Z28Wilson

Did you read PacerX's response or did you just choose to ignore it?

redzed

What was I thinking? I always though that GM had done a remarkable job in giving the LS1 a strong exhaust burble on start up and a refined engine note while cruising. I can appreciate some sound to go along with V8 fury, but after an hour or two on the interstate it gets annoying.

The F-bodies had remarkably little sound insulation for modern cars. Considering that some "refined" cars are carrying around 50-150lbs. of mastic, this might be why the F4 remained fairly light. As the LS-1 Z28 progressed, they even removed some sound deadner. It wasn't because of customer demands for more noise, but because the underhood sound insulation pad became discolored after an engine was steam cleaned. That, and it saved a little cash.

That brings me to the SS, a car that was louder than a modern Ferrari. The SS was the only Camaro that wasn't imported to Europe, despite the fact that this parkage would have increased the car's appeal "over there." The problem was that the SS could never have passed EU drive-by noise restrictions. Interestingly, the C5 Corvette didn't require any modifications to pass European sound testing.

In any case, I can't put down any manufacturer that tries to make a car a bit quieter. What I can criticise are "improvements" that are just plain annoying. The rotten F4 "skipshift" is one example of a silly fuel economy measure, but at least it could be disabled at a cost of less than $40 bucks. I doubt that the reinvented
4-6-8 will be so easily defeated.

PacerX

"I can appreciate some sound to go along with V8 fury, but after an hour or two on the interstate it gets annoying."

That's cool. But please realize that many of us WANT noisy. I drive around with an uncapped cut-out and drop a couple of gears when going under bridges because the car sounds positively EVIL.

You might not be the target market, but I'll bet you a dozen doughnuts that if the choice in a poll of owners was a couple of dBA in intake noise and 10hp versus a quiet motor and less power the 10hp and the noise would win every time - by a bigger margin than Reagan b!tchslapped Mondale.

Lots of folks have made lots of cash selling us lids bro.


"The rotten F4 "skipshift" is one example of a silly fuel economy measure, but at least it could be disabled at a cost of less than $40 bucks."

Yeah, skip-shift is annoying... but you have to realize that the feature granted you "X" more horsepower. For how much everybody b!tches about it, you can defeat it for a pittance, or ignore it entirely by holding 1st gear for a little longer. That's a good trade in my book if it got me 25hp. Heck, I'd take it for 10hp.

The afternoon I picked up my car I installed the skip-shift eliminator. Took me longer to figure out where to put the jackstands than it did to install it.

Maybe in the next generation of T56 they can just give us a switch to defeat it. We could call it the "Evironmentally Disasterous but We Don't Give a Damn" switch, although I think they'd have a hard time fitting all that lettering on the switch bezel.

Maybe we could just have a pictograph of a rain forest being clear-cut or something.



"I doubt that the reinvented 4-6-8 will be so easily defeated."

Betcha Harlan or someone like him already has that one figured out. All you'd have to do it interrupt the signal that activates it, and I bet it is frighteningly similiar to the skip shift solenoid.

Z28Wilson

DOD sounds like it will be completely computer-controlled, which means you can bet the farm that aftermarket companies will be coming out with software/resistors/Hypertech-style devices which will eliminate it if you really want to.

R377

Boy, did I get here late . Picking out some random points to comment on (sorry, I'm too lazy to quote the author).

1. Firing order is indeed a large concern in the balancing of an engine. That's one reason the LS1's firing order was changed from the SBC days, because it improved the engine's smoothness. Also, evening out the power pulses is the only reason engineers go to all the bother of splitting the crankpins on a 90º V6. They certainly don't do it because they love watching the pistons tear themselves up after being installed offset in their bores (in the case of V8s converted to V6s).

2. Designing an engine for use on premium fuel is nowhere close to being cost efficient. Premium fuels costs 10-15% more, and you'd be lucky to see a 2-3% increase in fuel economy in normal driving. Why? Because knock is rarely a factor in normal driving, so the computer doesn't retard timing, so power is not diminished, so no more fuel is required. I run nothing but regular fuel in my LS1 unless I know I'm going to the track. I'm willing to sacrifice the little bit lost power at WOT (the only time when you'll notice reduced power) to save $5 or more per tank. As to the detergent properties of premium gasoline preventing carbon build-up, well, where I come from the gas companies by law have to put the same additives in regular fuel as they do in premium. And even if they didn't, an ocassional can of Seaform is both cheaper and more effective.

3. The LS1's tortured intake is not a marketing decision, it was necessary to comply with noise laws. GM certainly did not want to make it that way.

WERM

If you think converting GM's whole line up to run on gas that costs 20 cents more per gallon is risk free, you need to take another look.

Another thing to consider - maybe many people who never bought cars with V8s (or even GM cars) before will buy them now because they will be very fuel efficient, very powerful, and run on plain old regular gas. Plus, many might think "V8 on demand" is pretty freakin' cool, you know - V8 TEC. VTEC, eat your heart out.

Maybe this technology will allow V8's to exist another 5 years in the market place. Maybe we'll finally get low sulfur gas, so that Gasoline direct injection can finally be used. Maybe the'll combine it with ever more durable CVT's. Maybe they'll just say F*** it, now we can make the damn DOD engine 15% larger. Maybe GM will gain market share...

A lot of history begins with failure and ends with success. A lot of people sat around and said "that'll never work" (Unfortunately, history tends to forget those people). Thing's have changed in the past 20 years. GM is a better company now than in 1982. Maybe they can make it work this time.

eyeguy2005

I presently own a z34, and yes have put some money into keeping the car running, but it's a very strong engine regardless of what you guys are talking about. Run 89 octane and have now for 6 yrs and the damn thing starts evertime I need to get somewhere. Oh, and lets not forget that the old freaking Ford T-Birds, not a chance. Have taking two of them but could never get those damn volkswagen vr6's. Anyhow, I think some of what you guys are talking about, the trannie, are right. The engine may have more power than the trannie can't allow and the result is problems with it, around 95,000.00. But, I've maintained mine and it runs great. Now, my old girlfriend had a 2000 z28 and that damn thing was guick, not anywhere near the lQ1 could go, but come on, it's a v8 right? GM has made some great strides, just waiting on the 2005 Monte with the V8 lS1 and then there will be some talking.

Jason E

In response to an earlier post, I agree...the 60 degree motor, while raspier than a 3.8, sounds sooo much meaner. I have on the lot right now an '01 3800 Camaro with a Borla...sounds VERY ricey over 4 grand. Now, I used to own a 2.8 '89 Camaro RS that I actually convinced 3 kids one night that it was a 350 it sounded so good

I hate to see the 3.8 go, but seeing as how I have owned and loved 3 60 degrees, I'm glad to see my motor sticking around

PGR

D.O.D. starts and idles on all 8 cylinders, and only drops down to 4 cylinders during light throttle situations, such as cruising and very light acceleration. I would expect that it reverts back to 8 cylinders during decceleration, in order to maintain normal compression breaking.

In 4 cylinder mode, GM's D.O.D. maintains an even-spaced firing order, firing every 180 degrees, vs. the 90 degrees for 8 cyl mode. In terms of power output, it would be just as smooth as any inline 4 cyl. engine. Inline 4's vibrate due to mass imbalance, not firing order. D.O.D. will not have this problem.

In 4 cyl mode, D.O.D. requires a larger throttle opening for a given rpm and load, which reduces pumping losses, and increases volumetric efficiency.

If D.O.D. was such a bad idea, Chrysler would have stuck with their original 5.7 OHC engine plan, instead of the Hemi 5.7. D.O.D. is relatively cheap to add to a pushrod engine, but can be cost prohibitive on a OHC engine. Ford is so set on OHC, one wonders what they will do to complete with GM and Chrysler.

I for one would welcome D.O.D.. 90% of my driving is just cruising. 8-25% better fuel economy is a great selling point for any car, truck or SUV. A 5th gen with 300+ hp AND 34mpg. Not bad. Or how about a Suburban or Hummer with 25% better fuel economy.

The technology for D.O.D. is actually quite simple and proven (micro-proccesor control and hydraulic lifters). The Caddy V 8-6-4 was an great idea way ahead of its time. Sometimes the best ideas are old, failed ideas revisited.

IZ28

Yup, concerning sound the 60* V6 is to the 90* like how the SBC 350 is to the LS1. The 60* and the SBC 350 just sound alot better.

You'd never know 4th Gens had the power they have if you went by sound. (LT1's were too low stock but sounded better than the LS1) Its almost laughable that I've heard low powered V6's and 305's sound better than a 360HP "346." They need to do something about that for the 5th Gen. And make some engines that have good sounding names too, 346?!

PacerX

"1. Firing order is indeed a large concern in the balancing of an engine. That's one reason the LS1's firing order was changed from the SBC days, because it improved the engine's smoothness."

That wasn't what we were arguing about, or at least wasn't what I was arguing about. Firing order is certainly critical to balance, but what is not critical is the size of the "bang" in the individual cylinders. In effect, you would have to have a dynamic mechanical counterweighting system to cover those variations - that's not going to happen.



"3. The LS1's tortured intake is not a marketing decision, it was necessary to comply with noise laws. GM certainly did not want to make it that way."

Please note that for the last year of production a lid similiar to all of those we have on our cars was offered as an option by SLP on SS's. Noise laws were not a consideration or GM wouldn't have been able to sell it. Besides, we're talking about intake noise here and not exhaust noise. In the Federal "Drive By" test the major consideration is exhaust noise, not intake noise.

It was a marketing decision, and a bad one at that - at least in my humble opinion. Let the V6 cars and Corvettes worry about intake noise, as long as it doesn't whistle or buzz. Serve my next Camaro SS (if there ever is one....) with a full plate of "Giant Sucking Sounds" and a side of Cowl Induction please.


Here's one other thing that will probably put me in the minority...

I think the LS1 sounds better than the small block.

Why? Well, every time I hear a loud small block I think "motor boat". Since GM dominates inboard motors (usually through MerCruiser), the signature sound of a boat with an inboard motor is small/big block Chevrolet.

I forget the exact cylinders in question, but there is a funny way that the small block Chevrolet fires from bank to bank (and within one bank) that almost sounds like a stumble. I generally notice it more at part throttle, and think they sound great full out - but it is definitely there.

LS1's always sounded smoother to me, and less like a MasterCraft.

3800's do sound raspy. Especially in cars like the GTP or Riviera or SSEi. Almost flatulent.

Just another worthless opinion on noise...

redzed

A big objection to DOD remains the unbalanced inertial forces created by the non-firing cylinders. As of yet, I've never seen a coherent explanation of how a 4-6-8 style engine would deal with this important refinement issue.

However, I can agree that the LS1 was a far smoother engine than any previous small block. I'm still amazed that GM was able to reconcile a fairly agressive cam with a smooth, low RPM idle. Sure, the old LT1 had more character, if you consider a slight tendency to misfire/backfire on downshifts characterful. GM took traditional OHV technology about as far as they could with the LT1, and then dramatically redefined the limits of the that technology with the LS1/LS6.

From where I stand, the LS1 remains a great comtemporary powerplant because of its simplicity and effectiveness. Heck, they even made it remarkably fuel efficient. That's precisely why I resist all of the unneccessary 4-6-8 complexity. If Ford resists this sort of "innovation" with their OHC V8s, I might be far more inclined towards FOMOCO products in future. Sure, normally aspirated Ford V8s aren't world class in terms of output, but they sure are reliable.

Z28Wilson

Here's an idea, why don't we all wait and see how these engines perform prior to forming an opinion. For whatever reason you have a big problem with DOD without any of us knowing all of its traits and how it will perform in the real world. For now, I will place some faith in GM Powertrain that they've developed this technology to be efficient, reliable, and smooth-operating. The way I see it, this innovation puts GM ahead of every auto manufacturer on the planet in terms of powerplant technology.

redzed

I'm sure in favor "wait and see" when it comes to DOD. Even if one these 4-6-8 concepts is passable when it comes to my first testdrive, I will still wait at least 2 model years before I'd ever consider buying one. Considering past history, you really have to wonder about all of the durability ramifications.

Of course, the rub is that my purchase of a new "everday" car is rapidly approaching, and I'll probably be forced to buy before GM's DOD is proven in the real world. As much as I've enjoyed GM products in past, I would gladly consider a Honda or a Toyota these days. Even Hyundai and Kia are becoming reasonably safe choices for reliable transportation. I've also heard wonderful stories about their excellent warranty service, all the way from the dealer to the corporate level. (This compares with the grief my family got from the local GM dealer. Thank god my Camaro never had a problem.)

There are alot of choices in todays market, and most of them have less potential for grief that a GM product with "cutting-edge" innovations that nobody ever asked for.

WERM

If you ask people if they would like 8-25% better fuel economy with no loss of performance and a cost of only $100-$300, I bet most would say yes... especially SUV owners...which drive the most profit at GM.

I doubt DOD has more "potential for grief" than any other multivalve engine with variable valve timing, drive by wire, or any other 'cutting-edge' technology. Can you tell me why DOD is supposed to be unreliable?