Very conservative. At WOT it's in the 20's. I figure I've got at least 10-15 degrees of advance to play with. This car should be making 190-200 whp. I just need to find dyno time to work on the timing.Nice numbers, what were you running for timing?
It backfires ALL. THE. TIME.Not gonna lie, I got goosebumps at the flame. Great numbers, man! Especially with your break in tune. That car is going to be SO much fun on track.
I guess, just keep in mind that paper pre-dates the Renesis engine by more than a decade and it does clearly state they could overcome it, but at the expense of fuel economy. Everything they learned from their experience racing eventually trickled down into the RX8.I just keep coming back to the R26B SAE paper. Mazda didn't make any power claims regarding port versus throttle body injection but noted an improvement in throttle response.
I'm running into a couple issues:I wish we had the same ECU so we could trade notes a little better.
Okay, that's pretty cool. What I have isn't too far off that. I'm targeting a little richer at idle and the low-to-mid range. I can live with that since my engine seems to like runner richer in general. Any above 13.5 or so below 2000 RPM is unstable. Ideally I'll get within +/- 0.1 of my target. My two oxygen sensors never read the same so I'm always averaging them anyway. But yeah, once I get close I'll call it "good enough" and turn on the closed loop control again.So before I do anything to my 85 RX7 I installed an Innovate Motorsports dual AFR gauge. The motor can Nikki carb are bone stock so I used it as a reference point for the truck. Below is what I came up with. The only exception is that 0-25% MAP and 3000-7000 RPM could be bumped to 15. These are the readings I’m getting on my 1st gen. Idles at 13.7, cruises at 14.7, and punching it will drop to low 13, occasionally high 12, but I’ve been told max power on N/A can be achieved at 12.5. Now to be clear, these are averages +/- about 0.5, you’ll never get a steady flat reading, so if you are close, let closed loop handle the last bit.
Yeah, I noticed this after my first attempt when I saw the IAT reading over 160F. In general I turn off all the fuel corrections when doing my tuning but the atmospheric effects are still there. The last couple attempts I parked in the shade and opened the hood, which generally kept the IAT at or below 140F.As for getting different readings at idle, keep in mind that intake air temp is probably messing with you unless the hood is open. On a warm day, get the car warmed up then park it. Watch the AFRs and have the air temp trim table open (I assume you have something of the sort). As the temp rises in the engine bay, adjust the trim a little. Or you could install a cold air intake. I still don’t have mine setup right and I noticed it in traffic when the intake temp shot up to 100 before the e fan kicked in to blow some cooler air in.
Yeah, I have the table from ID uploaded. My only "accessories" are the electric fan, lights, and interior blower. I have noticed when something is on and the idle drops a bit the car does run a bit richer despite my fuel settings being identical in that area. Mayb you're onto something there.Another thing it could be is the injector dwell. If you keep changing the values, check the voltage in the log. There should be a table to adjust how long the injectors open based on voltage. Injector Dynamics probably provides the correct settings for the table, but you can also tweak it by getting the car stable at idle, then turning on accessories until the voltage drops, and adjusting the table to fix the AFR.
So you're running a constant fuel pressure right now? I can't remember what size injectors you're running but I can't imagine you're max'ing out your system. What are your duty cycles in that situation? Haltech has a "decay rate" that can be adjusted. I'm sure Adaptronic has something similar. Perhaps your enrichment events need to be longer. On that subject I actually have my transient throttle enrichment disabled. Interestingly enough the car doesn't drive THAT much worse. I turned it off mainly so it wouldn't interfere with my datalogging. I'll turn it back on with the closed loop control when I get the fuel dialed in.In my last log, I noticed something new. When I punch the throttle, the portion of the log that matches with the accel pump (transient correction) is fine, but it’s a second after that where I get the lean condition. I think it could be fuel starvation. I don’t have a vacuum line connected to the FPR, so that’ll hopefully be a quick fix, if not, I will have to rethink my fuel lines, pump, and filter setup.
So you're running a constant fuel pressure right now? I can't remember what size injectors you're running but I can't imagine you're max'ing out your system. What are your duty cycles in that situation?
That fuel pressure seems low to me. Stock FC injectors are 460 cc/min and the fuel pressure regulator uses a vacuum reference with a base pressure of 34-40 psi. I don't know the rate of the regulated pressure relative to its source though. I'd think you're making more power than a stock FC so you'd want more fuel. My base fuel pressure is 45 psi and I'm using a 1:1 regulator so I have 38-39 psi at idle, which is around 4% duty cycle on my 1000 cc/min injectors (actually around 1035 cc/min at 45 psi).Yeah, constant 35psi. 4x 440cc injectors, not staged. I don’t think I’m maxing the system, but I think the FPR isn’t reacting fast enough to the change in demand. If I slowly push the throttle in, it is fine, but any rapid change leads to lean or rich conditions. I could probably hook up a fuel pressure sensor to confirm, but I’ll just try hooking up the vacuum line first.
That fuel pressure seems low to me. Stock FC injectors are 460 cc/min and the fuel pressure regulator uses a vacuum reference with a base pressure of 34-40 psi. I don't know the rate of the regulated pressure relative to its source though. I'd think you're making more power than a stock FC so you'd want more fuel. My base fuel pressure is 45 psi and I'm using a 1:1 regulator so I have 38-39 psi at idle, which is around 4% duty cycle on my 1000 cc/min injectors (actually around 1035 cc/min at 45 psi).
That reminds me; I really need to check my duty cycles at higher engine speeds/loads.I think I lowered it early in my tuning process because I was seeing a maximum of 50% duty on the VE table. Of course now I only get to 62% on the table. I’m definitely going to add the vacuum line and make sure at open throttle I get 45psi since that’s what the injectors are rated at. I know it’s going to mess with the whole table, and the truck drives now (as long as I go easy on the throttle), so I need to wait until I have a few hours to retune it.
That reminds me; I really need to check my duty cycles at higher engine speeds/loads.
What kind of fuel pressure regulator are you using? I assume it's a 1:1 rising rate aftermarket unit. If so, just increase the fuel pressure without the vacuum line to 45 psi and then connect the line. You're still stock port so you likely pull more vacuum than I do. Ideally your idle and cruise fuel pressures will be in the 35-38 psi range so you shouldn't have to change much there. Don't forgot to change the fuel pressure reference setting if Adaptronic has one. In the basic setup in my Haltech I have the choice between "constant" and "MAP-referenced" fuel pressure.