What is the point of all this? Ok so there are alot on missinformed people. Any subject I have ever searched on the internet, I have had to sift through the BS. Thats life. What is the point of trashing stupid people? I think just by reading his posts old stroker is one of the smartest people in this place, but then this. SAD. Maybe you guys should read the book How to live free in an unfree world, I think it would help you.

I don't get! I am done with this.

 

Maybe SStroker wants to discredit people who post BS. Just a thought.

 

The thing is that no matter how much we as people want an engine to respond to what we want to give it, it won't. It responds to what it wants. The technical ins and outs of what what makes certain engines repond to certain changes are huge. I honestly don't know if you could fit them in this forum.
Cascazilla answered the reason why the commonly held myth that velocity = torque is wrong. Did you completely understand what he was saying?? I didn't.

An engine is a combination of parts that work as a whole. The key is to have the best combination, not just the best parts.

Quik406, what are you through with?? I know a few of these people and they have explained alot of this stuff to me in laymen's terms that I can understand. I know I am not any smarter than you, so maybe I can relay what they told me.

 

I guess I am through with discussing HP on the net. I agree OLD Stroker has alot of info, I have learn much from him I also agree LS1 tech, is full of BS. The first time I looked it over it looked like a bunch of import tunners to me. I am a old school racer. I just don't see the point of trying to be a god and correcting so much dumb Sh*t, it will never happen you can't do it! I use to try some myself. I say just help(if you want) good people who are trying to learn. Not bash. Hell maybe it is to hard to do with all the lies. I don't know.

Agreed, but you just can't do it. The world is just to full of it! I just ignor it and race my cars, and help others if I can. What does it prove?

 

stupid? no. mis informed? yes. there is lots of stuff i do know, but i don't know everything. Every board has a wise *** who actually knows what they are talking about, but only hints at answers instead of answering them. I'm on here to learn, because all the basic stuff is boring to me now.

 

According to your profile, lxarlo, you have made 20 posts to date, not the 3 shown under your name. The only technical post was :

I checked your previous posts before I quoted you (without using your name, BTW). That gave you a chance to delete your post and your name would not be associated with it in my quote or others who continue to quote posts. I was trying to be just a little nice and give you an out.

If you are bored by "all the basic stuff" perhaps you didn't get the basics correct. In my opinion, and evidently Cascazilla's, you did not get them right.

If you are someplace to learn, the first technical words out of your keyboard probably shouldn't be something you may have heard but don't understand. If you had asked it as a question rather than stated it as a "known fact" you would have received a quite different reply.

Jon

 

actually,the basic stuff can be very interesting.as i learn more,and have an "ah-ha!"moment from time to time,i find i have to rethink the "basic" stuff..

 

There is nothing basic about hot rodding now-a-days.Except for the feeling I get while blowing someones doors off.

To inchup I would say that GM developed the smaller valves to be the most cost effective way for them to keep power up for the smaller motors.I have come to this conclusion cause they used the same intake and exhaust on 4.8 through 6.0 for the most part with some exceptions along the way.Remember that the engines are mass produced so any change can get real exspensive.

 

Yeah, it's not like they're extracting every last emissions legal pony out of a 5.3 like they are out of the 7.0.

 

I would say there is a larger % of 'emissions legal ponies' left in the LS7 than in the 5.3. The "Platform People" who are responsible for the whole car (Corvette in this case) needed 505 hp so that's what they got. They probably could have had more from the "Powertrain Folks" in the LS7 if they needed it. It isn't working all that hard @ 505 fw. Folks who modify/tweak them discovered that early on.

Jon

 

The LS7's at 72 hp/litre and at 300ish HP, the 5.3 is at 57 or so. That's a big difference in state of tune. With emissions measured at the vehicle level, the bigger engine has to be that much cleaner than the smaller engine...

Regardless, it seems to me that NOT getting every last emissions legal pony seems like an odd way of doing business... Why stop at 505 if you can have 550 from a package that weighs the same?
If the LS7 could make 550, for the sake of argument, then GM wouldn't have needed to develop the LSA at 550 for the CTS-V (And could have saved 100+ lbs of curb weight while they're at it, further improving power/weight).

Are the platform and powertrain groups really STILL that stovepiped? I'm working with Ukranian companies Yuzhnoye (design) and Yuzhmash (manufacturing) and it's crazy how much they don't talk. From some of the things I've read from you on that topic, it sounds like GM might still need to learn about integrated product development.

 

My personal take on this:

Many of the top Powertrain Folks (PF) really are dyed-in-the-wool gearheads. They want to do the same things that we like to engines, and have the funding to do so. That being said, they still have to answer to the Platform People (PP) because the company is selling a complete vehicle, not just an engine or driveline. That must be frustrating at times. It would be like an aftermarket or race engine builder holding back some of the power he could give you because you don't want more power because you are already leading the points in your class.

The PP need to make the car driveable even for the "less-than-skilled" who can afford to buy it. That means traction to put the power down, as well as driveline components which will survive for 100,000 miles on the OEM's pocketbook (warranty). EVERYTHING is a compromise in OEM vehicles.

Now if the competition threatens your grip on a certain market like where the Z06 lives, there should be something in your engine design to ratchet up the power 10-15% without a big and long development. The original Z06 (405 hp version) was ~15% stronger than the original C5 LS1.

If however you want 20-25% more grunt, and are putting it in a vehicle costing a lot more than your baseline car, some of your customers won't be enthused with the temperment of a 620 hp LS7+ engine. Being exotic also counts in this (80-100 Large) market. Enter the blown/intercooled 550 and 620 hp engine class. These are still at the "entry level", IMO. They are however matched to the vehicle. There is more to be had when the need arises. That also makes it fairly easy for us non-OEMs to make more power. I doubt that was the intent, however.

I think there is fairly good "integrated product development" going on given the size and inertia of the large OEMs. Folks like Bob Lutz have, IMO, done a fairly good job in that arena. It's easier to tame aggression than it is to instill it. That's why I like the idea of gearheads doing engines which have to be tamed rather than spurred to get the performance the PP need.

My $.02


Jon

 

I'll agree that GM still has a lot of corporate inertia and that there are probably still a lot of incompetent or uninterested managers that make questionable decisions, but Boeing is probably close to as big as GM and has done impressive things with IPD... like their recent aircraft offerings, Delta IV launch vehicle with RS-68 engine, etc.

Because of manufacturing volume, big aerospace has a much better incentive to get the first one right than automotive OEM.

Anyway... so the logic is that it's better to develop a new engine with more reserve capacity than max a current design? Again, that seems strange, especially when it adds over 100 lbs to a car that is supposed to be a lightweight sports car (CTS).

I disagree with a lot of what GM does. Fortunately LS1 enthusiasts don't have to deal with GM's utter and complete incompetence in fielding manual transmissions.

 

Volume (Cylinder) = Volume (Intake Port)

Mach Index = (Bore diameter ^2 / Number of ports * port diameter^2) (avg piston speed / speed of sound (@ STP))

 

Not to argue with you, but OEM autmobiles and passenger aricraft are vastly different busnisses. How long will we wait for the Dreamliner? It has been delayed at least 15 months from the plan, if I recall.

The current 737 is vastly different from the original. One of my buddies flies -700s with Southwest and another runs a small airline of -200s. The 737 is a lot like the SBC; it changed, grew and improved over it's lifespan as has virtually every other commercial airliner. Like an engine series, airliners are designed for a long product life. They even grow in "displacement" like an engine series, but mostly in "stroke" and not "bore".

The CTS-V is in the 2 ton class of high performance sedans. That's hardly a lightweight sports car. The competition attracts customers with multi-valve, multi-cam engines while the CTS-V is using another "exotic" route. What makes the car go is the torque curve, not how the torque is derived. It is probably easier to get the 550/550 or so with great driveabilty with the 100# extra FI system. To be a little more fair, 4-cam, 4-valve V8s are usually heavier than equivalent sized 2-valve pushrod engines.

I don't agree with all of GM's decisions in their high-performance cars, but then again, they never ask me either.

Just my thoughts. No reason for us to put on the gloves.

Jon

 

Not putting the gloves on, man... Maybe I need to use these more often Sometimes the internet makes it hard to tell what's just discussion and what's not. However, I do have thick skin, so maybe it's not the internet that does that...

I think that in terms of manufacturing process, the biggest difference between GM and Boeing is volume. At Boeing, variance in the finished product counts for a lot more than it does at GM because BA's volumes are dozens to hundreds, while GM's are tens of thousands. GM has statistics (and the fact that a problem is less likely to kill large numbers people in a very newsworthy manner) on their side.

While the businesses (margins, supplier lead times, etc) may be very different, the goal of manufacturing is the same everywhere: build it to design as cheaply as possible. I don't think things are THAT different...

Anyway... what were we talking about?

My beef with the CTS-V is that the old one was 3800# (IIRC) (less? This says the base CTS was 3500... http://www.cadillac.com/cadillacjsp/...ctsv&year=2007 ) or so, while the new one is 4200# with a stick. This is RIDICULOUS, IMNSHO.

The car's weight grew by over 500# from one generation to the next. The old car with an LS7 would have power/weight superior to that of the new car with LSA?
Something went very wrong.

 

What were we REALLY talking about?

Oh yeah... 5.3's and 4.8's have smaller valves because they have smaller bores.

:-P

 

I thought the ls1 had the same size valves but the LS6 has a bigger valve?

Did GM think they did not need specific truck engine heads and parts becuase they thought the gen IIIs were going to be so good they could just put a smaller cam in the truck versions and make really good low end torque for a truck?

 

Is this one of the reasons why all LS motors make peak torque at 4000-4500rpm? Becuase the cams are diffrent.

 

Haha thanks. I got that early on in this thread. Finally I returned to this thread amazed at how it got off tangent to the original discussion but that's fine by me. Have at it.