Don Terrill’s Speed-Talk

I'm working on a new throttle body style EFI system - the MAP can be routed to under the throttle, or be blocked there and routed to a nipple for boost reference. It can also be set up as a "dual quad." Has wideband closed loop fuel, fuel adapt (saves the fuel corrections for the next time...

If I remember correctly the holes in each runner connecting them to the vacuum chamber (pretty large) are 5 mm in diameter. The odd thing is that I can see the impact of the PCV (which is also connected to that same vacuum chamber) on AFR. I've pondered the throttle stop as well. IF the AFR is chan...

Yes, you'd need to connect the MAP sensor to the manifold after the blower. Most systems can handle boost just fine. You'd only need a 2 bar sensor. If you inject fuel above the blower, you don't need a boost reference for the fuel pressure regulator, just a reference from the area that the injector...

I did also notice some other strange behavior, like adding air via a stepper valve, doesn't give it more speed when cold for some reason. I've not quit figured that one out. IF the tubes connecting the log to the throttles are too small, they can't flow enough for the IAC to do any good. The more i...

In most conditions, the timing itself has little to no effect on the AFR reading for EFI. The AFR does have a pretty solid effect on what optimum timing will be, though. But, once your AFRs are in the normal range, e.g. 12-12.8 at WOT, 13.5-14.5 at light load, the timing requirements will fall in li...

If you don't need to control timing, you can install an MSD box and run the fuel injection on the tach signal. It could at least help you figure it out, if there is one available nearby for some testing.

https://www.youtube.com/watch?v=ieJUP9O9RG8#t=96

This would be better...

I'd just optimize IMEP vs. rpm for each individual cylinder via combustion pressure tuning, and let the timing, O2 and EGTs fall where they fall instead of going with preset notions of what values should be. IMEP is what counts. But this is getting off topic. With enough dyno time, you can sweep la...

Well anything greater Than a 15 degree angle will make high velocity sheer off , so yeah your gonna drop 12 to 18 hp off what you could have had, but 450 hp should still be doable ! I have a fix for this but it's under review at the Patton office right now so gotta be tight lipped ! A non-mandrel b...

I need that sound as a ring-tone. It would really let people know that I'm all about power - when someone calls, my friends will hear spsdddddppsdpppsdpsdpszzzzz, and look at me in awe, and maybe cover their nose.

It could some anti-reversionary benefits as well as being extra pleasing to the ears :lol: And, it's technically recycling if they use used parts - you know they want to look greener nowadays :mrgreen: Too bad F1 doesn't allow "exotic" :wink: materials or movable exhaust parts other than t...

https://www.youtube.com/watch?v=ieJUP9O9RG8#t=96

Might actually work!

I think that last statement is a major clue, but darned if I can figure out how one could maintain a much higher average expansion stroke pressure without a big peak increase. Some external high pressure source (e.g., another cylinder) feeding into the cylinder mid-stroke to 'top-up' the diminishin...

You'll have a hard time making something naturally aspirated that will beat a fully developed dominator setup, so i hear. But, I bet all of the pro-stock teams wish they could use EFI. If you allow better ignition control with the EFI compared to, say, a locked out MSD, and other electronic tricks, ...

Hi, I would like to know what would make more power; Fuel Injection or Mechanical Carburetor and why? I have an understanding of thermodynamics so don't hold back with your answers/theories/arguments please. FP :D You should be banned for asking this :lol: A properly designed EFI system is most lik...