Results 21 to 30 of 49
Thread: Chevy HP/Torq
03-24-2014, 06:36 AM #21
So you are going to compare different displacement engines and try to make a point? It didn't get made here. It still is not something to brag about that taking the engine to such a high RPM to reach max torque is admirable. Especially since the vast majority of people never operate their engines at those RPMS, even when working them. So, the typical vehicle owner has to deal with roughly 20-25% of unavailable torque compared to the numbers that the OEM's brag about and print in their glossy brochures. And the numbers are thrown out like marketing tools anyway and mean nothing. "our pickups beat the others in hp". Well they might, but it really is only a marketing tool and nothing for the consumer, because very few consumers operate their vehicles in the 4000-5000 rpm range it takes to get those hp numbers, while going to work. And GM really had no intention of people operating at those high of RPM's. After all, they stick stuff like 3.08 rear ratios in pickups along with double overdrive transmission gears. So it is all disingenuous clap trap about what these engines are.
Now you take the heavy commercial trucks, they are designed and spec'd so that during normal daily operation, they are at their MAX torque band consistently. So when the OEM says that their engines have a max torque of whatever, they mean you actually are going to be in that max torque band day in and day out and be able to take advantage of it, and it was designed to be that way. Not like a typical auto or pickup engine that the only real time anyone is going to operate it at max torque is if they put it on a dyno. That is the general beauty of inline engines. The meet their max torque usually at rpms that are more in line with what people will operate the engines on a daily basis. This is the primary reason, though not the only one, I have never cared for V engines. But since inlines are not offered as an option in pickups nowadays, then we are stuck with the V's.Hey there, VA, what do ya' say? How many vets did you kill today?
03-24-2014, 02:32 PM #22
Point was mainly that all you guys are bickering about max power being reached in the 4200 rpm range, which is where all the truck companies land for max power. A secondary point being that Ford claims much higher numbers with the 5.0 than chevy does with the 5.3, but the 5.3 actually puts out nearly the same numbers on the low end than Ford actually gets in the max range.
03-24-2014, 07:58 PM #23
I'm a 5.3 owner and was a Ford tech for four years. Ford has always built a good pickup as has GM. I F'ing love my 2011 GMC, it has it's ticks and taps as we used to say. As for RPM range and HP/Torque bands. You must except they design these drive lines for more than one type of owner use. As important as we may feel our use of that power plant is, the most useful is the broadest spectrum. I know the grass always looks greener but can assure you the guys on the Ford forums are flaming the hell out of the blue oval for sub par programing on the ecotech that has guys getting worse real world mileage than some V8's. Don't believe me do some Ford spying on a Ford forum. There is also blue oval guys pulling their hair out over bad injectors and a **** storm of arbitrations going on right now. I know first hand, my brother-in-law is one of them. 2012 took a dump and now his dealer, who took the truck off his hands after tearing the motor apart. When I say took it apart it's not an exaggeration, the stripped that bitch down. Now his 2013 is sucking gas like a pro stock car, that and the dread stutter under full throttle. Believe it guys everyone has issues. I can deal with fussy lifters on a 5.3, and if you want a 1500 and need more torque because you use it in that direction all the time, change the cut of the cam. It's not crazy expensive and there are several profiles that are AFM friendly and tow/haul specific. More tedious? Yes/no. More expensive or bigger pain in the ass than re gearing a front and rear diff? I don't think so. 5.3 lower end is solid as hell, if you need a different profile cam, it's vary do-able.I am a American solder, I am a member of the finest fight force on earth, I am the bump in the night. I will defend the United states of American Against all enemies both foreign and domestic. Repent now all those who would do my nation and it's people harm; For when we come it will be too late.
2011 GMC Sierra SLE, Z71 with 5.3 l and max tow/haul package
03-24-2014, 09:14 PM #24
But perspective is everything, so lets keep it all in house with GM engines, and do a little comparison to days gone by. I know I am showing my age somewhat by doing this, but it is what it is.
Let's start with the classic GM inline engines.. the 250 and the 292. Both solid, reliable engines. The 250 reached it's max torque at 1800 RPM. The 292 reached its max torque at 1600 RPM.
Inlines not a fair comparison? Ok, I can cotton to that, so let's take a look at two very solid GM small blocks, the 283 and the 327, which are basically the 4.8L and 5.3L of today in size. if anyone thinks these engines were slouches, they never owned one.
The 283 V8 reached it's max torque at 2600 RPM. How does that compare to 4200 for the 5.3L?
Still not fair? Ok, the 327. It had several incarnations, including a fuel injected high performance version for the Vette, but we will stick with the most common variety, a typical 327 with a 4 barrel Rochester carb on top. The 327 had a max torque of 350 ft lb, virtually the same as the 5.3L (328) has today. But the 327 hit it's peak torque at 2800 RPM! Now, pray tell, how is it that the 5.3L cannot do the same thing? Seems like someone dropped the ball in Detroit.
This is why the small block GM engines had such great reputations back then. The were working motors that would knock the socks off anything around. Easy to work on, a host of interchangeable components, strong as an ox. Great low end torque and fuel mileage that wasn't much different than today's 4.8L and 5.3L. And you didn't have to rap out the engine like you are on a track at the NHRA Nationals to get max torque.
As I am sure we all know, torque is the working part of the engine. When you are pulling a heavy trailer up a grade, it is torque that gets you up and over. Most people will operate in the 2000-3000 RPM range when driving down the road with a trailer. You will rarely see anyone running 4000-5000 RPM yanking a trailer down the road. The older small blocks I referenced, did their best work right where most people run these small blocks. Not true today. I contend that after almost a half century, GM has really screwed the pooch on their small blocks. And saying that everyone else's engines are similar... man, that is really lowering the bar. So since everyone else is mediocre, then mediocracy is now a good thing?
No, the engines now are barely even in the same league as the older engines. And that is my point about the 5.3L needing to almost hit the ceiling on RPM's just to get max torque. Just because it is now also the standard deal with every other OEM brand of engine, does not make it admirable. It just makes it as mediocre as everyone else's engines. Sad day that this is now the new standard. GM has done some really good things with the design of their vehicles, but when it comes to their engines, makes one wonder what they have been smoking in R&D for the last 40 years.
But there is hope! Someone woke up from their stupor at GM and now they are testing a great platform, the EBDI 3.2L. Just from what I have read about this design, it is going to really destroy anything out there if GM follow thru with it.
Out of that Extreme Boosted Direct Injection (EBDI) 3.2L, they are getting an equal amount of HP and Torque that the 6.6 Duramax Diesel puts out! And getting better mpg as well. They are currently testing these in some 3500HD trucks. It is designed around E85! Yeah, that nasty ethanol that gets lousy mpg. Well, when you properly design an engine around the fuel, you get different results. Nice thing is, this engine will compete quite favorably with the pickup diesels, will not need SCR or DPF like the diesels, will be lighter and cheaper to make as well! Now we're talkin!
03-25-2014, 02:41 PM #25
I run that nasty ethanol and lousy mpg e85 in my 2013. I wouldn't say that these gas engines hitting their max output in the high rpm range is a good thing...its junk. But the whole automotive industry is based around hp numbers and highway fuel mileage. Thats why our 2013s rarely ever see even a 3.73 rear end. Thats why we have afm engines that GM knows are not right yet and still have all kinds of oil consumption problems. It's all a numbers game anymore, but the numbers they are after arent the numbers people who actually use their trucks need.
03-25-2014, 04:26 PM #26
03-27-2014, 12:27 AM #27
Yeah, that nasty E85 comment was made out of pure sarcasm. I regularly use the stuff in my pickup when the price variable makes it cost effective to do so.
One thing I am reminded of about these newer engines. I remember watching one of the Star Trek movies, where they were stealing the Enterprise. The new Excelsior star ship was about to give chase, but conked out. The screen goes back to Scotty talking on the Enterprise where he says... "Aye, the more complicated they make the plumbing, the easier it is to stop up the drain!" I can't think of a better saying to put on a sticker and paste where anyone can see it when they open the hood of one of these newer pickups.
It is truly sad that GM has had almost a half century from the heyday of the 283 and 327 small blocks to really turn these engines into the envy of every other engine manufacturer on the planet. But, the unions and the government got involved and now we have what we have. Good thing these folks were not around when we were in WW II. We all might be speaking German or Japanese by now.
Overall, I really like my 2013 Silverado. It has some very nice qualities. But outside of the fancy creature comforts and such, it can hardly be called "state of the art". Compared to the other brands, it is a very good pickup, but that says more about how all of the brands have not really moved much forward either. And it is also sad that some would actually think that since the 5.3L meets the same low standard the other engines do in where it develops it power band, that it is a good thing and everyone should get all sorts of warm fuzzies over it.
Nope can't do that. I owned those previous engines and loved them. I grew up tinkering with Chevy small blocks and thought they wrote the book on how an engine should be. Actually the first Chevy small block I got my hands on was a 265 V8 in a 1955 Bel Air my dad owned, so I have put a wrench to all of them, clear up to a 400 V8 in a 1974 Pontiac Catalina I owned. It really is a let down to see what the small block is today. But then, I have the same problems with diesels of a decade ago and diesels of today. Seems like the OEM's are doing just about everything they can to screw up good stuff.
Last edited by Cowpie; 03-27-2014 at 12:47 AM.
03-27-2014, 07:37 PM #28
2008 Purple LTZ Crew Cab
03-27-2014, 08:32 PM #29
I think, like myself, j cat was just comparing to engines of the past. Anyone that is honest would have to admit that the TSB's flying around and problems cropping up dwarf the percentage of engine issues with engines of the past. You just can't pile on more stuff in the engine and expect a better outcome. Simplicity is the mother of invention. Makes me wonder if Ed Cole, the developer of the original GM small block engines, were still alive, would he be as accepting of the new designs and complexity as some on the forums are. We'll never know.
But there is something in the water in Detroit that makes those folks have to tinker with things. They can have a great component or design, no matter the OEM brand, and they just can't leave things alone. Almost as soon as the first production version roles off the line, they are back in R&D and trying to tinker with the design. This is evident bumper to bumper on late model pickups. Some things are more reliable and just plain work well when they are left alone. I never grew fond of CV boot type front axles. I always felt a 4x4 should have solid front axles. They hold up much better and are more reliable, for those of us that actually get our pickups dirty on a regular basis off road. But the OEM's know best.
And while they are fiddling with stuff and making it more complex and more prone to down time, they are overlooking proven stuff that would actually be a benefit. Air suspensions on the back come to mind. Commercial semi trucks have been using air ride suspensions for over 2 decades. 3rd party sources have air bag kits that one can put on their pickup. Yet the OEM's do not even offer it as an option or as part of a HD towing package.
It is this stuff that gives me no confidence that the OEM's have any real clue about the real world these pickups live in.
03-27-2014, 08:55 PM #30
they are telling you what you want, and what you need, rather then asking. ive said it for years, any of the big 3/4 could make a killing doing a any option, any package deal. I know some government regulations come into play, but still. and I agree with Cowpie, seems to me the engines of 20 years ago where much better. even the 5.7 was better about low end power, not revving to 4000+ to build power.
as for Solid front axles vs. IFS, different strokes for different folks. i think the 2500/3500s should be SFA, like dodge.
air ride suspesions should be an option from the factory as well IMHO.
2011 GMC Sierra SLE 5.3 Z71 4X4 Stealth Gray Metallic / 2004 Chevy Impala LS 3.8 Cappuccino
Tow mirrors - Diablew Tuned - Flowmaster Regular 40 - Ready Lift 2.5' lift - BFG LT A/T K/Os - Carr Light Wing - TruckLite LED lights - Optima Red Top - 50% Front Window Tint - Line-X bedliner - Airaid MIT - Tekonsha P2 - ARS Billet Grill - Fia custom fit seat covers
Tags for this Thread