bastarddsm said:

You want to know what cams are best for your setup, exhaustively test them all, then you can say that on this setup xx cam is better. But you still cannot make a statement that xx cam is better than yy cam by looking at the specs.

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Bastard I need to get your real name its just something about typing bastard when responding But at any rate I feel the same way about finding the right cam for your set up. Cams are important but as you stated before its just too many variables to take into consideration, no two engines are built exactly with the same specs, clearances, turbo sized, manifolds, exhaust systems ect. Therefore a cam that is right for my setup might not be right for the next man.

But, if the next man wants to get as close to my set-up in part for part then he can maybe start with the cam I am using and them go from there. I am a woodworker and never claimed to be a guru in building these engines , I am self taught and to some seem to have a caveman approach to how I do things but none the less I get results and have wowed the gurus locally with the power the car puts out.


Okay getting back to the cams I have personally found the specs listed by cams makers to be the standard and although ,according to dub are not accurate based on a can analyzer, nonetheless still to be a good indicator in lift and duration to putting the masses in right direction as to what cam to run and many have had much success with these standard. When putting together my set up I matched my cams, head flow, and intake manifold together in hopes of getting the righ combination and IMO I think I did a satisfactory job but it took a lot of thinking on my part.


The first thing I needed was to find out what my head was flowing on a flow bench. Then this gave me an idea of how this head and the bc272 would react together. Although I didn't have a means of testing the manifold I knew it needed a little help therefore I ported the heck out of it, took forever, then I put the biggest throttle body the cyclone would take, s90 70mm cyclone modified to the throttle opening 5 to 6mm increase and all worked perfect with the smaller bc 272 cams. below is my head flow sheet. the red and green lines are after porting the head.. the flow started to choke on intake side above .450 lift but was corrected with the porting. big difference also in the exhaust flow and valve velocity. As you can see the head with a different intake and slightly larger cam will show some more improvement in power and that my friend is where the jmf street and a set of 276bc will hopefully match the head flowing capacity a little better I am still waiting on stuff to get here.

I don't know why that pic didn't turn the right way

Before and After flow numbers

LandSpeed-DSM said:

Couple things.. Trap is going to be best correlated with power.. you know that.

If you are running low 10s @ 145mph you have the power to weight down, but there is much to be developed between the chassis and driver. So I'm not sure what this is supposed to be illustrative of with regard to the cam discussion.

For a setup that's objectively maxed on the turbo.. be it the compressor or turbine side, I would not expect a cam to pick up much power. Why would you? At that point it has become the bottle neck to inhale or exhale through at that, granted with enough bypass you can work around the turbine to an extent but once you have dealt with removing the exhaust as efficiently as possible.. that's it.

.

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This couldn't be more true, me for example, 133mph and only an 11.1?

Didn't net better then that simply due to suspension/spring and chassis/driver experience.
The trap was there for a mid 10 but the first 1/4 track just wasn't cutting it. Proves power really isnt everything, you need the suspension to dig, and be a confident experienced driver.

Granted I'm not near maxed and an intake would do more at this point for me then the cams I'm about to be swapping in.

urbansmoker1 said:

This couldn't be more true, me for example, 133mph and only an 11.1?

Didn't net better then that simply due to suspension/spring and chassis/driver experience.
The trap was there for a mid 10 but the first 1/4 track just wasn't cutting it. Proves power really isnt everything, you need the suspension to dig, and be a confident experienced driver.

Granted I'm not near maxed and an intake would do more at this point for me then the cams I'm about to be swapping in.

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Well stated.

LandSpeed-DSM said:

So I'm not sure what this is supposed to be illustrative of with regard to the cam discussion.

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My point was mostly looking at trap speed. People were making big power with little cams and old inefficient turbo designs. Nowadays everyone claims you need these super huge cams, billet wheel this, and not going any faster really.

It's even more silly for a street guy to run some huge cam trying to get peak power up around 8k, with our transmissions. You'd need to rev it like 11k in first and second to keep it in the power.

Like I said, if I could drop in a set of Kelfords, GSC's or whatever, and go faster, I'll eat crow. But I don't see it happening. The $500 it's going to cost to find out could net an easy 100whp if spent in another area. I mean that post by lucasenglish, only picking up 49whp going from hks 264 to GSC S2's that's a pretty big jump in cam, and the turbo was far from maxed. I'd see way less than that.

I guess what the real issue is, is that I'm tired of seeing all these vendors pushing these new tech cams, and how you have to have them to make power. It's been proven over and over again, that it's not the case. I do understand that they will make more power, but the bang to buck ratio is shit.

Landspeed, I can see in your case how it matters, your chasing records. No different than any of the guys actively racing. But for us mere mortals that are street guys, this is dumb.

Not to keep picking on ddub, but it's a prime example.
700whp on a 67mm? Why does cam choice even matter, I could spend 15min with my boost controller design and dial in a fatter power curve than he has now with some little cams.

Look at my setup. Why would I change cams? I could spend $300 buy an HX40, bolt it on and pick up 100whp, and run 140mph traps like I want. What's a set of kelfords or GSC's cost? How much would I gain.

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

bastarddsm said:

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

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I will be swapping it out here real soon. the jmf street is still 2 to 3 weeks out.

bastarddsm said:

My point was mostly looking at trap speed. People were making big power with little cams and old inefficient turbo designs. Nowadays everyone claims you need these super huge cams, billet wheel this, and not going any faster really.

It's even more silly for a street guy to run some huge cam trying to get peak power up around 8k, with our transmissions. You'd need to rev it like 11k in first and second to keep it in the power.

Like I said, if I could drop in a set of Kelfords, GSC's or whatever, and go faster, I'll eat crow. But I don't see it happening. The $500 it's going to cost to find out could net an easy 100whp if spent in another area. I mean that post by lucasenglish, only picking up 49whp going from hks 264 to GSC S2's that's a pretty big jump in cam, and the turbo was far from maxed. I'd see way less than that.

I guess what the real issue is, is that I'm tired of seeing all these vendors pushing these new tech cams, and how you have to have them to make power. It's been proven over and over again, that it's not the case. I do understand that they will make more power, but the bang to buck ratio is shit.

Landspeed, I can see in your case how it matters, your chasing records. No different than any of the guys actively racing. But for us mere mortals that are street guys, this is dumb.

Not to keep picking on d dub, but it's a prime example.
700whp on a 67mm? Why does cam choice even matter, I could spend 15min with my boost controller design and dial in a fatter power curve than he has now with some little cams.

Look at my setup. Why would I change cams? I could spend $300 buy an HX40, bolt it on and pick up 100whp, and run 140mph traps like I want. What's a set of kelfords or GSC's cost? How much would I gain.

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

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I highly doubt your powerband would be fatter than mine. But if it was what do you think will happen when I dial in my cams? So I'm not telling anyone to change their cam. I really do feel it is not all about just peak whp. All I am doing is stating a fact. Every car has a different setup goal but there may be a better or similar cam for your setup based off the real numbers at the cam over just advertised numbers at valve. That is if you are looking into getting another cam.

boost97gst said:

I want to rev to 10k on a 2l.

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How long do you think your engine will last?

bastarddsm said:

My point was mostly looking at trap speed. People were making big power with little cams and old inefficient turbo designs. Nowadays everyone claims you need these super huge cams, billet wheel this, and not going any faster really.

It's even more silly for a street guy to run some huge cam trying to get peak power up around 8k, with our transmissions. You'd need to rev it like 11k in first and second to keep it in the power.

Like I said, if I could drop in a set of Kelfords, GSC's or whatever, and go faster, I'll eat crow. But I don't see it happening. The $500 it's going to cost to find out could net an easy 100whp if spent in another area. I mean that post by lucasenglish, only picking up 49whp going from hks 264 to GSC S2's that's a pretty big jump in cam, and the turbo was far from maxed. I'd see way less than that.

I guess what the real issue is, is that I'm tired of seeing all these vendors pushing these new tech cams, and how you have to have them to make power. It's been proven over and over again, that it's not the case. I do understand that they will make more power, but the bang to buck ratio is shit.

Landspeed, I can see in your case how it matters, your chasing records. No different than any of the guys actively racing. But for us mere mortals that are street guys, this is dumb.

Not to keep picking on ddub, but it's a prime example.
700whp on a 67mm? Why does cam choice even matter, I could spend 15min with my boost controller design and dial in a fatter power curve than he has now with some little cams.

Look at my setup. Why would I change cams? I could spend $300 buy an HX40, bolt it on and pick up 100whp, and run 140mph traps like I want. What's a set of kelfords or GSC's cost? How much would I gain.

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

Click to expand...

It sounds like we are more or less on the same page.

Rarely will it be the cam that is the "limiting" factor in a turbo build.

I agree completely with the example of your car doing street/strip duty.

That unless you stepped up a full frame size (67mm+) it wouldn't necessarily be "worth it" in terms of $/HP with that 54mm already moving more air at greater boost and rpm than most thought was probable (myself included to be honest)

Though I will say that it's something that one can use to shift where in the rev-range the bulk of your torque will reside to suit their preference.

Imagining my turd as a street/strip car.. I certainly could run this HX52 on a stock cam or your HKS272s since we're talking about them, but it would certainly be leaving a lot on the table.

For her size she hustles into boost (super tall gearing to thank for some of that) and I'd still have plenty of usable power from at latest 5-7.5k rpm, but with the cam falling off so fast and so early it wouldn't really make sense. Not to me at least.

Granted my bias is towards cars that scream through to redline without perceptibly falling off, lag be damned.

I think part of your observation on cars today with "bigger" setups going slower could be explained by these parts making it easier but the tuning and setup retain the same learning curve.

The guys that ran 20Gs into the bottom 11s back in the mid 1990s on HKS VPCs were the meticulous sort that were going to make the most of anything they had.

Now we've made the procedure for making what is realistically a ton of power very easy. But as we know that is only a part of the game.

This was sent to me from a Cam Company


It's not that cam companies are being dishonest about advertised duration as it is just on these engines everyone lists the specs at the valve. The rocker ratios add anywhere from 14-18 degrees to the advertised and duration at .050. It all depends on the ramp speed of the profile and the rocker ratio. I have seen the rocker ratio vary from 1.7 to 1.73 thru the years on the DSM.


The fool proof way to degree cams on the DSM is the lobe center method as then you know the lobe is on the correct center


From what I see even then the numbers are still off.

bastarddsm said:

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

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It's will be interesting to see the difference! Swapping out the cyclone for jmf street.

Sweeeeet do you ever plan to move to the 64mm compressor

urbansmoker1 said:

Sweeeeet do you ever plan to move to the 64mm compressor

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No plans at the moment. 62mm has been more than enough for the streets. Lol

Any updates?

Yeah, I bought a set of Kelford 272's and the car went slower....They were a huge dissapointment, no increase in airflow, Idle quality went way down, and it isn't even lumpy.

It's like if they aren't gonna pick up airflow, they should at least sound good...

Anyone want to trade for a set of real HKS280's?

bastarddsm said:

My point was mostly looking at trap speed. People were making big power with little cams and old inefficient turbo designs. Nowadays everyone claims you need these super huge cams, billet wheel this, and not going any faster really.

It's even more silly for a street guy to run some huge cam trying to get peak power up around 8k, with our transmissions. You'd need to rev it like 11k in first and second to keep it in the power.

Like I said, if I could drop in a set of Kelfords, GSC's or whatever, and go faster, I'll eat crow. But I don't see it happening. The $500 it's going to cost to find out could net an easy 100whp if spent in another area. I mean that post by lucasenglish, only picking up 49whp going from hks 264 to GSC S2's that's a pretty big jump in cam, and the turbo was far from maxed. I'd see way less than that.

I guess what the real issue is, is that I'm tired of seeing all these vendors pushing these new tech cams, and how you have to have them to make power. It's been proven over and over again, that it's not the case. I do understand that they will make more power, but the bang to buck ratio is sh**.

Landspeed, I can see in your case how it matters, your chasing records. No different than any of the guys actively racing. But for us mere mortals that are street guys, this is dumb.

Not to keep picking on ddub, but it's a prime example.
700whp on a 67mm? Why does cam choice even matter, I could spend 15min with my boost controller design and dial in a fatter power curve than he has now with some little cams.

Look at my setup. Why would I change cams? I could spend $300 buy an HX40, bolt it on and pick up 100whp, and run 140mph traps like I want. What's a set of kelfords or GSC's cost? How much would I gain.

Same deal for Kelton, change that damn cyclone, and you'd make more power with smaller cams.

Click to expand...

I stated in a post I made not to long ago It was a boostleak why car only made 693whp at 29psi....but because of the cams it pulled like a freight train and the hp and tq never fell off. So even with the leak the car was still faster then other cars making similar power. The 1/2 mile is a perfect example. cars making 25-35psi at or before 5.5k and were much slower then me or I was within 1mph of them. and back then with the boost leak I was getting 4.8psi at 6.5k. Now still on Comp Turbo 67mm and where it stands I really do feel I'm make around 1000whp at 38psi and its on a low timing rich base tune. What cams did you run before the kelford 272? just going to a cam doesn't mean you will just go faster...even if you make more peak power. Every setup responds differently to mods. its all about setup. But this the first i've heard of swapping from a smaller cam to kelford 272 cams and not flowing more air.