JL222,
As for only bringing 1350 hp that is not even close to the output we can make. That is all we could use(in the Buick). More boost just caused wheel spin. But since that was way less then 15 psi boost I am sure we can cover what we need.
As far as the Black Salt car I would assume much less then 2100 hp to get that speed. Even the video shows lots of in and out of throttle and still making that speed and averaging about .2 g's acceleration most of the way.
If we could get traction then records would fall very fast! Since we run both ECTA and the Salt I can tell you traction is the key.
Look at Speed Demon. The records he has recently set was with a C engine with 2200 hp. As for durability they still have issues.
But from what I see they are still unable to put down the power (or at least most of it). and from my calculations is says he needs about 1850-1950 hp for these speeds ~480 mph.
I just think that most cars have real trouble getting 2000 plus hp to the ground at the Salt. Most I have experience with just spin the tires and are a hand full to drive. (Scary even) This whole conversation was about the rods so I will get back to that.
Looking at the pictures provided I think the tune (wrong A/F mixture or to much timing) that killed it. my experience says that a tune-up that is maxed out (like I run on 95% of my customers and my cars) will do this in a pedaling condition (driver in and out of the throttle) because you cannot get everything correct when it is changing rapidly. Again this is not about the true tune being wrong. It comes from the engine conditions changing and timing and fueling already being delivered. I see this in drag racing on quick pedaling with tire spin the fuel is there (with EFI or CF injection) the throttle closes, so the air is no longer there and the cylinder hammers rings, second they get back on the throttle and the fuel has yet to catch up but the air gets there and causes a lean condition. This is only compounded by the fact the timing can change also instantly (between fueling and combustion event). We have dealt with this on OEM cars for emissions by going to electronic throttle. This makes sudden changes controllable (since you control the throttle!!!)
Back to the rods. I use Aluminum in 90% of the engines I build. I also turn most of them over 9000 rpm. I will actually be out Saturday with one a twin turbo BBC promod. And we turn it 9800 and don’t have rod failures. But on land speed I think the cycles are too long and can cause failures. I use forged AL rods as well as plate but both have issues with fatigue. My experience is aluminum gives me a fuse in the engine that allows me to step over the line with the tune around come back for another pass. They crush bearings and compress before failing. I see this in bearings after the pass as well as rods when we take them out. With steel rods I kill bearings with detonation and can kill the engine in 1 pass!!!!
As for rod length “short”. I like to keep my deck heights low, rods short, piston short (with enough for a real ring pack). As you mentioned a real long rod and high piston weight don’t help anything and are made worse with high RPM!!!
I am sure you have more experience with this then I do but on my record engines this is what I have found. Also on all of my 15000 + rpm engines we have never been successful with anything but steel or Ti. But we were unable to stuff AL rods in a 600-1800 cc engine and make a full pull. Plus the beams are too wide to fit in most cases (motorcycles). From an engineering stand point I think Steel can fit your needs and be reusable!!
I also think that if you changed the tune to be a little more forgiving (less boost, more fuel {Less Power}) you can get away with the parts you have.
By the way I do enjoying debating things like this as I only get more knowledge and experience.
Paul Powell
Topic: Getting ready for Bonneville(rebuild) (Read 2047078 times)