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Im hoping someone can help with getting my secondaries staging better as I've been having a little trouble. The car in question is my FD rx7 that i'm in the early stages of tuning with a 2nd hand Haltech elite 1500 I picked up just running pump fuel for now. Injectors are the Oem 550cc and bosch ev14 2200cc secondaries, turbosmart fpr1200 reg set to 43.5psi. Using injector dynamics dead times and flow figures for the 2200's
I have stage 2 set to come on at 80% primary duty, I've played with the stage on enrichment and decay settings quite a bit to the point I have gotten rid of any lean spikes that were occuring but I always get massive enrichment to mid 8 afr's basically 1 second after staging despite the VE map not increasing much.
In the log pics attached you can see with 50% stage on enrichment and 42 engine cycle decay there is no lean spike vs 35% enrichment and 42 decay afr spikes lean. 50% enrichment and lower decay also leads to a slight leaner spike so it seems to want that larger enrichment and decay, but either way i get that massive overfueling immediately after.
Really appreciate any help! Thanks
I'm leaning towards the problem being caused by incorrect flow figures for the primary injectors. It's well known the FD injectors are rated at 550cc at 2.5 Bar, however in the haltech base map they have settings for the stock 550/850 injectors with 43.5psi base pressure so I assumed it would be fine to leave and maybe they were actually rated at 550cc @ 3 bar?
Will have a play with it, from looking at other injector data it seems like the increase from 2.5 - 3 Bar should give around 7% more flow at the injectors so I might try 590cc and see if it helps. When I add 10% to my ve table I don't get a 10% increase in lambda so something definitely seems off
I've had stock 550s flowed, they're pretty spot on at 43.5 when clean. Would you mind actually posting your map?
Ive made a few changes since but up until staging occurs this is my map, mostly based off the Haltech s6 single turbo base map. I have since added a bit of timing as it doesnt want to rev out with the basemap numbers. I did a run where i pushed through the rich segment and 3 seconds after staging it started to lean out to 12.5 afr and really started to liven up.
Interesting about the 550's, I did alot of searching hoping to find actual flow figures but only came up with speculation that they would flow more at 3 bar. If you look at the adaptronic injector data in their software they list the rx7 injectors as being 550cc @ 2.5 bar also.
Did one run with primaries set to 590cc and got a slight improvement, dipped down to only 9.0 afr but with an increasing ve value added for safety, I fouled my front rotor plugs when i pulled up to check the data and had to limp home after that so not alot to go off yet.
Appreciate any input!
Definitely thinking going to 590cc primaries was a bit of a swing and a miss. After all the guys that tuned the power fc I'm coming from had 550 and 2200cc settings and I believe it gives even less control over staging.
Maybe it's as simple as the wrong combination of stage on settings.
I havent used an Elite for a long time and never with staged injection, but most modern ECU's will have some way you can adjust the contribution from primary/secondary. So this is normally how you check your primary/secondary flow is set up correctly.
Run it at a medium RPM/Load site with 100% primary injectors, adjust the active fuel table cell so that measured lambda matches target, then change to 100% secondary - If the flows are set up correctly the lambda should be the same when running on either set.
Obviously you need to pick a site where either set of injectors should be happy with the required PW.
Good idea to change from 100% primary to 50/50 and then 100% secondary flow, but be careful if you're using the OEM throttle from the FD RX7. The second throttle plates are fully closed from about 0-30% throttle, and you will get really odd results if you spray fuel through the secondary injectors when the second throttle plates are closed or barely open.
That would be a clever way to check things out but unfortunately the elite only has 3 settings to play with, it has auto staging which I've only ever heard good things about lol.
Primary duty cycle % - above this secondaries will kick in.
Stage on enrichment % and stage on duration in engine cycles.
At first I tried staging earlier at 50% primary duty which lead to lean spikes and hesitation no matter what other settings I played with so now it's coming on at 80% primary DC at least there's no more stumble and I have been able to get rid of lean spikes, I've been a bit chicken in playing with the values much more though since it is coming on to boost.
I did a little bit of datalogging / reverse-engineering on a stock 1994 RX7, over 10 years ago with relatively primitive logging equipment. From what I remember, the primary injectors were much higher than 50% duty before the secondaries kicked in. If your options are 50% or 80%, I agree 80% is probably the way to go. I would keep the boost low and the ignition timing low while getting fuel dialed in. There's a good video here on HPAcademy about rotary engine ignition timing, if you have access to old webinars it's certainly worth finding and watching.
Yeah been watching all the webinars I can, some great stuff in there, the rotor ones in particular.
Been a bit busy so haven't tried anything new yet, thinking I'll try much lower stage on duration with a bit higher enrichment and see what happens.
After all the lean spikes I've seen it's given me a bit of confidence the engine isn't going to grenade at the slightest hiccup, not that I'm trying to push it over the edge lol.
I did a bit of math and there's about 24 engine cycles happening between staging and going overly rich so that might be a good place to start
Scott is right, the Mazda injector control strategy shoots into the low 90s on the primaries if asked. It's less than confidence inspiring. Rotaries are sort of my bread and butter, currently building/tuning a 3 rotor in a tube chassis with a 9180 strapped to it in an effort to keep up with the torque of the corvettes and vipers we race against here in southern California and while I haven't taken the time to look over your map, I'd be more than happy to help/make comments from the peanut gallery any time.
The efr's seem to be a rotors best friend, some pretty amazing results from what I've seen. The 3 rotor should be a weapon! Piston engines have been getting rediculous lately with power output, it's good to see the old rotors still sticking it to them lol. I'm just running the Borg Warner s300sx 8375 on my stock port.
The last guys to tune it didn't utilise the boost controller to help spool so it's been a bit lazy in the mid range, wastegate cracks open at 7 psi and slowly works its way up to 12psi spring pressure. I got my elite 1500 for a bargain so hoping to get it set up with traction control, have it control boost and get the FD moving down the strip a bit quicker.
I seem to be chasing my tail trying to get this issue sorted. VE map just doesn't make sense after staging. Almost no staging enrichment is the only way to keep it from bogging at the crossover though it still goes ~10% richer, if i hold that load point and reduce the VE number I end up with a crater in my map, push through the 0.60 lambda and I start to lean out up top even with that big step in the map :|
The common issues webinar has given me a few things to think about why my map is wack but I do keep coming back to incorrect flow data causing my problems, fuel filter is fairly new and unless my fuel pump has suddenly started to degrade it was fine up until I swapped in the Haltech.
I was planning on upgrading my primary injectors for e85 anyway so I guess I'll grab some flow tested "1650's" and hope with accurate data the issues are sorted. Also planning on getting fuel pressure into the ecu, currently have a gauge on my dash for it but pretty hard to see whats going on while road tuning.
[url=https://forums.haltech.com/viewtopic.php?t=33585]https://forums.haltech.com/viewtopic.php?t=33585 - this thread on the Haltech forum seems to be a little similar to what I'm experiencing.