bsboss

Anybody tried Whipple recalibration PCM for the 525? What kind of results did you see?

Raylar

Raylar has done a lot of extensive tuning analysis and work with the HP525efi engine in developing our HP675efi conversion package for this engine. I can tell you from our extensive experience that there is no "hidden" power locked up in the stock Mercury HP525 racing programming in that ECM. The program as stock is about as aggressive in timing, fuel, coil spark control and such as it can be without hurting this nice engine package. The only thing that would be really possible for reprogram could be the raising of current rev-limit of 5350rpms, but that could sacrifice engine reliability and shorten engine life based on the 525's stock valvetrain system.Iit is well known even from Mercury when these engines approach 250 hours or so valve spring life becomes an issue.
On our new HP675efi conversion offering we only made some changes in the programming to align programming with the slightly different camshaft profile we used, the enhanced intake manifold breathing and to add fuel to change fuel programs for the new larger injectors we used on this package. We also developed this engine conversion package for the 5350 rpm rev-limit threashold to provide good longevity and reliability to the engine.

My suggestion and opinion for HP525efi re-programming; If you love your HP525efi, leave the program alone and be happy with a nice package- want more power from your 525, then use an upgrade to the engine like our HP675 package and achieve more power with the same type of relaibility and peace of mind.

Best Regards,
Ray @ Raylar

Whipple Charged

I'm not sure, but I think this was a question in regards to modifying the stock PCM on a stock engine. And while your testing might have found nothing, our extensive testing on our dyno, with individual cylinder to cylinder tuning ability, did. Thats why nearly every race boat out there runs one of our calibrations, as well as countless others.

There is horsepower left in the stock PCM's with the help of higher octane. There's many different cals out there, some, lean, some rich, some just right. There's multiple timing tables and multiple ignition systems/setups. So there is in fact HP to be made, there is HP to be gained. Some vary depending on the base cal, but to say there is no gains is very inaccurate.

Just do a search on performance boats forums, a customer posted his results there. Go to Key West or any other boat race and ask any of the race teams what they thought about the gains.

Raylar

Dustin:

Not to question your findings or tunes and I have the utmost respect for your systems, engine builds and tuning expertise. We just fundamentaly disagree here on what the average HP525efi recrational user should do to his stock HP525efi Mercury tune.
I don't believe the HP525efi user here identified himself as a racer. My point here is that without changing fuel octane as you mentioned or using the engine for racing as I am sure most racers will always run on the "edge" to gain an advantage and wins. My opinion is that the small extra gains made by pushing timing and rev-limits is not really a safe place to be for most recreational HP525efi users.
If you are a racer, willing to run higher octane fuel all the time and seeking another 300-400 rpms out of the engine and have the pocketbook to repair or replace the engine if it fails from the added strain of a "pushing the limits" tune then by your choice use Dustins programming skill and avail yourself of the benefits.
Just curious as I am sure the readers are what kind of extra HP were you able to gain with these re-tunes. I am assuming you see about 540-560HP from the stock HP525efi with factory tune.
Obviously, these questions and input from me are just my questions and opinions and I think I will stand pat on them for now.

Best Regards,
Ray @ Raylar

Whipple Charged

Whats important is the results, and you can ask any customer that went with the updates, they've all had positive results.

Some customers are looking for cleaner transoms, some are looking for mid range torque or quicker plane time. Others are looking for torque and hp, luckily we can work with all of them.

As for racers, its proof in the pudding so to speak. They all run 91-93 octane gas (depending on race venue), all run WOT from green flag to checkered and run the engines the entire season, some a lot more including poker runs and other events. If you can make it live on the race course, you can certainly make it live in a pleasure boat.

Before and after results on the same motor showed 25-30hp and the same in peak torque. Peak HP is at 5650.

Remember, we have our own Superflow dyno with individual air fuel per cylinder and all other possible measurements to get real world results.

Raylar

I very much understand that their are some slight improvements that can be made to eliminate transom sooting from overly rich idles, and some possible midrange added torque that can be added by increasing timing advance in the midranges with the use of extra octane fuel such as 91-93 octane whcih would be definitly needed to eliminate the real possibility of detonation at these rpms from the added timing and we both know that on most 525efi engines from mercury the knock override programming is pretty much missing on most of the 525's. The stock Mercury HP525efi engine has dynoed on many dynos around the country at about 540-550HP at 5300 rpms with a rev-limit of 5350rpms.
You indicate another 25-30HP at 5650rpms which would mean the untouched engine now produces about 565 to 580HP at this 300 rpm higher point. Knowing the stock HP525efi camshaft that's in the engine it is possible but seems a bit higher rpm than we and some others have tested the peak HP at RPM's. Some HP525's might come close to those numbers at that higher rpm but I still feel that this is pushing the stock HP525 to the extreme limit of valvetrain and block reliability for long term recreational usage.
Again if HP525efi users want to go to this level of tuning, more power to them!

Best Regards,
Ray @ Raylar

HaxbySpeed

Are you serious? The extreme limit of valvetrain and block reliability at 5650. That's a ridiculous statement.

bsboss

I was hoping someone would chime in that had actually tried one?

Thanks

Raylar

Yes I am trying to be serious. There are a good quantity of Mercury Racing engines that have rev-limits at 5650 or above, right from Mercury Racing as standard programming. The HP525efi is not one of them and I am sure Mercury Racing has done a lot of testing and evaluation of the engine above 5300 rpms and the real reason they offer good warranties and extended warranties on the 525 is that they know from years of expierence and many hundreds of warranty claims that that this is the safe limit for rpms on this great engine package for moderatly long lived reliable engine hours in general recreational use.
Mercury Racing recommends valve spring changes at between 250-400 hours on this engine and this is because obviously valve spring poundage on the OEM springs starts falling off and there is an increased chance of valve float and subsequent engine damage that is sometimes very catistrophic in nature and expensive to repair. Obvously the engine rev-limit can be changed with new programming and almost all the racers using the engine and a lot of Poker Runners make this change when tweaking for that extra bit of power. When a racer breaks he goes back on the trailer, goes back to his shop and wrenches the engine back to life with the expectation that to win he has to push the limit and thats the costs of racing.
I believe and most in the industry would also support the idea that the reason the HP525efi engine has such a good reputation is that it offers good performance and reliability that bears out in the market place over its ten year industry life. If one could show that lets say over 50% of all HP525efi's have had their rev-limits increased to 5650prms and they still support the same history of good reliabilty and life I would gladly change my opinion. I just don't think this is even close to the case!

With todays average "Joe Boaters" tight economic condition many HP525 owners ,especially in twin engine boats cannot afford the cost of early failures and breakdowns in their 525's when they set them up to the limit and hence its always a great thing to do when its first done, but it usually becomes a big mistake the boater says he should maybe have not done, when he scatters one or both of his expensive HP525's.

Again, just my opinion and not Gospel. Every performance boater is free to do whatever he choses to do to his boat and engines. Just trying to put forth some reasonable food for thought.

Best Regards,
Ray @ Raylar

Whipple Charged

Again, which racer is "breaking" the motor and putting on the trailer from engine failure on the 525's? I know of countless race motors that are running 6000rpm, yet, no breaky. Many have well over 200 hours, I know of some approaching 400 hours. The factory valve train has ZERO problems at 5650rpm!

Keep in mind, that "extreme" limit of 5650 is only 50 rpm higher than the factory actual limit. Stock "warning rpm" is 5450. The PCM actual max rpm is 5600. So one can consistently run at 5600rpm with a stock setup from Mercury Racing.