Thread:

So....why a 600SCi instead of the 525????

Originally Posted by Beer:30

Hopefully, DILLIGAF, Probably the biggest benefit is having the same HP all the time. Regardless of temperature, altitude, or any combination of both (density altitude) - you have the rated HP at your disposal.

The ECM and a combination valve keep the HP of the motor the same regardless of the previously mentioned variables. So, let's say the HP is 600. You can go to Tahoe and have 600HP without touching the motor or ECM. You can go back to Havasu or even a lake at sea level and the HP is still 600. It can be 40 degrees outside or 114 - you will still have 600HP.

Clear as mud?

Comment:

The above statement is completely untrue---please forgive me I do not like contradicting a PB member such as Beer30 as he is a very knowledgeable person. However, I shake my head when this type of misinformation is quoted to the public.

Both the HP600 and HP700 are affected by altitude changes [1000ft+] and [arizona heat 100+] and to say that the motor produces the same HP all the time is untrue. Why! because there is no way the ECM can compensate for such changes and that is not muddying the factual waters when you drive the combination in those types of conditions you will simply not have the power delivery in 105 degree heat at lake Tahoe and that will be perfectly clear when you push the throttles forward.

If you need a second opinion, Team Mercury came out to Havasu in July to install two HP700 motors and said the exact same thing when conditions were very hot ie...100+ motors aren't gonna make the power for the top end we were looking for in those conditions.

Originally Posted by relaxalot

I have a 600 sci with a stage one program from whipple. 670 hp. Stage two is a smaller pulley which would be another 60 hp. These motors (the 600) is the exact motor as the 700 except for the cam and pulley. They are detuned and can be "adjusted" to be over 800 hp. This would require a larger intercooler and smaller pulley and a cam.

Mine has 140 hours and it runs perfect. It is somewhat sensitive to outside air temperature even though it is rumored not to be. I definately have more power in colder temps.

Initially I had some water pressure issues which have now been solved. The motor has a noticeable mid range power band which I think is the most noticeable over the 525. I have to admit that without the reprogram the motor seemed kinda sluggish. After the reprogram... wow!

Relaxalot has a HP600 and so does my buddy C-Ya they both have quite a bit of experience with this motor combination. Relaxalot is more diplomatic than I am in his responses.

Initially, the HP600 had some code problems with the motor wherein the water from the intercooler was being dumped directly into the exhaust and causing problems ie... creating to much back pressure and setting off codes. This was remedied by dumping the water out of the side versus through the exhaust.Once this was corrected the motor runs strong and pulls great everyone was happy.

If your friend currently has a HP525 in his boat--- he can explore the Whipple option [AX200] for that motor provided it is not under warranty. The Whipple option is not that expensive bolts on in a rather simple procedure and produces great horsepower depending on the boost level you choose for your application.

If you seek a complete motor swap going from a HP525 to a HP600 is not a prudent idea the HP gain is not that dramatic and only the delivery of the power ie...throttle response is the only real difference albeit it is quite noticeable--- but overall in my opinion I would simply Whipple the 525 provided it was still rather fresh ie...low hours.

More facts are needed in your scenario as your question is overly simplified but I hope this assists your friend in his/her decision making and/or gets you pointed in the right direction budget wise.

Your Friend,

KAP

Originally Posted by Beer:30

If I was incorrect on the power compensation dealio, I apologize. I was under the impression that the new 600SCi and 700SCi's both compensated and made their rated HP regardless of all of the variables. I'll have to look back at the previous news info that I got that information from. Is there another Merc motor I am thinking of? I could have sworn that was their new selling point for the new motors.

I am one for always providing accurate information when possible and don't like to see people get bad information.

The 700 is advertised by Merc Racing to maintain consistent HP under all conditions through the ECM's control of the boost relief valve resulting in varying boost pressure. Not sure about the 600. Mike (ClownRoyal) has confirmed to me that his 700's make less power on Coeur d' Alene Lake then they do on Havasu. Go figure

You guys know your stuff I knew if the comedy was set aside that some real good info would get posted.

Originally Posted by Beer:30

I know it was advertised that way somewhere. Still trying to find it. It is possible, though as a lot of turbo systems are designed these days to maintain boost level/HP regardless of altitude. My plane is that way, so there is no reason a boat/car can't do it. My Buick Grand National was fully compensating in Colorado when I took it to visit my sister. It took a bit longer to generate the boost, but it still went right up to 17psi.

Now, there will always be a "critical altitude" where the blower/turbo cannot generate additional boost due to lack of density. At 16,000 feet, my turbo is "all-in" and cannot maintain sea-level HP anymore. HP starts to drop from there on up.

I was lead to believe that the new PCM 07 modules controlled the air/boost valve on these SCi motors similar to a wastegate on a turbo.

My understanding as well. As I said however, a friend with twin 700's let me know, when we met in ID summer of 07, that he was down a few MPH, at about 2500 feet.

What kind of performance difference did you experience? Any concern about the added stress on the drive?

Originally Posted by relaxalot

I have a 600 sci with a stage one program from whipple. 670 hp. Stage two is a smaller pulley which would be another 60 hp. These motors (the 600) is the exact motor as the 700 except for the cam and pulley. They are detuned and can be "adjusted" to be over 800 hp. This would require a larger intercooler and smaller pulley and a cam.

Mine has 140 hours and it runs perfect. It is somewhat sensitive to outside air temperature even though it is rumored not to be. I definately have more power in colder temps.

Initially I had some water pressure issues which have now been solved. The motor has a noticeable mid range power band which I think is the most noticeable over the 525. I have to admit that without the reprogram the motor seemed kinda sluggish. After the reprogram... wow!

I know that in theory and in Mercury advertising the computer is supposed to adjust the motor so it generates the same hp and torque at various a ltitudes and temperatures but in reality this does not happen. It may be true that the supercharged motors are less affected by outside temp and altitude but they are affected. My boat runs about 5-6 mph faster in cold weather (75 degrees) than hot weather (115). Water temperature might be a factor also due to the intercooler temperature. All being said I would buy a 600 Mercury again. I would prefer the 700 with the NXT drive.

Comment:

Sorry Tom aka Dilligaf---I did not want to digress from the topic if possible could you give us more facts ie...

1. What is the end desired goal?
2. What is the driver looking for with this power plant?
3. Is this an engine swap or simply a quest for more power?
4. Is this a XR drive set-up or other?
5. Any budget constraints or can we suggest alternate power sources.
6. Is the choice limited to factory Mercury power?

I did not intend this to be a comedy act--- I understood your request to be a serious one----hence the seriousness of the contradictions in information. I want you to get the straight dope versus the advertised mantra.

KAP

Originally Posted by Trifecta

What kind of performance difference did you experience? Any concern about the added stress on the drive?

I was concerned about the added stress to the drive. So far no problems with it. Magnets are clean. I also run a five blade Maximus prop. I am careful out of the hole and I easy on and off the throttle.

The performance difference was VERY noticeable. The stock Merc setup was overprotected by the computer. After the program the motor has alot more torque all through the powerband. Full power is available all the time. I think that Merc has detuned this motor and drive combination a ton to Warranty their product. I actually don't remember the price that Dustin charged to reprogram the computer. I had Aaron at Absolute pull the computer and he sent it in to Whipple. I only had stage one done. I know someone with a stage two reprogram and pulley and he runs 5 mph more than me in the same boat. I would definately do it again! It just wakes up the motor alot. It is not only 70 hp it changes the torque band also. The only negatives with the motor is when you are pushing hard it gets thirsty. I also had some issues when I first got it with water pressure too low. Everything is fine now and I am a happy camper.... or should I say happy boater!

Originally Posted by KAP

Comment:

Sorry Tom aka Dilligaf---I did not want to digress from the topic if possible could you give us more facts ie...

1. What is the end desired goal?
2. What is the driver looking for with this power plant?
3. Is this an engine swap or simply a quest for more power?
4. Is this a XR drive set-up or other?
5. Any budget constraints or can we suggest alternate power sources.
6. Is the choice limited to factory Mercury power?

I did not intend this to be a comedy act--- I understood your request to be a serious one----hence the seriousness of the contradictions in information. I want you to get the straight dope versus the advertised mantra.

KAP

P.S. you will need to buy two of these motors and have a strong tailwind to keep up with Kap...