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Yes ...so far the highest I've logged is 17psi and that chart was drawn to show 18. I'm considering staying where i'm at right now and leaving it till the actual dyno before turning it up further . Mainly from concern about breaking drivetrain components. The car is getting pretty damn savage at these boost levels.
Brettus ; Hi Brettus, it's been a long time since we had a chat. You still make improvements in your RX8 project. I'm still using the DNA supercharger kit in my 2004 6 port rx8. It has worked well for many years with some improvements every winter.299 rwhp on a Dynapack at the most. But I wanted more power so 2017 I bought a new shortblock and geared up 18% to max SC speed 80000 @9000rpm by a larger crank pulley and a Gates RPM Racing v-belt 6 ribbed that doesn't slip. Made the RacingBeat groves in the waterjackets (35-40 hours work including building the devise to to make it possible). Limited revs to 8800rpm.and a wastegate to limit the boost to 0,65-0,68bar . Higher torque at lower rpms. and also ceramic apex seals from NRS Rotary,Sven Nilsen and nice pieces from Pineapple Racing. Started 2018 and got 314-316 HP @ max 0,65-0,68bar boost and got higher torque at lower rpm's, also very nice driving qualities. After 2500km on a trackday I had an engine crash . Rear rotor with ceramic apex ,half sideseal went away and middle iron+ rear iron + Rear rotor + rotorhouse. More than half of engine is totally distroyed.
Bought a new shortblock again 2020 and teared it down. Opened the exh port earlier by 3mm and polished all ports. Took the exh sleeves out (exiting work) to clean the irons from grinding metalparts also.
Now to the q about the side seal gap. I will use GOOPY Apex in this engine because the ceramics distroy so much when it happens.
What's your experience of side seal clearence when engine is boosted. I have searched and not found the figures for boosted engine. I realise that the seals grow in a higher engine temp under boost and to much clearence will make low compression. I haven't asked Rob@ pineapple Racing or Clive @ Racing Beat UK or Nandu @DNA yet.
Yes ...so far the highest I've logged is 17psi and that chart was drawn to show 18. I'm considering staying where i'm at right now and leaving it till the actual dyno before turning it up further . Mainly from concern about breaking drivetrain components. The car is getting pretty damn savage at these boost levels.
well even at 18 psi, it’s still operating well below that line is my assessment
I suppose you don't to address it any more than the other thing; have it your way then.
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if you mean the “restrictive intake on your particular low-mount design”, yeah, probably that and a few other things that might be particular to the way you’re doing it, in addition to RHD vs LHD differences. Just like I said several posts back:
Originally Posted by TeamRX8
ok, seemed like you were operating below that line, but I’m making some assumptions that you likely have the actual data for ...
If that’s your position, then thanks for finally clarifying it. I suppose it’s good to validate that there are potential improvements to be made by people willing to eliminate those limitations.
Sure ... I made mine 3" and as free flowing as I could. It's not too bad but a filter straight off the turbo or a 4" intake ...is def. gunna flow better.
three things that come to mind :
1/ I'm not sure that I could get that to fit in a lowmount (comp cover is a LOT bigger than what I have).
2/ I'm not sure it would make anymore power than I already do ( whp ceiling is engine dependent not turbo-see '450' thread)
3/It won't spool as well as what I have.
It will fit, just not the way you’re doing it. It’s essentially a EFR7670 EWG size and a much larger/longer EFR9180 IWG fits between the engine block and the chassis.
Straight up, spool would be somewhat less due to the larger wheels and their increased MOI. Except it won’t be a straight up comparison since it can’t fit the way you’re doing it. Which is fundamentally in the most basic sense the configuration and positioning of the Greddy manifold with an EWG added; not exactly, but similar in a basic sense. How the two compare as a result of the different configuration and positioning is not so straightforward to discern prior to running it that way. My armchair opinion is that it can be improved.
I would not have designed it that way if there was more room to work with so sure it could be improved on.
Re the "other thing" ..... let's see what you can do!
There is more room to work with, you purposely chose not to make any more mods than you already did is all. It’s not a critique, it’s just what it is. I’ve brought some of it up in past discussions, but not everything that I think is possible.
The G35-900 has the exact same dimensions as the G30-700, just bigger wheels fitted into the same housing castings. Again, an EFR9180 IWG fits in there and it’s quite a bit larger in every direction. It’s just a matter of what’s required.
It only requires the necessary modifications, which I’ll just go ahead and say that imo some of the wall is using the original parts intended for NA use that aren’t necessarily a good choice for an FI Renesis application. The issue in general is the avg. RX8 turbo build is trying to do everything the cheap, and/or easy, and/or monkey see - monkey do way, rather than possibly looking for a better way. That’s a general statement not directed at any particular person. You’re obviously not the avg RX8 turbo builder, yet are kind of doing some of that too. The extreme opposite of it is the Landspeed RX8. There’s a lot of open middle ground between the two.
The thing is; as much money as you’ve obviously spent over the years, how much could have possibly been spent taking it in a different direction instead? Hind sight is always 20/20, so certainly not faulting you for that, but at the same time it pays to be observant of those who did what they did. I think we’re both sincere in our beliefs; it seems clear you sincerely believe doing those things is a dead end street due to the whp limit theory, but my sincere belief is that you may have boxed yourself into a blind corner and aren’t seeing a path out.
So I’ll just go ahead and say that my concept started as a street purpose, but am now rethinking it for a competition purpose, which requires shuffling things around from maximizing low end torque to instead maximizing work area under the powerband curve. I’m sure you likely understand more what that means than most of the other forum members will. What is likely not so clear is the path being envisioned to try and make it happen.
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Yes...some good points in there.
I definitely approached it from the point of view of not deviating too far from what was already there. My goals were more geared towards doing something that could be easily replicated by others and proving that you don't need an engine swap to make an awesome sportscar out of an rx8.
In that sense , I'm happy with the results and not too upset about the money I spent getting to here.
Actual dyno at 15.5psi tapering down to 14.35 at peak (415whp@ 7563rpm):
Note : power is in WHP but torque is in NM (yes that is weird but it's just how they do it )
The red line is pretty close to the virtual dyno but that was the first run and was cut short just so we could review logs . All the runs after that matched the green line. I'm thinking heat soak into the LIM is what is causing the lower numbers so currently have it apart again to do some better heat shielding.
Below are from top : EMAP , IMAP , AFR
Below shows same info but cursor is on peak for the red line:
Didn't raise the boost as planned because I wasn't happy with the IAT logs ...more work to do there too
Hey @Brettus, I'm curious since you've clearly done extensive research regarding your turbo selection, have you considered a Xona Rotor turbo? I'm looking at the XR 6564S specifically. Unfortunately, since Xona/Tial is a smaller company (unlike Garrett & BW), there aren't any compressor maps available.
Seems to me like a favorable turbine to compressor ratio, akin to @TeamRX8's assessment of how your setup is equivalent to an EFR7670 compressor & EFR8374 turbine. But hey, what do I know? lol
Looking forward to seeing how your build progresses!
Edit: Btw, has there been any porting done on your motor? Apologies if this has already been mentioned somewhere.
Yes...some good points in there.
I definitely approached it from the point of view of not deviating too far from what was already there. My goals were more geared towards doing something that could be easily replicated by others and proving that you don't need an engine swap to make an awesome sportscar out of an rx8.
In that sense , I'm happy with the results and not too upset about the money I spent getting to here.
Brett,
I want to commend you for continuing to develop your ideas and spend time and money, and then post them here. You are doing real-world work, and I appreciate it. I am not a Renesis FI guy, (I own a turbo BMW with a very ancient and rudimentary kit installed), so the FI stuff is not high on my interest list, but I still read almost all of your posts. I know sometimes your ideas don't pan out, but you are curious, and you make your mistakes publicly, which takes courage. So thank you for providing so much information to the forum. And for not giving up on the Renesis.
01-16-2021, 04:11 PM
