353 500's vs. 525's
 

What is the real world speed difference between these 2 engines in a 353?

It seems like there isn't a substantial jump in speed in the 353 til you get to the 600hp mark.

So are the 525's worth the price jump over a comparably equipped boat with 500's?

This is an easy comparison for me to make because my 353 has the 525EFI's and good friend of mine that I boat with a lot has a 353 with the 500EFI's. There isn't a HUGE difference in performance, but even though the 500EFI's are great motors, IMO the 525's are worth the extra $$$ if you can afford them. The 500EFI is rated at about 470HP at the prop and the 525EFI is 525HP at the prop, so you are only talking about a 55HP difference X2. The REAL world difference is that I can still hit 80MPH with a full tank of gas and 4 people on my boat and he can't! :angry-smiley-038:

The cost of upgrading from a 353 FasTech with 500EFI's to a 353 with 525EFI's? ... probably about 15-20k

The feeling you have when you're out in the River on a Sunny Sunday afternoon and you walk by your friend's 353...? PRICELESS! :bunnydance:

If you can afford both senerio:
But cant you bump up the power in a 500EFI to greater than 525 with the extra 15-20k and have fresh power? May even have a little left over to do some updating of the interior since a 500 boat is likely to be a few years older?

What years did they offer the 500? and what years were the 525s? I think the big difference will be the X Dimension they did in the later years.

Perfect Storm, can you reliably hit 80? I was under the impression that the 353/525 combo was a close but not quite 80mph set up.

If you can hit 80 with 4 people and full tank of fuel, that is pretty impressive.

I realize they were still dialing it in, but the Illmor boat with the new 570hp motors, only did 78 in the test I read.

We just went thru the 500 vs 525 comparison and ended up purchasing a 2005 353 with 525s , ITS and XRs. I weighed the pros and cons and it came down to this for us:
-The ease of resale down the road
-Cabin, controls and , graphics are current updated style.
- I did not have to do any upgrades or fix or repair a thing.
The argument can be made to purchase a 353 with 500s and then refresh/build them, then do the drives, then do the interior, cabin, and everything at the helm. This will get you the same or better performance to the 525s depending on the pocketbook. As a recent purchaser who spent over a year on this process I can say that you will never get the return on the time and money you would put into the 500 project getting it to perform and look like the 525 boat. Buyers like myself are going to lean to a stock 525 equipped boat that is stock versus a 500 upgrade when pricing is scaled accordingly.
The 500s are perfectly capable and solid, I would not hesitate to own the setup. Buy it to enjoy it, if modifying it understand you are adding zero value.

VoodooRob, what speeds are you seeing with your boat? By that, I mean on an average day, not, once when the current was with you, wind at your back, 1/2 gallon of fuel, and a 80lb chick driving.

Just kidding, but it seems there are a lot of people that will use that magic number when they get asked "how fast" while in reality, it hit that number once and every other day it does 3-5 or more less than that magic number.

I personally am much more interested in what a boat will run in August, with 4 people, 1/2 tank of fuel and full cooler. Because that is closer to how I spend most of my time boating.

500 efi vs 525
 

There are other things to consider in this comparison besides the engines. From a Formula perspective, 525's typically came with xr drives, and often other props than the Bravo 1's that most 500's had. The cmi exhausts on the 525's don't seem to last as long as those on the 500's. I replaced my originals (500efi's) CMI's last year (pm), they were 11 years old and never leaked. The owner of the marina where I bought my boat had the same boat as mine but 1 year newer and over 600 hours on the clock on original cmi's and engines (500 efi's). My engines only have 260 hrs but no issues. I replaced the valve springs last year - preventative maintenance. My boat will hit 80 gps in salt water. If the only difference in two boats were the engines, I wouldn't spend any more for the 525's. The drive diff though, between the xr's and std bravos, might be important to someone who runs their boat hard from a stop. I haven't seen a problem with the std bravo drives with bravo 1 props and some restraint when getting on plane. If you want to use a more efficient mid-range prop than the bravo 1's, they will put a bit more stress on the drives, and the xr will handle that better. -Bill

Sorry but I cannot comment on the top speed, We are picking up the boat from the dealer next Saturday April 13! The dealer I am buying from sold the boat new so they have the info from the first run. The boat ran 84 with 2 people and 3/4 tank of fuel. Seems good enough for me, it matches all the homework I have done. Seems like there is on avg of additional 7mph of 500 EFI over 496HO and avg of 5 MPH of 525 EFI over 500 EFI. The few 600 SCI I have read about seem to be right around the 90 mark, maybe an owner will chime in. I feel you can't go wrong with any of the blue motors in the 353. Definitely worth the extra $ if its in the budget.

You will have NO problem with the 525's hitting 80 MPH in August, with 4 people, 1/2 tank of fuel and a full cooler. Our Buffalo Poker Runs are in August and I leave the boathouse with 4 people, a full tank of gas, a full cooler AND a full fridge and I never have a problem hitting 80 MPH during the run. I'm running 33P Labbed Bravo 1 props.

That is much stronger than I thought that package was, Perfect Storm, thanks for the info.

I wonder what the Ilmor boat will do when they dial it in. I was pretty shocked when it only ran 78. I believe those engines are a good bit lighter, and they are rated at 45 hp more each. It seems like that combo should be good for a solid 85

It ran 81 out of the box. I think your 85 number will be close after prop/gear ratio is finalized.

I don't recall seeing heat exchangers on the 500's. Are they fresh water cooled like the 525's? A major consideration if you are in salt. Didn't they go to aluminum heads on the 525's?

As far as I know, 500's are not fresh water cooled, and 525's are, also 525's have aluminum heads, 500's use iron heads.

525's are closed cooling and the 500's are not. Fewer valve spring issues with the aluminum headed 525. 2-4 mph difference. I think everyone nailed it down pretty good.

No x dimension changes, but boxes made a 1-3 mph difference.

Dave

Took the boat out for our "new to us" first run on Lake Erie, launched out of Black River in Lorain, OH on Sunday 5-19-13. Spent 2 hours just learning the boat and its layout. Drives like to be trimmed in on launch with tabs neutral, keep it at 3,000 rpm and wait for it to hook-up. Trim out drive and let it run! Did a couple of speed runs and 83mph with 2 people and 3/4 tank of fuel, great way to cap off a good day.

Just a suggestion, only tach it up to about 1500, then progress to 2000, then to 2500, and then to 3000 waiting 10-20 seconds in between changes. It lets the heavy boat "catch up" to the prop. It will also save you an expensive drive repair in the future!

Dave

I pulled some of my old power boat magazines out last night and in 2003 they tested 353 with 525s 33 labbed props 85 mph with Bob T at controls.

Older thread about 353 and speed :-)
I know for a fact that there is a 353 Fastech in Sweden with merc 600 tuned dynoed at 711 hp, doing
100 mph at the gps. The owner is sure that there are a couple of mph more in it :-)

I have a 2000 353 with 500's and it will run 80 moderately loaded - 4 people and 1/2 tank of fuel, bravos 30p not labbed, no boxes, 280 hrs on the boat, although I rarely run it flat out, the ocean often doesn't cooperate. Great engines, no problems other than a fuel pump relay. The CMI's seem to last longer than on the 525's. I replaced mine two years ago although I had no leaks on the originals. Also replaced the original valve springs which also had no problems. I always fresh water flush the engines myself after a run in the ocean. Met a marina owner (fresh water) who had the same boat as mine, a year newer with 600 hrs and he told me he had never done anything to his engines other than regular maintenance like changing oil and had zero problems with them. He had not replaced the valve springs. My boat does have the changed x dimension that formula instituted I think in 2000.

I have a 2000 353 with 454 500hp heads cam and a 250 single carb blower set up. I dynod and got 610hp 5lb booste.
Low fuel two people low wafter tank. The boat also has neutral extension boxes. GPS BEST SPEED trimmed all the way was 83mph! I don't know how some of these people are getting these speeds with 470 500 hp?? Maybe I'm doing something wrong.

I think powerboat tested the 353 at 90 with 600sci engines. Maybe you could see what the setup was on those boats.

Well, first of all, what are the torque numbers? Secondly, what is your max RPM in the boat compared to the dyno?

Boat test at 90 with 600's is very generous....85-87 is the real number.

Dave

That's what I was thinking. Dream O meter
5500 608 hp
5500 597 torque
83 mph best I've seen in the ocean,low on fuel, 2 people
5pounds booste

I'm on GPS garmin and handheld GPS, best so far was 84.7, have not got it there again. Always 83.5-83.8. My GPS speedo says 86, and there is no way the boat does that.

Voodoo what are you running for power?

525s with ITS, XR Drives and 5 Blade Maximus 28P worked by BBlades. 280 K-Planes. Little over 320hrs with top ends done last season.

Nice set up!
I'm thinking shortys will help me out a bit. Has to be good for 2-5mph

You have the first Gen hull? I do not have info about shorty performance on that specific hull. I know on my year the shorties do not add performance with my set-up, there was an OSO member that tried it and the boat did not run out well. There is an 06 353 with exact same running specs/hrs as mine in LEOPA but does not have ITS and the boat did not touch 80. There is something to having boxes on the 353 to get some speed out of it. Have you tried 380 K-Planes? That is next on my list if I can get the clearance.

I know for sure that these numbers ar the real thing, I do not know how many was onboard or how mouch fuel etc. That's not important when you go for a top speed run. Indy drives with 2" shorties 5 blades labben 34 pich propellens, reach 100 mph :-)
Boattest.com maxed out at 80,5 mph with 525 and bravo drives. When I wahced that test on YouTube it looks like they never got the boat "out of the water" ...

It is the 2012 353 test I am referring to

It seems that you need big power 650 + hp and boxes / shorties to get the 353 to real fast :-)

Marcus the owner of the mentioned 353,told me he is going to upgrade the engines with Whippels 900 hp ++
This year. Then it starts to get realy interesting ;-)

The boat did 80 mph with the original engines 500 MPI and Bravo drives

Not sure, it's a 2000. I have nutral extension boxes with the 380 k planes. Planes made the boat handle a little better and gave a little better ride to. If you can I would go with the 380s I wouldn't go back

I have a 2004 353 with 525's, xr's, stellings extension boxes. Best speed on gps was 86.4. Consistently hit 84. I have labbed 5 blade maximus turning out. This was formula factory setup. Problem is I am destroying drives. Any of you guys have recommendation for four blade prop?

BTW, the older fastechs were appx 1000 lbs lighter than the current model which may account for the variations in speed reported.

2000 353 any ideas on props? I would like to try out a new set. I currently have 28 4 blades. Any pros or cons to trying 5 blades? Anyone running similar hp in this boat?
5500 608 hp
5500 597 torque
83 mph best I've seen in the ocean,low on fuel, 2 people
5pounds booste

There are a few 353s out there with Merc 600SCI, if I remember correctly they run 30 Maximus 5 Blade props and run 90 mph or very close to it. The extension boxes help also, you might want to call Brett at BBlades. He has plenty of notes on the 353 with different power combos.

Thanks I will call him.
I do have neutral boxes on also.
Thanks for the input

I ran 30 pitch 5 blades until just recently (525's w/Whipples/XR's. 780 hp). Best of 97 in fresh water. They are for sale in the classified section.

Just put on 32 4 blades, but have not run it hard yet. Both sets were labbed by Bblades. I expect a few more mph out of the 4 Bblades and for them to be a bit easier on the drives. The only downsides thus far are a l itttle prop blow out with the 4 blades and more RPM at mid range cruise.

Hope this helps.