rotary nation

Dyno'd my 10th AE at RotaryFest 4 Orlando, Florida.

Here is the sheet:







It was 90*+ outside and even still it was about 88* inside where the dyno was.

Mods are:

Deleted ACV
Atkins Rotary alternator double pulley stock size
Rtek 2.1 (no tune just loaded the base map)
Stock injectors
Stock S4 motor 84k miles
Stock top mount
Corksport turbo inlet pipe
Racing beat downpipe + presilencer
Crush bent 3" (not true 3" at bends)

I installed the Rtek 2.1 for now just to monitor the sensor readouts and to lower the secondary staging to ~3200 RPMS. Boost was 10.7 psi and intake temps reached 185+ on both runs and what stunned everyone is how linear both runs were.

funkjaw

iTrader: (3)

What were your AFs?

TheAbsence

iTrader: (19)

Congrats! I'm also curious what your AFs were.

Black Knight RX7 FC3S

iTrader: (7)

was this in 3rd gear??

Most people would say, having a 1:1 ratio is better. Which is 4th gear.

rotary nation

Not sure what the AF's were, I need to install a wideband. I have a brand new AEM UEGO kit sitting in my garage but I think I want to install the wideband kit that can be modded to fit into the clock location.

Yes this was done in 3rd gear, I was told to do it in 3rd and not 4th. As to why, I really don't know. I never ran a car on the dyno before, a tuner always ran the car on the dyno when I would take it in. I always thought dyno pulls were done in 3rd gear.

rotary nation

Installed 750cc primaries and 880cc secondaries today.

Noticed car started up SUPER, and I emphasize SUPER, fast. Also power delivery was much smoother.

It's not spitting fire like I thought it would lol, but I'm pretty sure if my AFR's weren't rich or good before they are now, lol.

funkjaw

iTrader: (3)

^ Time to tune! Keep us posted please. I am curious what you will get out of your setup.

RotaryEvolution

iTrader: (30)

as far as a dyno run it doesn't greatly matter but you will get a more defined image of any possible issues with a longer gear.

for tuning, 4th is used because it is realistically your load gear. if tuned in lower gears the air fuel ratios will be off when more load is applied, such as in the higher gears.

tuning on the street in 5th for example is unrealistic which is why 4th is generally used and 3rd used as a comparative.

the dyno doesn't care if the ratio is 1:1 through the drivetrain or a fraction of that, it's just measuring the acceleration rate of the roller.


i would have to charge much more tuning to peak speed compared to peak power in real world situations. most people accept a simulated load tuning(dyno) for those more extreme builds. hell in most cases i have to point out where the car begins to feel unsafe pushing up to and beyond 120 mph as the owners usually don't go that far or further, it is not a great feeling to me out on the street in an unknown car, doing 100+ and start to feel vibrations or the car pulling with slight bumps. being that i drive many cars everyday i am quite accepting but at those speeds you begin to notice major faults in setup.

i must be getting old, i don't have quite the deathwish i once did. but i do giggle when i have a customer with me for some road tuning grabbing for the "oh **** handles" while i'm multitasking. about 450 to the wheels is the most i've done as far as street tuning goes with street tires.

gxl90rx7

iTrader: (1)

dont worry about the intake temps, on a dyno with a topmount they always get super high. last time mine was dyno'd with ARC topmount, it was too hot to touch also. but on the street with normal airflow, its usually 130-140F tops

SpeedOfLife

iTrader: (16)

rotary nation

I understand but to me it's amazing how I can still pull that much power and torque when the air is just heatsoaked and especially back to back like that. I guess Mazda put a special 13B in mine lol. She's held up for the past 23 years now going on 86k miles.

My question is, with the weather here in florida getting down to the 40's and 50's at night (when I usually drive it to and from work), my intake temps never go past 130*F @ 7.5k RPMS and my boost went from steady 10-11 psi to steady 14-15psi...If I could possibly be putting down more power than what I got on the dyno day a couple months ago. I know basic physics cold air is denser, but damn didn't know it made THAT much of a difference.

EDIT: Forgot to mention that I got rid of my old exhaust setup and installed Racing Beat's REV II system, car not only looks great like it should with dual tips but sounds SO much smoother and lower tone. Absolutely love it, you get EXACTLY what you pay for with this setup. And that my friends is pure quality.

sharingan 19

iTrader: (16)

I saw your dyno pull at rotorfest, beautiful 10ae. YES cool/cold air makes a huge difference, you could easily be putting down 20+ hp probably more.

I have a tired turbo that I'm getting ready to swap, and last night (45-50*) it pulled like it was brand new. However afr's were about .5-.75 leaner as well, so watch out for over boosting in cool weather with an untuned setup, you might have to rebuild that "special 13b"

flaco

iTrader: (7)

FU&% the street tuning crap!! im still young but screw that, i been in too much trouble thanks to street tunes. no matter what they pay , i dnt think is worth it

rotary nation

Unfortunately she gave me one last pull today. Went to give her daily dose of redline in 3rd gear getting onto the highway, as I shifted into 4th she had no power, boost/vacuum was erratic, needle was bouncing all over the damn place, and she sounded like a misfiring subaru (if any of you could POSSIBLY imagine what that sounds).

Limped her home and she didn't have any effort to idle so it fell flat on it's face. I'm doing a compression test on her in the morning to confirm it's a blown apex seal(s). Giving me the symptoms: no power under 4k RPMS, backfiring A LOT when shifting and giving throttle, and extremely difficult to crank over. I'll give it some credit, it died a dignified death, waxing a boosted Honda S2000 lol.

MaczPayne

iTrader: (5)

Cold weather without additional fuel usually results in a blown engine. That and the fact you saw 14-15 psi during those runs is a danger sign. It's happened to me before - I was lucky to just have a chipped seal.

funkjaw

iTrader: (3)

Yup, def sounds like a blown engine.. Sorry to hear it, I've been there before and it sucks!

sharingan 19

iTrader: (16)

Dammit! That sucks. It seems like every time I try to warn someone about this, its never in time. No ****, this is probably the 4th time I've made a comment like this and come back a few days later to find the OP has blown their engine.

Before I got my rtek and injectors I could barely even merge into traffic or get onto the highway without hitting boost cut when the temp dropped below 60*. I was annoying as **** ( and not exactly good for the engine either..) but I refused to waste money on an FCD for exactly this reason.

rotary nation

It's all good. Thank you all for your condolences. I'll be rebuilding the engine myself soon once I get back from my TDY.

I'll be starting a new thread when I do with a step-by-step and picture process of everything I'm doing.

I'm very excited, it'll be my first rotary build. I have a lot of support from my friends and family with it, so we'll see how well it goes.

Thanks again everyone.

Wms10th

iTrader: (2)

Wow, almost the samething happened to me. I now have my Rtek 2.1, I'm deciding on injectors and making other repairs to the car, and even though I have done quite a few engines(I was a Mazda Technician in the 70's - 80's), I'm trying to decide who will build this one. I think my apex seal is just chipped, as it starts as good as always but idles low and rough...no noise,no smoke and runs good except at idle.

RotaryEvolution

iTrader: (30)

as soon as i saw these words in the same sentence: "colder temps" and "boost now at 14-15psi" i knew that the ending to this story would not be a happy one.

sorry but these are the reasons these engines have a bad name. you don't get more power for free. you had a standalone and were getting a wideband... but ignored the basics of forced induction which is air/fuel ratios.

the stock fuel system is only really safe to about 11psi and that is pushing it, even with a tune you still needed more fuel from somewhere. 14-15psi will pop a motor just because the stock fuel system cannot support that level at all.



i'm honestly more than tired of seeing people mod these cars without knowing the basics. unfortunately you had to learn the hard way and hopefully don't blame the motor for what happened.

13bpower

My jaw about hit the floor on the "14-15 lbs of boost" comment. If my boost went up 1 lb from what it should be I wouldn't be driving the car until I figured out why.

Everything Karack said above it 100% true.

rotary nation

Thanks for your input karack and I understand you frustration. Also it might help to explain what I did do to try and compensate for the colder weather that I didn't mention here online:

I installed a walbro 255LPH in the fuel tank a few days after I installed the 750cc primaries and 880cc secondaries. Performed the fuel pump rewire while I was installing the pump as well. Once that was completed I went into the fuel tables on the rtek2.1 and up'd the fuel trim from stock 10% from 10psi and below and 15% above 10psi.

The only portion I neglected was installing the wideband.

Something else to consider is the age of the seals in the engine and the unknown storage of the vehicle by the previous owner, he had it in a garage for 11 years, who knows how often he ran the engine or if he properly stored it.

Ever since I owned the car it always had very low vacuum. Even when I had it serviced by a mazda rotary specialist to repair all the vacuum leaks by the FSM, I never saw greater than -12 in/hg. So who knows if I already had a chipped or cracked apex seal from the get go and I just made it worse until it popped.

I hope this sheds light on the subject, sorry for not divulging the information earlier that I mentioned in this post.

RotaryEvolution

iTrader: (30)

ah ok, at least you got started in the right direction where the stock fuel system would have never supported that.

another thing to keep in mind is as far as i know the stock timing tables are still wayyyyy too aggressive even with the stock rtek basemaps. in fact all stock ECU timing mapping is far too aggressive beyond about 11psi for the FC and FD.

sharingan 19

iTrader: (16)

That engine must have been very weak indeed.... I have 580 primaries (don't ask, that's what they came back flowing) and 720 secondaries with a rewired FD pump on an rtek 2.1. I have have -5% correction for fuel that tapers down to 0% correction @ 10psi and +5% @15 psi.

In normal weather it hits 15 psi and tapers to 10-12 @ redline, but in cool weather it shoots to 20psi easily, although I never stay in it when I see bost climb that fast(Yes this turbo is dead, and will be swapped shortly). And the higest AFR I've seen is mid 12's. [I understand and appreciate that 12's are a bit on the lean side, however it was running low 10's in warm weather, the 12's didn't pop up until it got cool and boost shot past 15].

Karack great point about the timing, I'm about half way done inputing some boost based timing maps Arghx posted in the Rtek section. Should make things a lot safer, wonder what impact, if any it will have on AFR's?

RotaryEvolution

iTrader: (30)

AFRs should barely be affected at all, shouldn't have to make any adjustments.