Why is the LS1 so much better than a 351W?

[2000xp8]

Everyone that i see here builing up a 351 uses a crummy combo, it's like they want a 351 but they truely can't afford it.
With the right heads/Cam/intake, close to 500rwhp is very possible NA.
But you can't use old ass junk yard heads, or heads meant for a 302, that is not going to cut it. It's not gonna be cheap.

I've also seen nearly 450rwhp from a 347, which would likely make short work of the 450 in a Camaro, due to wieght differences in the cars.

 

[QDRHRSE]

I didn't read each thread although the reasons for why a 351 can't make the same amount of power as an LS1 have been clearly stated. The factor that I did not see mentioned is time. The Windsor is a derivative of a motor that was designed over 40 years ago. So now compare a High Def Plasma TV to the best black & white that they had in the early 60's....get my point. There's not much of a comparison. Every aspect of the new generation motors is better.

 

[tjm73]

Every aspect of the new generation motors is better.

I disagree. Newer does not automatically = better.

 

[69Rcode_Mach1]

Everyone that i see here builing up a 351 uses a crummy combo, it's like they want a 351 but they truely can't afford it.
With the right heads/Cam/intake, close to 500rwhp is very possible NA.
But you can't use old ass junk yard heads, or heads meant for a 302, that is not going to cut it. It's not gonna be cheap.

I've also seen nearly 450rwhp from a 347, which would likely make short work of the 450 in a Camaro, due to wieght differences in the cars.

I disagree with this. I am going to be matching up my combo and I probably won't see anything over 400rwhp if I am lucky. If you think of a better way to combo this thing let me know.

 

[tjm73]

I have been asking a few questions about how to get 400 RWHP out of my future 351W swap, and most replies were I could not do it and be emissions legal. WTF?

You should read this if you haven't already..... If a 347 can put 421 down....a 351 surely can too.

http://www.fordmuscle.com/archives/2005/10/BuildersNotebook/index.php

 

[QDRHRSE]

I disagree. Newer does not automatically = better.

Depends. In this case its computer vs old guy with protractor and compass. Metalurgy, and other materials technology, has come a long way in the last 10 years. A computer can model a port design thousands of times a second....I'm not knocking the old stuff but the new stuff is better.

 

[Dbeck002]

I really have to disagree with you. I don't know why it is but all Mustang and LT1 guys seem to think the LS1 has no bottom end grunt.

WRONG​

They actually make nearly all there torque at 2500rpm, they then have an almost completly FLAT torque curve to the PEAK @ 4400rpm where it slowly drops off.

The make more low end torque than an LT1 STOCK for STOCK.

In many ways this is half the reason they make such good high end power.



There are TWO main reasons for this. Both related.

Firstly, how HP is derived. To get an HP reading we use a BRAKE device (hence the B in BHP), this is either an engine or chaissis dyno like a Dynojet or Mustang Dyno.

HP = torque (lb ft) x rpm / 5252

So to get a higher HP number you must either:
-produce more torque at the same rpm
-produce the same torque at a higher rpm
-or produce more torque at a higher rpm

The LS1 manages to produce a lot of torque very high in the rev range (~350lb ft @ 4400rpm). The 351 may make similar torque but it will be lower in the rev range, and thusly the BHP figure will be lower.

So this is WHY LS1's produce more power.

The HOW they produce it is far more complex.

In simple terms it is a better engine (I know this is a Mustang forum, but the truth is the truth).

The key to power is efficency. The LS1 has as already mentioned very good flow rates. But more than that it gets more in percentage terms from every combustion cycle.

Light weight and low friction components play a big part, as does the combustion chamber (piston, valve position size, spring rate, size and shap, spark plug location and so on). Even the material used. Not too mention that modern engines are designed with CAD (Computer Aided Design) and built using CAM (Computer Aided Manufacturing). This all adds up to better built, lower tolorancies and fewer descrepancies. Back in the 60's when the 351w was being used such accurate manufacturing methods where decades off.

The oil and cooling system (internal engine pathways) also will help. As does modern electronic ECU's and fuel injection.

In every area the LS1 will basically out perform the 351w. But the 351 is not alone as the LS1 also out performs ANY (Ford, Dodge, GM, etc.) engines from the past that are built along the same lines.

And it doesn't stop there either. The new Dodge Hemi out flows nd out performs the LS6 in almost every area internally. And at least has the potential to outperform it in the BHP department too. And chances are newer engines yet to be released will out perform that as well.

Efficency is the KEY and always has been. That is why OHC/DOHC engines can produce a much higher specific output than a push rod OHV engine. The only limiting factor is they are usually of a much smaller capacity, so their total PEAK HP numbers are not any higher if at all. But if they produced large capcaity DOHC engines then they WOULD outperform the OHV push rod engines. An irony really.

Think about it, even the best LS1's struggle past 450rwhp and remain streetable as a n/a motor (yes of course more is possible, but at a sacrifice). So that's only about 500bhp at the engine.

It's specific output is only 500 / 5.7 = 87.7bhp per litre. Which is pretty darn good for an OHV. Many older OHV engines will struggle to make it past 75bhp/litre and still be streetable (even when forgetting about emmissions).

Yet an DOHC design will often support 100bhp/litre or more.

Image if Honda (yes I know, I know, but bear with me) made a 4.0 litre V8 out of their 2.0 4 cylinder engine.

It would be a 32v DOHC lightweight aluminium engine. With the potential of 120bhp/litre specific output.

So from only a small capacity it could produce 480bhp STOCK and emissions LEGAL.

However, there is no need for such engines so it is rare to see any actually produced.

The best I know of is the TVR Speed 12 engine. It's an all aluminium DOHC V12 7.7 litre with 880bhp STOCK LEGAL EMISSIONS on what would be 91-93 octane fuel.

It makes the new LS7 7.0 Litre C6 Z06 engine with only 512bhp look like it's 'slightly' under performaing doesn't it.


Dynamically newer technology will always win through. In the case of the 351w vs the LS1. The LS1 is the better designed engine, hence it produces the most power. But the LS1 is by no means the pinnacle of engine design however. It just happens to be VERY good and very available, especially in the USA.

Hope this helps.

Please RE-READ my first post, i was not racing a stock LS1.

Please dont explain what horsepower and torque is to me, it is not new in my field.

 

[Dbeck002]

I forgot the dyno graphs, here ya go.

Wheres that torque at again?

 

[300bhp/ton]

Please RE-READ my first post, i was not racing a stock LS1.

Please dont explain what horsepower and torque is to me, it is not new in my field.

oooohhhhh!!!!!! :SNSign:

How do I know what field you are in????? - Grass, corn, cows???, lol.

Nah seriously, I don't though do I.


Here's a dyno graph from a STOCK 99 LS1 Fbody (manual I think). As posted on LS1tech.com, looks like a pretty healty torque curve to me. Might be wrong though.

View attachment 496098

 

[Dbeck002]

Yes that is a nice torque curve.




But let me mention again that i did not race a stock LS1, it was an LS6 so my friends dyno graph would be similar to those i just posted.

 

[300bhp/ton]

Oh BTW Dbeck002, if you ACTUALLY looked at the graph you posted you'd see the torque on the left is using a different scale to the HP on the right. I misse dit first off, but that's why it appears to be a very steep curve. If it used the same scale as the HP then it would appear very flat, although of course the meaning behind the data would remain the same.

The 4th line equals 330lb ft, the LS1 has exceeds this by 1500rpm. I would say it is VERY impressive, would you not? In fact considering an LT only makes a PEAK of 325lb ft @ 2500rpm, it's considerably more powerful down low as well as up top.

And sorry I didn't realise you'd raced anyone. Not sure I mentioned a race at all, will check. And sorry if I did.

 

[white 89 GT]

You can.

There is no reason why you cannot make the same power.

If it seems that the chevy has no low end put some 3.7`s or 4.10`s in it and you will see just how fast it gets to the power range.

 

[Dbeck002]

I never said the torque was unimpressive, all i said was that it makes most of its torque too high in the RPM range for my liking. I prefer a grunty engine, with good torque everywhere.

The LS6 is the engine of discussion here since that is what i raced. Torque numbers by themselves arent going to tell me much, but torque to weight ratio is important. the LS6 has a poor torque to weight ratio down low, yes it makes good torque but we must consider the weight of the car as pure numbers mean nothing unless the cars were the same weight.


EDIT: Yes i am aware of the scale of the graphs but that would not change the fact that peak torque occurs at 4700 RPM for the LS6, (as you mentioned).

 

[300bhp/ton]

I never said the torque was unimpressive, all i said was that it makes most of its torque too high in the RPM range for my liking. I prefer a grunty engine, with good torque everywhere.

You make no SENSE what so ever.

According to the graphs you posted:

LS1 PEAK torque of about 370lb ft @ ~ 4300rpm. However it makes over 330lb ft @ 1500rpm.

Which means an LS1 produces 90% of it's torque by 1500rpm

The LS6 admittidly produces it's PEAK @ nearer to 4700rpm, but it is 390lb ft.

And at 1500rpm it is still making about 320lb ft. So that's 82% by 1500rpm, which is still pretty impressive.

If an engine produces it's PEAK torque very low down, say 2500rpm then the engine will feel breathless if you try and push it high in the rpms. The LS engines will MATCH and EXCEED many alternative engines in the low rpms range yet will be happy at 5000+rpm.

So to re-quote you I would say the LS1 and LS6 are:

a grunty engine, with good torque everywhere.

The LS6 is the engine of discussion here since that is what i raced.

I'm sorry, I thoough this thread was started by '9 Deuce GT' NOT Dbeck002. With a thread title of:
"Why is the LS1 so much better than a 351W?"

I'm sorry I though Torque numbers by themselves arent going to tell me much, but torque to weight ratio is important. the LS6 has a poor torque to weight ratio down low..

You are making yourself look a little bit silly here. You do realise the only production car to have the LS6 fitted as standard was the Z06 Corvette.

which depending on options weighs ~3100lb

.., yes it makes good torque but we must consider the weight of the car as pure numbers mean nothing unless the cars were the same weight.

:Word:

How heavy is an 'average' Fox 3 Mustang?

Would circa 3200lb sound about right?

 

[Dbeck002]

You are making yourself look a little bit silly here. You do realise the only production car to have the LS6 fitted as standard was the Z06 Corvette.

which depending on options weighs ~3100lb

Deuce GT is specifically talking about a HCI LS1 Camaro which REFERS to an LS6, and he was also referring to my race with one which is in the TALK section.

I'm sorry, I thoough this thread was started by '9 Deuce GT' NOT Dbeck002. With a thread title of:
"Why is the LS1 so much better than a 351W?"

Read the first post on this thread again, you seem to have a hard time absorbing it.

You are making yourself look a little bit silly here. You do realise the only production car to have the LS6 fitted as standard was the Z06 Corvette.

which depending on options weighs ~3100lb

For crying out loud man, read the first post and get it into your head. 9DEUCE is referring to my previous race with an LS6 CAMARO that weighs 3800 lbs.

No one brought up a corvette until you decided to change the subject to prove the torque to weight ratio of a vette is better than a mustang, which indeed it is. BUT WE ARE TALKING ABOUT A CAMARO...
















I dont like to make enemies on this forum but you are starting to get on my nerves... So far I am completely correct in saying that peak torque of the LS6 is 4500 RPM (its even higher than that) AND that this engine in the camaro performs poorly down low AS OPPOSED to a lighter fox with HCI...


I physically proved this by racing one on thanksgiving... Are you going to tell me otherwise now? lol...

geesh...

 

[Dbeck002]

Here is a simple calculation that will help you understand my point that was empircally proven 2 weeks ago during the race.


Case 1 at 3000 RPM
Comparing torque and weight of both cars.

My car

3000RPM – 310 ft-lbs
Weight of car = 3200
Weight/torque ratio = 3200/310 = 10.325 lbs per ft-lbs

LS6 Camaro

3000 RPM – 340 ft-lbs
Weight of car = 3800 lbs
Ratio = 3800\340 = 11.176 lbs per ft-lbs





Case 2 at 5500 RPM
Again comparing torque and weight.

My car
5500 RPM – 300 ft lbs

Ratio = 3200/300 = 10.667 lbs per ft-lbs


LS6 Camaro
5500 RPM – 375 ft lbs
Ratio = 3800/375 = 10.1333 lbs per ft-lbs



In case 1 my torque to weight ratio is better, since its at 3000 RPM i pull ahead of him right away and stay ahead until he gets into the higher RPMs where Case 2 is now the scenario.

Case 2, his torque to weight is greater than mine and by that time i am in 4th gear and he is still in 3rd riding out the higher RPMs which is strictly the case 2 scenario, thus he wins.

 

[300bhp/ton]

Deuce GT is specifically talking about a HCI LS1 Camaro which REFERS to an LS6, and he was also referring to my race with one which is in the TALK section.

Read the first post on this thread again, you seem to have a hard time absorbing it.

For crying out loud man, read the first post and get it into your head. 9DEUCE is referring to my previous race with an LS6 CAMARO that weighs 3800 lbs.

No one brought up a corvette until you decided to change the subject to prove the torque to weight ratio of a vette is better than a mustang, which indeed it is. BUT WE ARE TALKING ABOUT A CAMARO...

I dont like to make enemies on this forum but you are starting to get on my nerves... So far I am completely correct in saying that peak torque of the LS6 is 4500 RPM (its even higher than that) AND that this engine in the camaro performs poorly down low AS OPPOSED to a lighter fox with HCI...

I physically proved this by racing one on thanksgiving... Are you going to tell me otherwise now? lol...

geesh...

my bad I didn't realse it was with reference to ONE specific Camaro.

However adding LS6 heads and cam does not make an LS6 engine, so unless the Camaro had every thing else changed to make it an LS6, it was a modified LS1 you raced.

Also there are many other options availble in terms of heads and cam.

However, if they have gone to the trouble of swapping heads and cam over, then they probably also have more mods such as exhaust, LT's, lid, pulley and so on. Plus they should really have a tune as well. Not saying they did, but it is a logical assumption.

If it is the case then they will be making alot more hp and torque than a stock LS6 (or did they have a dyno graph of what it was making). Although this is regardless as I'm meaning hypothetical anyhow. Yet in the other post it's claimed they have over 400rwhp, so it is likely they also have over 400rwtq. Which would mean the 340lb ft you are using in your calculations is WAY off. Remember manufacturer claimed figures are SAE Net, which is at the engine. If the Camaro is producing ~400rwhp and thus ~400rwtq it will be producing ~450lb ft at the engine. Which is subtantially more than the numbers you are using.

Someone on LS1Tech added some LT's to his C5 Z06, they only picked up 13rwhp PEAK, but throughout the range they picked upto a maximum of 22rwhp. This means it must have been producing more torque in the lower rpms.

Also I think you are a little off in your calculations. A Camaro should have a curb weight of ~3550lb not 3800lb. http://www.edmunds.com/insideline/do/Drives/Comparos/articleId=43923/pageId=1121

And unless you Fox is stripped it should be weighing about 3200lb (curb weight). so there is likely to be only 350lb or so difference in weight. Basically half what you are stating.
_______________________________

So if I'm understanding it.

You raced a h/c Camaro, you pulled ahead off the line and they pulled it back at higher speed? - Right?

Well there are lots of reasons for this. The biggest one is driver and owner. If they ain't so hot behind the wheel then that may be part of it. Also if they have not matched the mods correctly and got the car running 100% then it will hinder them.

Where they M6 or A4 as this will affect how the car behaves. And from a 5mph roll was traction an issue. I know my Z28 is stock and on stock rubber, but I've had it spin the wheels at 40mph in kick down. So 5mph roll may have meant a lot of wheel spin.

Also I don't get this LS1's are great up top thing. Espcially when people say it has no low end grunt and they only really start to pull once at higher speed.

Now bear with me on this.

If you are in 1st gear and floor it what happens? The revs rise all through the range to the red line. In 2nd they do the same and so on.

So at 1500rpm in 1st the engine is producing the EXACT same amount of hp/torque as it does in top at 1500rpm.

This all means that the engine performs the same in each gear. Not that it has more pull at higher speeds. In fact due to gearing the amount of pull will decrease as the gearing numerically increases. This is the same for all cars.

What an LS1 does however, is it has fairly long gears and because it produces a lot of torque in the higher rpms as well as the low rpms, it will pull much better at speed with the tacho between 3000-5500rpm than many other push rods V8's.


You beat them off the line no really that's good. The power your car had plus the evident grip (by the chassis twisting comments in the other thread) and the lighter weight all played a role in that. But undoubtably so did the driver, i.e. YOU. Which in many ways is better than just achieving the same result by means of a more powerful car.

This however does not prove LS1's have no low end grunt. Or even a low grunt to weight ratio.

 

[ThreeWhiteGT]

Nothing can stop an LS1. God himself could not produce a faster car then a Trans Am

 

[mustangGT85]

300bhp/ton makes very good points. and although i've grown in the car world loving mustangs and fuel injected 302's, i'm loving the Ls1 motor more and more. if i have any complaint about the Ls1(and this is weird), is that it makes too much power too easily. lol. i see guys swapping the exhuast and cam, and making over 400wrhp. its like, wtf. i can only imagine what the 4 cylinder racers think about that lol.

about the low end grunt, i can personally verify it has plenty of low end grunt. i drove a friends Ls1 Rx-7 FD(the only thing changed was the exhuast, which is the same size as the stock Rx-7 exhuast) and when i was cruising at about 25mph or so in second i believe(also this car turns around 1800rpms at 80mph in 6th), i had gunned it, but with a long step. meaning i didnt hammer it down, but pressed down fairly quickly, and it just jerked both mine and my buddies head into the seat like crazy, i was actually too nervous to shift into the next gear and keep gunning it, so at around 4000-5000rpms i had just let off. truely awesome. and i'm considering using an Ls1 on my next project car. even though i'm ahuge ford guy. i want to see what kind of numbers i can pull out of my current set-up.

also one other thing, that really inspired me when i first got into the 302s. was when i saw fox mustangs running 12 second time slips with 300rwhp. hell, if i could dip into the high to mid 12's, i'd be extreamly happy. i forgot the point i was trying to make in this last paragraph, i think...oh yeah, who cares about max hp ratings, its all about power delivery. i'm more concentrated on time slips then hp numbers. i dont care if you have 400hp more than me, as long as i get to the finish line before you. a toyota supra can make over a thousand hp, but runs like a 400hp mustang or worse. now thats a top end car.


~Steve

 

[JB66]

BTW...The Corvette was not the only production car fitted with the LS6. My son had a company car which was a Caddy CTS-V. Came with the LS6, 3.73's, a 6spd, weighed 4200lbs and would do mid 11's. Without the traction control, it would've kept spinning the street tires through the first 4 shifts. The intake looked like it was from a Formula 1 car and he said it had variable valve timing on the canted valve high compression
head. The design as well as the technology make the difference. My 351C-4v came stock with 11.3:1 compression, canted valves and ports you could put your fist into. The 2.20" intake valves didn't hurt, either. Too bad Ford chose to discontinue it.