Out of interest , this is from the rx7 forum G25 660 0.92 on 12.5 psi at peak rpm of 6500
Note EMAP is 23.0 psi at peak ! https://cimg7.ibsrv.net/gimg/www.rx8...4d3b68ab43.png Not trying to say this is a good comparison with mine ( TeamZ4 ;) ) because there is a lot we don't know about the setup. But combine this with with what we are seeing on u-tube etc and there is already reason to believe the G25-660 isn't the way to go vs the G30-660 . |
Will you be testing the .83 housing or just sticking with the 1.01. Would be interested to see how it spools
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Originally Posted by MasonV
(Post 4951844)
Will you be testing the .83 housing or just sticking with the 1.01. Would be interested to see how it spools
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Was just looking over your coolant temps and it's quite cool especially being boosted, what have you done in terms of cooling to get it to those temps?
Also, sorry to be a pain but do you think you'd be ready to sell these manifolds some time this year, possibly next? I know that isn't your primary goal and totally understand you want to be completely satisfied with it before you're comfortable with selling them. Really appreciate the effort you've put into this build and the Renesis in general! |
Originally Posted by MasonV
(Post 4952510)
Was just looking over your coolant temps and it's quite cool especially being boosted, what have you done in terms of cooling to get it to those temps?
Also, sorry to be a pain but do you think you'd be ready to sell these manifolds some time this year, possibly next? I know that isn't your primary goal and totally understand you want to be completely satisfied with it before you're comfortable with selling them. Really appreciate the effort you've put into this build and the Renesis in general! Setup with original bumper: Note the air gap underneath the IC, particularly on right hand side where many people have IC exit hose blocking flow. https://cimg9.ibsrv.net/gimg/www.rx8...1c27f62515.jpg New setup with MS bumper : https://cimg4.ibsrv.net/gimg/www.rx8...b1ea23b311.jpg As for the manifold , I'm getting some made right now but not sure if I'll have any left over at this stage . PM me. |
Originally Posted by Brettus
(Post 4952515)
...The main thing though is that I've worked to ensure the intercooler is set up to allow sufficient air to bypass around it and have a direct route to the radiator. Interestingly , I've found that if you get that gap about right , both the radiator AND the intercooler work great. Only this week I fitted the Mazdaspeed front bumper ... . If anything I think it's actually improved the way the IC is working and so far I'm not seeing any issues with the radiator (although it's not hot here yet).
.... What is your average ambient high temp? |
Originally Posted by jcbrx8
(Post 4952559)
I've always liked the MS, and don't particularly care for the "smile" of the OEM bumper. However, the OEM bumper openings are effective in allowing direct airflow separately to the IC, rad, and oil coolers. With no bottom horizontal opening on the MS it'll be interesting to see how the rad (ECTs) perform when things get hot there. Major concern in my neck of the woods where ambient temps top 90°F four months of the year.
What is your average ambient high temp? BTW ..... with the MS bumper I'm now seeing cruise IATs between 0 and 1 degree C above ambient. We very rarely see temps above 90F here with average daily highs in peak of summer being around 77F. |
Great news regarding IAT performance w/ the MS.
Originally Posted by Brettus
(Post 4952565)
... One of the things I realised with the OEM was that if you fit a large IC with in/out at the bottom , you actually block off a lot of flow with the hoses. ...
Originally Posted by Brettus
(Post 4952565)
...If you take up most of that bottom inlet with IC but leave the area at the sides free (by using an IC with in/out in the middle ) you still get enough flow to the rad...
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Originally Posted by Brettus
(Post 4952565)
I agree that potentially the MS arrangement might not be as good for engine cooling. One of the things I realised with the OEM was that if you fit a large IC with in/out at the bottom , you actually block off a lot of flow with the hoses. If you take up most of that bottom inlet with IC but leave the area at the sides free (by using an IC with in/out in the middle ) you still get enough flow to the rad.
BTW ..... with the MS bumper I'm now seeing cruise IATs between 0 and 1 degree C above ambient. We very rarely see temps above 90F here with average daily highs in peak of summer being around 77F. |
Tested new bumper on my favorite test road .IAT still lookiing great and engine temp isn't a problem This log was at 18C ambient.
https://cimg9.ibsrv.net/gimg/www.rx8...4dd086505a.png https://cimg9.ibsrv.net/gimg/www.rx8...4cad23800b.jpg |
Here are the 3D prints for the first production run. These are all spoken for :suspect: . Should be turned into cast stainless in the next few weeks covid lockdowns permitting !
https://cimg2.ibsrv.net/gimg/www.rx8...e90fbd8ee2.png |
Originally Posted by Brettus
(Post 4954473)
Here are the 3D prints for the first production run. ...
Seriously, well done. Very promising... :icon_tup: |
Originally Posted by Brettus
(Post 4954473)
Here are the 3D prints for the first production run. These are all spoken for :suspect: . Should be turned into cast stainless in the next few weeks covid lockdowns permitting !
https://cimg2.ibsrv.net/gimg/www.rx8...e90fbd8ee2.png |
Originally Posted by 3toedSloth
(Post 4954484)
That's awesome! How do I get on the list for a future run?
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Finally got hold of the proper dyno sheet for last February . Lot better than the pic of screen I originally posted.
https://cimg0.ibsrv.net/gimg/www.rx8...47f4eae74d.png |
saw where Garrett released the G30 1.01 IWG v-band turbine housing; your thoughts, particularly wrt your manifold setup?
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Originally Posted by TeamRX8
(Post 4957522)
saw where Garrett released the G30 1.01 IWG v-band turbine housing; your thoughts, particularly wrt your manifold setup?
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yeah, that's a pretty good assessment.
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Took the 3582 along with the cast manifold out after it's initial testing period. Yes it gets hot as evidenced by the change of colour. But there are no signs of any issues so very happy with how it's working out so far.
Final version ready to test . T3 flange is slightly forward which will enable better fitment for the G30-660 0.83 which will be going in in the next few days. The 3582 setup was awesome. I have high hopes the G30 will be even better. https://cimg7.ibsrv.net/gimg/www.rx8...f9bf64407c.jpg |
Brett - please post more pictures of the installation and piping after the new version is installed. Just scrolled through the thread again and see the 2" 90d elbow off the turbo outlet but can't tell if the next pipe stays at 2" or transitions to 2.5" before increasing to 3" at the IC.
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Originally Posted by northzone
(Post 4958253)
Brett - please post more pictures of the installation and piping after the new version is installed. Just scrolled through the thread again and see the 2" 90d elbow off the turbo outlet but can't tell if the next pipe stays at 2" or transitions to 2.5" before increasing to 3" at the IC.
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looking forward to it and best wishes :)
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Originally Posted by TeamRX8
(Post 4958272)
it will better on multiple levels, but s recently discussed on RX7Club per the G40 thread not as good as a T4 divided manifold, even on a 6 port Renesis imo, best regards. :icon_tup:
. But definitely not for a Renesis where: 1/We have an external WG diverting flow from the flange. T3 is more than sufficient to efficiently flow what the turbo needs. 2/We have 3 exhaust ports. Remember I've already experimented with a twin scroll and found limited gains and an unbalanced flow with this current layout. 3/We have limited space to work with. T4 turbine housing simply would not fit in this configuration, even If I thought it was a good idea. |
Just saw this on the ATP site.
Is the 'V band' cross sectional area more on the T4,....... or is the divider on the T4 making the difference? Interesting because it shows how at lower flows (smaller AR) the difference is pretty insignificant but the difference becomes more of a factor as flows increase. I think we might see a similar thing with the T3 vs T4 debate ..... https://cimg6.ibsrv.net/gimg/www.rx8...ee6435885d.png |
apology, I had deleted the comment because it wasn’t really relevant to your efforts and didn’t want it to distract from what you were doing.
since you beat me on the edit though, imo the comparison won’t be the same due to the size difference. I would suggest going back to when you started with a comparison between the past and present. Because I feel like a few details were possibly missed or overlooked that do represent a more significant impact on a G30 than what you’re referring to on the G40. imo a divided housing can offer close to the same advantage over an undivided housing on the 3-port Renesis exhaust, but as you stated; just not with the manifold as configured here. That’s not to take anything away from how you have it configured, because what you’ve done is fairly ingenious wrt to working around the OE motor mount configuration etc., but again that design configuration existed for the 13B in several old school variations over the years. Yet again, I don’t want to distract from your effort here and choose not to expound on it further. I’ll only add that the performance difference between a divided and an open housing is not truly represented on a turbine map. That will only be fully represented when the pulses are occuring in the actual engine application and the spool differences can then be measured/seen. When you only have one without the other though, it’s often not as apparent as having both side by side. . |
Originally Posted by TeamRX8
(Post 4958348)
imo a divided housing can offer close to the same advantage over an undivided housing on the 3-port Renesis exhaust, but as you stated; just not with the manifold as configured here.
. Would be interested how you would configure a twin scroll to do better? |
Originally Posted by Brettus
(Post 4958243)
Took the 3582 along with the cast manifold out after it's initial testing period. ...
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well the offer stands if so choose.
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Originally Posted by TeamRX8
(Post 4958418)
well the offer stands if so choose.
. |
First test drive with the G30-660 0.83 . Initial thoughts
*Today is a good 13-14C warmer than the day I did the 3582 log so results for the 30-660 are handicapped by that somewhat. *Yes it's faster spooling than the 3582 0.82 but not the big difference I was expecting *From a roll in 3rd we get 10psi by 3000rpm which is only 150rpm improvement on the 3582 *But .......... the slope of the maf curve is a lot steeper (the comparison log on 3582 I hit wot a lot earlier) so I'm expecting 15-16psi by 3400ish which would be 250rpm improvement. *At same boost level and a hotter day it is making more power than the 3582 as we can see below .... suspect lower emap is the key to that . Will do an emap log later. *transient response from 4000 and above is exceptional ! Virtual dyno at 9.5psi ..... G30 green line 3582 red line . https://cimg0.ibsrv.net/gimg/www.rx8...dba606cd43.png |
Yaaz, the 3.5k+ rpm transient response for a daily, as in my case, is the beees-nees. :icon_tup:
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VD for same run as EMAP log below . 9.5psi
https://cimg8.ibsrv.net/gimg/www.rx8...4d2df013f3.png Emap log at 9.5psi taken with g30-660 0.83 need to check boost at high rpm because VD shows an extra 25whp over the 3582 (maf is higher also).Blue line at 8000 (no boost cut) https://cimg7.ibsrv.net/gimg/www.rx8...f5f2d88c49.png 3582@9psi blue line at boost cut 7700 https://cimg9.ibsrv.net/gimg/www.rx8...dcd1ab3b4e.png All pointing to better emap (around 1 psi ) from the g30 over the 3582 at similar boost levels |
in other words … :suspect: —> G25-660 0.92 <— :suspect:
. |
Originally Posted by TeamRX8
(Post 4958657)
in other words … :suspect: —> G25-660 0.92 <— :suspect:
. |
his build has issues creating that result imo
same compressor and if the Garrett turbine map is accurate, the G25 0.92 has a slightly higher flow capacity than the 0.83 G30 housing for the full curve . |
Originally Posted by TeamRX8
(Post 4958661)
slightly
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Originally Posted by Brettus
(Post 4958255)
The elbow is actually 2" to 21/4" then 21/4" through past the steering column then 21/2" to IC . Without the steering column there you can probably clock the turbo to have the exit vertical and go straight to 21/2".
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Originally Posted by Cgoebel
(Post 4958670)
so my LHD should be fine:)
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Originally Posted by Brettus
(Post 4958662)
You should take a good look at that word and stop splitting hairs.
https://cimg8.ibsrv.net/gimg/www.rx8...12e07550a2.jpg . https://cimg9.ibsrv.net/gimg/www.rx8...3c60732061.jpg . it's just a friendly conversation, but if you feel like my word choice is off-base then please suggest your own words that may better describe the situation. :) if anything the data suggests lower emap for the G25 0.92 than the G30- 0.83, but to be fair some people still question the flow capacity of the G25's smaller turbine under real world conditions. Yet the smaller impellers in theory should have faster spool to offset the PR differences indicated above. On the one 13B-REW with G25-660 0.92 IWG build you mentioned, I still say the v-band on these is not a good match for a 2 rotor wankel engine, evident by the merge on his manifold and also the change on your own to the T3 flange, and it also has a cat converter of unknown flow capacity. Most people are too cheap to buy a proper cat converter. The HJS converters I ran on my NA Renesis are likely much better flowing than what anyone uses over on RX7Club with an FI engine. The G25 0.92 is readily available in an open T3 EWG, so it should be a straight bolt on to your manifold and easy to get real world numbers, even if by someone else. What the heck, just put my name on the list and let me know when you need payment. of course I'd still want it in a divided T4 configuration for my own purposes, which unfortunately they dropped it off the availability chart again with no indication when or if it will ever be offered. . |
Originally Posted by TeamRX8
(Post 4958711)
it's just a friendly conversation, but if you feel like my word choice is off-base then please feel free to offer the words you feel better describe the situation. :) . I really have to question your motives here . Because it seems you are really clutching at straws trying to one-up me on tiny little details. Do you truly believe it's worth bringing this up over and over again? |
No, it has nothing to do with any of that. Nor can I recall those exact specifics, but then it's not a personal subject for me, nor is it intended as one against you.
At the risk of being considered insensitive; I'm not going to apologize for commenting on a public forum. Mostly because I don't see it as being off topic and it's not directed against you or intended as such. If anything, it seems that an alternative turbo selection may highlight the effectiveness of your manifold even more. Because again, it's the same compressor housing with two turbine size alternatives, both of which are available in a T3 EWG configuration and should be interchangeable on this manifold. It's just as much on topic as when I suggested using the 0.83 AR housing back in the beginning of this thread almost a year ago. Which was and still is all part of the same inter-related G25/G30-660 discussion in my mind. So in further response; no, there's neither an argument nor straw grasping. If it's anything, it's just a disagreement, if even that; certainly nothing more and certainly nothing less as far as my intentions go. However, if you don't want to discuss it; then don't, but don't blame me for responding back to your replies on it. I honestly thought your reply was sincere and I'm replying sincerely. I otherwise have no desire in being your enemy or nemesis, but only have control over my own thoughts and feelings. . |
Ok .... that's fine . Maybe I'm misreading you totally, as I often do. You do tend to bring out the worst in me .....
So yeah the g25-60 0.92 would be a decent alternative and could be worth a try. IMO spoolup will be about the same as what I have and emap very close to the same (better flow with worse efficiency balancing it out). So given that is how I honestly feel about it ...... it's not something I would do myself given the G30 has better options for more power with the 1.01. I really think you need to try a few different combinations yourself to get a feel for how things work out in reality vs what you think might happen . I have found over and over and over with turbos and the Renesis that the result rarely matches the anticipated outcome . As an example I'm sure you think the g25 will spool better because of better moi etc............... but I don't . Simply because of the various combinations I've tried over the years and knowing there is always more to it than just moi ....like , efficiency of turbine and compressor , the extra rpms that need to be achieved etc. If you saw the wheel sizes of the 3582 next to the G30 you would wonder how the 3582 even gets close to the g30 in spoolup ---- yet .......it does. As far as my decision to go T3 vs 'v' band ... That was on the sole basis of ease of fabrication and fitment ...nothing else. Not something you could know unless you had fabricated and attempted to install it yourself. And for the G30 T3 open vs T4 twin scroll I still don't think that would achieve anything significant so I'll leave that one for you to try. |
thank you Brettus, I get that and recognize the history between us as well as my role in it, but am hopeful that we can at least get past some of it to have a better dialogue between us
and yes, I understand why you did V-band/T3 swap, but also that possibly it’s still not being recognized why it makes a difference just as when we had the T4 housing inlet discussion. As I mentioned previously, the Garrett V-band housing is not a good choice fot a 2-rotor wankel. Not that it can’t be made to work, but is going to eat up a bunch of space and create more fabrication work funneling the exhaust streams together effectively. The larger rectangular openings of the T3 and T4 flanges lessen that consideration. Whether it’s a T3 or T4 sized volute isn’t the actual issue. on the otherhand, the Garrett v-band housing is perfect for mounting a turbo directly on on a peripheral exhaust port housing, i.e. twin turbo 13B-REW :suspect: . |
Had a decent drive on my favorite road today .
I have to say ...I seemed to have underestimated how good this setup is . Lag ...............what's that ? Check this out : Turbo fully spooled same instant as throttle fully depressed ........... https://cimg8.ibsrv.net/gimg/www.rx8...295537a906.png |
Originally Posted by Brettus
(Post 4958806)
... Turbo fully spooled same instant as throttle fully depressed ...........
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still only 10 psi boost?
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for now ....yes . I'll bump it up once I get the low comp. renesis rotor engine in.
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Originally Posted by Brettus
(Post 4958806)
Had a decent drive on my favorite road today .
I have to say ...I seemed to have underestimated how good this setup is . Lag ...............what's that ? Check this out : Turbo fully spooled same instant as throttle fully depressed ........... https://cimg8.ibsrv.net/gimg/www.rx8...295537a906.png Is it that engine at 5000+RPM and engine load of 50% produce enough exhaust energy to have more or less correct turbine speed for WOT and 10PSI? That you might have found a sweet spot, where 1. Turbine wheel get good initial speed at ~50% load 2. WOT is applied 3. Compressor loads turbine more, trying to slow turbine down(shortly increasing EMAP or forcing WG to open) 4. Almost immediately, chambers filled with WOT:) exhaust gases hit the turbine 5. Speed is more or less maintained Plausible explanation -ish? If so, how is EMAP in the transition area? |
Originally Posted by AAaF
(Post 4958971)
I do not quite understand how its possible with more or less instant response. After all, there's inertia in the wheel, what do I miss?
Is it that engine at 5000+RPM and engine load of 50% produce enough exhaust energy to have more or less correct turbine speed for WOT and 10PSI? That you might have found a sweet spot, where 1. Turbine wheel get good initial speed at ~50% load 2. WOT is applied 3. Compressor loads turbine more, trying to slow turbine down(shortly increasing EMAP or forcing WG to open) 4. Almost immediately, chambers filled with WOT:) exhaust gases hit the turbine 5. Speed is more or less maintained Plausible explanation -ish? If so, how is EMAP in the transition area? Well ...it's not no lag at all, just very quick spool. Time from starting to depress throttle to 10psi is around 0.4 seconds, which is the same time as it is taking to open the throttle, so it's spooling up as the throttle opens. At 5000rpm you have a LOT of energy in the exhaust and yes the turbine will already be spinning reasonably quickly. Emap is around 7-8psi as it's transitioning from spoolup to constant boost. Probably the biggest difference I'm noticing is coming out of low speed right angle corners in second gear ...... this setup is spooling a good 4-500rpm sooner than the 3582 was. |
Originally Posted by Brettus
(Post 4958972)
this setup is spooling a good 4-500rpm sooner than the 3582 was.
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