Thats smokin with 500s
Did you have 502s at one time? You said the drives are too high from the 415s and blow out the props?
How fast were you with 502s? Are your 500s stock? Are you in salt or fresh water? lots of questions..........
I like what your sayin

Plus is the speed verified by GPS or radar? I assume so. If the bottom is blue printed and the X dimension is running high, it seems like that speed is attainable.

Yes the speed is verified by a tattle-tale gps speedometer. The motors in this 380 are strong 500 efi's.
Here's the low the down on the boat.
Order it special in March of 98 had 415 mag's put in it at he time. Ran with the stock motors when I got it and didn't like getting past up. The best it would do is 68mph.
That October the youngest son and me put Stainless Steel Marine headers on it and took out 368 lbs of weight out of the back end and gain 4mph.
Ran it the next season and still was gettting past up so I brought two M-1 Prochargers and put on it. The boat was a rocket. Going up the Ohio river it was doing 87 mph on the radar gun. Couldn't contol it as it was all over the place. Send it back to the factory and they blue printed the bottom. The wife got tired of listening to the wine of the belts and couldn't listen to the radio.
That February at the Miami boat show brought two 500efi's/ Some smart ass punk told me I couldn't afford the motors so I went out and brought them anyway. I got more money then he has.
I had them put in a tattle-tale GPS installed when I had the motors put in. This boat will do 80 mph with 4 people in it and 3/4 tank of fuel going down Lake Clumberland anytime I launch it. When I get it under 1/2 tank thats is when it is on top of its game.
Right now its is turning 5200rpm's with 4 blades Bravo's 1 30 pitch lab finsh props. The only thing I don't like is that when I trim out past two on the trim it blowns the props out. That is why I think the drives are mounted to high. Yes I could put spacers in the drives but after the Pro-chargers I am done screwing with the boat. Now all I want to do is turn the key and go cocktailing down the lake. Age has foundly caught up with me. Replacing drives and working on the boat every other weekend gets old. Besides now I am into looking at the finer things in life namely good looking WOMEN.
Blondes Preferred

Sounds like it is dialed in pretty well now, not sure you would see any performance gain with a spacer. Probably a slightly better hole shot, but I doubt any efficiency in cruise or top end.

I have a 2000 Viper and the guy I bought it from has a 2004 380 with 525 efi's and claims he's getting 84 on GPS and thats on Lake Michigan!!

This is what I hear, but tell me why this is............

How can a 38 Fountian, with less stuff in the cutty, or nothing at all..... Do almost 100 with the same power (525s) ????
Are they that much better hull or are ours that much worse?

My 2000 38 with 502s runs 73.5 on GPS in the right water, 71/72 all the time. I thought that was pretty good for 502s. I was running with a 38 Fountian with the same power, same year too, and we were almost exactly the same speed. I could not pass him and he could not pass me. So if they put 525s in that boat does it go 90+? And the same PQ goes 82

Someone needs to tell me why that is? I have a hard time beleving that hull design makes 10 MPH diff, thats like an additonal 150 to 180 HP per side......

Anyone have the article from powerboat that had the 34PQ and 35 fountain in same issue. I think it was around 2001 or so. Both had 500efi's, PQ ran 86+mph and fountain was 82mph or so. To me the 34 PQ is a much larger boat. I was dealing w/ Kevin Hirdes on fixing my 38 @ the time and he was telling me how he was excited about all they have learned about stepped bottoms and refered to those articles, 2 months later he sold the company. Kinda left me hanging and had to fight tooth and nail to get anything fixed after that.

We have a 2004 38 w/ 500efis and xr's that will run 80-81 every day, have to trim the piss out of it, like higher than the indicators go but it will go that fast safley. My question is how many 38 owners also have to use excessive trim to reach top end??

I dam near need to go to the trailer button, but she is safe and well mannered. Im only going low 70s though.

This may sound silly, but all of powerquests numbers are made on lake Macatawa in Holland, MI. When the wind is west or southwest it sets up a tight little chop on that lake which these boughts just love. My 2002 380 with 500 efi's reached its best ever speed on this lake (82 MPH) but cannot duplicate it on lake Michigan on a regular basis.

Any one considering ITS should think twice. From what I have been able to ascertain, It actually slows the boat down. A stock bravo transom is lighter (cheaper!!) and seemingly faster. Imagine my surprise when I opted for a pretty expensive option package including 500 EFI, ITS and Arneson rocker plates only to find that a 500 EFI on a stock transom with K-planes is as fast or faster. I would have thought the extra leverage would have carried the bow better but it doesn't seem so. Oh sure the Sh*t looks cool hanging of the back when on the trailer.

I don't think my rocker plates have enough pitch authority in rough conditions Any one care to throw in some ride quality comments in 3 to 4 footers and what tab settings are being used if using K-Planes. As to the blowout past 2 index on the trim guage, that has to be a seriously aggresive X. I raised mine 2" from factory with shortened lowers and can trim to the scale limits w/o blowout using 29" P5-X's. I think I need a bottom guru cuase I am getting sick of testing and changing. It seems like I may use the lifespan of my motors getting dialed in.