'70 SP Chassis Dyno Numbers!

Discussion in 'Small Block Tech' started by MrSony, Sep 21, 2018.

  1. MrSony

    MrSony Well-Known Member

    206.8rwhp @ 5003 rpm (211 weather correction)
    258tq @ 2781 rpm (263.2 weather correction).

    Stock Heads
    Stock Intake
    Stock Bore
    .042 gaskets (9.5ish:1)
    Stock exhaust manifolds, 2.5" dual through thrush chambered, exit behind rear tires.
    Crower Level 3 cam installed straight up at 0* with a TA 3 way timing chain setup, comp 942-16 springs.
    Everyday Performance 17057241 Qjet

    Vehicle is my '85 Buick Regal, Th350 with transgo 350-1-2 shift kit, GN 3.42 8.5 10 bolt Posi rear.

    I'd say these are pretty good numbers, what say you guys?

    The chart at WOT said my AFR was 10.8... the carb has an L hangar and CK rods in it. I assume I'd need fatter rods to alleviate this issue? Carb is decent in all other areas.

    Also, anyone have any guestimates as to what those numbers would be at the crank? I'm thinking around 275-290hp, and 350-360ftlbs.

    Me and the dyno guy were pretty surprised how much it put down being 99% stock.
     
    Julian, 300sbb_overkill and alec296 like this.
  2. Mark Demko

    Mark Demko Well-Known Member

    Lean the secondaries a bit yah might pick up a few hp:cool:
    Otherwise sounds good to me!
     
    MrSony likes this.
  3. 300sbb_overkill

    300sbb_overkill Well-Known Member

    An air/fuel gauge would be a great tool to help you easily optimize those air/fuel ratios.
     
  4. MrSony

    MrSony Well-Known Member

    Yep. ran out of time before my dyno date, but that's a thing I desperately need.
     
  5. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    Those are good numbers for what it is. Well done and thanks for sharing. Now hit the track and see what it will run.
     
    MrSony likes this.
  6. Mark Demko

    Mark Demko Well-Known Member

  7. MrSony

    MrSony Well-Known Member

  8. MrSony

    MrSony Well-Known Member

    The WOT AFR is 10.8... anyone have any insight as to what rods I'd need to go to to get it up about a point? It has CK rods and an L hangar.
     
  9. johnriv67

    johnriv67 Well-Known Member

    I've been told that a rod that is .100 fatter at the tip is about .75 points, but that depends on your primary jetting, as long as that is jetted correctly.
     
    MrSony likes this.
  10. BuickV8Mike

    BuickV8Mike SD Buick Fan

    How much was the dyno? Looked into it here and it seemed expensive.
     
  11. MrSony

    MrSony Well-Known Member

    It is expensive, especially if the shop doesn't use the dyno all that much. It was $80 for a test run to see if the dyno was hooked up correctly, and another run. Was a slow day, guy said what the hell and we made 1 more because power was still climbing.
     
    Last edited: Sep 23, 2018
  12. BuickV8Mike

    BuickV8Mike SD Buick Fan

    I recall it $160 for one run with no adjusts here in San Diego.

    What do you mean by power was still climbing? Did you make any adjustments between runs?

    Cheers, Mike
     
  13. Mark Demko

    Mark Demko Well-Known Member

    Suppose to be a pic of the unfinished aluminum head for the 350, but its telling me it doesn't have a file extension.
    I can click on the link and view, but I guess I cant share it:(
     
  14. MrSony

    MrSony Well-Known Member

    Nope. Made the test run to verify dyno setup, made 1 run to 4500, said power was still climbing, so we made another to 5000. Peak hp was the previously mentioned 206.8 at 5003rpm. Didn't have the time nor money on hand to do more than that, they had a full schedule that day, and I scheduled for the "cheap" dyno option, which was a test run, plus a power run. The timing was a very conservative 8* base, 22* advance, all in by 2800. Vacuum advance on ported vacuum, don't know what it is. It's the way TA set it, runs fine. Next time I will bump the timing upto 10* (if the engine will tolerate it on 91), and hopefully have an AFR gauge and have better rods on the secondary side. No adjustments were made between the trial run and the 2 power runs.
     
  15. Fox's Den

    Fox's Den 22 years of racing the same 355 Buick motor

    Now you should just go back to the track Without doing anything to see what kind of time you run.

    Note all the weather conditions along with tire pressures and such. Pressure, humidity, time of day, what track and what elevation.

    I have a Ap called Drag Times and it is pretty cool you can go to any race track in the country and put in all the numbers and get a corrected time and et with power. You can also go back in time and check that day at any race track and get corrected numbers for that day. Plus it has a full weather radar with the Ap using Weather Underground. There are also ET times of just about every car made There is a lot of stuff on this Ap we should all have it.

    After you back to the track and make a run, then you turn up that timing and see what happens do that until the mph or time falls off then go back 2* then you can work on the fuel the same way.

    Then you work on the throttle response with the 60 ft time and once you get consistent you start to do the bracket race thing and you can win a few bucks on a Friday night Lots of fun.

    I put in your RWHP numbers in the ap and you should run 15.34@88.85 mph if your car and you total wt is 3800 lbs. My car weighed 3660 on the scale so with a body in there it is at 3800.
     
    Last edited: Sep 23, 2018
  16. MrSony

    MrSony Well-Known Member

    Whenever I can make it it will be colder than it was. Tire pressure was 35psi. Will check out those apps.
     
  17. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Do you run through all the gears during the test?
     
  18. MrSony

    MrSony Well-Known Member

    Yes, but the final readout was taken from 65mph to whenever the power started to drop off, in my case over 100mph, about 102, so it wouldn't downshift on the dyno and misrepresent the numbers. Plus with a Th350, 3rd (Drive) is 1:1.
     
    Last edited: Sep 24, 2018
  19. Mart

    Mart '71 350 GS, almost stock

    Just wondering,
    Why didn't you put the correct .020 thick steel shim head gaskets back on?
     
  20. Fox's Den

    Fox's Den 22 years of racing the same 355 Buick motor

    You get your best times in Sept-Oct.
     
    MrSony likes this.

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