Of course. However, the point of this thread still holds. I am not trying to give people the information to design their own camshafts. That won't happen. I'm trying to give them information and knowledge to make better decisions.

 

I love this post Denz...
I will get ahold of u and possibly come up to your neck of the woods to flow my heads later in the yr.
Then you'll get me a nice grind for my setup

Erik I agree with u to a point but we arent talking about max effect trailer queens.
We're talking street/strip LS1 cars,If I wanted one of those I'd build a 2700lb glide equipped S/B car

 

Like I said if you want good low end performance because of a tight converter and/or taller gears you need a larger engine and/or smaller cam but the weight of the car doesn't really change that. You gear or converter the car for the way the engine runs. You don't have to run smaller cams just because your car is heavier.

 

I assume you mean s/b = small block? I'd build the same deal with a big block and smoke you!

 

"You don't have to run smaller cams just because your car is heavier."

I never said u did,But when talking about a heavy car I still say more tq over a broader range is better.The truth is most people overcam an engine when they couldve gotten the results going smaller.

U better look at some of the S/B with the 15/18 degree stuff.There making SERIOUS hp,Granted the BB is still IMO the way to go but the little S/B can hold its own

 

I think folks are missing the point again. You put the right camshaft in for the purpose. In the LS1 world, people over-cam all the time. That is why so many end up with high stall converters and stump puller gears. They can't generate enough torque to get off the line and accelerating. These folks aren't building Pro Stock cars, they are building heads-up street/strip cars. Considerably different animal.

Half of the problem on this board is the mixing of race and street/strip. Someone builds a peaky race engine and then the heads/cam guys think they can do the same thing on the street.

For example, the latest 500rwhp 346. That sure as hell isn't a street or even street/strip engine. If you can't run in closed loop because you can't get a manifold signal within the granularity of the MAP then it isn't a street car. I have no idea if they claim it is, but I'm sure some street guys are going to try it.

 

Denzss I think intended this thread to give you some info to make you think. . .and have some basic knowledge of what maybe the "ballpark" you need to start out with.

If anyone is coming to the NHRA O"Reily Nationals in Bristol this weekend, I will be there all day Friday and part of Sat. If you want to meet and ask some questions I will be glad to. Not after 7pm on Friday, I will be indulging in adult beverages. PM me and I will give you my cell number. I will also have some hardcore engineers with me that have developed valvetrain and bottom end parts for the industry.

Chris

 

What do y'all think of this cam?
Duration (intake/exaust) 228/231
Lift (intake/exaust) .574/.592
Lobe Center Separation 113
Intake Centerline 110

This would go on my 01 Formula with all bolt-ons (Hooker LT's, Katech TB, ASP pulley, etc...) M6, 12 bolt with 4.30's.
I currently have a Comp XER 228/224-.588"/.581"-112

Would I see any significant gain from this cam and where would the gain be? I'm loooking for more low end torque/ overall hp.
I don't know exactly how the cam events would change performance compared to what I currently have.
I also plan on a set of Stg II heads in the very near future.

One more thing- why is it the reverse/ straight/ standard grind cams ALL work so well in N/A LS1's? I've never seen a significant difference between the different styles of cams. From what I've seen, a 228/224, 224/224, and 224/228 all seem to make about the same power on our cars (naturally aspirated of course). What is the optimum grind for our cars N/A?
Would I have anything to gain by putting the longer duration on the intake side? what would the difference be compared to a straight or split?

I would like to add that I enjoy my gears, and the 6800rpm redline doesn't bother me, but that's about the extent of how radical I want the car. I want the car to be as fast as possible with these limitations and a 3500lb race weight. I do not have to have the T-Rex for bragging rights- I simply want the most power I can get in the useable range.

 

Isn't it true that by increasing the LSA you can increase your "avg power?" IE, broaden your torque curve? So in other words, you can run a higher duration, higher lift cam with wide LSA for better driveability. Yes/no? (Perhaps this has already been addressed but I didn't want to read 11 pages worth. )

 

I agree with DenzSS. You don't want a 1 cam fits all, because it doesn't. At VHP we have cams for each individuals particular needs and using accelerated lobe lift technology on a wide variety of cams, we can give you more cam without some of those driveability issues. We were curious as to why so many people liked & recommended the 224 cams. We built a 551/551 224/224 114 cam and installed in a 98 A4 Z28 with air intake and catback exhaust. WOT was not bad and it made good peak horsepower. BUT, partial throttle response and driveability were horrible. Also, it took quite a bit of tuning to idle and to also bring back low end torque lost under WOT on the dyno.
Here is a link to our cams and specs (including overlap) and we can also build custom grinds. http://www.vincihighperformance.com/...AGE%20LS1.HTML

 

Yeah... I kinda noticed this too...

Sounds vaguely familiar... ... Where have I heard this before?

Wow... I got in trouble with some "people" for saying that!

There's that word again... ACCELERATION

Absolutely!

That's why "combination" is so important. Leave the ego (dyno numbers) at the door. No fun in a 450 hp "dyno" engine that's slower than a 375 hp "engineered" powerplant...

In my dumb-*** opinion, the success or failure of these dual purpose cars really depends on who is doing what with which parts. From what I see in this forum, people live and die by the infamous "dyno number" instead of actual track results. Yeah I know, "I don't have a racecar" or "I don't go to the track" but stoplight to stoplight is still a "track" of sorts...

Anyway..

The LSX thread from a while ago shows this viewpoint very clearly. People only looked at peak numbers and never track results. Probably because the nano-second the intake was obtained, it was bolted on and set to a dyno for testing. Good idea but not the true benchmark for whether or not the intake was successful.

I don't even want to get into the BS throw around with the latest "big cam" and "flow number" threads. That stuff has me laughing every time I read them.. Sorry.... I digress...

This misapplication of information is not "LS1 only" either. I was talking to Tony at AFR and he keeps telling me not to talk about how we go over 8000 rpm with those Ford hydraulic roller camahfts. I told him was a "race only" application but he still gets a lot of people asking why they can't do that with their street engines...

As I said previously...

Goals are all different for everyone so be sure the "shop/person" you work with "knows" this and doesn't go off on a tangent just to get the "hype" factor up for the shop...

Ed

 

Well, I'll take this a few steps at a time...hopefully others will jump in as well.

I'll start off with this:

If that is the case, don't make any camshaft changes or decisions until you have your heads and flow sheet in front of you. If you can, get them to flow the head with your intake attached in .050" lift increments from .100" - .650". Then start down the camshaft route with your info in front of you.


Well, the blunt truth is they are all "meh" designs. They work and produce decent power but each is flawed in its own way. What each design does well in one aspect is offset by something it does poorly in another. The net result is roughly equivalent performance. Kind of like a Fermi solution.


Do you realize that a big chunk of the LS1 community has been using only 2-3 lobe designs? That leaves a hell of a lot to be desired on the table. There are a whole lot of "will work" camshaft designs out there, but there are very few "good" camshaft designs.

The different designs are crutching different portions of the intake/exhaust process. The "reverse split" designs were implemented to work around the LS1 manifold. The single duration cams are just a "best guess" and hitting the middle road. The "traditional split" duration cams leave me wondering. I can fully understand a small crutch on the exhaust side, but these +4* - +8* crutch exhaust duration camshafts leave me wondering if the designer shouldn't have put down the crack pipe before calling Comp.

The best designs are taking care of the limitations and bottlenecks through small refinements in duration and handling the rest through lobe changes.

 

I tend to recommend the TR224 to people who are determined to just call up a shop and order a camshaft they saw on the internet. It isn't perfect, but it makes decent horsepower and torque and is relatively easy to tune. I know they are going to come to little harm using it. It doesn't need a lot of gear or converter and has good driving manners. Not the best in the world, but heads and shoulders above what is generally offered.

 

I think I thought of an analogy that may help this topic out a bit...

Ok. You've decided that you want to buy a new car. You want it to look good and it should be fast.

You have two choices. You can either:

Look around and find a car made by a mass producer like GM. It has some things you like and some you don't, but you can buy it off the lot today. It isn't perfect, but it is fun and cost you little time or effort.

Or

You can go to a custom shop and tell them specifically what you want it to look like, how you want it to handle, and how much power it needs to produce. This is going to be more expensive and take quite a bit of time from both you and the custom guy. However, you're going to get exactly what you wanted.

Canshafts are the same way. You can either grab it off the shelf and call it done or you can put a little extra time and money into it and get exactly what you want.

 

Ok we have a rough formula to point in the right direction for intake duration and that's a good start but what about the exhaust duration?

Let's say in the top example there the heads flow 280 cfm with the intake in place and we are looking at ~224 intake duration that the exhaust flows 210 without a pipe and 240 with a pipe.

How do we decide on exhaust duration?

Not knowing I would tend to stick with 224 on exhaust or maybe add 2-3 degrees for a 224/224 or 224/226 depending if I went with the exhaust numbers based on the pipe or without the pipe.

 

BTW

Say a typical heads and cam car makes ~420rwhp peak at say 6,000 rpm and ~405rwtq at 4800 rpm with an off the shelf 224 cam. On the bottom end the this set up makes 300rwtq at 2,000 rpm, 350rwtq at 2,700 rpm, 380 rwtq at 4000rpm.

What would a "custom" cam be worth in both peak numbers and area under the curve?

 

Black,
To broad a topic, what I can do is give you a % of increase on a combination specific scenerio. Denzss and I discussed one a couple of days ago and it was 11% HP and 8% torque over what was in it.

Chris

 

Chris,

A real world example of a combo with something we are familar with and the results with a custom would be very enlightening.

Thanks

BTW - How do we calculate exhaust duration?

 

Black,
Scoobie posted his Absolute Flow#'s on a thread, if we use those #'s on an 11 to 1 stock CID, will that work? You name the shelf cam and the max rpm.

Chris

 

Are those dyno proven gains or calculated gains?