaching it's full potential, it really isn't going to hurt anything and we will all get to see a before and after dyno of untuned vs tuned with cam. And when I go back later, we are really going to see just how bad the manifolds are. But I still think thay are close to shorty headers.

Instant gratification can be hurtful, and Patients is a Virtue.

Actually it Can hurt your engine, Reversion is a Mean thing to engines.
You have to see it in person to appreciate it.

The entire intake manifold will be coated with Exhaust Soot.

I will give you a good example that happened here a few years ago.
Cobra Kit Car, 500 Cubic in all aluminum FE V8, 625 Engine Dynoed HP built by a very reputable engine builder, The cam card was included.

Engine is in the Car now with headers and side pipes but too small for this engine, the overlap on the cam was too much to deal with the back pressure.

Car made 321 RWHP and watching it make a pull on the dyno with no air filter was Amazing, there was a Cloud of Fuel Above the carburetor during the pulls from the exhaust reversion pushing the fuel up out of the carb.

I dropped the side pipes so it had open headers, and it made 522 RWHP and the cloud was GONE.

Restrictive exhaust and big cams Don't Mix.

Ted.

[4xchamp]

What are the specs on your cam ? The cam I did that with was a 226/242 but seriously , I really felt the addition of headers and high flow cats when I passed 4500 revs .

[4RD H8R]

Not 100% sure of the specs as they are not officialy public. This however is what I found after a quick forum search here for the specs.

235/245 @ .050, 642/608, 111 LSA

While I agree that headers will make a power difference, I find it hard to believe that there would be a signifigant enough restriction to cause engine damage. I can understand a 500 inch carb. motor with huge overlap having a big enough problem to cause what you described (I had a 406 sbc with enough overlap that without a race carb it would overscavenge the cylinder and run lean with a 1050 dominator jetted so rich the car wouldn't even idle). Were using a car with a carb. relying on a fuel metering from boosters and juts to a programmed, fuel injected car tuned for this particular setup. That's a little apples to oranges don't ya think. I know you are light years beyond me when it comes to these car, but do you really think I will hurt the motor because I don't have headers with a big cam?

[mikeSS]

i would ask around if you are worried. your shop said it would be ok, Ted said its not a good idea. i wish some more shops would reply to this thread giving there thoughts.

[4xchamp]

That's a pretty big cam , luckily you have a stick . A good tune will be in order and headers next .
I'm guessing that cam could make upper 400s rw with the right bolt ons .

[THE EVIL TW1N]

Originally Posted by 4RD H8R

Not 100% sure of the specs as they are not officialy public. This however is what I found after a quick forum search here for the specs.

235/245 @ .050, 642/608, 111 LSA

While I agree that headers will make a power difference, I find it hard to believe that there would be a signifigant enough restriction to cause engine damage. I can understand a 500 inch carb. motor with huge overlap having a big enough problem to cause what you described (I had a 406 sbc with enough overlap that without a race carb it would overscavenge the cylinder and run lean with a 1050 dominator jetted so rich the car wouldn't even idle). Were using a car with a carb. relying on a fuel metering from boosters and juts to a programmed, fuel injected car tuned for this particular setup. That's a little apples to oranges don't ya think. I know you are light years beyond me when it comes to these car, but do you really think I will hurt the motor because I don't have headers with a big cam?

Not sure how possible that is since Jets don't affect the idle on carbbed engines because you are still just using the idle circuit. You can essentially remove the jets and leave it like that and have "mega jetting" or whatever and it still won't affect idle. Sounds like maybe u needed to do some air bleed tuning as well especially with a dominator. My 1150 3circuit gave me headaches before when I first started tuning it. these carbs can be finicky sometimes since these carbs were originally designed for max power at wot and high rpm off throttle.

[4RD H8R]

OK, the results are in from the cam install. There is a time when you have to eat a little crow and say you were wrong. For me, that time is now.The car went on the dyno before the cam and tune and made 412hp/415tq with cats, x-pipe, flowmasters and a CAI intake. After the cam and retune the car ended up making 423hp/408tq. Power below 5K is down across the entire powerband. I was going to go to the track tonight and see how it runs but wasn'table to make it. I am guessing the car will slow down a couple of tenths and pick up maybe 1 mph. I'm still not sure how much I would have picked up with the L/T instead of the cam, but I really wanted to try this and see. Headers will be on the car soon, I just have to go rob a convenience store or something! The guy at the shop seem to think there will be a MAJOR increase with the power after the headers and I agree (or this G6X3 cam really sucks LOL!). On the positive side, the car sounds pretty damn wicked at an idle now!

[csjcsj]

Sound clip please!!!!!!!

[twopigz]

If you're on a budget may I suggest XS power exhaust/ full exhaust (3") from headers (1 7/8) to tips roughly 850.00 Shipped. I love mine and sounds awesome.

[csjcsj]

OR hit Ivan@southwestspeed. His Doug Thorleys are like around $600 or so shipped! I like mine!

[csjcsj]

Originally Posted by twopigz

If you're on a budget may I suggest XS power exhaust/ full exhaust (3") from headers (1 7/8) to tips roughly 850.00 Shipped. I love mine and sounds awesome.

So your saying $850 for headers and catback????? Wow!

[mikeSS]

Originally Posted by 4RD H8R

OK, the results are in from the cam install. There is a time when you have to eat a little crow and say you were wrong. For me, that time is now.The car went on the dyno before the cam and tune and made 412hp/415tq with cats, x-pipe, flowmasters and a CAI intake. After the cam and retune the car ended up making 423hp/408tq. Power below 5K is down across the entire powerband. I was going to go to the track tonight and see how it runs but wasn'table to make it. I am guessing the car will slow down a couple of tenths and pick up maybe 1 mph. I'm still not sure how much I would have picked up with the L/T instead of the cam, but I really wanted to try this and see. Headers will be on the car soon, I just have to go rob a convenience store or something! The guy at the shop seem to think there will be a MAJOR increase with the power after the headers and I agree (or this G6X3 cam really sucks LOL!). On the positive side, the car sounds pretty damn wicked at an idle now!

i think on top of all that, your dyno reads a little high. a lot of people here are making 415WHP with headers, and you are making 3 less WHP with just high flow cats. thats a little off IMO. even with your tune, i still feel its a little off

now you made 13 more HP with the cam, and lost TQ. that would make me pretty mad. when i added my cam, i gained 40WHP, and like 35WTQ. its time for headers my friend.

[4RD H8R]

How much if any "massaging" did your headers need for clearance? I just got a quote back on some and will probrably ordering some later today. Just wondering how big of a hammer I will need?

Originally Posted by twopigz

If you're on a budget may I suggest XS power exhaust/ full exhaust (3") from headers (1 7/8) to tips roughly 850.00 Shipped. I love mine and sounds awesome.