Quote:
Originally Posted by ZL1Atlanta
A couple years ago I made a spreadsheet of all the stock A10 ZL1 dyno numbers I could find and averaged them out. The number was 15 I believe and the average drivetrain loss was 16% (assuming every engine actually made 650 HP). That isn’t exact science, but gives an idea. That said, 1400 x 84% = 1,176 RWHP available to you. Naturally parasitic loss has to be removed from the power the engine is experiencing, so you’d take some number away from the 1400 and then do your x 84% if you’re trying to back in what is safely left for you at the wheels. Maybe TooHighPSI will chime in as I’m sure he has a pretty good idea of what parasitic loss is from his days at Magnuson developing the blower. I know it is more than 50 HP at these levels.
None of these guidelines are exact with possible factory flaws in blocks, pistons, rods, how hard it is being ran, tuning, etc. But all of those uncertainties are why I didn’t want to sleeve a stock block when trying to max out the 2650. It gave me maybe an extra 2-300 HP and we had just dyno’d over 1300 RWHP when the stock cylinder wall cracked. That said, we ran my car at ~1,100 RWHP for over a year and 100+ passes with no issues using LME’s 1400 HP offering.
Edit: In this video he is talking about a test Kenne Bell did between one of their blowers and a 2650 on an engine/blower dyno stand. At 22 psi the 2650 took over 200 HP. Much higher than I thought!
https://youtu.be/AvJ1nLRYteE?t=485 |
Didn't one of the C7 ZR1 engineers make a comment about how the 2650 consumed around 150-or-something HP to turn (at OEM power level), too? He tried to make it sound like an LT5 made similar numbers to the Demon or something by saying something to the effect, "... if you consider the power it takes to drive the 2650, it makes similar power to a Demon...", or something like that? Now I have to find that...
EDIT: Here's the article/quote:
https://www.lsxmag.com/news/2019-cor...n-development/
The supercharger actually spins slower than the one on the LT4: 15,860 rpm versus 21,000 rpm. The boost is 13.9 psi at peak.
We wanted to slow the supercharger speed down to introduce a lot less heat, said Lee. So running slower is more efficient.
Nonetheless, the LT5’s supercharger is drawing 110 hp to keep it spinning. That’s so much that it needs an 11-rib drive belt to accommodate the extra energy required to spin it. The LT4 only needs eight ribs on its drive belt. So effectively, this engine’s making 865 hp according to Lee.”
So - around 110-HP at stock LT5-levels, so I bet you guys can't be far off in your estimates (I wasn't questioning them - just trying to support them with this info
).