VictorJR vs performer RPM

Discussion in 'High Performance Modifications' started by HULKZ28, Aug 19, 2006.

  1. HULKZ28

    HULKZ28 Veteran Member

    1,572
    0
    Oct 15, 2005
    Jeffersonville NY USA
    THE MOTOR

    355 sbc 9.4 1 comp ported 624 heads 2.02 1.60 valves XE 274 cam .487 .490 lift al. roller rockers edel 750 vac sec. carb. 1 3/4 super comp headers 3'' flow mster ex. 3.73 gears stock 4 speed

    what can i gain/lose by switching from the RPM to the victor jr.
    If anyone can dyno this with AFRs new 195 eliminator heads in place of the 624 id appreciate it. comp ratio will ba 10.5 to 1 with the AFRs

    thanks Hulk
     
  2. Marv D

    Marv D Veteran Member Lifetime Gold Member

    Let's put it this way,,,
    Rerformer intake idle to 5800
    RPM intake 1500-6500
    Vic Jr 3500-7500
    Super Victor 4000-8000

    Where are you going to operate this motor most of the time?
    yeah,,, I thought so ;)

    Intakes are not any place that bigger is better. In fact it's quite the opposite for a street driven car. When you open the plenium up and have huge runners, you allow volocity of the a/f to slow down. That allows the fuel droplets to fall out of suspension and puddle inthe bottom of the intake (under extreme conditions). Just IMO,, when your intake is a restriction to the rpm you are attempting to spin, THEN it's time to step up.
     
  3. lluciano77

    lluciano77 Guest

    I used the Edelbrock A/B epoxy to extend the runners of my Victor Jr. It took forever, but I ended up with more bottom end than my old RPM intake.
     
  4. Rick WI

    Rick WI Veteran Member

    10,400
    1
    Jul 9, 2001
    Madison, WI
    You want the Performer RPM. You'll loose torque and power everywhere below 5500 with the Victor. The amount will be between 10-20 ft/lbs
     
  5. night rider

    night rider Veteran Member

    6,401
    3
    Aug 6, 2002
    Bremen, Ga
    I agree with marv and rick. Stick with the RPM. The single plane victor will loose torque through out most of that engine's useable RPM range.

    Even if it's a weekend track car, why give up torque between 2000 and 5000 rpm just to gain alittle HP at 5500 and up when most of your run will be at RPM below that 5500.

    If you had the cid, cam, compression, and gear to launch the car at 3500 or more, shift at 7000, and cross the traps at over 7K then the vic jr. would give you the better E/T but that aint the case with your combo
     
  6. HULKZ28

    HULKZ28 Veteran Member

    1,572
    0
    Oct 15, 2005
    Jeffersonville NY USA
    OK guys, ill stick with the RPM on this motor. Im already down on torque due to the large exhaust system. someone build me a strong 355 with a solid lifter cam use the vic jr AFR 195 elim. heads. I wanna be very close to 500 hp and 500 ftlbs. on pump gas..
     
  7. lluciano77

    lluciano77 Guest

    With the AFRs and a big solid cam he may want to step back up to the Victor Jr. Don't forget, the Edelbrock series are rated for around 9:1 engines that are mildly built. As you add parts that want more air, the intake should be able to add to it as well. If he is talking about the 195s, already has bigger headers, and adds a big solid cam, I think the Victor will be a better choice hands down.

    Like I said, with my 11:1 400, my car picked up a noticeable amount more bottom end. It just wanted more air with a better intake port. Dual plane intakes are pretty turbulant where the ports meet.

    The major limiting factor with almost all dual planes is that you can't port them and get much airflow gains. The ports are pretty much the same size going back from the head towards the carb. The Victor Jr. ports come to a V shape. When you start to open them up, they really gain airflow. I opened mine up quite a bit and it actually did something, unlike most dual planes where you can't.

    An engine is still an air pump, so adding more air will almost always add more power. The powerband it is added at can be changed. You aren't stuck with 1,500-6,500 or 3,500-7,000. Those are baseline figures and can't be taken like the word of god.
     
  8. Mwilson

    Mwilson Veteran Member

  9. stangslayer

    stangslayer Veteran Member

    1,030
    0
    Nov 20, 2001
    Radisson, Sask, Canada
    With my combo, which is just a little more radical my time slips tell me the RPM is about two ans a half tenths faster than the super victor I recently put on. Went from consistant 12.39-12.42's with the RPM to 12.63-12.69's with mildly ported (little more than cleaned up) Super victor. By adding a 1" 4-hole spacer to the SV I got back down to 12.58. The one plus I noticed is my MPH has gone up 1 MPH and when nitrous is used and it yields a 2 tenth benifit over the RPM which puts them almost on par with each other in my books. Hope that was helpful.

    O yeah. Here is my combo quick for reference sake.
    10.3cr 406sbc
    ported vortecs
    247/254*@.050 .504/.498"
    holley 780VS
    1 5/8 headers
    3000 stall
    3.42 gears
     
  10. Rick WI

    Rick WI Veteran Member

    10,400
    1
    Jul 9, 2001
    Madison, WI
    Even with the AFR's and a solid roller in the 245 @ .050 range and .550 lift, your STILL going to be better off with the Performer RPM. That's based on about 40 dyno sessions with engines similar to those specs.

    A Performer RPM flows more than enough to feed a 383, or 400 for that matter.
     

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