Well, there is no issue w/ the dash cover hard base itself. The issue lies in the black vinyl covering ...on the base cracking. That's why I'm gong to investigate some other suitable covering to apply over the base that allows airbag deployment, is consistent w/ the cabin surfaces, and won't crack. I believe finding a suitable material w/b the most difficult challenge. May enlist my wife's assistance w/ that. :icon_tup: Attaching it via adhesive or other means s/b simple. At least so says he who hasn't attempted it yet...:yelrotflm

Or....................... don't leave it in the sun all day.

That shouldn't be an issue...as my car h/b garaged at home and work virtually it's entire history.

What do you guys think about these leading plugs I pulled (1L & 2L)?


https://cimg7.ibsrv.net/gimg/www.rx8...6ccd21fa4f.jpg.

Dang, those sure are fouled. I’d imagine the trailing being better but probably not ideal. Which plugs you going with? NGK iridium? Or the race ones?

The colour isn't too bad but the amount of crud for the mileage is a lot . Kinda says to me the the heat range is fine for the high boost runs you are doing but the fouling is from the sedate driving in between..... So colder would help with that.

Spark Plug Config.
 

I'm thinking that my AFRs being rich d/t my contaminated MAF didn't help matters either.

Moving forward I'll run:
- L: 7420-9s (aka NGK 6448)
- T: 7420-10s (aka NGK 5501)

Update:

Installed my NGK 7420-9 plugs and did a few pulls. The below is at ~13 psi: 345 HP / 260 ftlbs. She's a blast to drive. I've a number of To Dos to complete before spring, and will work to sustain torque profile across the rpm range..., but otherwise very pleased w/ the project. Initial objectives h/b met. :)

Team - Are you not entertained? Are you not entertained? ;)
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You Tube

https://cimg9.ibsrv.net/gimg/www.rx8...0ced785960.png
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If the torque kept rising after peak torque then it wouldn't be peak torque :dunno:

Touche' :yelrotflm

Power level is ideal for my objectives, i.e. high enough to h/b worth the investment, ...low enough to hopefully sustain reasonable reliability for a Renesis. :fingersx:

While some of the HP & Trq slope decline post 5k rpm is likely d/t a boost leak and my dynoing process..., I've no doubt there is decline, which I w/b working to minimize. I'm hoping to find untapped power via:
- eliminating boost leak
- EBC optimizing
- freer flowing intake & exhaust
- perhaps tuning (I'll consult w/ /Brett)
- potentially EBC capable of provisioning boost per rpm range

Thoughts? Any other ideas?

To get your boost to hold better it could be as simple as taking the line that goes to the solenoid from just before the throttle instead of from the turbo. What that does is supply air at a slightly lower pressure to the actuator. Be careful of how you route it and ensure it's secure as you don't want that line coming off !
That should give you maybe another 10-15whp at peak rpm.
Past that it's about how efficient your system is ....... I recommend setting up a line to measure EMAP which will tell you exactly that. You will be able to monitor improvements as you make them.
Your exhaust would be the first place to start ...IMO.

While I think of it ...we need to lower your rev cut if you are going to keep pushing limits like this :).

Thanks, Brett.

My solenoid signal line is plumbed to the last charge section (just prior to throttle body). :yesnod:

I agree that an EMAP w/b a useful tool in measuring & monitoring system back-pressure. But atm I believe I m/b able to achieve my goals by simply enacting obvious measures to reduce opposing intake &/or exhaust pressures, e.g. air filter (next week), ...later perhaps a higher flow catback. If that doesn't get me to my objectives... then I'll install the EMAP. :icon_tup:

oh ... didn't realise you had already done that ...lol

:icon_tup: Absolutely, ...don't mind sacrificing a few rpm at the top of my declining torque curve at all. :yelrotflm

it should be flat, like you’re thought process except for torque that’s a good thing :)

So it’s not a curve either Einstein and it wouldn’t make the engine anymore prone to failure once past the peak. Go look at that 719 rwhp graph on RX7Club, that’s so beautiful; flat 500 ft-lbs torque for about 3000 rpm range.

sad sad pandas is crying ...

I was curious if the torque decline I'm seeing is EBC settings...or hardware related. So, reduced boost a bit, and experimenting w/ EBC settings to see if I can reduce torque decline. Initial results are positive... as compared to the v-dyno in post #538.


https://cimg2.ibsrv.net/gimg/www.rx8...28eed37d43.png

The issue is you have a turbo capable of 500 whp. It was never my intention to give you grief or goad you into blowing a motor. I had perceived that you chose that turbo for it’s intended purpose, but now realize that’s not the case.

At this power level a BW S257 SX-E or even the S251 would be suitable for your current power level with a notable response benefit. Kind of where you are now is an oversized turbo operating at an undersized output level. It’s just finally starting to get spooled up and then being neutered with a low boost setting. That’s not a criticism; just an honest assessment of what’s going on with it. It could likely be handled better with a boost by rpm setting strategy by incrementally bumping up boost to ramp it off flat and hold it out to redline. I don’t know if that’s possible without changing the pcm, which then you’ll lose emissions compliance capability.

I realize and believe that now. And my response c/h been better. Water under the bridge. All good. :icon_tup:

You're right: I did not realize the potential of the 6266 turbo. Not that I'm displeased w/it, but had I known...I w/h selected a smaller turbo w/ better response for my objectives. That said I'd always planned to increase boost some, but only after transitioning to E30.

Having transitioned to E30 I've increased boost a bit. But thinking thru the torque decline post peak,... that I'd seen at every boost level...on a turbo capable of blowing more air than I'm pushing thru it didn't make sense, and caused me to suspect it was EBC tuning vs. hardware related. :rolleyes: I had provisioned my EBC actively utilizing WARNING & LIMIT to constrain max boost...RATHER than tuning max boost using SET, GAIN, and SET GAIN only. Then using WARNING and LIMIT essentially as a safety net, which should rarely be engaged except in the event of a hardware failure. As seen above...early indications reducing the % LIMIT support my suspicion that the LIMIT features constraint was having the unintended effect on torque as well.

edit: I've considered a progressive controller, but believe I m/b able to achieve my goals w/my existing EBC using better tuning philosophy.

It's been raining lately and I've some loose ends to sort..., but I'll continue retuning my EBC in this way and am interested to see the upper rpm range of the natural HP/torque curves of my 6266 with the LIMITING feature constraint fully lifted. :yesnod:

Ok, well looking forward to seeing you get some positive results. :biggthump

Thinking about the sizing of the 6266 for my set-up a bit more...I believe it is, albeit in the upper range, a good fit for my goals: a reliable DD at ~340HP / 250Trq . :) 2nd gear is spooled by ~3800, and 3rd by ~ 4100 rpm, which means during normal driving I'm typically under full torque, BUT on it's rising edge. So, my system sacrifices the immediate torque / responsiveness of a smaller turbo,...but not by much :nono: ...as even slight tip-in brings full torque nearly instantly. I actually reduced throttle sensitivity to better govern torque onset through this range. And this set-up operates the turbo in its higher efficiency islands, reducing heat and wear, yet doesn't run out of puff ...when pushed.

So, I've no experience DD'ing a car w/ turbo fully spooled during normal driving, but w/b interested to hear perspectives from those who do. I'm sure I'm overlooking some benefits of that system set-up.

IMV for all right reasons, e.g. comparing and contrasting across systems, we can become so focused on system metrics that we lose sight of the "point": the desired driving experience, While biased...I'm actually quite pleased w/ mine. :ylsuper:

edit: She's still teaching me how best to tune and drive her. :yesnod:

To what exactly are you disagreeing? :dunno:

First, my turbo current max output is ~52 lb/min. That places me on the ~62% island of the BW S257SX-E w/ little room for growth. :nono:

Using the T66 compressor map, the closest approximation I could find for the 6266 given Precision notoriously holds their maps close to the vest, 52lb/min places it at ~ 74%, w/ growth potential, should i desire, out to ~60 lb/min while remaining at ~70% efficiency. So, admittedly, what is sacrificed in responsiveness is gained in efficient growth potential.

https://cimg3.ibsrv.net/gimg/www.rx8...6666692dbb.png

I am not claiming the 6266 is squarely in my sweet spot...responsiveness vs. top end. I have said I w/h selected a slightly smaller unit. However, my larger point was that it "all" has to do w/ a) individual objectives and b) resulting "driving experience"... to which IMV the 6266, though in the "upper (size) range", fulfills mine.

Aah, you're basing your calculations on the v-dynos *I've posted.* :)

I'm pulling g/sec (lb/min) directly from M/E data logs. :yesnod:

IMV for all right reasons, e.g. comparing and contrasting across systems, we can become so focused on system metrics that we lose sight of the "point": the desired driving experience, While biased...I'm actually quite pleased w/ mine. https://www.rx8club.com/images/smilies/ylsuper.gif

Curtis : a better comparison to your turbo would be a Garrett GTX3582 as Precision and Garrett use very similar design and the T66 is very old tech plus I think that's a bigger compressor .... 66mm inducer wheras yours is a 62mm.

Team : Your matchbot examples are showing a horizontal line for the compressor output which suggests to me that you haven't factored in the increase system backpressures from exhaust,intercooler,intake etc with increased flow. Have a read of the Matchbot notes!
The difference between a 1.00 and a 0.83 isn't going to be anywhere remotely close to 100whp. More like 15-20 at peak power.