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Brett/Team, I was hoping we could be a bit more educative, it started off very well!
1:
To start with, I'd like to be educated regarding the x.xx housings you are vigorously discussing. I think I got how to estimate compressor requirements, but I do not understand this discussion. Could it be possible to explain with some numbers/pictures please? That would be much appreciated!
2:
To stick my neck out regarding compressor map interpretation:
I made a Excel sheet where I estimate requirements for my 6 port. Ve is just visually found in below picture from the curve with S-DAIS(6-port):
If these calculations are remotely correct, it seems to me like 7061 compressor is not suited(pressure is absolute, so 2bar is what we normally would call 1 bar or 14.7PSI charge pressure). And by the same logic, 7670 is equally unsuited, since it only have higher capacity at higher pressure, as Team mention:
It could be that I have overlooked something in my numbers, like decreasing Ve when pressure is above atmosphere(..?), but if I put in the numbers for Ve in the same stupid way for 13B-SI in the same table, this changes the picture drastically, and makes 7163 a good match:
Since Team have 4 port, it will be slightly better than for the estimated 6 port, since 4 port have a bit lower Ve, but only marginally.
Not trying to remotely give an impression that I have any expertise(and zero experience!), but as mentioned earlier at this forum, I like to understand thing to a basic level, therefore I would really appreciate someone explaining me what's wrong. Mistakes is what you learn from
This also makes me think that reduced Ve as RPM increase is actually a benefit when turbocharging, if you want a broad power band. And this again makes me thing that Renesis is really not playing along with a turbo, not only do we cover a broader RPM range, rising Ve is also making it more difficult to find a suited compressor.
First, you’re only looking at peak choke values on the compressor map. As I stated, this is not intended as a track car. As a street car it may possibly see those peak numbers for the occasional run out to redline, but otherwise it would normally be operating at much lower values in the more efficent flow map area
Second, the fuel of choice for this is E85. It allows much higher boost levels than premium gasoline, even if those higher boost levels are programmed in to only be used at low - mid rpm levels and then possibly tapering down from mid-redline rpm range. In theory it should easily support mid-20 psig boost, but initially I figure to limit boost to 20 psig. EDIT: That's also NA VE, which is not the same as turbo VE
The engine will be built for this and in general, if all the other parameters are setup properly, the only thing that’s in question is how long the Renesis side seals will last due to the expansion and exposure in the exhaust port area. I do want to stress that this is a known issue for FI Renesis in general, and the plan is to do everything possible to address it and several other key points in the build process. If this happens, ithe engine won’t be some cobbled together garage build reusing old parts. This will be a full pro engine builder job with all the internal features and components required for the application duty.
Otherwise in general, your overall assessment is correct. The preferred turbo for the job, especially a 6-port engine, would be the BW EFR 8374. However, for low mount in an RX8 I doubt you could ever get that to fit in the low-mount position regardless of how much subframe and chassis structure customizing you do down there. In an RX8 chassis it pretty much has to be forward/top mount only. The best RX8 example I know of this would be Firecran’s car with an REW 13B engine. He sold it early last year. I wasn’t around on the forum much at that time and when I finally saw it was for sale and contacted him somebody in AZ had already beat me to the punch by several weeks.
So again, for this particular idea I only want to use a BW EFR turbo and only in the low mount position for a specific purpose; low-mid rpm power and torque on a street car. The EFR 7163 is the turbo that meets these requirements and for that purpose is the best fit. Now you might get the EFR 7670 to fit with reworking the structure to provide more space, but as was already discussed it becomes a moot point unless you intend to run 3 bar boost or higher because the EFR 7163 can otherwise provide the same flow coverage within 2 - 4 percent less efficiency at the choke line.
The forum used to fawn vigorously over the idea of fitting a Garrett GTX3076 back in the day. Now everybody thinks it’s too small. Well yeah, it always was too small and not a good choice in general, but it could fit in the low-mount position. Kind of amusing in general now.
Also, I don’t care to see any more childish commentary regarding me and anyone else and it won’t be tolerated. They can do their thing in their thread and I’m going to do my thing here. Please can that BS asap or I’ll be asking a Moderator to come assist you with it if you can’t handle it on your own. To address a particular point though, I don’t agree with Brettus on a number of technical issues, but otherwise have only respect and admiration for his efforts as well as forum contributions. My reply to his “it’ll never do that” comment several posts earlier shouldn’t be taken to mean anything other than we disagree on that assessment.
This concept is intended to only prove out my own ideas and objectives for a Renesis FI application. This thread doesn’t involve him otherwise. So if you feel like he needs your attention then please take it over to his thread.
Second, the fuel of choice for this is E85. It allows much higher boost levels than premium gasoline, even if those higher boost levels are programmed in to only be used at low - mid rpm levels and then possibly tapering down from mid-redline rpm range. In theory it should easily support mid-20 psig boost, but initially I figure to limit boost to 20 psig.
The engine will be built for this and in general, if all the other parameters are setup properly, the only thing that’s in question is how long the Renesis side seals will last due to the expansion and exposure in the exhaust port area. I do want to stress that this is a known issue for FI Renesis in general, and the plan is to do everything possible to address it and several other key points in the build process. If this happens, ithe engine won’t be some cobbled together garage build reusing old parts. This will be a full pro engine builder job with all the internal features and components required for the application duty.
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Do you have a rough idea of what engine modifications you'll want to accommodate these levels of pressure, or will you leave that up to your engine builder to recommend? Since most people swap Renesis internals for RX7 internals, like springs and seals, how "stock" are you going to try and keep this Renesis? I'm honestly very curious as to what your build will yield, and I hope you'll include more than just the turbo design configuration/information. Good luck man.
Assuming it happens, the engine will have new rotor housings and new rotors/corner seals/etc. that are EDM cut for the deeper 2mm RX7 apex seals. I had intended to use Iannetti “Gold” seals and springs, which are their premium turbo application offering, but there’s a new steel seal coming that if it’s everything certain Pro builders are claiming (meaning they are) is pretty much going to blow everything else out of the water wrt quality at an extremely reasonable price. Not sure if I’m at liberty to talk about it publicly yet though, so that’s all I can say for now except they’re rated for 20 psig boost snd E85 compatible. Also, over the years builders have shared their secrets with me on a number of things and I show my respect by not throwing them under the bus by blabbing about it on forums. So sorry, I won’t/can’t tell you everything in full detail.
My reply to his “it’”ll never work” comment several post earlier shouldn’t be taken to mean anything other than that.
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What I actually said was "it is a good choice" and "it wont make 360" .
I actually think it will work fairly well , just below your expectations and not even remotely close to what the same turbo would do in an REW.
Well it equated that in my mind, but just the same; my apology for not representing your comment properly, which I'll go back and adjust it to state that instead.
Otherwise I and others disagree. Maybe we'll find out sooner or later ...
20psig definitively changes the picture to the better. But still, it looks like the different Ve makes significant difference with the same turbo on the two engines. For a 13B-SI it looks perfect, but from below picture, I would guess that we should not expect the same HP from Renesis as on the 13B-SI? Did a slightly better job than last time:
But the low and midrange looks to be quite equal, and thats the goal.
One thing, when I was guesstimating on the different numbers, I was really out of my depth, does these look remotely correct? If not, which and what should they be changed to?
what's going to be harder to plot on MatchBot is the lighter and tighter turbine on the EFR 7163 13B-MSP side-exhaust port engine as compared to the EFR 7670 13B peri-exhaust port engine.
I'm expecting that to offset at least some of the exhaust pulse energy difference, but then until it's actually done that's just an opinion based on theoretical logic rather than actual results. SOme people disagre with that premise. I think they're discounting it too easily.
Also,the 350 rwhp estimate for this concept is based on 47 lb/min @ 7500 rpm redline on the compressor map and you have it plotted out to 60 lb/min @ 8000. I have zero intention to run that much power or rpm level with this turbo build concept.
If you go look at Punchy Lightbeers ( that name still cracks me up) boobtube video he's at almost 290 rwhp @ 11 psig with the not so well thought out EFR 7163 on a 6-port Renesis.. In the 7670 dyno run thread link I posted earlier, Howard Coleman cranked out some rwhp estimate @ certain boost levels for the 7670 turbo. Which his number for 10 psig is pretty much on target with Punchy's result. That's no guarantee that it will still match at higher boost pressures, but it's one of several indicators which has been overlooked by some people. You can 't just look at the results and go blah-blah-blah. Well I suppose you can do that, which is most of disagreement issue imo. You have to look at what they may be doing right or wrong in the overall sense to make a proper assessment.
I probably know those figures better than you do. I didn't have to go there because other people did and shared their detailed info with me. Again, I disagree with your position.
I probably know those figures better than you do. I didn't have to go there because other people did and shared their detailed info with me. Again, I disagree with your position.
would you mind sharing ? I've been using 0.6 which seems to line up pretty well with my setup ............. up to the point that it doesn't .
You’d be better served to focus on figuring out your own mistakes that are being overlooked.
Otherwise anything Brettus has say doesn’t have any influence on my decision to spend the necessary finances or not to do this. I really don’t understand how people come to such ridiculous conclusions.
Well ....if he doesn't do it ...this thread is nothing but fluff !
Look, I’ve made it clear that there’s no rivalry between us and I’ve also done everything I can to put a stop on that. I’ve also gone out of my way to speak favorably about you with as much respect as possible. Otherwise you seem to have treated me rather unfairly in your thread and then a hate filled vulture or two swooped in to sh-t bomb me knowing full well I couldn’t respond without breaking my word that it was my last post there.
Now I’m not a grudge person and could really care less about being petty because in the end none of that bs really matters in life. However, I’m not going there again with you. As far as I’m concerned you can go back to your own thread and park your “I’m the turbo Renesis God” ego there. I’ll still continue to pray for God to enlighten you and save your soul, but otherwise likely won’t be responding back directly to anything you ask or say here. It’s not personal, I just don’t care any more as far as your RX8 ideas and opinions are concerned. That’s all I have to say about it. Again, best wishes at reaching your target goal with your own turbo project. I do look forward to seeing the end result.
What part about “from now on” implied in the last reply don’t you understand? I also don’t appreciate you bringing your personal beef with me here trying to egg him on and getting involved between me and him when it’s none of your business.
The earlier reply about getting a moderator involved if you can’t handle it yourself applies as much to you as anyone else. If you’re only interest is engaging in petty bs that doesn’t involve you rather the topic then I don’t have any issue dusting the dirt from your town off my shoes to also ignore you or anyone else who wants to sail that tack either.
I very much want to see where the technical discussion goes. Something outside the box is refreshing, and with the amount of experience here something could actually be made of it.
thanks RIWWP, and good to see you back on the forum recently!
I'm more open to the idea that it might fall flat on it's face or come up way short as Brettus suggested more than it may come across by my replies, but I've shared the idea with people who imo have the experience to trump any one of us on this forum and they think the idea is thought out and sound in general. There is a chance that eliminating the UIM might have more impact than I think, but honestly what it takes to put it back; move the discharge outlet to the other side on the IC discharge header, install UIM & T-Body, pipe between those two points, is easy enough to just go ahead and try it without first.
it looks like the different Ve makes significant difference with the same turbo on the two engines.
I'm not sure how you're deriving Ve values?. I did see where you were referring to some Mazda Ve values in an earlier post. Which I edited my reply to that post after going back and catching it.
That graph is indicating NA Ve values on unmodified ports as supplied by Mazda. Once you port and/or use a turbo they can be vastly different from the Mazda graph and not necessarily in a linear or easily estimated way either.
I also want to include the attached pdf document, which shows some of the early issues Pettit Racing experienced on the Garrett GT35 turbo’d Renesis they supplied for the Diasio 962RT race car company. They were finally able to sucessfully run 3:1 PR and higher after making the necessary improvements to allow doing so ...
Note that this is counter to some of the opinions and comments by some of the nay-sayers.
01-08-2018, 06:55 AM
that name still cracks me up) boobtube video he's at almost 290 rwhp @ 11 psig with the not so well thought out EFR 7163 on a 6-port Renesis.. In the 7670 dyno run thread link I posted earlier, Howard Coleman cranked out some rwhp estimate @ certain boost levels for the 7670 turbo. Which his number for 10 psig is pretty much on target with Punchy's result. That's no guarantee that it will still match at higher boost pressures, but it's one of several indicators which has been overlooked by some people. You can 't just look at the results and go blah-blah-blah. Well I suppose you can do that, which is most of disagreement issue imo. You have to look at what they may be doing right or wrong in the overall sense to make a proper assessment.
