Oh I get it SilverSurfer; You think Aussies are all just toothless “retarded” “Mad Max’s” who drive on “long straight roads” with “no innovation” caught up in some “ridiculous” “competition” to see “who can stick the biggest cam in an LS1”.

Here’s a postcard of my “Mad Max” country town which I reside in, work in, and travel over 60 miles a day in during peak hour bumper to bumper traffic with my 600+rwhp LS1 powered daily driver work hack truck on XE-R lobes FWIW.




With all your open mindedness, perhaps you have you missed some of the testimonials? For example;



I have read all of this thread totally and it contains some very useful information for folks who are really interested as I am. However, very little regard has been given towards the tuning of engines with the various camshafts mentioned. Tuning the engine for drivability and performance is probably the most important factor when selecting a camshaft design for street/strip use. Without a doubt many of us have witnessed some good and not so good tuners within this world of LS1’s. Indeed some may battle for months to make a small camshaft behave in an acceptable manner, whilst others have no problem in getting some of the larger camshafts with tighter lobe centers to behave like stock and all within minutes of adjusting the original PCM correctly via the tools which are currently available. I’m dwelling on this correct tuning point a little as I feel it is very important and seriously goes hand in hand with the many layman perceptions of various camshaft experiences shared not only within this forum but also within the realms of street talk. We only need to drop back a couple of years, prior to some of the more correct OEM tuning availability we get to use these days as with some of the tuners abilities approaching these LS1’s at this time to realize the ever slow moving creep towards camshafts that once were considered ridiculous . I, as many in here would remember the days when any LS1 camshaft with a duration of more than 220 coupled with a lobe separation tighter than 114 was considered full race and no way street able, let alone a realistic choice for the new car owner. Interestingly though, these days in the hands of a good tuner, these little cams are not only considered easy to tune but in many circles, pollution compliant. What happened there? I’ll tell you in one word…. TUNING.


With regards to some of the Australian cars getting around using larger than main stream camshaft designs with stock displacement 346ci engines, just bare in mind some of theses larger camshaft cars employ the use of 8 separate throttle body intake manifolds tuned in speed density and TPS. These manifolds have tuned length intake runners, tuned on both the engine and chassis dynamometer for various capacities as with selected uses for certain applications such as weekend circuit work as not everyone over here is into the measurement of straight line performance over the ¼ mile.


In an area as large as the USA, Australia, we only have a hand full of drag strips available however, with our heavy GTO style cars, running 10” slicks through IRS we have seen a few N/A 346’s consistently running high 10’s with 125+ mph trap speeds and still they are daily drivers with a 4 cylinder Japanese motor bike like idle at less than 800 RPM and the throttle response to match.


SilverSurfer; Next time you’re sitting at the stop light, chewing on that Big Apple of yours with your steady fillings, spare a thought for some of us open minded Mad Max’s of this world who are driving daily and enjoying the benefits of learning, testing and understanding stuff.

 

I see frequently where (paraphrasing) "good tuning makes a big cam idle like a stocker". I have a 232* cam, and while I am not a professional tuner, I have a hard time believing that anyone could make it idle at 750 and sound like a stocker. "the secret is in the tuning". Ok perhaps, but what is the secret? I have studied this thread and do not recall having seen that. You only have two variables, fuel and spark - the rest (cam, heads, compression, etc) are constant. What is the magic you work with those two variables to make "a big cam idle like a stocker"?

 

I agree critter, you can only tune sooooo much.With a carb set-up there are tricks such as drilled butterflies,airbleeds,etc. but with fuel injection your airfuel ratio and your spark curve is about it.I think Silver Surfer may have offended Plan B and the guys down under although he didn"t mean to,his point was that if it don't work over here how could it work over there????260 duration and 104 LDA is not a street cam,thats huge!That would be huge in a race only car.Also I think there may be a few shops (in the USA)that can tune an LS1, do you think???Check out the new HPE S cam and its 115 LDA,completly opposite from the narrow LDA cams from downunder. This will go on for a while longer I'm afraid!!!!!

 

OK…. Remember though, this is what I said…

That was what I said and I’m certainly not offended, because I read and expect responses like this;

And this;

Honestly FASTONE and critter….. You blokes are OK in my mind but realistically, show me someone within your field of experience who can report the same set-up as what I have previously stated and I’m certain our stories will correlate to a tee.

Lets take a look at some little itty bitty production performance vehicles as an example;


2004 SUZUKI GSX-R 1000 possesses the following camshaft profile

VALVE LIFT .384 .360
DURATION 272° 252°
DURATION @ .050 248° 242°
LOBE CENTER 104° 104°

What do these stock bikes idle like? They are only tiny little engines too and I bet my ***** if the designers and tuners wanted to induce more standing bottom end torque, the lobe center would move prior to the duration. Or if the RPM limit was to move up a little, you’ll see the lobe centre move again prior to the duration. Just take a look at some of the after market camshafts available for these things and you may get a better picture.

Perhaps referring to high end production small engines isn’t relative, though, I’d rather talk about engines before air pumps and certainly look at the larger picture before I stated engines with a capacity of 500cid +.

As a suggestion, for those who are interested, grab one of these cheapish multi cylinder production engines such as the 2004 SUZUKI GSX-R 1000 and try to make them idle nice through a shared common manifold controlled by one single throttle blade and I’ll see you on the other side of 3,000 rpm.....

Now what do we get with a 5.7litre V8 LS1 utilizing 8 separate TB’s? I know the answer regardless of what others may imagine.

In saying all this, there is really nothing wrong with a common manifold throughout the entire rev range providing it was designed correctly in the first place as LS(*) manifolds are to a point…. Typically, there is nothing to gain peak horsepower wise and at “wide open throttle” between the various designs with lower horsepower levels. Though, the idle and tractability is as smooth as silk with separate throttle bodies… I guess, this is why BMW, Porsche, and many other high end transport producing companies use em…… On a daily basis!

 

Actually this all make very good sense to me.
By syncronising the ICTB's one can make sure all cylinders are running an equal amount of air, thus eliminating variables.
Look at the cams we have today in the US market. I remember a little more than 2 years ago when a 224 was the *****, top of the cam chain.
Having had some experience myself with single Webers on SBC's, we were able to run much larger cams and CR than 4 barrels or twin 4 barrel setups. The bitch back then was holding the syncro together as the Webers were capricious to say the least (Which didn't make them ideal for street setups.
Nowadays, things are very different with new tech and 25 more years experience.
Come to think of it, I would love spending 2 months down under and getting some maf-less tuning experience amongst other things within the LS1 community there.

 

I wasn't referring specificly to you - only to the fact that we have these claims of success with big cams that idle like stockers, but no one seems to divulge the secret(s). Also note that I did not say impossible, just hard to believe in my experience.
Well, it has been a long time and I no longer follow the crotch rockets, but as I recall our Z1 idled pretty much like my LS1 only at 1200 instead of 900.
OK, so you are saying the secret to getting a "big cam" to "idle like a stocker" is individual butterflies? The reason being what? Pump back due to late intake valve closing doesn't couple from one cylinder to another? At first blush, that does seem to make some sense. Pete Jackson makes an LS1 setup but I don't know cost and it would require serious hacking to work in my Y2K Z28. Lot of fun to get an air cleaner on too ... I would be willing to give it a try if I could afford it.

However, as I said earlier, I wasn't referring to you as much as the guys who get big cams to idle without a blade per valve.

 

I am not a "credited Fuel injection tuner" but i will say recognizing the condition changes a large duration overlap cammed motor exposes to MAP, MAF,02's, and PCM logic, is the key to getting stable, clean idle quality.
For examble, is 14.7 ideal A/F at idle speed for this type setup, probably not. Next recognizing effect reversion has on MAP and MAF, is the key to compensating tune of them for consistent, predictable, results. Mixture and timing can affect combustibility of exhaust contaminated intake charge at idle and low speed. Intake valve margin top cut treatment can also help to minimize exhaust dilution into intake port. I can see how this type of combo can be tamed, I think it only helps us all to have such a wide range of cam and power options for Ls1 and other EFI motors, thru others hard work and determination.

 

Here is something for you cats to chew on. I met Pete and all his mates while I was in Australia. I almst ended back there for another 4 months which would have been a hoot (but thats another story). Anyhow, I saw these cars on teh dyno. I drove them around, etc... So I'm not speaking as someone taking a SWAG at this. I have seen it with my own two eyes.

Here is a video 242/242 106 LSA 105 ICL idling @ 875-925... I know, I know tell me how his filling are about to fall out...

http://users3.ev1.net/~black_ops/video/242-106.mpg


I wanted to also say that in talking about some of the VE's that Sam is picking out, they happen to jive with some of the stuff a few other folks have found to be what the LS1 like. So, before you say the Aussies are smoking crack, you might want to give them a little leeway.

BTW, I promise Pete and all his buddies have all their teeth.

I think that you will find that they run a lot of symetric profiles since that works well with the intake systems a lot of these cars are running.

Also, a lot of the stuff they run is Ls1 headed since LS6 heads don't come on anything down there. So before you knock anything from down there, understand they don't have 5.3L 6.0L or Ls6 heads, just LS1. As Pete said, a lot of the cars running down there are 3600 lb full weight Monaros. So going an 11 in one is pretty decent if you ask me.

As for what is "old school" and what is not. Just about everything in your motor is old school. The oldest hydraullic roller setup I have personally seen was in a some of the old Cadillac V12/V16 stuff. So, its not like hydraullic roller is something that just showed up in 1988 for the first time.


Anyhow, the thing that I saw which I thought we might have been past, but some folks who have read bits an pieces of this thread (and not all the right bits) is not to look at just one point on the cam, and also not to look at one point on a dyno graph. Don't just look at lift @.050 and in addition, don't look at only peak HP on a dyno graph. You can look at some of the turbocharged import cars out there with a dynograph like a ski jump. So, what does that get you, 600 HP and a 13 second timeslip. Again, it looks good on paper.


The idea of this thread is to get some people to start thining about what they are doing. Some of these cam manufacturers are making you cams because you beat down the door wanting the biggest cam out there because you think its going to make the best power. Folks are clamoring for the biggest lobe they can possibly get on a stock headed stock bottom end motor, and these folks are more than happy to oblige you. I don't fault any of them for giving you EXACTLY what you are asking for. But, the point is, is what you want and what you need the same thing? My point here is that chances are if you know what to ask for, and have a better idea of what you really need instead of the "bigger is better" you can go faster. again, the idea of building smarter, not necessarily bigger.

Folks still won't get off thiniking about LSA as being some magic number. How many times does it need to be said that LSA is a byproduct, and not the target. Figure out the right valve events for your motor and the VE is what falls out the bottom. Lets just go from smallest to largest. If you take a MTI T1 on a 114 and a G5X3 on a 114 what do those cams have in common. The answer is nothing. Yet folks seem to have this idea that 112 and 114 are some magic number. 112 and 114 are not the holy grail people.

Lets go back several pages and try some of this again, as folks seem to have forgotten. Ok, we'll start with a Z06 cam which has a good idle, and then go from small to large keeping the 114 since everyone gets hung up on 114 as being whats required to get a car to idle.

2002 Z06 Cam 204/218
IVO 19
IVC 43
EVO 42
EVC 4
ICL 120
ECL 115

Generic 224/224 114/+4 Cam
IVO 2
IVC 42
EVO 50
EVC -6
ICL 110
ECL 118


Big standard split 232/240 114/+4
IVO 6
IVC 46
EVO 58
EVC 2
ICL 110
ECL 118


Ok, so lets diverge just a bit...


Australian 242/242 106/+1

IVO 16
IVC 46
EVO 48
EVC 14
ICL 105
ECL 107

Now, is any of this making sense to you? Do you see that even though LSA stays at 114 the valve events move around? How about this, maybe this will help you. Lets pretend for just a second that you decide that you want to keep IVC and EVO the same, but you want to make the cam "bigger".


224/224 114/+0
IVO -2
IVC 46
EVO 46
EVC -2
ICL 114
ECL 114


230/230 111/+0
IVO 4
IVC 46
EVO 46
EVC 4
ICL 111
ECL 111


242/242 105/+0
IVO 16
IVC 46
EVO 46
EVC 16
ICL 105
ECL 105

Can you see that as the cam gets larger, and keeping the same valve events forces LSA to change.

1. So in summary motors don't "like" a certain LSA, people spec'ing out cams do, motors just like correct valve events.

2. Bigger isn't always better.

3. Not everyone is Australia is a toothless Road Warrior with a leather fetish, and a thing for big choppy cams.

4. Picking one point on a cam (.050) , or one point on a graph (peak HP) isn't the key to going fast.

 

IMO, the best 45 words in this thread. Unfortunately, it's probably falling on deaf ears. Keep that message going, J.

 

Hmmmm...

This all sounds SOOOOO familiar... Ain't that right Jarrod

Guess even a "Mustang" guy (as PSJ refers to me as. ) can actually make some sense too...

Ed

 

Old SStroker -
Not all ears are deaf ... there are a few of us here who appreciate and (more or less) understand the lessons.

J-Rod
Refresh us - is it mainly IVC that controls "idle quality"? IIRC, it was shown that overlap has nothing (or maybe little) to do with it, and that the major contributor to poor idle is the pump back into the intake from the late IVC until you get enough velocity/inertia to keep the mixture trapped until the intake closes. If so, this ties it up neatly. The Aussie 242 is only 4* later with IVC than the US 224 and the same as the big 232/240 split, so idle quality should be no worse than the big 232/240 and not much worse than the 224.

 

Wow J-Rod, that car is really impressive! Definitey more docile than I would have though.

 

Critter,

Actually I don't IVC is too important for a plenum car and it's also not all that important for an independent runner car either. Overlap is by far the biggest killer of idle vacuum and quality on both.

The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.

With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.

Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.

 

Huh. I wish I could remember where I read that it is a common misconception that the lope at idle is caused by overlap. The argument (IIRC) was that there is not enough pressure on either side to cause much air movement in either direction at idle, and if anything you have the a large mass of air moving out of the cylinder into the exhaust and you have air stacked up behind the valve waiting to get in, so you get flow of unburned gas out the exhaust. However, when the piston is rising and you don't close the intake until 45* ABDC, you have the means to pump back into the intake. All that seems to make sense, but at the moment I can't see why that would cause poor idle. Maybe the author was full of ****.
Yeah, that is what I thought and what I alluded to several posts up, but perhaps for the wrong reason (IVC instead of overlap).

 

This is good thread on cams,I don't think badly of the guys down under as most would agree they have had the ls1 longer then we have and have done a lot to further its developement and power output.I don"t think the comment about the Australians and their cams was meant to downgrade them in any way or to tag them as uninformed or as Madmaxes as stated we just don"t see those cam specs as ones that will work with the ls1 we have as streetable.
Good point J-rod on the valve timing events as being whats important and not LSA, I can agree with you on that but the LSA is what changes those same timing events therefore the hang up on this LSA is relevent to a good cam.
Also I don"t get your point about the BIG cams that everybody wants to stick in their car as being stupid or uninteligent while you try to get us to buy these narrow LSA #"s and huge duration figures.Not trying to argue with you just trying to get your point Also you say that the wider LSA cams have a narrower torque band and peaky hp numbers,I don" agree.This holds true on say the bigblock Chevys as well even on the Big cams.I would like to see an accelaration test on a dyno to compare engine response from one rpm to the next with different LSA"s that might prove interesting and imformative too! Of course the dragstrip would prove what works the best anyway!I agree with a lot of your info but not all, don't take it personal and keep it coming.

 

Critter,

At low rpm with a true load or anotherwords with the throttle OPEN at least some or all the way you are actually CORRECT since the manifold's pressure is now raised HIGHER than at idle where it is always LOWER. At IDLE you have the pressure difference going the WRONG way since the throttle blades are CLOSED and the manifold pressure is LOW or in vacuum compared to the exhaust system and chamber which is always HIGHER than atmospheric (otherwise exhaust wouldn't be flowing out of it and into the atmosphere).

At this point air (exhaust) is stacked up against the intake valve with HIGHER pressure but from the wrong side (chamber side instead of the intake port side) or reverse direction and waiting to go UP INTO the manifold where the pressure is much LOWER instead of the reverse like when you are on the gas. This is exactly WHY you lose manifold vacuum with more overlap since with a smaller overlap cam you are pulling air MORE through the carb or throttle body instead of filling it up with exhaust reversion from overlap or at least LESS exhaust reversion or EGR.

When you are cracking the throttle or cruising though the engine will clean up since now you have re-pressurized the intake plenum's pressure and the reversion stops and so do the misfires and the engine changes tune and starts pulling.

 

Yea, I noticed that too. J-Rod goes down under and he goes from talking about how everyone's putting cams in LS1s that are too big to a wild mega godzilla cam toting LS1 hillbilly with a big knife and hat! He's like "Cam Dundee" now or something! Talking crazy talk and putting 270@.050 cams on a 106 LSA in street cars and such! Australians are crazy crazy people but they are also real men with real cams! No girl scout cams for these guys!

 

I think I explained that up above. I went to Australia several months ago, when I came back I posted inof related to it in this thread. Since then I have posted in other threads, and then this one got resurected.

Just so we are clear. I posted the info on the cams they are using down in Australia to show that a car can run on something other than a 112 or 114, that a 106 or a 108 when coupled with the right valve events can get the job done.

I'm not advocating a 273/273 104LSA/103ICL for everyone, but likewise, I am alos not advocating 234/234 117LSA/113ICL cams either.

Again, understand the central theme of this post which is properly selecting your camshaft based on properly selected valve events. That is all I am trying to get across. Some of this other information is to help illustrate that point, and to show you some folks who are thinking outside the box. Other folks have brought Peter and my buddies from Australia back into this with comments about how undrivable their cars are. Those comments were made out of ignorance based upon a set of specs folks had never seen before, and a pre-concieved notion about what will and won't work (if it isn't 112 or 114 it just won't work). The "oh that cam can't idle" and now you have seen it idles quite well. In addition, they have cams like that runing with stock manifolds along with the 8tb setup.

I explained up top that even though the cam they are using in that one video I shot is a 242/242, if you look at the lobes, the cam is pretty small. If you look at the .200 duration, the lobe is small, plus the cam is mid .500's in lift. So, even though @ .050 it is a much milder lobe than a XE or XE-R lobe.

Ok, I drive a pretty extreme Z06, its one of the faster H/C in the country. In the CFM thread I posted my head flow numbers, and both Chris and Ed posted how they would design a cam for most folks based on those head flow numbers.

stage 2.5 heads



Here are the numbers Jay gave me on the heads we are running.


AS LS6 225CC

Intake None LS6 LSX
.050 - - -
.100 69 - -
.150 - -
.200 155 152 154
.250 - - -
.300 212 204 208
.350 - - -
.400 259 243 251
.450 280 260 269
.500 301 272 280
.525 - - -
.550 313 281 290
.575 - - -
.600 323 293 299
.625
.650
.700

Exhaust
.050 - - -
.100 - - -
.150 - - -
.200 117 117 117
.250 - - -
.300 160 160 160
.350 - - -
.400 206 206 206
.450 213 213 213
.500 222 222 222
.525 - - -
.550 228 228 228
.575 - - -
.600 231 231 231
.625 - - -
.650 - - -
.700 - - -








Thats based on a more max effort street car.
4.10 gears
McLeod Dual Disc (Now Exedy Dual Carbon/Carbon)
LSX intake
90MM TB
LGM long tubes (32” primaries) with 3” exhaust (no cats)
Meziere Electric water pump
Comp 977 Springs
Comp R lifters
Stock rockers
G5X3
Jay’s heads

Rev limiter is 6900-7000 I shift the car at 6600 – 6650.



Transmission is an M12

M12 -
2.97 1st
2.07 2nd
1.43 3rd
1.00 4th



I’m going throught the traps at 124-126 (its been as high as 128). I’d like to be able to run 130 or so… After 130-131 we’ll have to switch to a 3.90 most likely.

Best 60’ is 1.42 (average is about 1.44) best ET @ -300DA was 10.671

Peak HP numbers are 501-503 RWHP / 455 RWTQ


If you get into what we are doing with Tommy's car and rev'ing the car to 6900-7000 and shifting @ 6600 , with Chris' cam, you end up around ~240 degrees of duration, on Ed's cam I dunno Ed doesn't give out cam specs. The cam above he posted was on a "milder" setup in a heavier car.



Now, as for which valve event is better, I guess I need to go pull all the opinions folks have about which valve event is more important and post it up. Seems that there are several schools of thought on this.

 

BTW, I know we discussed how different the dynos (Australians use Dyno Dynamics, we mostly use Dynojet) we are using differ also. I found this which counterpoints this....

https://ls1tech.com/forums/showthread.php?p=1451419

Here is a DynoDynamics run from a Z06 Vette with a Remapped ECU:

329.9whp recorded on a modified 405bhp car (which is more than likely making about 420+bhp)


Same here, look at stock numbers: 323.7whp (20% loss)
with a different throttle body, intake, thermostat and Remapped ECU it made 345.9whp (~435 corrected brake horse)
Different dynos give different numbers[/QUOTE]

Here is my dynojet graph:




So, 323-329 on a stock Z06 on DD vs 350-360 on a DynoJet... See, the Aussie numbers ain't that bad...

 

LOL! You give me way too much credit, Erik! I am just a dumb hick quoting something he read. It isn't like I actually understand this stuff

But, I agree. What you say makes more sense than what I read, and I no longer remember where it was or who was the author, so I can't offer proof that it is not my memory that fails. Perhaps he was writing about off ilde, as you say the theory is true there. Getting old is hell