You would probably find ECUProject.com interesting. A friend and I started it because Saab tuners were charging $1,000+ for what was mostly crappy recycled tuning. The group of guys that got involved cracked Saab's Trionic 5 and Trionic 7 management system. Software is free, and you can use common market BDM devices and/or CAN bus interfaces (to monitor and modify RAM in realtime). It's pretty cool! Literally, you can tune your own car, full access to everything, stock ECU, with a well documented real time interface for $150 to buy the CAN device and an hour to splice into the bus.

The Trionic systems were and are way advanced for their time. T5 is pressure-based, T7 is mass-based. Both don't use knock sensors and have a single crank sensor and synch themselves with rotation during startup. They use the spark plugs as realtime sensors to determine the combustion charasteristics (as well as knock) on a per instance basis, post combustion, by ion analysis. I believe BMW has licensed the technology and is using it on their M6 V-10 engines.

I have a stock internal 2001 2.0L running a Mitsubishi 19T compressor wheel (15T is stock) that made 310whp and 320ft-lb torque at 22psi during the last dyno (Dynojet) on 93 octane pump gas, at a steady 12.5:1 under boost. Stock compression ratio is 8.8:1. (I've since damaged something internally experimenting with higher boost, but it's mechanical breakage from torque onset, not pre-detonation or knock, stock engine with 147,000 miles).


Anyway, now that I've found and fixed the wiring problem on the boost controller on my FD (caused 2 boost overshots, didn't find it the first time), I'll have a chance to really work through the dual S-HSV direct port water injection system that I've built. Of course, that's after I replace the broken apex seal from the last boost overshoot....*sigh*.

Before the boost overshoot, on 93 pump gas, I was running 20psi with knock numbers in the 'teens running about 12.0:1 AFR and 50/50 water/denatured alcohol.

It seems like the root issue with the rotary is the lack of sufficient heat rejection and a corresponding increase in combustion volatility, tendency to knock and pre-combust, because of: 1. the fact that there's more ignition events per comparable combustion surface per crank revolution, and 2. compounded because of limited rotor cooling, and increased heat retention.

With some extra heat rejection and the stock 9.2-9.3:1 CR there shouldn't be any problem at all running more correct AFR's on these things under boost.

Now that I have the boost control issue solved I hope to hear back from Sven soon regarding delivery on a single NRS 3mm 2-piece so I can get this thing back together and keep testing. :)

why didn't you have any overboost protection set up? fuel or spark cut? It kills me that people would rather run no overboost fuel protection at all than hit even a fuel cut

Heh heh, sometimes I forget about the big heads around here; you rotary guys can sure be nasty for no reason. :) Consider for a second that I'm coming from the world of modern and effective engine management systems that work well. It just might be possible that it didn't occur to me that it's necessary or a good idea to add a hard external cut of some sort.

So! Thanks for the suggestion, seriously. I have a hobbs switch and a n/c relay laying around, won't be hard to add pressure-based ignition cut; good idea.

Send me a PM if you're interested in any of the Saab control stuff. Saab is/was a pioneer when it comes to turbos and control; the Trionics really are one of the most advanced systems around, and we made them open. It's no problem for me to send some .bin files to you to look at in the free programming suites; there are some white papers detailing the ion technology that you might find interesting too. The suites are so good you can even look at the reverse compiled code if you want to take it to that level, that may be a little beyond what your interests-are though.

Also, you guys probably know this already, but when tuning with one of the wideband setups using the common Bosch wideband probes (VW, AEM, Innovate, etc.) your wideband signal is only going to be good down to 9.8-10.2 or so because the probe goes blind, lower than that and your reading is nonsense no matter what the displayed reading says, limited by the sensor. Seems like Arghx is showing targeted values on the control request side, but just realize that you actually can't even measure as low as some of the requested values with a common WBAFR setup. Setting targeting that low doesn't make sense anyway unless you're trying to control heat, and if that's the case, a little water is a much much better tool.

http://img.villagephotos.com/p/2004-...mp_Current.gif

(picture borrowed from here: http://www.daytona-sensors.com/tech_wego.html)

I can't think of a turbo car that doesn't have a fuel cut from the factory. On those cars without a MAP sensor the fuel cut is based on a max signal from the airflow meter. For example, on the Evo 8, 3000GT, etc the fuel cut is when the signal frequency is above something like 2400 hertz. Cars with a factory MAP sensor usually have the fuel cut based on boost. The 2nd gen FC3S turbo had fuel cat back in 1986 (it was like 8.5psi). Any Subaru will have boost-based fuel cut and knock-based boost cut. Ignition cut works too. A fuel cut is built into the Power FC and people just disable it completely. Part the reason for that is the fact that the PFC manual from Apex'i actually tells you to do that if you are using an external boost controller. And that's just silly. I've hit overboost fuel cut plenty of times. It's not good

Will do.

Got your PM, I'll send you some .bins and a link to the software download later today. You should probably get both the T5 and T7 suites to look at the difference, compare/contrast.

As for the a hard fuel cut, I didn't say that Saabs don't have one, I said that I'm used to a control system that works well. The knock control schemes in Trionic are very effective so it's rare to hit a fuel cut. In fact, I've never hit a fuel cut tuning on my own car.

And actually, now that you mention it, I met up with Chuck down here back a few years ago, and I think he disabled my fuel cut; since then I've re-scaled for 3bar, converted to e85, changed injectors, basically everything is different, but I know I didn't add fuel cut. I totally forgot about that. I agree with you, I'll have to go check through the settings again. I like the idea of ignition cut a little better, probalby do both I think.

having seen a few of each, id say that the subaru engine is more fragile than the rotary, the piston ring lands are very weak, even STOCK cars can break them. i'm in CA, so we have 87 octane that acts like 85 octane, our subaru dealers stock the ring set....

or data point 2, on the subaru engine, there is a freeze plug on the block that lets you change pistons without taking the rest of the short block apart, no other engine is like that.

by contrast, its very rare to see an FD with the factory main cat have an apex seal failure.

Lots of good info, Thanks Guys.

Barry

Here's more to consider. This is a chart of WOT AFR's on a completely stock Series I Rx-8:

https://www.rx7club.com/attachment.p...1&d=1271052890

Source data is attached. I got that from somebody on rx8club if I remember correctly. AFR is measured with the factory Rx-8 wideband.

Here's the target AFR table for a 175hp nonturbo Subaru Outback:

https://www.rx7club.com/attachment.p...1&d=1271052890

The Rx-8 is maybe a little richer than that in some places, but it also revs a lot higher and higher rpms usually have a richer commanded AFR in stock calibrations. Now here's the target WOT AFR table on a 2007 C6 Z06:

https://www.rx7club.com/attachment.p...1&d=1271052890

The Z06 is actually tuned richer than the Rx-8. So that's two naturally aspirated engines that make either way less or way way more power than the Renesis while still running AFR's in a similar range.

rich AFR ZO6?
 

Speaking of ZO6, check out the linked dyno video. I'm pretty sure this ZO6 was stock, and tailpipe AFRs were in the 10's!! Not sure if that's normal or not, or how reliable the dyno's air/fuel readings are. When I ran my car, the tailpipe AFR was indicating a little richer than my wideband upstream of the cat, maybe by 0.2-0.5. Go to 1:17 in the video. Car made insane power too, wonder how much more he could get if he leaned it out some...

http://www.youtube.com/watch?v=Ca3baOfF1P8

its also lean before it goes WOT...

Maybe i'm missing something about this thread, but I've ran 4cyl and 6 cyl turbo Honda engines at 12.5:1 on 91 octane, something you don't ever want to do on a rotary, hence why they run rich.

Hondas do seem to tolerate a little leaner mixture on lower octane fuel. But you also have to be careful doing a comparison because of differences in overall combustion chamber pressure due to lower flowing turbos. Also, for comparison purposes no Hondas came with a turbo from the factory except for the RDX--and the RDX was tuned to AFR's in the low 10's. http://www.turbomagazine.com/tech/tu...ash/index.html

so Honda did the same thing as every other manufacturer

the thread title should be changed to FD's don't run rich comparatively

way back in the day we tuned the Na FC ITS/PS1 car on the dyno, with a haltech. it made best power @13.1 afr, more fuel lost power, less fuel lost power.

the current car is an integra with a non vtec b18. for the 08 25 hours of thunderhill, the tune was about 13.3 afr, and we actually broke stuff with detonation http://picasaweb.google.com/MWStockl...40827802289746

for 09 we again tuned it on the dyno, the stock map ran in the mid 12's (like 12.4) at high rpm WOT, and MADE MORE POWER than the 13.3 map....

we eventually ended up with a nice 139fwhp tune that was around 13.1, or THE SAME as the rx7

links to pics of the racing is in the siggy