552.8 HP C7 Corvette LT1
#21
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Thread Starter
I am unable to find any car company with Double overhead camshaft (DOHC) engine and a warranty greater than 5 year 100,000 miles power train.
My Friend's "P" car was refused warranty on engine for lack or proof of "authorized service intervals"
(Internet search today.)
Maybe GM has the correct configuration.
505 HP normally aspirated engine!!.
I will bet good things are in store for the LT1.
My Friend's "P" car was refused warranty on engine for lack or proof of "authorized service intervals"
(Internet search today.)
Maybe GM has the correct configuration.
505 HP normally aspirated engine!!.
I will bet good things are in store for the LT1.
#22
Team Owner
And that's with a 4" long stroke and a large heavy piston at the end of the rod, unlike the short stroke crank and a small diameter, lightweight piston at the end of the rod on a tiny little DOHC engine.
Last edited by JoesC5; 01-19-2013 at 08:14 PM.
#24
Team Owner
#25
Melting Slicks
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I'm not saying it's IMPOSSIBLE that it could do that hp/liter. In fact it IS possible...I guarantee...but is it possible to do it on a mass production, assembly line scale, with a warranty, in all the temperatures and elevations the car will be sold, on 91 octane cali gas, etc....probably not.
just tell customers they need minimum 93 oct, and that it actually would love 94.5 oct.
I think most of High HP performance car in Europe call for 98 octane (we have different rating) you guys has RON+MON/2, we only show RON
so our 98 is aprox your 93.5
But we do have 100 octane and 102 octane pump fuel......
crank it up GM and forget about 91 oct and penny saving people
Rune
Last edited by Z06Norway; 01-20-2013 at 11:08 AM. Reason: typo
#26
Tuned R/C cars make almost 1 hp per CC. Even stock ones, Losi 454, makes 3.5hp from 4.54 cc.
By that math a 6200 cc LT1 should make 4780hp. GM, get of your lazy asses and give us a proper 5000hp LT1...
#27
Racer
120HP/L isn't that much. My mildly tuned (no headers, stock pistons, cam, etc. - just larger intercooler and downpipe, bigger injectors, and software) '98 2.3L Saab made 320 HP, or ~140HP/L. Many of my Swedish friends get 450 HP out of the B234 9000 engines. Once one gets up to 500 HP, the stock pistons have to be "improved" - which partly explains why Saab was losing money producing the 9000. Then there was the 2.0 L 900, which set a record a Pikes Peak - it produced over 700 HP but needed a Sentrac AWD set-up. I now drive a '03 Z06, and I love the LS6, but also appreciate that there are other methods that are just as viable in obtaining high HP/displacement ratios.
#28
Le Mans Master
Forced induction is always going to be a game changer. My z06 is making way beyond 100hp/liter, but its doing it at a much different bsfc than any n/a engine could achieve. Making 100hp/liter n/a is always going to require rpm. This just becomes an inherent limitation of oem based pushrod engines. Dohc, direct valve actuation is a more capable design, but in terms of size and arguably cog, the pushrod engine has got its benefits.
Like I said though, volumetric efficiency goes way up with DI. Air and fuel arent sharing space in the intake ports. Also, you can safely increase compression due to better fuel atomization creating more stable combustion/anti knock characteristics.
There are essentially four core methods to create higher hp in an n/a engine:
Increase rpm in which peak hp is achieved
Increase compression
Increase displacement
Increase volumetric efficiency
DI contributes to two of those. Variable cam timing influences displacement (dynamically), resulting in better ve.
This engine has capability beyond what it will do stock/with a warranty, no question. Its really up to reliability, longevity testing , marketing, gm, etc
Like I said though, volumetric efficiency goes way up with DI. Air and fuel arent sharing space in the intake ports. Also, you can safely increase compression due to better fuel atomization creating more stable combustion/anti knock characteristics.
There are essentially four core methods to create higher hp in an n/a engine:
Increase rpm in which peak hp is achieved
Increase compression
Increase displacement
Increase volumetric efficiency
DI contributes to two of those. Variable cam timing influences displacement (dynamically), resulting in better ve.
This engine has capability beyond what it will do stock/with a warranty, no question. Its really up to reliability, longevity testing , marketing, gm, etc
#29
Le Mans Master
Love it!
http://media.caranddriver.com/files/...ebuary2012.pdf
So I guess the V6 is good for 7300RPM! And the C7 is good for 6700RPM! And the C5.....
And lets see getting all the way back to the OP's point:
Thus
321 (hp)/3.6 (liters)
89.16 hp/liter
Corvette C6 LS7
505 hp/7.0 Liter
72.1428571429 hp/Liter
sooo
7L x 89.16 hp= 624.12 HP???
without the supercharger???
Last edited by johnglenntwo; 01-20-2013 at 05:08 PM.
#30
Le Mans Master
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Can someone tell me why a top performance sportscar has to be limited on 91 oct ?
just tell customers they need minimum 93 oct, and that it actually would love 94.5 oct.
I think most of High HP performance car in Europe call for 98 octane (we have different rating) you guys has RON+MON/2, we only show RON
so our 98 is aprox your 93.5
But we do have 100 octane and 102 octane pump fuel......
crank it up GM and forget about 91 oct and penny saving people
Rune
just tell customers they need minimum 93 oct, and that it actually would love 94.5 oct.
I think most of High HP performance car in Europe call for 98 octane (we have different rating) you guys has RON+MON/2, we only show RON
so our 98 is aprox your 93.5
But we do have 100 octane and 102 octane pump fuel......
crank it up GM and forget about 91 oct and penny saving people
Rune
#32
Team Owner
I'm lucky though that we have a half dozen stations locally that carry 93 octane ethanol free gas. My Z06 can tell the difference.
#33
I'm still baffled at HP/L being discussed as if it has some actual meaning. I suppose if you lived in a Country where they misguidedly associated engine displacement with efficiency it would. In the context of this discussion it is useless. The LT1 and the LSx engines before it are less complex, lighter and more compact than the engines they compete with. They usually make comparable power with better fuel efficiency. The last time I checked the only 400+hp and 500+hp engines made that do not incur a gas guzzler penalty are the LS3 and LS7.
The LT1 makes the power it does because it was likely designed to hit certain fuel efficiency, emissons and performance targets. It's quite easy to coax more power out of any LSx derived engine. But evidently for better or worse GM feels the LT1 is where they want it. Could they push it further? Of course.
As far as the octane question goes, here in Iowa it is very hard to find anything over 91.
The LT1 makes the power it does because it was likely designed to hit certain fuel efficiency, emissons and performance targets. It's quite easy to coax more power out of any LSx derived engine. But evidently for better or worse GM feels the LT1 is where they want it. Could they push it further? Of course.
As far as the octane question goes, here in Iowa it is very hard to find anything over 91.
#34
Le Mans Master
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Right. My point is that even hinting at the idea of throwing on a 93 tune just because a couple of states have 93 (rather than 91) is like saying that Apple should develop iPhones strictly to work with left handed people only.
#35
Heel & Toe
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Horsepower potential - scalability
Extrapolating a small displacement, high output engine's numbers linearly to a large displacement engine is not a good engineering premise. For instance, Honda once made an experimental 4 cylinder, 16 valve 50 cc motorcycle engine that had some ridiculous hp rating - [16?] at 12 or 14 thousand rpm. I don't recall a Honda 1000 cc engine that made 20X that amount of hp.
The old Formula 1.5 liter engines are another example - scaling them up 4X to a 6 liter never got 4X the hp the little guys put out.
The old Formula 1.5 liter engines are another example - scaling them up 4X to a 6 liter never got 4X the hp the little guys put out.
#37
Burning Brakes
I believe the direct injection 3.6L Cadillac engine is the MKII version of the previous standard fuel injected 3.6L V6 used by Cadillac and also in my wife's Malibu LTZ. It's DOHC, 4 valves per cylinder with variable valve timing. Redline on the wife's car is around 7000RPM and it's an incredibly smooth and powerful engine for its size. You WON'T get that kind of BHP/L out of a naturally aspirated pushrod V8 without it being unsuitable for the street, and a warranty. FI-different story. My $.02.
Last edited by PhilsFRC; 01-22-2013 at 10:44 AM.
#39
Le Mans Master
Agree that HP/liter displacement is useless. 1) Europeans and Japanese are taxed based in part on their car's engine displacement, so for them, it is much more important to limit the displacement. It has nothing to do with performance - it's all about the taxes.
2) More complex does not equal mo' better. What it equals is weight. When I order an LS1 head from Summit or Jegs, the shipping weight is 22 lbs. Know what the shipping weight is on a Honda dohc head? Not counting the cams, it ships at 64 lbs.
A much more pertinent measurement for us would be horsepower per pound of engine weight. GM pointed that out already. Or horsepower per volume. Not displacement, but the total volume the engine takes up.
2) More complex does not equal mo' better. What it equals is weight. When I order an LS1 head from Summit or Jegs, the shipping weight is 22 lbs. Know what the shipping weight is on a Honda dohc head? Not counting the cams, it ships at 64 lbs.
A much more pertinent measurement for us would be horsepower per pound of engine weight. GM pointed that out already. Or horsepower per volume. Not displacement, but the total volume the engine takes up.
#40
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People confuse complexity with "high tech". More moving parts does not make an engine higher tech than an engine with less parts. That is false logic or a warped view of high tech. High tech would be using the latest materials and technology to produce the best results versus the design criteria.
It is clear that swept volume is not an important design criteria for the Corvette engine, nor is there any reason for it to be an important criteria.