High Flow Water Pump With UDP's

[98MK8]

Hey everyone. I just purchased a set of underdrive pulleys, from SCP. I figure when i install them i may as well install a new water pump. I seen the High flow water pump on SHM, here's the link http://www.seanhylandmotorsport.com...d=816&osCsid=40a532db508a2d809f1940493d12a66d


1. Would this be a good addition to the UDP's since the water pump's going to be underdriven? That way i have a better flowing water pump?

2. This high flow water pump will correctly fit my 1998 Mark VIII LSC as well, correct?

Thanks alot in advance.

 

[98MK8]

Does anyone here run Under-Drive Pulleys in their Mark VIII's? If so, how many miles have you had them? Brand? Noticeable gain, MPG, power? I am new to these forums, and to Mark 8's, so any help is GREATLY appreciated! Thanks!

 

[driller]

Welcome.

As a general rule, the under-drive pulleys are not recommended for the Mark VIII because of cooling and charging issues, especially at idle. Generally, it is acceptable to have an under-drive crank pulley but leave the stock alternator and water pump pulleys. However this will necessitate a shorter serpentine belt.

Of course if you install steeper gears you could argue that point, but still at idle you will most likely see diminished cooling capacity and under charging.

I asked many the same questions and arrived at a rather unorthodox compromise. I installed a Steeda under-drive crank pulley leaving the stock water pump and alternator pulleys. It did not take long to notice diminished charging. Cooling was perhaps somewhat affected but not to extremes, however I live in a generally temperate climate.

To cure the charging issues I actually swapped in a smaller alternator pulley to increase the idle speed of the alternator close to that it was stock. Later I installed an electric water pump(for different reasons). I have no charging/cooling issues with such a setup.

While I am not familar with the SHM high flow water pump, I surmise it is only a change in the impeller design. You can get the same by installing a Cobra water pump of the same heritage. Any water pump for a '96-'98 Cobra 4.6L DOHC will work, but there may be others. Evans cooling also has a high flow water pump for the 4.6L DOHC mill.

 

[98MK8]

Welcome.

As a general rule, the under-drive pulleys are not recommended for the Mark VIII because of cooling and charging issues, especially at idle. Generally, it is acceptable to have an under-drive crank pulley but leave the stock alternator and water pump pulleys. However this will necessitate a shorter serpentine belt.

Of course if you install steeper gears you could argue that point, but still at idle you will most likely see diminished cooling capacity and under charging.

I asked many the same questions and arrived at a rather unorthodox compromise. I installed a Steeda under-drive crank pulley leaving the stock water pump and alternator pulleys. It did not take long to notice diminished charging. Cooling was perhaps somewhat affected but not to extremes, however I live in a generally temperate climate.

To cure the charging issues I actually swapped in a smaller alternator pulley to increase the idle speed of the alternator close to that it was stock. Later I installed an electric water pump(for different reasons). I have no charging/cooling issues with such a setup.

While I am not familar with the SHM high flow water pump, I surmise it is only a change in the impeller design. You can get the same by installing a Cobra water pump of the same heritage. Any water pump for a '96-'98 Cobra 4.6L DOHC will work, but there may be others. Evans cooling also has a high flow water pump for the 4.6L DOHC mill.

Well, i don't think i'll get the UDP's, i mean i can just take that money and put towards something else, because he hasn't shipped it yet. I thought about what you guys said with the charging/cooling/oil pump issues, and decided the price of having all those systems functioning good instead of LESS, is much better than 10HP, lol, not even a choice in my book. I'll call SCP tomorrow and have them put my money towards something else. Probably the MAF kit with conical. Thanks for all the help, its appreciated.