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-   -   Im the Happiest Person Alive, also DYNO! (https://www.rx7club.com/1st-gen-general-discussion-207/im-happiest-person-alive-also-dyno-1042534/)

Fungus Mungus 08-15-13 11:29 AM

^Agreed, even with SAE correction, I was seeing variances like this when dynoing on a cool day vs a hot day. SAE correction is supposed to take this all into account, but for whatever reason, my experience is like yours.

16 flat is an excellent ET, and completely believable given you have no cat and unnecessary belts have been removed.

fm

MilkStout 08-15-13 02:29 PM


Originally Posted by Fungus Mungus (Post 11547202)
Max bhp is achieved at 6000 rpm on stock 12a and 13b engines (84-85-spec 13b that is). Max torque is at 4000 for the 12a and at 2750 on the 13b. If the car has mods, such as carb, header, or any sort of porting, that power bad will shift upwards.

Milkstout, by killing the dyno at 4000 rpm, you're not seeing the true power you're making. You should run it to at least 6000rpm. With mods, a little higher, just to see where your power actually peaks. Also, you're not doing yourself any favors by dynoing the car in 85-degree weather. The heat will kill your power. I saw a 15 whp difference on the same setup on an 85-degree day and a 55-degree day.

At what rpm are you shifting? Remember that even though you may not be making more power above 6000 rpm, you want to go past that so your shifts drop you into the sweet spot of your power band. If you shift too early, you'll be struggling to get the car back into its power band and lose valuable time.

fm



Whe

it was about 105+ degrees outside in the shade we were under. i asked him to shift to at least 6k but he said he was gonna stop at 4500. thats why i believe if he went to at least 6k and it wasnt boiling hot outside i should show a bit more hp to the wheels.

but im still happy to have made what i did givin the harsh conditions. :nod:

Fungus Mungus 08-15-13 09:24 PM

If you made 95whp in 105 degree weather at 4500 RPM, you definitely are making decent power up at 6K.

I think you may have misunderstood my question about when you're shifting. At what RPM are you shifting when doing your 1/4-mile runs? You should be shifting at 6500-7K at least. Again, you may not be making more power up at 7K, but you'll drop right down to the meat of your power band after you shift.

fm

t_g_farrell 08-16-13 07:50 AM

On the day I dynoed my car it was in the 90s. I took it up to 7200 rpm, the power peaked at
about 6800 rpm if I remember right.

Sounds like the dyno guy had never run a rotary before. He's used to v8s that explode above
5K LOL!

Fungus Mungus 08-16-13 12:32 PM

^x2...even my Civic made peak power of 220whp at 8200 rpm. If he would have stopped at 4500 on that car, it would have made 100whp at best.

V8s may explode above 5k, but they still would make 400whp/370tq. :)

fm

mikeric 09-20-13 05:21 PM

Looking good!


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