I going to buy a JRSC due to the fact that I like the eaton blower the best. A couple of questions for the SVT JRSC's out there.

1. I have heard the JRSC in the SVT is underspun, is it?

2. I want to change a pulley on the supercharger to up the boost, what size is the pulley and where do I get it (besides that where do I get the belt to fit it).

3. Also I saw a boost upgrade on Focus Central for the JRSC to boost it 1-2 psi, is this a crank pulley or a SC pulley that I am looking for?

4. Do underdrive pulleys have to come off when I do this, or can I run a ultra light crank and SC pulley in the same combo.

5. What is the max limit to what the JRSC can put out safely (not to damage the internal components)

6. My friend owns a GTP and when he changed the pulley to up the boost, he also changed the pulley rod, is this possible in an SVT JRSC.

Originally posted by DilSVT
I going to buy a JRSC due to the fact that I like the eaton blower the best. A couple of questions for the SVT JRSC's out there.

1. I have heard the JRSC in the SVT is underspun, is it?

2. I want to change a pulley on the supercharger to up the boost, what size is the pulley and where do I get it (besides that where do I get the belt to fit it).

3. Also I saw a boost upgrade on Focus Central for the JRSC to boost it 1-2 psi, is this a crank pulley or a SC pulley that I am looking for?

4. Do underdrive pulleys have to come off when I do this, or can I run a ultra light crank and SC pulley in the same combo.

5. What is the max limit to what the JRSC can put out safely (not to damage the internal components)

6. My friend owns a GTP and when he changed the pulley to up the boost, he also changed the pulley rod, is this possible in an SVT JRSC.

You have a few options with the pulley, you can change out the Sc pulley with a regular ZX3 pulley, 3.0 inches instead of 3.6, i believe bri on FJ was getting 8-10 lbs. You can also go the route of installing an Overdrive crank pulley(C-F-M.com is a good company to deal with if you are going this route). An underdrive pulley will reduce the boost you are running, since i believe stock is 5.2, and an udp is much smaller. If you looking to run the JR safely with an upgrade pulley id suggest the water injection from Snow or other companies.

Originally posted by hogy72
If you looking to run the JR safely with an upgrade pulley id suggest the water injection from Snow or other companies.

I don't know what this is, but will the 3.0 pulley change the boost to around 8-10psi.

Also what is the JR black box I hear about.

yea i believe Bri is getting 8-10 pounds of boost out of the pulley. the black box is JR's from of tuning. Id suggest getting a tune from either mcnews, tom or focussport. BTW, you have a PM

I don't know if I can answer all of your questions but here I go.

1.)I don't know if it is underspun or not.

2.)I wouldn't reccomend getting the pulley upgrades on stock internals. I called Jackson Racing and asked for the pulleys, I was told they weren't ready for sale yet (Jackson racing sells belts with their pulley upgrades). But I think a company in florida make some, I think. If not you can have some fabed up, but that will cost a pretty penny.

3.)The boost upgrade pulley you saw on Focus-Central is a crank pulley.

4.)You can't run a underdrive pulley with the S/C, but you can run the supercharger pulley and the Focus-Central boost upgrade pulley combo. Again, I wouldn't reccomend it, brcause it is high boost on stock internals or SVt compression.

5.)I don't know how much boost you can run on a stock internals, but my S/C puts out 9psi.

6.)I don't know if changing pulley on th JRSC is like that, because I haven't made it that far yet on my mods.

The "little black box" that comes with the JRSC kit is a good idea, but it isn't very efficient. On my car the box causes the car to run rich fouling out the plugs and making the check engine light to come on. While driving down the road withcruise control on, when I get to the top of a tall hill, my car starts cutting out as if it were out of gas. I strongly reccomend that you do get some sort of tuning to override the "little black box."

If you have any more questions, I might be able to answer them. If you'd like you can email me at mysvt2002@aol.com.

that good info.what kind of hp/trq can you gain on a svtf to the wheels.

JR's website says: 204.4 whp and 154.5 wtq, but above and beyond that: ???