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90% of that motor was salvaged parts from a clapped out blown motor I purchased from an importer 6 years ago. No telling how many rebuilds some of those parts have been through. It's all on the houses tab at this point, give it hell at the dyno haha.
well it did hit the 30 psi boost cut at 6100 rpm in 4th gear before I dialed the controller DC% back some for that run above, gave me a pretty good scare when it backfired on the cut thinking the apex seals just exited stage right out the tailpipe
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The gunshot back fire takes getting used to. Your heart rate hits 200, you assume the worst, check the gauges and everything seems normal, motor sounds normal, then you convince yourself you must have hit ignition cut all in about 4 to 5 seconds....
90% of that motor was salvaged parts from a clapped out blown motor I purchased from an importer 6 years ago. No telling how many rebuilds some of those parts have been through. It's all on the houses tab at this point, give it hell at the dyno haha.
Seems to be a thing.. I had one that I built and blew up the first track day with new everything... and one that was built out of crap... housings that had score marks and old side seals that lasted 3 years at 500+
Sometimes it doesn't make sense and it's more situational luck
Honestly this engine has more lives than an alley cat, because technically it should have blown the water seals on all three coolant losses. Yet it fires up immediately from a dead cold start after sitting a week and now runs a bit too cool even under WOT; ~170°F (fwiw with an RX8 radiator being blocked by an intercooler with ime ~550 whp output ). God gifted me the perseverance, patience, and means to keep climbing out of the ever-deepening pit though, lol. 🙇♂️
Glad I'm not the only one seeing much cooler water temps than with the Renesis and the stock Rx8 Coolant System. With my Greddy boosted Renesis water temps ranged anywhere from 190F to 205F, sometimes reaching 208-210F at hot idle. Found that letting it idle in my 60F heated garage last week (overhead door opened a couple feet with a fan blowing exhaust out) I was only able to achieve a water temp of 174F. Of course the was just warming up at idle from cold; at cruise I'm seeing about the same temps ~ 172 to 175ish with it warming up to about ~180F if I park and let it hot idle. Maybe the biggest contributing factor for my setup is after swapping engines, I have less "stuff" behind the rad allowing more free air flow through it; but ultimately, I'm seeing about a 10-15F water temp difference between the two setups.
well I’d hardly attribute it to the engine, especially wrt 2.5x+ the power output under WOT conditions. Which was my reference in the comment, but in general towards other thread discussions wrt RX8 cooling. That was just addressing the basics. The details that matter more will be addressed later to further improve the heat transfer effectiveness. Honestly my only goal at the moment is to document what Stroker did in reference to what will come later.
Accurately calibrated the 3.5 Bar MAP sensor to 37 psi peak tonight; was only reading about 2.5 - 3 psig high @ 30 psi indicated from the other day
Then dashed over to the Country Mile drag strip to get a quick run in before the gate closed for the night . Haven't drag launched any car much in the last several years; let alone this one, so was a bit of a hack at it the first go around. Based on the log I'd estimate there's at least 1 second to be gained on a good launch through 1st gear. Also got a video of it, but am using new software and the displayed data is upside down along with a too flexy shakey-cam mount so not really much to see, but more the sound. I don't have any way to host it though, so just the screen shot. Also added some P gain to the closed loop boost PID, but without any damping gain it's just flipping back & forth between 23 - 27 psi around the 25 psi target boost map setting. I'll probably just wait and not bother with it further until dyno day later this week. It will be much easier to work through then.
The car is real tough to launch. I either bogged hard or the tire shake that would rattle the radio faceplate off.
That was my whole reasoning on going back to the 245/45/18 R compounds, I wanted a tire that would spin out of the hole but have enough grip to stick in the higher gears with help from softening the boost curve.
It will never be as fast as a true drag tire, but its asking a lot of a drivetrain that was spec'd to put down the 130 lb/tq from the factory MSP.
I’m just out of practice. Have cut 2.0 sec 60 foot times in my NA RX8. It’s obviously easier to modulate the launch. When I finally put my foot down the log shows how steep the accel rate is; 21.5 mph/sec in 1st and 16.5 mph/sec in 2nd.
Pretty confident it can do a mid-11 sec run, maybe low 11s even with the trap speeds to match.
Hammered on it for 16 Dynojet runs with the majority at 29 - 30 psi boost. That should be considered a success in itself.
Most puzzling though is that I'd have expected about 100 whp more than was recorded based on on the Borg Warner S369 SX-E turbo with 1.00 A/R turbine. It would almost seem like something is restricting flow through the engine based on where it'd fall on the compressor map. The one mistake I made was forgetting to try and make a run with the water/meth injection turned off. Presently operating on ~E45 fuel with 100:1 Redline premix and 0.75 oz. top lube (88:1 net pre-mix) and ambient today was 75*F & 35% humidity. I'm thinking it might not need any water/meth at all or at least not the large injectors that are on it. I otherwise have it as delayed as much as possible without changing injectors; not really much else that can be done because the max boost setting for 100% is 30 psi and the max initial turn-on delay is 10 psi. Couple of sensor/electrical glitches though; the log AFR is way richer than what I saw displayed for the run and the flex-fuel sensor reading is dodging around. I'll have to look into those.
Not 100% sure, but i think i had the ecu pull timing above 100F IAT, and maybe even alot by 140F. I may even set a doomsdayscenario of timing pull above 140F. Add the leading ignition timing to that log and we can see what was being commanded. It could have been diving down to 10 degrees and excessive water may have been keeping power down further. Just a thought. I think the back housing is a 1.0.
Also third stage duty cycle on that 1650 injector will provide some good data to compare to some of my old runs to see if the map sensor was truly that high because the gauge was always reading about 3 to 4 psi higher than the 3 bar map sensor. Some rough calculations on total fuel flow, ethanol content, duty cycle, and afrs made give us some better info on how much air is getting through the motor.
Good news is the engine stayed together so you should have good data to make changes going forward....
I also had issues where the ethanol sensor would drop signal throughtout a run, but adaptronics lets you set a base ethanol level so if the sensor drops it will refer to that value. So if you are at 45%, make sure to set that value to 45. I would change that value constantly to keep afrs correct during pulls.
I beleive those jets are 500cc/min each on the water/meth injectors. Probably does a real good job of keeping knock down but could be robbing you of a good deal of power.
One more trick. That run you started the pull at 120 IAT which is mostly heatsoak from the IAT located in the UIM. Right before the run, hit the test button on the meth controller for 2 to 3 seconds and let off, wait 10 seconds and hit it another 2-3 seconds and the IAT will drop to near ambient temps. The misting of water and methanol in the intake tract at idle will take all of that heatsoak out for a few minutes. Make the pull during this time and it should be happier.
Last edited by strokercharged95gt; 12-02-2021 at 09:23 AM.
The boost is 100% accurate; the voltage output and indicated pressure are matching up with both the manufacturer's MAP sensor calibration chart and a high-accuracy pressure gauge. There's no need to question it because what was causing all of the previous issues has been corrected per private discussions. It shouldn't even require a pressure gauge at all; just the MAP calibration sheet, except that wasn't possible previously due to the very nature of the problem. If you go up several posts to where I reply copied your comment about it reading 3 Volts at atmospheric, that was a critical piece of information. You knew it wasn't right, but didn't understand why. Because 3V on a 3 Bar sensor is about 1 Bar of boost (200 kPaA). If any boost readings are in question, they're the ones listed on the previous pages.
Otherwise I knew it was getting heat soaked and not overly concerned, because my goal was not to make or even look for max power. I was there to get the closed loop boost working properly to set & forget it rather than chasing conditions manually adjusting duty cycle. There are many runs listed in this thread about being cut short due to hitting the over-boost limit cut. That's not happening anymore, even running higher boost settings. I'm not really going to get too wrapped up in it otherwise, because I agree that the potential is much higher than indicated. However, it never was my goal to keep on marching down this same path. They're may be some more testing and I might post some times to reflect the capability. Did run a 1.99 sec 60 ft and 4.6 sec 0 - 60 mph time while shifting early during the 60 mph crossover, but then lifted before the 1/8 mile yet still logged 8.3 sec 91 mph, establishing the potential for improvement. The goal was always a drivetrain overhaul geared toward highly responsive low-end torque without it breaking. That will all be covered in a new thread and this one is likely not going to see much more new posting. I need to get back on to finishing my other car for next year and this one will be a side project going forward.
Those water temps though! 163F on a WOT dyno run? I'm sure the info is buried somewhere in this thread but what cooling mods are involved? I already know you said its the stock Rx8 Rad; but those water temps seem quite low for the scenario no?
Sorry if I was unclear on that; not a dual-pass or racing radiator is what my reference was.
It has a Koyo S1 radiator with FAL420 fan assembly that I know of, maybe a lower temp t-stat (?); Stroker would need to confirm. Haven’t done much other than just get what’s there to operate fully by bypassing the OE fan temp controls; the Select doesn’t directly have any control over them, or the idle speed, and quite a few other things like the Modular ecu does. In 75°F ambient it will maintain mid 150-ish just idling, but eventually it will be set to 180°F with the extra capacity in reserve. I have a new S2 Koyo for the future project and will further improve the capacity more with modifications then.
Yes it's a low opening thermostat (something like 165) which I installed when I was battling cooling issues most related to worn out stock fans on a OEM strategy and a FMIC that blocks the radiator.
If the hood open and the car has a huge fan in front of the motor which is likely what happened during the dyno run, I could see it being in the 160-170 range,
As long as the car is fully warmed up and the oil is good and hot, I don't think 160 would be an issue.
I think most people think of the optimal temp being 180. Many manufactures design them for 200+, which is probably related to emissions. I know some drag racers that race at 160.
Last edited by strokercharged95gt; 12-03-2021 at 07:28 AM.
could you post the dyno sheet with zero smoothing?
and, yes, 30 psi with a SXE 69 should just on the other side of 600. generally if you are looking for that much of a diff and the motor is running fine it is a flow problem.
congrats on continuing what is, IMO, the most valuable single turbo rotary thread on the net.
Having started off conservatively and then ramping it up with numerous runs, by that point it was heavily heat soaked with 160°F IAT. The tuning is set up to pull back timing and grossly lower AFR values for protection against that. I’m surprised it wasn’t misfiring, gotta love those IGN-1A coils.
the intention was just to get it past blowing off hoses, overheating, and boost-cutting, all of which after some prior dramatic moments were all achieved.
due to my lack of familiarity I didn’t think to cool it down manually operating the AI system for a final peak power attempt, but after two hours of ear ringing, sweating, and eating/breathing rich/oily exhaust fumes I was ready to wrap it up. The other thing I noted later is that the dyno ramp speed was only equivalent to what is being logged when being driven in 3rd gear despite running in 4th, which is going to be a slower ramp up of boost.
I haven’t even had it out of the trailer since then, but maybe this weekend. Honestly I wish it still had the prior S362 SX-E on it instead with maybe a larger AR. That’s basically where I’m taking it back to with the Garrett G30-770 turbo per the new continuation thread. I’ve also noted that the intercooler is not keeping up even in cool weather with it mounted fully in front. The plan is to convert to a direct low mount turbo position with a hood vented v-mount setup. So it will get a complete makeover eventually as per the continuation thread, but this will require quite a bit of work and time.
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so I came across an interesting Borg Warner hybrid turbo; an S262 SX-E, the S362 SX-E compressor wheel retrofitted into an S257 SX-E compressor cover/turbo, which with a 1.22 A/R divided T4 turbine housing to account for the smaller turbine wheel should make a potentially hyper-peppy version of the S362 SX-E that Stroker previously had on this setup.
It will be close to a direct bolt on since it has the same downpipe connection as the S369 turbo on it now. So I went ahead and bought one as a testing comparison against the Garrett G30-770. They both peak flow approximately the same. The BW appears to be more efficient earlier in the compressor map flow. It will be interesting to see how that with the BW journal bearing CHRA plays out against the Garrett roller bearing.
It was just slightly under 1/2 the cost of the Garrett too and should be small enough to fit in a low-mount position on the RX8 chassis if it plays out well.
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Can also get an aftermarket 0.83 divided T4 turbine housing for relatively cheap to replace the 1.00 A/R housing on the current S369SX-E turbo. I’m considering it just to see what the difference is. This turbo with 1.00 A/R housing dyno’d at 719 whp and 500 lb-ft on RX7Club. So it’s way oversized at the current power level. I get why Stroker did that trying to keep torque from kicking in too early and eating the transmission, but it’s really stifling the mid-range potential imo. The question is whether I want to chance it before swapping the drivetrain to avoid that. 🤔
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Happy to see some real world testing Team, and this hybrid turbo assembly is very interesting, I am curious to see what you're results turn out to be!
Also can I ask why your dyno chart has so many spikes in it? Does the fuel map need smoothed out or just a sensitivity setting in the dyno? FYI I am clueless about dyno setups and parameters, I just haven't see a chart that had that many small spikes in it
you can't just look at the pictures, but need to read the discussion that goes with them
edit: in addition to the discussion, most likely had something to do with crap piston engine sparkplugs being installed with most of the grounding strap gone resulting in a huge spark gap. Hard to believe it even ran like that
the plugs that came in the engine when the car was purchased
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11-26-2021, 09:42 AM
). God gifted me the perseverance, patience, and means to keep climbing out of the ever-deepening pit though, lol. 🙇♂️
. Haven't drag launched any car much in the last several years; let alone this one, so was a bit of a hack at it the first go around. Based on the log I'd estimate there's at least 1 second to be gained on a good launch through 1st gear. Also got a video of it, but am using new software and the displayed data is upside down along with a too flexy shakey-cam mount so not really much to see, but more the sound. I don't have any way to host it though, so just the screen shot. Also added some P gain to the closed loop boost PID, but without any damping gain it's just flipping back & forth between 23 - 27 psi around the 25 psi target boost map setting. I'll probably just wait and not bother with it further until dyno day later this week. It will be much easier to work through then.
