Don Terrill’s Speed-Talk

You could compare to afr site they list there min. They seem to flow little less here 4ish %, on a few of there cnc I tested. Sbc china,ported. Raised floor/roof some, for my own project. I just a hobbyist. It's decent for what it is. Lure juice shrunk little,low spot by entrance. So mold isn't perf...

You can blame the 620 on me.. Remember that had little different fuel when I had the wrong cam and was trying to make sense of things

So explain the data from 7,100-7,500 on the actual dyno that doesn’t match the sim? Thanks. 🙂 [/quote] I can make it match You probably should know there is probably nothing you can't match I gave you something to think about in the last sim pic. Depending what your ign is doing. No dip would of sai...

For me, I learned how to match my dyno to neels sim years ago. Something like this engine I ,figured I could match peak torque rpm and torque peak pretty close if I had enough data . Which it did. I wouldn't expect peak hp to be perfect. But I know from 1000s simulations how data is going to react a...

289nate wrote: ↑Sat Oct 21, 2023 3:05 am At this point I have to wonder if we are validating a sim or trying to understand a real world dyno pull?

Both. There is only one way to validate a sim. I would of guessed torque and peak torque rpm right on without a dyno.
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Pump 26 .
Redid combustion at lower rpm last night.
I am sure there is huge difference in how these sims see intake manifolds. mine is 11 pages of inputs.

Who here thinks there is more after 7500?

if I took the time to match his bsfc.
It would look different. Just like his in the lower rpm. And I assume combustion would take a hit upstairs/less power. I only wanted to see peak torque honestly. I know the method I used worked for me in the past. Did anyone predict peak torque rpm correctly?

You really want to know why the combustion efficiency aka bsfc is the way it is. Parts being used. Not easy to answer, probably intake manifold . I did a quick sim with basic numbers I knew would show peak torque should be correct. I could put way more time into it. But that wasn't my intention

Peak torque rpm here.


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You didn't misunderstand I ran from 5 to 7500 in sim this morning My bsfc doesn't match his. He is making good power in the 5 to 6500 range . OP's engine is making good power. Can you post a sim graph with BSFC, torque and HP ? What RPM does your sim calculate the lowest BSFC? Probably not what you...

Ya should go more.he has to prove it. I would imagine my bsfc looks normal.but I can look I may have misunderstood. Is the graph actual dyno data or a computer program simulation? You didn't misunderstand I ran from 5 to 7500 in sim this morning My bsfc doesn't match his. He is making good power in...

Ya should go more.he has to prove it. I would imagine my bsfc looks normal.but I can look

Short Inner runner intake. Probably pretty close to Op. That I had on file. Solid 250/260 .050 cam Sim nails peak torque/rpm and hp. And No comments With head info/logical dimensions on throat etc and basic header/collector and basic combustion . Just enough Info for it to work and.a picture worth a...

Some guys post what pm thinks sometimes I wondered what what eng mod thought Head info. Csa,flows came from afr website. Minus some for pipe on ex flow. 700,680 lift 250/260 cam. Vic junior port lengths ,cause i have one,matched to heads little taper Basic headers. Straight line ign. Basic combuston...