Don Terrill’s Speed-Talk

Ecclesiastes: "there is nothing new under the sun" Your remarks ...... "Lol. Yes a Jan 2000 article repeating 1990s information. Peak cylinder pressure location is a "result" not a target. The "result" could be anywhere from 6 ATDC to 22 ATDC depending on what eng...

Guess AI needs some work yet...................

The big thing with gasoline engines is whether the engine is octane limited or not. Optimization accommodates the knock constraint fairly dramatically which moves the peak pressure timing and also completely reshapes the pressure curve. Unless boxed in by rules or lack of good fuel availability, sm...

Nope, not 1990s information. Allen W Cline wrote an extensive article on ign, detonation etc, printed in Contact Mag, Jan 2000. I printed it out, 11 pages. I believe he is a GM engineer. 14* ATDC was the magic number. He also talks about 'pinging'. It is NOT the pistons rattling in the bores... Lol...

RDY4WAR wrote: ↑Fri Aug 14, 2020 8:16 am Peak cylinder pressure will always be around 14-18° ATDC.

Nonsense. That is 1990's information from back when people didn't know what they do now.

Well those look like a real handful. Probably spend a significant % of their WOT time approaching or on the rev limiter, at least in the dirt sections. Less than you’d think, because they have surprisingly good traction even on the dirt sections. You can hear in this video when the lead cars shift ...

Maybe I missed it but what was the application ? Mini/micro sprint, or motorcycle, or other ? https://www.instagram.com/p/CysLPd9NVe7/?img_index=1 Crosscart Xtreme. 420kg/926lbs minimum weight with the driver after the race. Solid rear axle and no differential so the inner rear tire needs to lose t...

Maybe I missed it but what was the application ? Mini/micro sprint, or motorcycle, or other ?

What is limiting you to 15k, is there an rpm limit imposed by some rule, or is 15k simply where the powerband wraps up as the combo currently stands ?

With primaries shorter than 45cm, the torque curve dips in the middle of the power band. 38cm vs. 48cm primary simulated below… Thank you for taking the time to show me your simulation results. They are very different than imagined. Obviously more going on than can be addressed with a simple equati...

digger wrote: ↑Tue Oct 03, 2023 7:30 pm

nitro2 wrote: ↑Tue Oct 03, 2023 2:16 pm

hoffman900 wrote: ↑Tue Sep 26, 2023 5:06 pm

Pretty sure they were like 4-6” expanding stubs

I think not lol.

We don't believe you, best post up some pics to prove him wrong

Lol.........I'll get right on that.

hoffman900 wrote: ↑Tue Sep 26, 2023 5:06 pm

ptuomov wrote: ↑Sun Sep 24, 2023 5:58 pm
That thread never reveals the super duper secret exhaust.

Pretty sure they were like 4-6” expanding stubs

I think not lol.

F-BIRD'88 wrote: ↑Wed Sep 14, 2022 11:06 pm The moment of max piston-rod stretch "elastic" at rpm, happens @ a bit after TDC.

True. Only happens during overlap though when at WOT.

Bear in mind if the piston is just barely kissing the head at WOT, it is only doing so at TDC overlap. It's not kissing the head at TDC combustion.

If you close the throttle at high rpm then the piston could touch the head at both TDCs, instead of just TDC overlap.

We are looking to do a special project with ONE team, any type of racing (well almost any type lol). Preferably a team capable of winning a championship but historically falling just a little short. We would be providing cylinder pressure equipment (discounted from retail) and free data analysis ass...