The LT1 should have +15% more power than the LS3||||||
01-16-2013, 06:25 PM
#61
Melting Slicks
01-16-2013, 06:33 PM
#62
Instructor
Based on what Bigg_Gunz posted and the engine info posted by GM late in 2012 I would say that the LT1 is GM's first cut at a 2V stratified charge engine. The key element in this form of engine is not to have a uniform air/fuel mixture but rather a very controlled but not homogeneous mix of air/fuel. This is hard to accomplish over a wide rpm range and prob why the engine control logic is locked down by GM.
A lot of papers have been published over the last 5 years dealing with this engine configuration. For example the folks at Ford published this:
http://www.sae.org/mags/aei/SAEWC/10965
Cheers
A lot of papers have been published over the last 5 years dealing with this engine configuration. For example the folks at Ford published this:
http://www.sae.org/mags/aei/SAEWC/10965
Cheers
01-16-2013, 07:17 PM
#63
Burning Brakes
Acutally, they are estimating 30 mpg highway driving.
For hp, let's take the LS3 as a reference point. I believe it has 436 hp.
Here are the numbers we know: Add an additional 1.8% thermal efficiency for the increased compression ratio and add 3.6% for the increased dynamic air flow (based on CrystalRedMetal ZR-1's post).
Let's make a SWAG (scientific wild a$$ guestimate) as to the increase in thermal efficiency from the port/piston design and the potential ability to advance ignition timing using DI. let's assume these add up to an additional 3% of hp.
That puts us around an 8.4% improvement in peak hp. 436*1.084 = 472 hp.
I think the final hp number will very close to 470, maybe +/- 10 hp. Since there will be no parasitic losses due to a hydraulic steering system, maybe assume another realizeable 2-3 hp (guess on my part).
For hp, let's take the LS3 as a reference point. I believe it has 436 hp.
Here are the numbers we know: Add an additional 1.8% thermal efficiency for the increased compression ratio and add 3.6% for the increased dynamic air flow (based on CrystalRedMetal ZR-1's post).
Let's make a SWAG (scientific wild a$$ guestimate) as to the increase in thermal efficiency from the port/piston design and the potential ability to advance ignition timing using DI. let's assume these add up to an additional 3% of hp.
That puts us around an 8.4% improvement in peak hp. 436*1.084 = 472 hp.
I think the final hp number will very close to 470, maybe +/- 10 hp. Since there will be no parasitic losses due to a hydraulic steering system, maybe assume another realizeable 2-3 hp (guess on my part).
As for your math, 470 is about what I was expecting (and 470 is probably the minimum for me personally to be happy with the base power output). I like the optimism of some folks here, though, heh. You wouldn't hear me complaining if it ended up being 480-500 by some chance...
01-16-2013, 07:25 PM
#64
Team Owner
I remember when the CTS-V was being developed, and the estimated horsepower was 550. It came in a 556. It would not surprise me at all if the final figure was around 460.
01-16-2013, 07:40 PM
#65
Safety Car
I am going to guess that the 450 estimated horsepower to be way under-estimated. It would be impossible for a DI high compression motor to make only 14 more horsepower with the same c.i.d. unless the entire motor was de-tuned with the cam profile, and ECU tuning.
Here is why:
The horsepower should be at least 54 more (490) than the C6 LS3, since the 11.5:1 CR coupled with DI should net 6.8 more hp/cylinder. I could be wrong, but the LT1 would have to be detuned to make only 14 more than the LS3. We will know soon. Why do I think that DI will make more power? "Cadillac sells the CTS with both indirect and direct injection versions of its 3.6 liter V6 engine. The indirect engine produces 263 horsepower and 253 lb-ft of torque, while the direct version develops 304 hp and 274 lb-ft." which is 6.8 more Hp/cyl. on their 6 cylinder motor.
Read this article on what DI should bring to the table. This increase assumes the higher compression ratio vs. non DI versions of the Cadillac motor.
We'll see.
Here is why:
The horsepower should be at least 54 more (490) than the C6 LS3, since the 11.5:1 CR coupled with DI should net 6.8 more hp/cylinder. I could be wrong, but the LT1 would have to be detuned to make only 14 more than the LS3. We will know soon. Why do I think that DI will make more power? "Cadillac sells the CTS with both indirect and direct injection versions of its 3.6 liter V6 engine. The indirect engine produces 263 horsepower and 253 lb-ft of torque, while the direct version develops 304 hp and 274 lb-ft." which is 6.8 more Hp/cyl. on their 6 cylinder motor.
Read this article on what DI should bring to the table. This increase assumes the higher compression ratio vs. non DI versions of the Cadillac motor.
We'll see.
01-16-2013, 08:27 PM
#66
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St. Jude Donor '09
I would say on 93 Octane... Base 490, Mid ( Z06 rep ) 625 with supercharger, and Max 750+ with twin turbo. The port move seems to have been to accommodate a twin turbo setup. Why put in high flow injectors ( enough for 1xxx hp ) unless you plan to use them. I tend to think Bigg_Gunz was on point. If these numbers were announced today what would the current inventory of new Corvettes be worth..a lot less $$ for sure.
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01-16-2013, 10:06 PM
#67
Is there anything you can tell us about the Z06 Jim? I am thinking it won't be a grand increase. Wasn't the c6 z06 rated at 500hp then after corrected sae numbers it went to 505hp? The most I see is another 5-10hp/TQ. However I would not be mad at another 30-40 either.
01-16-2013, 10:23 PM
#68
They said the ZR1 was estimated at 620 and came in at 638. The ZL1 was estimated at 550 and hit 580. They'll squeeze what they need out of it.
01-16-2013, 10:29 PM
#69
Burning Brakes
I said this a while back-
I think I did some looking and the smallest increase GM got from converting to DI on an engine was 13%. Considering they are going DI, better heads, better manifold/header, better exhaust setup, better tuning
They would have to purposely keep the engine below 475.
Now, some of that could be lowered by them targeting better gas mileage, better power through the range, having to go with a smaller cam due to AFM, maybe limiting it due for a hotter model........but I'd still think that they'd get more than a 14hp increase which is what, 3%??????
They've also had a 50hp increase the last 2 generations. I think they could accomplish everything they want while still doing the same 50hp jump to be rated 480/486 or close. I think at least 475 would be good enough, because people would be happier with that number mentally, if that makes sense.
I think I did some looking and the smallest increase GM got from converting to DI on an engine was 13%. Considering they are going DI, better heads, better manifold/header, better exhaust setup, better tuning
They would have to purposely keep the engine below 475.
Now, some of that could be lowered by them targeting better gas mileage, better power through the range, having to go with a smaller cam due to AFM, maybe limiting it due for a hotter model........but I'd still think that they'd get more than a 14hp increase which is what, 3%??????
They've also had a 50hp increase the last 2 generations. I think they could accomplish everything they want while still doing the same 50hp jump to be rated 480/486 or close. I think at least 475 would be good enough, because people would be happier with that number mentally, if that makes sense.
Last edited by jdhommert; 01-16-2013 at 10:32 PM.
01-16-2013, 10:33 PM
#71
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I strongly suspect that GM has more in mind that a final HP number. Largely: a highway MPG target that they need to hit in order for this car to continue to be viable now and in the future. With tuning alterations, they can change the HP # and the MPG # fairly easily. I don't think they're done with said tuning, but when it is done, I'd be highly surprised to see a number as large as 490.
My guess is closer to 460/460. I think folks expecting a lot more than that are going to be very disappointed.
jas
My guess is closer to 460/460. I think folks expecting a lot more than that are going to be very disappointed.
jas
I was thinking that maybe GM was suggesting 450 WHP, but that would put it closer to 500 crank HP, and I don't think it will be SAE rated that high.
I do look forward to seeing the final spec and independent dyno and 1/4 mile runs, which matter more to me.
I guessed 497 awhile ago
01-16-2013, 10:42 PM
#74
Race Director
GM is waiting because it builds hipe, keeps everybody guessing and talking about the new car, once the talk about the car slows down they will release the numbers on the engine and the talk will start up again.
01-16-2013, 11:16 PM
#75
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St. Jude Donor '09
Only that it will have more power and less weight, which is obvious. Like I said, someone has already posted a picture of what is coming, and mentioned it. I think it was overlooked in the heat of discussion.
01-16-2013, 11:27 PM
#77
Thanks! Less weight than base c7 or current z06?? Im sure whatever it comes to be, the Z06 will always be a beast and my dream car.
01-17-2013, 01:10 AM
#79
Instructor
I agree with you and I think GM is sandbagging hard, and I love it......they finally learned there lesson with Ford for the issue with the Super duty diesel and the ZL1 vs Shelby HP release.
GM will not mess this up like they have in the past.
01-17-2013, 01:18 PM
#80
Safety Car
Correct http://forums.corvetteforum.com/c7-g...lt1-470hp.html
I agree with you and I think GM is sandbagging hard, and I love it......they finally learned there lesson with Ford for the issue with the Super duty diesel and the ZL1 vs Shelby HP release.
GM will not mess this up like they have in the past.
I agree with you and I think GM is sandbagging hard, and I love it......they finally learned there lesson with Ford for the issue with the Super duty diesel and the ZL1 vs Shelby HP release.
GM will not mess this up like they have in the past.
My thoughts exactly. Ford sure didnt pull any punches with the release of the 2013 shelby performance numbers. How people still compare that car with the ZL1 still puzzles me but it is what it is.
Anyways, I sure hope gm learned that ford is out to hurt some feelings lately and that with the new releases of the z06 and or zr1 they'll return the favor. Obviously hp isnt everything but it surely does raise some eyebrows.
I cant wait to see the garage over on svtp when those cars hit the streets.