sn 2000

[mani]

the best time i did was 13.50 at a 108.88 cause i dont have a tire and my 0 to 60 is like 2.5 2.6 garbage i dynoed the car i got 323 at th rear wheels you sai dto change the disc on the fmu well i not using the fmu cause it was bogging over 4500 rpm so i kinked the hose and what cam do i use and what diff would there be more power or ???

[speedytang]

So what size injector are you using since you are not using a FMU. Kink the Hose, what is that. 'B-Cam" is a Carb. camshaft and the duration and centerline is incorrect for building power for forced induction. Use eaither the stock cam or get a custom style cam for forced induction but if you need to worry about emissions use the E-Cam and it seems to do really well.

[Crazyhorse88]

How good is the stock cam? Is it worth getting a blower cam or just keep it stock?

[mani]

i have 24 pound injectors and the fmu was hooked up but when it was the car was bogging so i pulled the little hose that goes from the fmu to where ever and tied blockin the air and that stopped the bogging prb

[speedytang]

crazyhorse88, Keep the stock cam, With a rather stock car I make 483 rwhp with only 10psi and had no problems and it still drives like a stock car around town even in 100 degree weather. mani, You will not be able to build any more boost with the 24lb injecters without the FMU hooked up. Did you change the Disc in the FMU when you went to the 24lb injectors. You are lucky that your not building any more horsepower than you are because you would be replacing head gasket each time you get to 5psi.

[Crazyhorse88]

speedy whats your setup? Nice #s

[mani]

THE FMU IS BY PASSED CAUSE OF THE BOGGING I THINK ITS THE ORIGINAL ONE IT CAME WITH .WY DO I CHANGE THE DISC AND WHAT WILL IT DO THANKS

[speedytang]

mani, the reason your running so rich with the FMU is because the unit is calibrated for 19lb injectors which needs more fuel than a 24lb injector but you will need that additional fuel when in boost so order the 24lb disc from Paxton or you probably can find one for sale used on this or another board.
crazyhorse88. Stock short block 140k miles, ported E7 heads, Interceptor II(custom), 42lb injectors, 80mm MAS, 70mm TB, Cobra Intake, 3.08 gears, MSD Digital 6Plus. 255lph internal.
I granny shift at 6500-6800 rpm, stock T-5 140k miles, street 265x50-15 Pep Boy specials on Welds. 2.20+ 60ft and goes thru the traps in 3rd at 6500 rpm and turn between 11.60-11.89. My car makes 450is rwhp at 8psi and 480is at 10psi. I have driven the car with my 14psi pulley and rev the car at 3,000rpm drop the clutch in 3rd totally destroy the tires and ran 12.27 at 112mph to win a bet at the track(With the weight of a passenger to validate the rpm). My car could easily run with slicks and the safety equipment(bell housing-I like my feet) and 3.73 gears in the low 10's. But I drive the car 7 months a year and put 20k miles and still get 22.5 on the freeway.

[mani]

WHATS IT CALLED EXAC AND WHAT WOULD IT COST AND WHATS THE BENEFIT OF HAVING IT MORE POWER OR SAFER

[Crazyhorse88]

Hey Speedy what kind of Blower do you have? Can my sn-92 make that kind of power? Alot of people are telling me that my sn-92 makes 100hp but takes 50hp to turn it is this true? Thanks For all the info

[speedytang]

I have the VR4 racing ball drive. All superchargers take a lot of energy to turn and the ball drive takes no more than the others. People think because it is harder to turn when your using your hand that it takes more power to generate power. When you are moving air and your spinning the impeller all the air is force against the impeller and that is the same and usually takes the same amount of force to rotate. Back in the early 90's testing was done in every Ford type magazine and even in my Chevy magazines to see what supercharger built more power at the same boost level and the SN Paxton always beat the Vortech 'A' at the same boost levels (5-6psi). Boost is not the only thing needed to build power. You need the unit to push enough volumn and that is done by housing size and impeller design. In the 17 years I have used the Paxton I always here the same thing when people switch from the SN to another brand or even to the Novi1000 and the Novi2000 when they switched from the VR4, that the Paxton always built more power and drives much better with the same setup. You can look around at all the BBS and do a search and you will see it, people asking how come the new supercharger has less power than the old ball drive . The reason is the SN builds more CFM of air at the same boost levels. The real numbers on a SN series is about 800 cfm at 6psi below 6k rpm and I have seen this tested in person. My VR4 at 5400 rpm and 15.2psi was pushing 1376 cfm and this was also on a blower test dyno back in '94 when I had it tested after the billit impeller was completed. When the Novi2000 came out and everyone was using the VR4 most teams lost power for many months till they could change combinations and after a season of racing still matched power numbers of the VR4 and some teams went back to the VR4 to even finish the season because the VR4 ran cooler and built better numbers. I collect magazines and if you raced Renegade you ran a VR4. The SN always gets a bad rap because if it is over revved it takes out the main shaft and the balls in the drive. Well for under $300 you can repair these units yourself and it takes about 1 hour to take apart and put the new internals in and you don't need a press or any special tools. I see on these boards all the time that the Novi or Procharger or Vortechs are leaking or the bearings are going out. You must send them in and if not under warranty spend $700+ plus shipping and weeks(months) to get them repaired and they won't sell you the parts outright to do yourself if you have the means. I have 3- VR4's and combined I have over 150k miles on them and have only purchased new rear seals twice at $55 including shipping and $450 for one master rebuild kit excluding bearings. I have never replaced a bearing yet and that is also because the design does not put a rear load on the front bearing since the SN is a two shaft design.
If I ever did purchase another Supercharger it would be a Procharger because of the RPM limits but I can even use the power I have now safely because it is my daily driver and at the track it is 'ET' racing anyways so I dial in at a 12.50 so that I don't need all the safety equipment (Roll Bar) and at my IHRA track you can run till 11.49 so I always dial in at 12.00 and usually break out anyways. Now that I am off my soap box yes it takes horsepower to make horsepower and it is closer to about 30hp to make 5psi of boost and the more force(boost) you make the more horsepower it takes.
My VR4 dyno sheet back when mine was tested at max boost 15 psi my supercharger was using 98hp or close to it.

[speedytang]

Mani, FMU Calibration Disc.

Increases fuel pressure in proportion to boost pressure.
Recalibration kits available separately.
P/N 6Z170-010 Recalibration Kit, 6:1
P/N 6Z170-015 Recalibration Kit, 4:1
P/N 6Z170-020 Recalibration Kit, 8:1
P/N 6Z170-030 Recalibration Kit, 12:1
P/N 6Z170-040 Recalibration Kit, 10:1
P/N 6Z170-050 Recalibration Kit, 3:1
P/N 6Z170-060 Recalibration Kit, 7:1
P/N 6Z270-010 Recalibration Kit, Includes 4:1, 6:1, 8:1, 10:1, and 12:1
http://www.vortechsuperchargers.com/.../fuel_fmu.html

Now I forget which one is for which injectors so go to the site above and it should be listed someplace.

[Crazyhorse88]

speedy what are the limits of my sn-92? I have a stock pulley on there now and I want more boost but dont want to kill it, what do you recomend?Thank you for all your Help I really needed it! Everyone is saying to get rid of my sn and get a gear-drive but i think I will get it to the track and see how it goes!

[mani]

speedy you know your **** lol what fmu would i need i have the stock one that comes with the sn2000 but it bogged at 4400 to 5500 rpm so the mec bypassed it then the car didnt bog. should i leave it . or put the right one. I have 24 pound injectors now, always had 255 fuel pump. which fmu do i need for 24 pound injectors. thanks

[speedytang]

mani, I will try to find the Disc ratio for you I just have not used a FMU for many years. At your horsepower level you could be safe with 30lb injectors but with 24lb injectors you are or will go lean at the top end under full boost. I think you can find the ratio on the link I added above but I will check on it for you. Do you also have the correct MAS meter for the 24lb injectors.