Anyone here running both underdrive pulleys and an electric water pump?

Casey4s said:

I have a Meziere Electric water pump already on my car and I am contemplating adding a Steeda pulley set. I have an email off to Steeda but haven't received a reply yet. I asked if there was any incompatability problems.

The pulley on the electric water pump is a free wheeling idler pulley so I don't think it will need to be changed out. (in fact the Ford or Steeda pulley will not interchange with the Meziere pulley anyway)

I read the install instructions and you simply re-install your existing serpentine belt, the tensioner takes up any slack.

I will repost after Steeda answers me...

Click to expand...

If you're not dead set on the Steeda pullies, I just took delivery of my set of the Summit Racing U/D pulleys and they really look great. They're 18.1 approved and seem to be a quality piece. I did a little bit of searching on them before buying and read posts from guys that have had them on several months to a year now and haven't heard anything negative at all about them.

Based on what I've found, it looks like they may be made by UPR and sold through Summit. This is only a guess however, which I'm basing on the fact that the UPR pulleys look identical the the Summit ones?

05-10 Mustang GT SFI Pulley Kit

The best part is that they're only $149.95 for the complete set, compared to $199.99 for the UPR and $209.95 for the Steeda's.

Summit SUM-C2512 - Summit® Bracket Racer SFI Damper and Pulley Kits - Overview - SummitRacing.com

If you are set on the Steeda pullies, check out Brenspeed first. They will sell just the crank pulley to guys like us using the Meizier pump.

Mustang GT Steeda Underdrive Crank Pulley Only (05-10)

It'll save you a little bit of money over buying both pulleys, just to not be able to use the water pump one anyway?


They also quote a short belt for the swap,

GATES BELT FOR MEZIERE & STEEDA CRANK 05-10 MUSTANG GT

which brought me to my original suspect and probably the answer to your question. The tensioner should be able to pick up the slack with both the underdrive crank and water pump pulley installed, but the underdrive water pump pulley is a fair bit larger than the stock one....which I imagine is mostly responsible for taking up the majority of said slack. If its not on there, then you've got both a small crank pulley and a small (stock size) water pump pulley on the Meizier...which by the looks of it means you need a shorter belt.

...so, back to my problem. I would normally just go and order the belt, but the 5.4L block is taller than the 4.6L and the Truck pulley configuration and therefore belt length may be different than that of the Mustang, so I don't really have any guarantee that the belt is the correct length.

But, if I knew the stock Mustang GT belt length and compared it to the length of the one sold through Brenspeed, then I should know roughly how much shorter the drive belt on my F150 needs to be.


....so, again....what's the stock '05-'09 serpentine belt length pretty please?