| Re: HP estimate |
Subject: Re: HP estimate by jsup on 2008/8/19 1:54:33 [quote Andrew wrote: Jsup, I have to humbly disagree with you. It is probably 20% at some point in the RPM / HP range, but I doubt it is 20% at it's peak. In other works, at 2500 rpm, if the motor makes 100 hp, 20% loss would be about 20 hp. Most of the parasitic loss of power has already taken place, so when the motor spins up to it's tq / hp match (5252 rpm) and it produces 300 hp, the parasitic loss may only be 30 hp, or 10%. I guess what I'm trying to say, but not doing it very well, the parasitic loss to the rear tires does not increase at the same rate that HP does, since power has already been used to start the spinning momentum. After seeing a few LT4's on the dyno, they produce about 295 - 300 rwhp stock and the factory claims 330 at the crank. Granted, the peak HP is higher in the rpm band than the L98, but the parasitic loss should be similar. My guess if motor produces in the 350 chp range, it would be more like 310 - 315. I believe 280 would be extremely conservative. All of this is just theory of course. Does this make since or am I just out in left field somewhere? One thing is for sure, if the motor produces 350 chp, you will definitely notice a difference over the stock rating!![/quote] The LT4 is a strange animal. Many suspect it was WAAAYYY under rated. That being said, 20% is on the high side, probably closer to 15% many will say 15-18% Point is, 350CHP will not yeild 300 RWHP under the best of circumstances. I think closer to 285. |
