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jcbrx8 09-22-2020 10:28 PM


Originally Posted by JimmyBlack (Post 4928224)
...Edit: Here's a link to my back pressure experimentation. I installed the sensor, recorded some results, upgraded the turbo, then recorded more results to compare old and new turbo. This was all on a Greddy manifold (t25 turbine flange).
https://www.rx8club.com/series-i-maj...3/#post4730979

Jimmy, Your EMAP experimentation... interesting stuff. Still digesting it...

Brett's been recommending I install an EMAP sensor for a while now.

Brettus 09-22-2020 10:39 PM


Originally Posted by TeamRX8 (Post 4928235)

With that size turbine at that output though, I was thinking it’d be less than 6 psi, but that might depend on the exhaust.

Edit :plugged it into matchbot to get an approximate and yeah ... a good setup should do 6psi differential. Or 20psi EMAP

Brettus 09-22-2020 11:07 PM


Originally Posted by jcbrx8 (Post 4928240)
Jimmy, Your EMAP experimentation... interesting stuff. Still digesting it...

Brett's been recommending I install an EMAP sensor for a while now.

Yeah , I only started doing it after Jimmy did. It made me realise how useful the info was at determining how good the system/turbo is.

jcbrx8 09-23-2020 09:45 AM

So, I've pretty well gotten boost tuned to ~14 psi, what I believe / hope :fingersx: w/b a moderately aggressive boost level ...for my set-up, which will also yield reasonable reliability (yes, of course... relative).

Below is a comparison of a 15 vs 14 psi profiles in which it c/b seen that AFR is in a more comfortable range relative to the AEM recommended upper limit at 14 psi.

15 psi:

https://cimg9.ibsrv.net/gimg/www.rx8...9fd63dbbdf.png
9-20-20: 15 psi
.

14 psi
https://cimg0.ibsrv.net/gimg/www.rx8...80a0ba64db.png
9-22-20: 14 psi

RotaryMachineRx 09-23-2020 10:37 AM

Solid looking boost curves. Any chance those graphs can be converted to an RPM based X-Axis rather than time without any hassle? I'm assuming that's just a pull through the RPM range anyways but would still be nice to see. The AFR definitely appears to look a bit lean on the back half of the 14psi graph, maybe even a little on 15psi (assuming low 11's would be ideal AFR target).

jcbrx8 09-23-2020 10:50 AM


Originally Posted by RotaryMachineRx (Post 4928257)
Solid looking boost curves. Any chance those graphs can be converted to an RPM based X-Axis rather than time without any hassle? I'm assuming that's just a pull through the RPM range anyways but would still be nice to see. The AFR definitely appears to look a bit lean on the back half of the 14psi graph.

Thanks, Jesse.

Not to my knowledge via AEM b/c it doesn't have a rpm feed. However, I can do a VD which does log w/ rpm on the x-axis. Then the M/E VD and AEM profile c/b sync'd using "Load" and an estimate of rpms transferred to the profile. I'll try to remember to do that next time a do a legit VD, as most of these are just spirited driving...i.e. no formal start rpm, and not necessarily WOT, and post the result.

Edit: The estimated rpm range boost "peak to drop" via the above process on previous pulls is ~4200 - 8000 rpm.

Brettus 09-23-2020 01:07 PM


Originally Posted by jcbrx8 (Post 4928258)
Thanks, Jesse.

Not to my knowledge via AEM b/c it doesn't have a rpm feed. However, I can do a VD which does log w/ rpm on the x-axis. Then the M/E VD and AEM profile c/b sync'd using "Load" and an estimate of rpms transferred to the profile. I'll try to remember to do that next time a do a legit VD, as most of these are just spirited driving...i.e. no formal start rpm, and not necessarily WOT, and post the result.
.

The AEM failsafe gauge can be set up to record rpm ...... have never bothered to get that set up myself though as I believe it's quite a mission. Curve looks good. Looks like it only drops 1-2psi at high rpm end ?

jcbrx8 09-23-2020 01:38 PM


Originally Posted by Brettus (Post 4928267)
The AEM failsafe gauge can be set up to record rpm ...... have never bothered to get that set up myself though as I believe it's quite a mission. Curve looks good. Looks like it only drops 1-2psi at high rpm end ?

Correct..., but it requires a rpm feed, which it currently does not have. So, it's back to the challenge of deriving a solid rpm signal.

Thanks. yes, I'd say a drop of ~1.5 +/- psi across the rpm range.

RotaryMachineRx 09-23-2020 04:03 PM

No need to go out of your way for it, was just curious if it was possible with the current inputs. Thing must feel like a rocket!

TeamRX8 09-23-2020 07:21 PM

looks good Curt

jcbrx8 09-25-2020 08:47 AM

Update: Pineapple Oil Pan Gasket

Just wanted to provide a bit more color regarding my experience w/ the Pineapple oil pan gasket. I was optimistic about the ease of oil pan installation and removal using it; but it didn't work out.

Obviously, installation using Permatex Gray is a bit more daunting, but each time it has created a very high quality seal. In the past on removal... the bond was so strong that I literally had to grasp the pan, suspend my upper body weight, and bounce and pull for 2-3 mins to break the seal. Lol, ... and I thought this was a bad thing.

Well, I removed the pan last night... having used the Pineapple gasket, and the pan was literally falling down before I could get the last bolts out. Though I'd used a smear of Perm Gray above and below the gasket...it had bonded to the metal, but not to the gasket at all. It seems the gasket was actually the barrier to a good seal.

Perhaps it was my process..., and others have had a better experience..., but I'll be using Perm Gray only going forward.

Brettus 09-25-2020 11:29 AM

Had my share of issues with oil pan leaks myself .A turbo engine seems to need special treatment vs N/A These days I have a set process using Permatex Black that works every time (touchwood).

strokercharged95gt 09-25-2020 11:45 AM

I have resealed my oil pan probably 6 or 7 times over the past 5 years. I have used Toyota FIPG, Permatex black, you name it. It seems to always leak no matter what I do. I always find about 5 drips under my car after parking it overnight. I just accept it now.....

jcbrx8 09-25-2020 12:16 PM


Originally Posted by strokercharged95gt (Post 4928417)
I have resealed my oil pan probably 6 or 7 times over the past 5 years. I have used Toyota FIPG, Permatex black, you name it. It seems to always leak no matter what I do. I always find about 5 drips under my car after parking it overnight. I just accept it now.....

I had no problem w/ oil pan leaks once Gregs recommended using Perm Gray. Lesson learned: it wasn't broken...I shouldn't have tried to fix it.

My larger issue is the turbo oil drain. It's connects ~3.5" up into a cavity and snakes thru an ~ 1" access slit between the oil pan and exh. manifold. It literally lays against the manifold as it passes thru this opening, and the heat deteriorates it over time. I've already replaced it once, and even w/ shielding know it's a matter of time before needing to do it again. As TomD suggested when I replaced it before... I'm going to have to find a way to install a hard pipe there.

This pic is from when it started leaking before.
.
https://cimg3.ibsrv.net/gimg/www.rx8...2e460943e2.jpg

RotaryMachineRx 09-25-2020 02:14 PM


Originally Posted by jcbrx8 (Post 4928418)
I had no problem w/ oil pan leaks once Gregs recommended using Perm Gray. Lesson learned: it wasn't broken...I shouldn't have tried to fix it.

My larger issue is the turbo oil drain. It's connects ~3.5" up into a cavity and snakes thru an ~ 1" access slit between the oil pan and exh. manifold. It literally lays against the manifold as it passes thru this opening, and the heat deteriorates it over time. I've already replaced it once, and even w/ shielding know it's a matter of time before needing to do it again. As TomD suggested when I replaced it before... I'm going to have to find a way to install a hard pipe there.

This pic is from when it started leaking before.
.

I would give some DEI heat wrapping a shot. It's good for 500F direct contact and 2000F radiant heat. It probably won't last forever but it can be removed and replaced easy enough where that's all you're replacing and not the drain line.

https://www.designengineering.com/heat-shroud/

I found a 3ft roll of it on Amazon, so if you're only using 8" of it at a time should last you a while.

jcbrx8 09-25-2020 08:18 PM


Originally Posted by RotaryMachineRx (Post 4928424)
I would give some DEI heat wrapping a shot. It's good for 500F direct contact and 2000F radiant heat. It probably won't last forever but it can be removed and replaced easy enough where that's all you're replacing and not the drain line...

Thanks, Jesse. I had a similar idea and used Fire Sleeve the last install. It's holding atm, but I agree... any shielding is a temporary fix.

Ideally, I'd find a way to install a hard pipe just to get past the manifold. Otherwise I may need to play the shielding game until rebuild. When I have everything apart I'll install the hard pipe. Right now the clocking is like 3-4 degrees off to install a straight pipe....easily.


https://cimg4.ibsrv.net/gimg/www.rx8...d661c009a.jpeg


TeamRX8 09-25-2020 09:31 PM

I started to post that I prefer Fire Sleeve to the velcro wrap, but then deleted it.

jcbrx8 09-26-2020 08:26 AM


Originally Posted by TeamRX8 (Post 4928437)
I started to post that I prefer Fire Sleeve to the velcro wrap, but then deleted it.

Bro., Thanks... , but perhaps you need to delete your "delete" button. .:dunno:

TeamRX8 09-27-2020 03:10 AM

except i didn’t actually post and delete it; had it written and then decide not to, hit back page, and backed out of it.

just want make sure i have it right though; you condemn me for not using the like button, but also condemn me for using the delete button. anything else you want to look into and see in my heart to pass righteous judgement on?

maybe for not using caps? it’s ok, i have broad shoulders, let her rip.
.

jcbrx8 09-27-2020 12:56 PM


Originally Posted by TeamRX8 (Post 4928480)
except i didn’t actually post and delete it; had it written and then decide not to, hit back page, and backed out of it.

...you condemn me for not using the like button, but also condemn me for using the delete button. anything else you want to look into and see in my heart to pass righteous judgement on?...


Sigh...again...?

T, I did not condemn you for not using the like button...you actually had...24 times. You then said "ALL" of these were mistakes... :yelrotflm, and...summarily deleted them :suspect:. I merely "observed and asked a question" regarding an observation, which...IMV...I found odd. You can go back and re-read the exchange b/c I have not deleted it. ;) I'll do better...It's reprinted here:


Originally Posted by jcbrx8 (Post 4912344)
Team, On another...or perhaps similar note... how do you have a 22,398 post count to date, ......yet have only given 24 "Likes"? :scratchhe

So, barely one tenth of a percent (~0.1%) of your time among this "community"...since 2005, did you find someone else did or shared something...anything worthy of a "Like" ??? :dunno:


If you feel condemnation it's not from me..., perhaps... from your conscience...or common sense?


I appreciate your previous positive comment regarding Fire Sleeve b/c it contributed to the discussion at hand: products suitable to resolve the situation I'm encountering. But you offered up the bit about having "hit the back button", aka deleted it :rofl:, and given your....ehh...history w/ "deleting things"... thought it's application poetic here.

So, lighten up...take off the thespian robe, and let's talk about our cars, yeah?

jcbrx8 10-12-2020 10:24 AM

Update: Turbo Drain Permanent Solution...hopefully

Well, as expected the braided SS turbo drain started leaking again. As Tom D. suggested a while back, the only permanent solution really is to find a way to install a hard pipe to extend past the manifold. So, I started w/ that as an objective this time. I was able to find a hard flex-drain pipe, but it would require removing and reinstalling the two 6mm flange mounting bolts, one of which is difficult to reach (there's always one.) TBH, the perceived difficulty of removing and re-installing those bolts was a major reason I'd not pursued a resolution requiring removing the flange previously.

As I laid under the car... staring at the bolts...I had an epiphany: the bolts were allen-head bolts, and could potentially be reached w/ a ball end hex socket. So, a trip to HF..., the flex-drain order..., a wait for delivery...; and the flex-drain is installed w/ a section of Fire Sleeve (just barely visible in the last pic) at the section nearest the mani.

Hopefully, this issue is permanently resolved. :fingersx:In some instances...having the right tool is everything.

.
https://cimg0.ibsrv.net/gimg/www.rx8...a4f6e0638e.jpg
Old flange
.

https://cimg9.ibsrv.net/gimg/www.rx8...abb16f883c.jpg
Old flange finally off

https://cimg8.ibsrv.net/gimg/www.rx8...673eef2119.jpg
New flex-drain pipe installed
.

https://cimg7.ibsrv.net/gimg/www.rx8...be49c5e2fe.jpg
Flex-drain extension past mani
.

https://cimg4.ibsrv.net/gimg/www.rx8...46631ab4a0.jpg
Flex-drain installed w/ a section of Fire Sleeve (barely visible here) at the section nearest the mani.
.

RotaryMachineRx 10-13-2020 12:58 PM

So the hard flex has clearance from the manifold on all sides now or you just anticipate it to hold up to the heat better? Or both?

jcbrx8 10-13-2020 02:51 PM


Originally Posted by RotaryMachineRx (Post 4929406)
So the hard flex has clearance from the manifold on all sides now or you just anticipate it to hold up to the heat better? Or both?

The latter. The clearance is about the same, ~ 1/8 - 3/16" - see 3rd pic in my post. But I'm optimistic the flex-pipe will hold up better to heat. Since the previous line was a "rubber-like" inner surrounded by braided SS... the heat from the mani would degrade the inner hose over time; and increasingly allow oil to seep out between the braided SS. Conversely, the flex-pipe drain is all metal, and I was able to slip a section of Fire Sleeve around it at the section closest to the mani.

Time will tell... :fingersx:


TomD_Cincy 10-14-2020 05:25 AM

You may want to periodically remove the drain tube and inspect the interior for signs of oil coking, especially if the interior is corrugated like the outside is. Though I would expect the fire sleeve to help prevent that.

jcbrx8 10-14-2020 08:04 AM


Originally Posted by TomD_Cincy (Post 4929468)
You may want to periodically remove the drain tube and inspect the interior for signs of oil coking, especially if the interior is corrugated like the outside is. Though I would expect the fire sleeve to help prevent that.

Yeah, I tried to keep the line as vertical as possible nearest the mani, and used the Fire Sleeve to try to mitigate coking, but good idea... as the inside is corrugated as well.

Thanks again for suggesting use of a hard drain pipe. :icon_tup:

TeamRX8 10-14-2020 11:30 AM

while it serves the purpose at the moment, that small piece of hose to the oil pan connection at the bottom seems like a weak point/issue waiting to happen.

you might consider replacing that with a tube-tube connectors/adapters along with some hard tube if needed as a longer term solution.

if that breaks or comes loose the oil pan would drain quickly
.

jcbrx8 10-14-2020 01:15 PM


Originally Posted by TeamRX8 (Post 4929499)
while it serves the purpose at the moment, that small piece of hose to the oil pan connection at the bottom seems like a weak point/issue waiting to happen.

you might consider replacing that with a tube-tube connectors/adapters along with some hard tube if needed as a longer term solution.

if that breaks or comes loose the oil pan would drain quickly
.

Thanks, T. Valid point... my thought precisely. :icon_tup:

jcbrx8 11-25-2020 11:09 AM

Quick vid of a recent morning roll out en route to enjoy another hobby. :icon_tup: My tools awaiting my command ...at the rear of the car.

.


https://cimg3.ibsrv.net/gimg/www.rx8...7d3bab71a1.jpg





Staf00 03-22-2021 02:16 AM

So I noticed the RX8Performance kit uses a PT6266 turbo. However, they don't specify whether it's the Gen1 or Gen2 model. Do you know which one is you currently have installed in your 8 by any chance?

jcbrx8 03-26-2021 11:20 PM

Gen1

jerpa 03-30-2021 01:50 PM

Hindsight being 20/20, and being close to taking this plunge myself, I wonder if I could pick your brain a bit?

I've read through the entire thread but admittedly did not take notes. Your goals are the same as mine, roughly 300-350whp with reliability and street manners trumping any raw power aspirations. You also set out to modify as little as possible on your rx8performance kit. I believe you did the following:

-Modified exhaust manifold to allow more ideal "clocking" of turbo

- Had numerous bungs welded into various pipes to facilitate your EBC and monitoring systems

-Replaced the provided intercooler with a smaller size and modified the mounting brackets to allow more airflow to your radiator. You ended up finding a faulty thermostat which seemed to be the cause of most of the issues. Would you still advise the smaller intercooler mounted higher up in retrospect?

- Modified the connection between the TB and charge piping with a straight pipe for better sealing

- Ground weld "tabs" off most piping and beaded to get proper sealing

- Modified the oil pan provided with the kit with a new bung to solve clearance issues causing a leak

I apologize for any mixed up terminology but I believe that covers most of the changes you found necessary. If you were embarking on this journey today would you still use this kit as a base or possibly go the custom route?

I'm also curious about the turbo sizing. There's been a fair bit of back and forth but I believe there is a concensus that this turbo does sacrifice a bit in the spool up department to provide more total power gains, which are beyond the scope of my goals. If building a kit from scratch would you sacrifice some of that potential for a quicker spooling system?

TeamRX8 03-30-2021 02:51 PM

I sent Scott an email maybe 6 - 8 months ago asking (for someone else) about using a Precision 6062 Gen2; which you can get with a 1.05 A/R SS V-band, but never heard back. To be fair, he and I aren’t on best terms so can’t really hold that against him and covid was all the rage then too. However, timely delivery and QC have always been sore spots for some customers and the covid stuff seems to exacerbated the situation. Just make sure you do your diligence and understand that things might not be perfect or timely if you go that route. Not at all trying to imply for you not to do it. That’s between you and him.
.

jerpa 03-30-2021 03:19 PM


Originally Posted by TeamRX8 (Post 4941275)
I sent Scott an email maybe 6 - 8 months ago asking (for someone else) about using a Precision 6062 Gen2; which you can get with a 1.05 A/R SS V-band, but never heard back. To be fair, he and I aren’t on best terms so can’t really hold that against him and covid was all the rage then too. However, timely delivery and QC have always been sore spots for some customers and the covid stuff seems to exacerbated the situation. Just make sure you do your diligence and understand that things might not be perfect or timely if you go that route. Not at all trying to imply for you not to do it. That’s between you and him.
.

I appreciate the input and I've read about inconsistencies that gave me pause, along with the modifications necessary in this thread. That being said, we all know I have very few options that are even remotely off the shelf and I haven't developed any relationships with local welders... yet. Lol

I imagine a custom setup would have run more than this kit, but I imagine that gap has closed somewhat with the various issues they have run into and modifications made. If it's relatively negligible I'd prefer to go the custom route and use the knowledge gained in the last 4 years to optimize as much as I can.

I'm obviously not smart with my cash though, I'm going to boost a Renesis.

jcbrx8 04-04-2021 01:09 PM


Originally Posted by jerpa (Post 4941270)
...If you were embarking on this journey today would you still use this kit as a base or possibly go the custom route?

I'm also curious about the turbo sizing. There's been a fair bit of back and forth but I believe there is a concensus that this turbo does sacrifice a bit in the spool up department to provide more total power gains, which are beyond the scope of my goals. If building a kit from scratch would you sacrifice some of that potential for a quicker spooling system?

Jerpa, Glad you found my build thread helpful. Yes, you're correct about my initial objectives, and modifications which I found helpful in optimizing my system.

Couple quick clarifications:
1. At my request Scott welded on the extra bungs prior to shipping the kit.
2. IMV the large IC is too large for the limited space to provide sufficient air flow to the rad. to maintain acceptable ECTs under spirited driving, except perhaps for those in cool climates, w/effective ducting, or in a reverse v-mount config, which I did run for a while...but ultimately changed to front mount which I prefer. I found this... to be true aside from the bad thermostat issue, which did arise at a point in time, and complicated things.

So, to your question: would I purchase the RX8Perf or go the "custom" kit route?

That's really an individual decision based on one's time, talent, tools, skills, finances, etc.

IMV the RX8Perf kit is well designed...from a flow perspective..., well fabricated, and a solid kit ...w/a few issues that needed sorting. But then ...there's an entire thread on Greddy "fixes". Sooo... :dunno:. I had no interest in fabricating a kit myself, (I have a family, active life, and that's not what I do), or offering my car ...for who knows how long ...to have someone fabricate a kit from scratch. Nor did I have interest in cobbling together a questionable used Greddy...potentially requiring multiple "fixes". So, my intention was to begin with a "new" complete base kit. Once received...while admittedly not perfect, I've been satisfied, i.e. this kit allowed me to meet my objectives. :icon_tup:

Finally, there is a third option: "do nothing "at all, which is what I chose for many years until I perceived that better hardware AND tuning options had emerged. I'm glad I pulled the trigger ...as it's worked out for me. However, as I've stated elsewhere ...the extraordinary delays experienced waiting to receive the *entire* kit were ...off putting to say the least. IMV this is the best complete kit on the market, or at least was at the time - I've not checked lately. I hope fabrication timelines and communication have improved, but am not sure that's "knowable". ??? I would only purchase, given my experience..., via a different process, e.g. an initial down payment, followed by incremental payments commensurate w/ progress, etc.; w/out which I may choose to "do nothing" or build a different platform altogether.

Agreed IMV the 6266 is a bit large for DD objectives / goals. It does sacrifice spool-up responsiveness every acceleration for great top end power which is only used from time to time in a primarily DD application. I am considering whether it's worth swapping in a 5862 :rolleyes:, which I believe w/b ideal, when a refresh is necessary.

Happy Easter! All the best.

jcbrx8 05-29-2021 09:13 PM

2021 Refresh

Well, it's that time ...for a refresh. So, work is underway to complete the following:
- installing a new reman engine (delivered)
- stripped bay & pulled old engine
- undressed old engine to core
- checking & cleaning APVs and SSV

- swapped hardening bits to new engine (enhanced oil regulator & Turblown stud kit)

- transitioning to a new turbo Precision 5862

*NOTE: I'll likely have some items FS when refresh is complete:
  1. Precision 6266 BB E CC, .82AR v-band inlet / outlet
  2. 12" IC

A few pics:
.
https://cimg4.ibsrv.net/gimg/www.rx8...73f1cbdb65.jpg
New reman.
.

https://cimg5.ibsrv.net/gimg/www.rx8...98b131b3be.jpg
Old engine ...pulled
.

https://cimg6.ibsrv.net/gimg/www.rx8...eeafd3395f.jpg
stripping...
.

https://cimg7.ibsrv.net/gimg/www.rx8...fe2ac69e99.jpg
checking & cleaning APVs
.

https://cimg8.ibsrv.net/gimg/www.rx8...226b514c28.jpg
Checking the SSV
.

https://cimg9.ibsrv.net/gimg/www.rx8...1300721011.jpg
clean SSV reservoir
.

https://cimg0.ibsrv.net/gimg/www.rx8...5ebe5b7143.jpg
Old core -1
.

https://cimg1.ibsrv.net/gimg/www.rx8...8ed943f6ec.jpg
Old core -2
.

https://cimg3.ibsrv.net/gimg/www.rx8...45f0821e76.jpg
New core -1
.

https://cimg4.ibsrv.net/gimg/www.rx8...c37005e0b2.jpg
New core -2
.

https://cimg5.ibsrv.net/gimg/www.rx8...c9a48b552e.jpg
New core w/ OEM bolts
.

https://cimg6.ibsrv.net/gimg/www.rx8...acb289c5d9.jpg
New core w/ Turblown stud kit installed

strokercharged95gt 05-30-2021 02:00 PM

Smaller turbo?

TeamRX8 05-30-2021 05:03 PM

wow, wasn’t expecting that … :suspect:

given they don’t provide maps to reference, the 58 compressor wheel over the 60 would make me a bit nervous.

jcbrx8 05-30-2021 08:03 PM


Originally Posted by strokercharged95gt (Post 4945229)
Smaller turbo?


Originally Posted by TeamRX8 (Post 4945232)
wow, wasn’t expecting that … :suspect:

given they don’t provide maps to reference, the 58 compressor wheel over the 60 would make me a bit nervous.

Yes, my 6266 was fully spooled at ~ 4200 rpm under WOT, and provided more than enough top end, 415+ wHP. Since I was undertaking the refresh I thought it an opportune time to optimize the turbo to my DD objectives: fully spooled ~3700 rpm w/ sufficient boost to support ~ 360-375 wHP.
.
Team, Agreed, I'd have preferred to have used compressor maps to base design, but using my known 6266 performance as a base, ...and having visited w/ Precision tech assist ..., and w/ Brett leveraging his wealth of turbo knowledge / experience; I'm fairly confident that the 5862 will be a good fit for my objectives.

I should know w/ in a few days or weeks ...just depending on my schedule to get the work done. Looking forward to a tight engine and responsive set-up.

jcbrx8 05-31-2021 09:17 AM

Not a compressor map, but an estimate...

6266: Precision rated 735 HP: ~4200 rpm observed spool, ~450 rotary wHP
5862: Precision rated 640 HP: ~3700 rpm estimated spool, TBD rotary wHP

(640/735) x 450 = 391 estimated capable 5862 wHP

If accurate, my power band w/b expanded by ~500 rpm: I.e. shifted 500 rpm earlier...while "effectively" sacrificing nothing on the top end.

Unable to consult efficiency islands of a compressor map, the unknown w/b the affect on operating IAT load.

TeamRX8 05-31-2021 02:22 PM

yeah, but where is that occurring because without a map you have no idea

i.e. if that point occurs at 3.5 - 4 Pr on the far upper RH corner of the map with a small displacement piston engine that likely means a much lower peak hp at 2.3 Pr on a 13B 2-R at the far right lower edge of the map. The other question is the efficiency there.

If it’s low then the power level will basically stall. However, if the efficiency is sufficient the turbo will continue to charge right on past it’s rotational speed limit and either wear out quickly or fail (assuming you don’t have a turbo speed sensor or control strategy in place). That’s where all the new technology is heading.

those assumptions will get you if you’re not careful …

actually the Gen2 5862 is rated 700 and 6062 Gen2 is rated 750. Are you intending to use one of the older turbos instead?

Brettus 05-31-2021 04:43 PM

To put things into perspective .... The EFR7670 (same compressor size as 5862) will make over 400whp no problem on a 13b, as has been demonstrated on numerous occasions on the rx7 site. That has best efficiency in the 3.5-4.0 Pr range, which is pretty much the worst case scenario as you pointed out Team.
Sure It would be nice to have maps but IMO the 5862 will work just fine for Curtis's stated goals.

TeamRX8 05-31-2021 09:18 PM

never said it wouldn’t, it’s just the reasoning for the words that I did post so he’d understand my thought process


so we don’t have maps, but if we can find other examples then those can be studied for reference with hopefully enough information to grasp the variances and their impact.

most of the references found on RX7Club were for wanting quick boost, but below 400 whp (350ish)


Did find one REW w/dyno graph (below) that made 415 whp 312 ft-lbs on pump gas @ 14 psig, but it was fully BP’d.

With water/meth added the same REW BP engine with same 5862 made 513 whp 385 ft-lbs at 22 psi. The turbine housing was an 0.84 A/R divided T4. Again, with full bridge porting and is likely to add some variance wrt the flow vs. boost requirement.

This is from 2015, so likely not the latest 5862 version either, which is still not fully defined yet here. The result imo tends to suggest low efficiency.


https://cimg9.ibsrv.net/gimg/www.rx8...fbe49c5a2.jpeg

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jcbrx8 05-31-2021 11:31 PM

Team - I went w/ the Gen 1 PT5862 w/ a CCE comp cover b/c it has a 3" inlet same as my previous 6266. The Gen 2 PT5862 ONLY comes w/ the CCS comp cover which has a 4" inlet, and I wasn't going to try to shoehorn a 4" inlet into that limited space.

And ...again, agreed ...I would prefer a comp map, but am optimistic about the 5862's performance based on what is known.

During an earlier conversation Brett recommended that I review the GTX5876 compressor map as comparable to the PT5862. They have very comparable compressor: turbine wheels:

PT5862: (58/76 : 71/62)
GTX3576: (58/76 : 68/62)

...and the GTX3576 generated the following at 10 and 18 psi on a street ported FC:
.
https://cimg1.ibsrv.net/gimg/www.rx8...8a7e336868.jpg

TeamRX8 05-31-2021 11:59 PM

looking forward to seeing your results, will even promise not to mention the boost knob setting :suspect:

jcbrx8 06-01-2021 12:06 AM


Originally Posted by TeamRX8 (Post 4945292)
...will even promise not to mention the boost knob setting :suspect:

:yelrotflm

jcbrx8 06-01-2021 09:36 AM

Using best comparable GTX comp maps ... I'm anticipating compressor performance *similar* to as shown below:

6266: max ~ 90k rpm compressor speed @ min. 78% efficiency
5862: max ~100k rpm compressor speed @ min. 75% efficiency

Good numbers... though again just estimates as A/Rs aren't the same, etc.

EDIT: Compressor map plotting here was rubbish. See 6/5/21 post w/ improved compressor map plots & insights.

jcbrx8 06-01-2021 10:41 AM

On another topic I'd like to garner some feedback for any who'd like to chime in.

I'm still running the OEM flywheel. While I'm doing this work I'm considering and reading up on lighter weight fly wheels. I've read to expect:
- slightly twitchier starts from a stop,
- faster 1st, 2nd, & ...perhaps 3rd gear spin up,
- but a quicker loss of rpms d/t less spinning inertial mass on gear shifts.

For those w/ experience &/or running lighter flywheels ...what are your opinions / thoughts pro or con for running a lighter fly-wheel in ... albeit a spirited ..., but somewhat DD (I work from home)?



RotaryMachineRx 06-01-2021 11:50 AM

Will you be changing the clutch as well? My thoughts are that the clutch will have more affect on driveability than any lightweight flywheel will; but I'm not saying that with a whole lot of experience. My twin disc Exedy took some getting used to but I'd say driveability was still very simialr to stock. The clutch grabs more and has a slightly different engagement point compared to stock, but IMO that only affected me during stop and go situations, shifting on the fly had no noticeable change in my situation.

I also didn't put many km's on this new clutch/flywheel setup before parking the car and learning I had a blown motor this entire time....... I've been saying this for far too long, but should be back on the road soon....

TeamRX8 06-01-2021 12:10 PM

with a street turbo application my advice would be to not really bother with a flywheel change. If you were racing or trying to get everything you can out if a high rpm NA engine that would be different. It just needs a suitable clutch for the projected torque output.

I won’t fuss over it any more than I already did, but disagree that you can just size up different wheel sizes to compare one manufacturers turbo to the map of another. Then trying to use those efficiency points to me suggests a lack of understanding.

Just out of curiosity, did you give any consideration to hacking off the Precision v-band & replace it to use a Garrett G-series turbo instead?
.

jcbrx8 06-01-2021 01:22 PM


Originally Posted by RotaryMachineRx (Post 4945322)
Will you be changing the clutch as well? My thoughts are that the clutch will have more affect on driveability than any lightweight flywheel will; ...


Originally Posted by TeamRX8 (Post 4945327)
with a street turbo application my advice would be to not really bother with a flywheel change. If you were racing or trying to get everything you can out if a high rpm NA engine that would be different. It just needs a suitable clutch for the projected torque output....
.

Jesse - Hadn't considered changing the clutch as well. Was really just considering doing the flywheel ...since everything's apart and as a potentially simple enhancement. However, Team - precisely to your point..., was wondering if it's even worth the $ and effort on a turbo application. Will likely forego it.


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