LS7 Dyno Results + Aftermarket Cams

[Vitamin J]

Yeah Z06 is a good car (and its amercian, wow ). I say its still ridiculous that 7 liter and it only puts out 519 hp (stock). I just dont get the point of this engine.

HP/L is one of the stupidest arguments one can make about an engine. It doesn't show you the awesome torque and hp curves like this:

Also, HP/L also depends a lot on engine size and max rpm. A 7L LS7 making 519hp at 6800rpm is just as impressive as a 1.3L Hayabusa engine making 195hp at 13,000rpm.

"The LS7 weighs 458lbs dry, the BMW M5 V10 weighs 528lbs dry."

True... :?

For more comparison, the S54 M3 I6 weighs over 600lbs, the RB26DETT weighs over 700lb and the 2JZ-GTE weighs over 750lbs. The Enzo V12 also weighs over 600lbs. Not to mention the physical size of pushrod engines allows them to be mounted low and far back.

And personally, I think the Z06 is an amazing car...What was Clarkson's only complaint, that he thought it was too much of a track car for the street? That only makes me want it more; comfort is at the bottom of my priorities list.

Tiff Needel says it's fine on the road. Clarkson may have a point, but its hidden behind years of hate for Corvettes.

those are some good numbers for a cam change

I dont even think FI would be the way to go with the LS7, just a feeling

Cam changes usually only gain 30 to 50hp with everything else stock, this gains almost 100hp.

Also, 11:1 comp ratio is bad for boost.

It's close to happening. But what can you expect for a thread that could be basically titled "Look how good our american engine is".

The thread is not for that at all, if you want to see how good the LS7 is, watch Lemans.

That potential just tells me that GM saved up on parts and decided to take less power instead of using the full potential. That is pretty much the essential difference between american and euro/jap engineering. If it were a euro/jap engine it would have all those aftermarket parts as stock, it would make 800hp+ and it would cost twice as much

This motor wouldn't be nearly as driveable with that much horsepower. What pushrods gain in torque and power, they lose is drivability with hot cams.

The LS7 is basically the C6R's motor with a cooler cam, less compression, and some catalytic converters. The C6R makes well over 800hp N/A without restrictors.

Ok, I see the point of it. Still, I dont like it. I dont agree with throttle respose though. As I can see on the pic posted on the first page, there are no Individual Throttle Bodies. Dunno, maybe there is, but I cant see it on the pic. M3 has got Individual Throttle Bodies, thats why it has ultimate throttle response.

ITBs don't = better response, they can help, but there's much more to it. Reciprocating mass plays a bigger part in response.

 

[geeman]

The thread is not for that at all, if you want to see how good the LS7 is, watch Lemans.

What is this thread for then?

This motor wouldn't be nearly as driveable with that much horsepower. What pushrods gain in torque and power, they lose is drivability with hot cams.

The LS7 is basically the C6R's motor with a cooler cam, less compression, and some catalytic converters. The C6R makes well over 800hp N/A without restrictors.

Do you realize those two sentences contradict each other? On hand hand you are saying that pushrods lose drivability with more power and on the other you are saying how you can easily take more power out of them simply by changing the cam and C6R which basically has the same engine, but with more power.

I get the feeling that you are the only one keeping the flame on this war. Others have just accepted the reality that LS7 is good engine, Z06 is a good car and can compare it to other cars objectively.

 

[Vitamin J]

What is this thread for then?

God forbid I make a post about some cool technical article in an AUTOMOTIVE FORUM. If this was about an Audi FSI engine or a Bimmer V12 you guys would be jacking off all over your keyboards.

Do you realize those two sentences contradict each other? On hand hand you are saying that pushrods lose drivability with more power and on the other you are saying how you can easily take more power out of them simply by changing the cam and C6R which basically has the same engine, but with more power.

The C6R doesn't need to drive in traffic, or get 26mpg on the highway, or idle easily. It's a race car, it's at WOT ever second of its life.

Because pushrod engines only have one cam for both intake and exhaust, you can't make it driveable at low rpm while retaining huge amounts of lift and power up top. That's why cammed V8s idle so lumpy.

I get the feeling that you are the only one keeping the flame on this war. Others have just accepted the reality that LS7 is good engine, Z06 is a good car and can compare it to other cars objectively.

I'm the only one giving facts and numbers.

 

[WheatKing]

exactly, mass and proper rod ratio = good response..

LS7 is a street legal emission approved motor for mass consumption.. it has to be reliable, and unlike ferrari engines or other hyper exotics, uses normal oil, don't require $7500 of maintenance at 30K intervals, and generally designed to last atleast 100K miles (160K km) before any major maintenance

and if you DO blow up the motor.. you walk into any GM dealer.. tell them you want part # 17802397, drop about $13K USD (about 9,900 euro) on the counter and have it drop shipped to your garage.. and be good for another 100K miles.

$/hp = $26USD / hp

your average turbo kit for an import engine.. your looking at $5K or so.. for what.. 100~150hp boost? mostly unreliable at that.

or more than $50USD/hp

a 550 maranello engine will run you $75K USD for 485hp.. or $136USD/hp BIG difference.. on an engine that requires major service at 30K

 

[WheatKing]

Because pushrod engines only have one cam for both intake and exhaust, you can't make it driveable at low rpm while retaining huge amounts of lift and power up top. That's why cammed V8s idle so lumpy.

new viper engine (pushrod) supposedly has VVT.. should be able to phase the cam for less overlap, preserving idle qualities and then phase it for more overlap so it has more topend power.

 

[Vitamin J]

^^Yeah, the new GM pushrod V6s also use the same technology. The LSx series doesn't have it yet though

I'm excited for the new Viper, tuned by McLaren

 

[marcos_eirik]

For more comparison, the S54 M3 I6 weighs over 600lbs, the RB26DETT weighs over 700lb and the 2JZ-GTE weighs over 750lbs. The Enzo V12 also weighs over 600lbs.

The Enzo V12 weighs 471lbs (214 kg)... Carrera GT's V10 weighs 449lbs (204 kg)...

ITBs don't = better response, they can help, but there's much more to it. Reciprocating mass plays a bigger part in response.

Mentioning individual throttle bodies reminded med about this car. This is the Jaguar AJV8 that powered Rocketsport engineering's XKR Trans Am to victory several times in the Trans Am championship It's based on the very same engine fitted standard in the XK roadcar, it's enlarged to 4,5-litres, got new headers, racing pistons/conrods/crank and individual throttle bodies. The result is an increase of power from 300 hp @ 6000 rpm to 650 hp at 9200 rpm. (Now that's peaky)

 

[mancs]

"S54 M3 I6 weighs over 600lb"

Uhm..:
"S54: Inline 6 cylinder DOHC 24V Solid Lifter Valvetrain with double VANOS and Individual Throttle Bodies 148kg 326lbs"

:? I found this. Dunno witch one of us is correct, but I dont think it is more than 400 lbs, cos here in hungary they put this engine in E30-s, and they still handle quite well.

"ITBs don't = better response, they can help, but there's much more to it"

Cant agree with you 100%. ITBs ARE needed for better response. Of course there is 100 of things that are needed for better response, not just that.

"Reciprocating mass plays a bigger part in response."
Yeah thats true. That was always the first thing to do with my engines so far, but lightning the parts is only good when its not overdone, cos you can loose torque, but than you can raise the compression to counterbalance the torque loss.... Back in the old days, they changed the length of the intake"pipes" (is that the correct word?), cos the length of the intake pipe also effects the working band of the engine (a mechanism made the "pipe" bigger/smaller depending on the revs). Yeah, an engine is a comlicated thing

"Because pushrod engines only have one cam for both intake and exhaust, you can't make it driveable at low rpm while retaining huge amounts of lift and power up top. That's why cammed V8s idle so lumpy."

Yeah, DOHC +VTEC ftw imho . BMW's Vanos was never sympathetic for me, it works well though. VVT is a good thing. Thats why ferraris big v8-v10-v12 are so high revving, still they have a big fat torqueband.

 

[geeman]

God forbid I make a post about some cool technical article in an AUTOMOTIVE FORUM. If this was about an Audi FSI engine or a Bimmer V12 you guys would be jacking off all over your keyboards.

That's just the attitude that keeps these flame wars going. You except people to act like idiots, guess what you get?

I see that you are posting numbers and I even believe that they are true. But what I still don't understand what do you except us to do. We already have admitted LS7s goodness. What more you want?
IMO we were even having a reasonable conversation about LS7/Z06 for a one page there and then you came misundorstood some things, quoted few people, insulted intelligence of others, posted some of your facts and said LS7 is teh win (which is stated about 25 times on this thread already).

 

[mancs]

The Enzo V12 weighs 471lbs (214 kg)... Carrera GT's V10 weighs 449lbs (204 kg)...


Mentioning individual throttle bodies reminded med about this car. This is the Jaguar AJV8 that powered Rocketsport engineering's XKR Trans Am to victory several times in the Trans Am championship It's based on the very same engine fitted standard in the XK roadcar, it's enlarged to 4,5-litres, got new headers, racing pistons/conrods/crank and individual throttle bodies. The result is an increase of power from 300 hp @ 6000 rpm to 650 hp at 9200 rpm. (Now that's peaky)

Now thats what I call an engine! Lovely!

 

[Vitamin J]

The Enzo V12 weighs 471lbs (214 kg)... Carrera GT's V10 weighs 449lbs (204 kg)...

True enough, the CGTs engine is a masterpiece. I was wrong about the Enzo V12, I must have found the weight of a 575 V12 or something.

Mentioning individual throttle bodies reminded med about this car. This is the Jaguar AJV8 that powered Rocketsport engineering's XKR Trans Am to victory several times in the Trans Am championship It's based on the very same engine fitted standard in the XK roadcar, it's enlarged to 4,5-litres, got new headers, racing pistons/conrods/crank and individual throttle bodies. The result is an increase of power from 300 hp @ 6000 rpm to 650 hp at 9200 rpm. (Now that's peaky)

Racing engines make me weak in the knees. There's a Silver Corvette that races in Speed World Challenge that revs the 6.0L V8 well over 8,000rpm, it sounds AMAZING.

"S54 M3 I6 weighs over 600lb"

Uhm..:
"S54: Inline 6 cylinder DOHC 24V Solid Lifter Valvetrain with double VANOS and Individual Throttle Bodies 148kg 326lbs"

Yeah, that's just the valvetrain, doesn't include the bottom end. Add the weight of the IRON block.

"ITBs don't = better response, they can help, but there's much more to it"

Cant agree with you 100%. ITBs ARE needed for better response. Of course there is 100 of things that are needed for better response, not just that.

Motorcycle engines and even the Carrera GTs engine don't have ITBs

"Reciprocating mass plays a bigger part in response."
Yeah thats true. That was always the first thing to do with my engines so far, but lightning the parts is only good when its not overdone, cos you can loose torque, but than you can raise the compression to counterbalance the torque loss.... Back in the old days, they changed the length of the intake"pipes" (is that the correct word?), cos the length of the intake pipe also effects the working band of the engine (a mechanism made the "pipe" bigger/smaller depending on the revs). Yeah, an engine is a comlicated thing

I think you're talking about velocity stacks, which are awesome.

"Because pushrod engines only have one cam for both intake and exhaust, you can't make it driveable at low rpm while retaining huge amounts of lift and power up top. That's why cammed V8s idle so lumpy."

Yeah, DOHC +VTEC ftw imho . BMW's Vanos was never sympathetic for me, it works well though. VVT is a good thing. Thats why ferraris big v8-v10-v12 are so high revving, still they have a big fat torqueband.

Yeah it is a good thing, but pushrods have their own advantages and their own place.

I see that you are posting numbers and I even believe that they are true. But what I still don't understand what do you except us to do. We already have admitted LS7s goodness. What more you want?
IMO we were even having a reasonable conversation about LS7/Z06 for a one page there and then you came misundorstood some things, quoted few people, insulted intelligence of others, posted some of your facts and said LS7 is teh win (which is stated about 25 times on this thread already).

All I'm doing is corrected people on weights, figures, and helping people understand what makes engines working. You're the only hostile one here.

I mean look at what types of posts this thread generated, completely devoid of fact and any sort of logic whatsoever:

"no power until you get it revved up to 7K rpm"
^True

"and then the power band is only 1000rpm wide"
^ Not true

"takes 5 seconds to rev from 1000rpm to 7K "
^ Not true

And this 7 liter engine weights, around hm... 10 tonns? while the european/japanese engine weight like nothing.

Yeah sure... I dont have any problem. Shitty american cars need shitty american engine. True . How cool is a noseheavy, "I cant turn in a corner but I can go fast in a straight line" car? Not my choise, thats for sure.

Dont take my wrong, I love the sound of american muscle. No other sound is so noisy, deep etc. But everything else is.. Sad.

Like I said, if this was about a Bimmer or Audi engine it would be the opposite.

 

[Hatmouse]

Mancs, you might be interested to know that

ACCORDING TO THE INTERWEBS!

the LS7 is actually lighter than the V10 in the new BMW M5, while producing similar max HP.

It must be true, because it is

ACCORDING TO THE INTERWEBS!

 

[mancs]

"Yeah, that's just the valvetrain, doesn't include the bottom end. Add the weight of the IRON block."

Uhm. Nope.

http://www.bimmerforums.com/engine_faq/

 

[mancs]

Mancs, you might be interested to know that

ACCORDING TO THE INTERWEBS!

the LS7 is actually lighter than the V10 in the new BMW M5, while producing similar max HP.

It must be true, because it is

ACCORDING TO THE INTERWEBS!

Uhm we had discussed that a few post earlier

 

[Hatmouse]

Uhm we had discussed that a few post earlier

Just realized. whoops.

God, I hope this doesn't become a flame fest.

 

[mancs]

Btw isnt the bmw 2 liters less, and revs more?

(I dont want to fight, just discuss Thats why there are forums, and finaly a good discussion is going on)

 

[Vitamin J]

Mancs, you might be interested to know that

ACCORDING TO THE INTERWEBS!

the LS7 is actually lighter than the V10 in the new BMW M5, while producing similar max HP.

It must be true, because it is

ACCORDING TO THE INTERWEBS!

BMW's Production Information Guide lists it at 528lbs dry and Sports Car International lists the LS7 at 458lbs dry on page 25 if you want to look it up.

"Yeah, that's just the valvetrain, doesn't include the bottom end. Add the weight of the IRON block."

Uhm. Nope.

http://www.bimmerforums.com/engine_faq/

All those weights are dry with no accessories. 600 lbs may have been exagerated, but it's certainly heavy.

Btw isnt the bmw 2 liters less, and revs more?

Yeah, its 5.0L and revs to 8000rpm. It's a pretty awesome engine itself, partly based on the BMW F1 engine. Heres a cool picture I took of one when I visited the Nurburgring:

 

[jetsetter]

You've gotta be kidding me?! Peaky? 8000rpm is peaky. 6800 is pretty average medium speed engine unless you're used to tractor and truck engines!

Compare 6800rpm to the two other 6300rpm results and you will know where I am coming from. The engines I deal with usually don't have to rev much over 6000rpm to make power.

 

[NAIDANAC A]

on a side note, didn't aston say they were not competing in the ALMS this year?

 

[Vitamin J]

I'm trying to find a video of the sweet Silver Vette I mentioned, but here's some other cool cars from Speed World Challenge GT

http://www.youtube.com/watch?v=OCkIfCq5rEg
The sound of this car brings a tear to my eye. I wish it didnt have the music.

http://www.youtube.com/watch?v=ELt-6-xKWUM

http://www.youtube.com/watch?v=pLmoVsnru-U

http://www.youtube.com/watch?v=Hqzhu1mBAVo

on a side note, didn't aston say they were not competing in the ALMS this year?

Yes, it's costing them too much to be competetive. Specifically with the C6R.

I say its still ridiculous that 7 liter and it only puts out 519 hp (stock). I just dont get the point of this engine.

I've already adressed this, but I can do it again.

The Pagani Zonda F makes "only" 604hp from 7.3L, the BMW 6L V12 in a 7-series "only" makes 300hp, and the 6.0L W12 in the Phaeton "only" makes 444hp.