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Thread: Pinto FR32

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    Pinto FR32

    Spec. 040" overbore
    cast piston
    injection rods
    44.5mm intake valve
    38mm exhaust valve
    45mm webbers
    38mm chokes
    12.5:1 compression
    Measured at the wheels. Flywheel corrected to 128kw. No Dyno debates. It's a point of reference and I've been running my machine for 5 years so know how it compares to OEM specs....

    For some reason I cannot get this to make power to 7000rpm. Down our main straight it tends to hit a brick wall. I like the low down torque coming out the corners. Any ideas.....
    Attached Thumbnails Attached Thumbnails image.jpg‎  

    Last edited by SA Tuner; 20-10-2015 at 19:08. Reason: Incomplete

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    Re: Pinto FR32

    12.5:1 is way too high for cast pistons, you wont want to rev it past 7krpm or you will break your pistons lands and make a right mess. If you want more top end drop the compression to slightly below 11:1 and fit an RL31 cam, it will work far better with 38mm chokes than your Fr32 which would be better with 36mm chokes. You could try retarding the cam but i would sort out the compression first. Whats the AFR throughout the rev range???
    Is that 11.8 - 12.2 AFR im seeing, if so its a tad rich.
    Last edited by Erikmex; 20-10-2015 at 19:47.

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    Re: Pinto FR32

    Great will try the 36mm chokes.
    I am running avgas and mappable ignition albeit with no knock control. Timing is happiest at 36*.
    Will the RL31 still give me the low down torque that I want?

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    Re: Pinto FR32

    Quote Originally Posted by SA Tuner View Post
    Great will try the 36mm chokes.
    I am running avgas and mappable ignition albeit with no knock control. Timing is happiest at 36*.
    Will the RL31 still give me the low down torque that I want?
    Possibly less low down but very driveable, 36mm chokes will give more bottom end to your existing engine rather than top end so possibly not what you want to do if your looking for more more high up, an Fr33 cam would be a good middle ground....although an RL31 will be very good with 36mm chokes, what are you using the car for???

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    Re: Pinto FR32

    It is used for circuit racing. Primarily on 2 tracks and the tracks couldn't be more different from each other. Interesting note though, the spec sheet says range is 2500-7000rpm.

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    Re: Pinto FR32

    Spec sheets dont mean much to be honest....RL31 is defo the cam for you, although running that sort of compression on cast pistons on the track?? your engine aint gona last long, if you were to keep the same compression and use forged pistons id say to use a BF63 but you really need to drop your compression if your staying on cast pistons.

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    Re: Pinto FR32

    cam spec sheets tend to give teh widest possible range a cam will work in, few do, i wouldnt expect an FR32 to make any usefull power at 7000.

    id be amazed if cast pistons will stand any real running time at that compression.

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    Re: Pinto FR32

    Are you using your dyno in acc. mode against a flywheel or do you make a slow run against a brake like EC or water brake?

    36 is way to high, specially if you got 12,5/1 and FR32. It should be lower as 28, I think it must make full power below 26 already because of the high CR. Or do you advance until you hear pinking an back of a little? This AVGAS is a serious protection against detonation and maybe the reason why the pistons are not melded yet.

    For a FR32 I think the power curve is just perfect. It will indeed not rev any higher. Honest, all good Pinto's I've ever seen did not make much power past 7K. Only the bad ones with no torque and no power where running higher because cams to fast.

    You only need 38mm in a very big engine. I would start with 36 and even try 34 if you find the time (as long as you stick with FR32).

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    Re: Pinto FR32

    These are inertia runs.

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    Re: Pinto FR32

    OK, something you often see with inertia dyno's. The run is very short, little time for for the head to "stabilize" at the measured RPM's. And also, due to the nature of the way your are launching the flywheel (?) they seems to like a lot more advance as strict needed.

    Try a loaded dyno and hold it at different RPM's at full load and see what is really needed as MBT (minimum best timing). The correct ignition numbers for this CR and engine combination must be a lot lower.

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