The LS engine thread:

[SUX2BU99]

Compared with say the 505 HP LS7, I'm not sure how docile and streetable an equally-performing SBC could be.

Not trying to downplay what you said, I agree wholeheartedly, but if it were a 500hp 427 SBC, it could be very docile, would produce much more than 470 ft-lbs, and would only need to rev to less than 6000.  Oh, and it could be built for MUCH less than the LS7 crate's price.

Very interesting for sure. What kind of cam and heads would you say are needed for a 500 HP 427 SBC?

Not exactly a great comparison perhaps but I read an article last year I think in either Chevy Hi-Performance or Super Chevy where they took an LS2 I believe it was (alum. block 6.0L) and a 400 SBC and tried to make the same power and compare the manners of the two. I think the HP goal was 450 or something. Basically the 6.0 came out very nice and smooth and the SBC was all rough and snorty like you'd figure a big cam, big valve SBC might be. Again, perhaps they could have done it up better.

Another thing I don't like about HP ratings is how factories use net ratings in OEM applications yet magazines can use pretty much any rating they choose and most of those would be considered like the old gross rating system ie. absolutely zero accessories to draw any power from the motor. Although I believe OEM crate motors use more of a gross rating. I can't seem to find reliable data though to confirm this.

[Captkaos]

I really dislike the sts rear mount kits. 99% of the sts cars I have seen run are turds from a stop.

I can assume you are insinuating lag when you type this.  If so, it is definitely not true as there isn't any noticeable lag.  All the ones we have turbo'd are definitely not turds out of the hole.  My brothers pickup does 60ft sub 2 seconds.

[eventhorizon66]

Very interesting for sure. What kind of cam and heads would you say are needed for a 500 HP 427 SBC?

Engine build #10 on the very last page of this book (everyone with the slightest interest in SBC engines should own a copy).

http://www.amazon.com/Build-Chevy-Small-Blocks-Budget-Performance/dp/1932494847/ref=sr_1_1?ie=UTF8&s=books&qid=1252633449&sr=8-1

The author compares the engine to the LS7 as a matter of fact.

[Captkaos]

Not trying to downplay what you said, I agree wholeheartedly, but if it were a 500hp 427 SBC, it could be very docile, would produce much more than 470 ft-lbs, and would only need to rev to less than 6000.  Oh, and it could be built for MUCH less than the LS7 crate's price.

But could it last 100000 miles or 6 years under warranty, be abused to death and be a daily driver and 99% of your target audience would put up with?  Probably not. 

I disagree, an old school SBC making that kind of power would have crappy idle, poor startup, temperamental to weather changes, need a huge stall and would need to turn at least 7000rpms to make the same power levels if you are talking carbs, the generaly public would reject it.

Can you make one that makes more power yes, would it be cheaper, maybe, could you mass produce it 100000 times at the same cost, no, cover it with a 6 year 100000 mile warranty knowing the people driving it are going to pound on it daily, no.

GM went to supercharging on the ZR1 and a smaller engine because the 7.0L making the same power N/A wouldn't cut the warranty period, but would make bigger power.

[jimbo]

I really dislike the sts rear mount kits. 99% of the sts cars I have seen run are turds from a stop.

I can assume you are insinuating lag when you type this.  If so, it is definitely not true as there isn't any noticeable lag.  All the ones we have turbo'd are definitely not turds out of the hole.  My brothers pickup does 60ft sub 2 seconds.

No, I can't say anything about lag, as I have never driven or owned a rear mount turbo car.  I am an avid drag racing enthusiast and have kept a keen eye on these rear mount turbos because it seemed so odd when I first saw one.  So every time I see one at the track I make sure to watch it run, and 99% of the rear mount turbo vehicles I have seen have been very sub par performers when compared to similarly built front mount turbo cars.



I do have other issues with the mounting, like the housing being exposed to water/weather, road debri, the oil system needed to run them, the ridiculous expanse of piping needed, but those are all personal opinions.

[choptop]

Oldyellers Firebird has the 5.7 LS1 in it rated at 320 hp, and it is a blast to drive. It will not only smoke the tires on the rear as long as you want to stay in the throttle, but driven normally (her driving, not me) it will get around 26 MPG. I know this car has lots more potential. Ive been told just changing the airbox lid adds substantial power. These engines facinate me. I have been reading stories about these engines and dyno charts where 400hp is easily changed with just a cam, headers, intake, and a program. You cant do that wil any stock small block and get the fuel economy and longevity, so I have to agree with Capt on the design being better. I have one going into my 86 hopefully within the next year. Im not looking for a speed demon, I want to be able to get in it, and just drive it without worrying the way I do our newer trucks. Stock they were 285 hp which isnt much, but considering the 305 at 150hp? that is in it now can spin the tires, at almost double the horsepower the truck should run great.

Stewart, you asked earlier about putting on of the displacement on demand engines in one. I have that in my 08 work truck. It doesnt make any difference. I keep up with my mileage due to business expenses. My 04 K1500 4x4 extended cab with the regular 5.3 got 19mpg at best, and mostly lived around 17mpg. My 08 with the same setup other than the displacement on demand gets the same. It shows you on the dash when it goes into the 4 cyl mode. The only time I"ve ever seen it is going down hill or letting off of the throttle. I dont see a benefit at all.

[Captkaos]

How many is this 99%?  In the beginning everyone questioned them, that was over 6 years ago.  They have more than proved themselves in my opinion and the turbo runs much cooler and keeps the heat out of the motor by being remotely mounted, big killers of performance.

You don't worry about your exhaust being exposed, or your engine being exposed currently do you?  No difference.
How can you compare 2 completely different cars and say them are simularly built.  You don't know what either driver has done other than mounting a turbo.  You can get a bigger turbo in the front or rear mount version, how can you say they are simular if one has a larger turbo, or one has a different size engine, you can't you are just speculating.

Example: We put a TT kit on an aniversary Corvette recently because the owner (an older fellow) wanted big power.  Without a tune and 5lbs of boost the car made 400hp, they tuned it to make around 525/575 on 10lbs.  The owner was scared at 5lbs and has only ran the 10lb once because it really scared him so he keeps it at 5lb all the time.

The 2000 Silverado regular cab we first put one on made 400hp with 130K miles on a stock 5.3L motor at 8lbs of boost in 2003 and was running 12.23 quarter miles , it dyno'd around 525hp/653 on 14lbs and ran 7.50 in the 1/8th.  Truck now has a stock block 6.0L with a bigger turbo and makes 490/613 on 9lbs and 606/800 on 14lb.  It is no slouch, especially for a stock motor out of a 2003 van.  BTW, the truck runs 1.6 60ft times, which is also no slouch.  They are dyno'ing it again this weekend again to get more out of it to hopefully get to the track again.

[jimbo]

You are totally missing my point.

How many is this 99%?  In the beginning everyone questioned them, that was over 6 years ago.  They have more than proved themselves in my opinion and the turbo runs much cooler and keeps the heat out of the motor by being remotely mounted, big killers of performance.

99% would be all but one rear mount car I have seen run (murillo's, although its obviously not sts)  It's probably only about ten or so total.  I'm glad they are cooler, but I don't see some of the quickest turbo cars in the nations' "performance being killed" by thier underhood turbos.

You don't worry about your exhaust being exposed, or your engine being exposed currently do you?  No difference.

There is a difference, my exhaust and oil pan are not extremely hot turbine housings or air intake piping or air filters. But once again, if both are properly setup, its just a matter of taste/opinion.

How can you compare 2 completely different cars and say them are simularly built.  You don't know what either driver has done other than mounting a turbo.  You can get a bigger turbo in the front or rear mount version, how can you say they are simular if one has a larger turbo, or one has a different size engine, you can't you are just speculating.

That is speculation on your own part, captain. I can compare them by knowing details about the cars by talking to the owners/ builders or personal knowledge of vehicles I have built or worked on.  I wouldn't say it if I was speculating.

Example: We put a TT kit on an aniversary Corvette recently because the owner (an older fellow) wanted big power.  Without a tune and 5lbs of boost the car made 400hp, they tuned it to make around 525/575 on 10lbs.  The owner was scared at 5lbs and has only ran the 10lb once because it really scared him so he keeps it at 5lb all the time.

The 2000 Silverado regular cab we first put one on made 400hp with 130K miles on a stock 5.3L motor at 8lbs of boost in 2003 and was running 12.23 quarter miles , it dyno'd around 525hp/653 on 14lbs and ran 7.50 in the 1/8th.  Truck now has a stock block 6.0L with a bigger turbo and makes 490/613 on 9lbs and 606/800 on 14lb.  It is no slouch, especially for a stock motor out of a 2003 van.  BTW, the truck runs 1.6 60ft times, which is also no slouch.  They are dyno'ing it again this weekend again to get more out of it to hopefully get to the track again.

I don't believe I ever said they didn't make power.  I've seen the dyno numbers.  I said they are unimpressive at the track.  It sounds like that 2000 silverado runs good, although I have seen an NA 5.3 swb's run mid twelves.

[Stewart G Griffin]

1) RE: the car and driver review:  the problem with these car and driver writers, and for that matter most automotive "journalists" is that i don't think they really know (or believe) what they are talking about.  Here's a car for 26K that turns a 14.1 1/4 mile, sub 6 second 0-60 time and carries 6 adults to business meetings on a daily basis AND gets 24 mpg and they think it's a loser.  Meanwhile they give the malibu car of the year?  Hello?  Aren't the malibu and impala built on the same/similar chassis?  For that matter how is the malibu's chassis that far removed from a citation's chassis?   And we all know how these "journalists" feel about the citation/X-bodys.

2) RE: turbo'ing the LS:
While this thread has taken an unexpected turn, please continue to discuss turbocharging the LS series engines as i am learning quite a bit.

[VileZambonie]

You can turbocharge or supercharge any sbc or LS. I'm still unimpressed with the LS design and that's why someone like me who is always knee deep in the latest and greatest in new technology doesn't get excited over the "newer" engine design. In my opinion GM flopped with this design. Sure there are improvements in many ways but impressive? I'm more impressed with more innovative 4 cylinder designs. I'm not knocking these engines just not enough to get excited about. I'd still rather build an old school bbc...

[Stewart G Griffin]

Yes, my thoughts on the Ls engines vs. the SBC are that the LSs are updated with improvements but they do not "blow away" the SBC;  The SBC is already a great engine---the LSs have refinements and updates and other nice touches.

We are not comparing gold to crap.  It's more like the sbc is a porche and the LS is a ferrari.  In stock form it's obvious which is the higher performer but with some mods, the porche can outperform the ferrari---because the porche is a very good platform to begin with.


2) UPDATE:  impala SS discontinued for 2010  So, i guess the impala ss haters win----for now.  This news basically means my interest in the LS engines has now virtually evaporated.  But you can still discuss them---the LS series.  And please do.

a) strangely enough, the impala ss had higher top speed than the G8.  Of course, none of this really makes a difference as both cars are canned.

i think gm is basically finished.  They need better leadership.

[Captkaos]

You are totally missing my point.

I don't believe I ever said they didn't make power.  I've seen the dyno numbers.  I said they are unimpressive at the track.  It sounds like that 2000 silverado runs good, although I have seen an NA 5.3 swb's run mid twelves.

Your point was MOST of them are slow. 
My point is MOST of them are not slow.

The ones that you are seing are are not making the same power as underhood systems.  The STS kits were made to add 100 to 150 on a STOCK motor with minor tweaking and target a broader consumer base than a specific built underhood setup.  They are completely bolt on and require nothing for installation, it is a complete kit.

If they are making big power to the tires and hooking up, it doesn't matter HOW the power was made.  Same vehicle making the same amount of power whether it be underhood turbo, rear turbo, supercharger, NA will run simular times.  How the power is made is irrelevant which is my other point

I don't think that NA 5.3L is stock nor was it being driven daily as a service vehicle during the week either, which this one was.

[jimbo]

You are totally missing my point.

I don't believe I ever said they didn't make power.  I've seen the dyno numbers.  I said they are unimpressive at the track.  It sounds like that 2000 silverado runs good, although I have seen an NA 5.3 swb's run mid twelves.

Your point was MOST of them are slow. 
My point is MOST of them are not slow.

The ones that you are seing are are not making the same power as underhood systems.  The STS kits were made to add 100 to 150 on a STOCK motor with minor tweaking and target a broader consumer base than a specific built underhood setup.  They are completely bolt on and require nothing for installation, it is a complete kit.

If they are making big power to the tires and hooking up, it doesn't matter HOW the power was made.  Same vehicle making the same amount of power whether it be underhood turbo, rear turbo, supercharger, NA will run simular times.  How the power is made is irrelevant which is my other point

I don't think that NA 5.3L is stock nor was it being driven daily as a service vehicle during the week either, which this one was.

No, one of the sts Fbodies that I remember was said to have put down in the mid four hundreds rear wheels and was running a second behind a stock internal nitrous fbody.
Most sts cars I have seen and researched are putting down good rwhp numbers, but aren't able to get good et's, they seem to run well from a roll though. Peak hp numbers mean little when compared to power under the curve, especially when drag racing.

The 5.3 was not at all stock, it had tires, cam, gear, and exhaust, + bolt ons.  But for a daily driver truck with no power adders I personally thought 12.4's were awesome.

[eventhorizon66]

Running well out of the hole is a balance between engine power, traction (tires, chassis setup, track conditions), converter stall or launch rpm (MT), and gearing.  I really don't see how the location of the turbocharger alone can be held responsible for poor ETs when so many other factors are responsible.

Jimbo: Maybe you are seeing a trend, but drawing the wrong conclusion.  Maybe the typical racer who simply wants a bolt on turbo kit won't take the time or doesn't know how to make the rest of the car work as a package.  But those who go to the trouble of fabricating an underhood system will also take the time to make the whole package work successfully and do have the technical expertise.  This certainly wouldn't be a rule, but could explain what you are seeing.  Just a thought.