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JR Supercharger info

1K views 27 replies 15 participants last post by  jonszx3 
#1 ·
Im looking into buying a JR SC with the 2.6 pully and have a few questions id like answerd if possible.

1. On a stock car what would the HP to the wheels be around?

2. What size injectors would I need to run this setup without maxing out the duty cycle and still have room for other power increasing mods?

3. How much work would it take to get the car to 190-200 whp?

4. Would it be better to look into a 2.5 long tube header/flex/exhaust or would 2.25 be more to the cars likeing?

5. Overall reliablity of the JR, ie how has the car/engine survived the test of time.

6. Is it a loud SC or pretty quiet?

7. Some idea of track times with it?

8. Looking at running nitrous with it later on, (2 summers from now) what would be the safest way to set it up?

9. Any comments you have on the JR in the way of performance or whatever else.
 
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#4 ·
Get a copy of Focus Fanatic and read...
You'll find all your answers in there...
 
#5 ·
Search, young Jedi


And, to answer one of your questions, yes, it will be louder, esp under boost. But it's a good loud.
a very good loud indeed. took my first ride in a jrsc'd svt yesterday and the sound was beautiful. at 4k the blower was screamin and the car was pullin. great buy in my book.
 
#8 ·
I'm in the end stages of trying to get serious power out of my JR M-45. I just got it back from Endyn with a 2.3" pulley, so I have an extra 2.6" I used for about 5 months. To answer as many questions as I can:
about 170-180 WHP / I am trying to get 200 WHP or better with the refit & coating from Endyn and have run 42 lb injectors right from the start / I can't comment on your choice of exhaust - I have a Random Tech cat & a custom exhaust (nice and quiet) / I blew up the stock motor (shattered piston #1, bent the rod - have for souveniers)
because of TUNING PROBEMS / got a new block @ 9.2 - 1 CR from Tom's shop / and lastly the thing screams under boost -
it scares the s#*! out of other "performance" cars when I pass them. NOTHING sounds as cool as a blower whining when you have a quiet exhaust that doesn't drown it out. It was barely noticable with the original pulley. Performance wise it is much better than original, but you have to get PROPER TUNING by a pro rather than a guesstimate chip burnt.
Good luck.
 
#11 ·
I'm in the end stages of trying to get serious power out of my JR M-45. I just got it back from Endyn with a 2.3" pulley, so I have an extra 2.6" I used for about 5 months. To answer as many questions as I can:
about 170-180 WHP / I am trying to get 200 WHP or better with the refit & coating from Endyn and have run 42 lb injectors right from the start / I can't comment on your choice of exhaust - I have a Random Tech cat & a custom exhaust (nice and quiet) / I blew up the stock motor (shattered piston #1, bent the rod - have for souveniers)
because of TUNING PROBEMS / got a new block @ 9.2 - 1 CR from Tom's shop / and lastly the thing screams under boost -
it scares the s#*! out of other "performance" cars when I pass them. NOTHING sounds as cool as a blower whining when you have a quiet exhaust that doesn't drown it out. It was barely noticable with the original pulley. Performance wise it is much better than original, but you have to get PROPER TUNING by a pro rather than a guesstimate chip burnt.
Good luck.
I didn't notice the supercharger whine much at the stock configuration. However, with each boost increase, it got louder (naturally). Even with my fairly loud exhaust (RT cat, FocusSport flex pipe, FS "stealth" resonator, and FS ceramic coated exhaust and running 14 psi.) my supercharger whine is VERY noticeable (i.e., LOUD) outside the car. The exhaust doesn't even come close to drowning it out. Of course, I'm sure there are Focus people with louder exhausts than I have. Yes, it is pretty scary (deafening in an enclosed dyno chamber). According to Lidio, you can spin the hell out of these blowers with no loss of longevity of the blower.
 
#12 ·
I just got it back, but it's not on the car yet. I feel like an 8 yr old the week before Christmas - I CAN'T
WAIT !!!!!!! The only thing I need to hear is that somebody can tune the ATX whether it's a chip or reflashing
the computer. Tom? Mike? How's that coming since you got your ATX?
 
#15 ·
you can get 30 lb injectors cheap enough - try going to a Mustang site. They are the common size for N/A 5.0 upgrades and maybe you can get a used set for a song. Hell, they're not that tough to install. If you've changed spark plugs then you've got the basics down for injectors
(but be careful of the fuel spillage)
 
#17 ·
ive got a jrsc, 2.6 pulley, and vibrant exhaust, and 3 grand to make it faster! what kind of engine/supercharger mods are there to get max hp with that base and 3000$. I like the idea of nitrous...

Jon
 
#18 ·
For three grand, I am pretty sure that you could get a Whipple charger, a custom adapter plate that incoporates a Laminova air-to-water intercooler and the custom tuning needed to run it. Since screw chargers are efficient above 20psi, it will not be the weak point: you will three grand to upgrade the motor to take advantage of all that it can give you!
 
#19 ·
yep, didnt understand any of that!
 
#21 ·
that sounds like a lot of things that dont mix well together. im thinking 65mm tb, kamikaze haeder, 2.5in stainless exhaust from trubenz, and some cam gears. any people that have done different tuning wit the jrsc want to enlighten me?

Jon
 
#22 ·
back to the second post... not to be a dick but whats the point of posting anything if all you do is search? with the questions he asked there could be some new answers, thats the whole point of the forum, to answer new questions and update the old... granted searching is a very powerful tool it is a lot easier to post something new... i guess what im saying is that if everyone searched there would be no new information and no posts because im sure almost every topic has been covered... people would soon lose interest in the forum and we can't have that happen now can we?...
 
#23 ·
ok guys I'll post whats on our car, again


JRSC M45
7lb pulley
prototype JR short ram intake with MAF and conical JR filter
30lb injectors
65mm JR TB
JR "R4" control box (prototype)
FocusSport long tube header, flex pipe
Magnaflow resonator, center exit exhaust

we have FRPP cam gears, but they've never been tuned
stock head & motor

last one at dyno day was 184 whp on a cold motor, with a splash of NuTec thrown in to smell good


If you decide to go bigger boost, you'll need to a handle on fuel delivery. This prototype kit uses the R4, some guys do a chip, etc. I'd be happiest with a Pectel, but beggars can't be choosers. Remember that superchargers like lots of air, and they don't like to suck through a long intake. Keep it short. The ultimate deal would be some sort of ram air setup thru your hood--I'm pondering the idea for our car, maybe graft in a naca duct setup, as well as a vent back by the SC to draw out a bit more hot air.

We've driven our car all over, including up through Central California on a 115 degree day, passing rigs on long grades. No detontation, runs fine on pump gas.

If you're looking more for 200whp+, you might look into the M62 instead of the 45. It has been done, and is do-able again.
 
#24 ·
Ill be running the 2.6 pulley on my jrsc. is there any need for different fuel management? I believe Erik (TRUenemy00) is sending me a custom shorter intake so im covered there. is there any chance that the prototype things will become available, or should i look for Tom from focus-power and get a MIC from him

Jon
 
#25 ·
yep, didnt understand any of that!
Sorry, was typing fast.

Here is the best way I can put it: at some point your 45 cid roots supercharger will no longer be working in the proper range. Imagine getting a custom chip for an otherwise 100% stock Zetec that raised the rev limit to 8000rpm. Sure, you can now go to 8000rpm, but the motor is not at its best there. Same thing with a blower. As you reduce pulley size, you are spinning it beyond it's natural sweet spot. The result is heat, which, if you are not aware, is really bad.

So, my suggestion is to chuck the roots blower (what you have) and go to a screw type blower. BTW, Mercedes just did the same thing on the C-class, so I am not alone in this opinion. Screw chargers add a lot less heat and can be spun much faster and still work really well. Problem is, that your JRSC manifold is not designed for a screw type blower's bolt pattern, so you will have to get an adaptor. Since you are at it, and it might not add much in terms of cost, it might be possible to get the manifold reworked so that not only can you bolt the better blower on, but you can also tuck a small intercooler in there. Having made this many changes, it will be custom chip and dyno time.

Simple, no, but good in the end run.
 
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