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Turbo Build from Hell :)
Welcome to my 2010 RX8 R3 Zoom Zoom Boom project! I figured I would test my luck with installing a Turblown EFR 7670 T4 .92 IWG Turbo Kit ordered back in November of 2020. I am currently piggybacking with Adaptronic M2000 modular wire-in ECU with DBW module for engine control leaving the factory PCM to control the rest. I am not particularly happy with the DBW control function of this ECU as it’s not smooth and will cause bucking with low cruising RPM; I found it difficult to balance the car on the track with this. Now that Adaptronic has been discontinued, my tuner would rather not support it so the next push will be wiring a Haltech Elite 1500 in its place.
AEM X-Series UEGO Gauge Bosch LSU4.9 via serial, Continental SE1002 Flex fuel Sensor, Stock primary’s & ID2600 secondary injectors, Black Halo Racing Ignition coils, BHR Resonated midpipe, Exoiticspeed R1-T exhaust, Denso 5752 [T-31(10)] & 5754 [L-27(9)], Turbosmart IWG75 wastgate, Turbosmart Kompact Dual Port BOV, DW300C fuel pump, Koyo performance radiator HH062267 https://cimg2.ibsrv.net/gimg/www.rx8...e639376e13.jpg E85 @12psi (IWG 14.4psi & 26 EMAP) https://cimg4.ibsrv.net/gimg/www.rx8...2f4c113585.jpg 93 Octane @10psi Dyno Clip: |
Couple videos of autocross launches:
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Congratulations on getting to this point. Looks like you've had quite a journey!
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Okay TeamRX8, you got me questioning everything now; you has posted in a different thread "surprised your emap is that high, must be the 0.83 A/R IWG then?"
I have been looking back at specs/photos and based on this EFR data sheet a .92 A/R would have a twin scroll T4 while the .83 A/R would be a single T3. Based on the photos I had taken it looks like I have single scroll, non-divided T3 housing. An overlooked give away is probably Eliot’s (turbosource) hand written part # on the exhaust flange. What is everyone’s thoughts, does this look Frankensteined? https://cimg2.ibsrv.net/gimg/www.rx8...f9abc7f28f.jpg https://cimg4.ibsrv.net/gimg/www.rx8...63c1135bb4.jpg https://cimg6.ibsrv.net/gimg/www.rx8...35a2608901.jpg https://cimg5.ibsrv.net/gimg/www.rx8...ecb3cc3207.jpg |
Pretty obvious that it's a T3 single scroll from the pics so it follows it must also be a 0.83. What did you actually order?
Putting in some estimates into Matchbot with that turbo gives me slightly less (24) than your measured 26psi EMAP so it's within expected range IMO. Improvements could be made with a more free flowing exhaust possibly. |
it must spool up pretty good :)
given that it’s a long tube front mount open scroll manifold, which will delay the response some, but is shown in the dyno graphs by how quickly it peaks and then levels off … which to help Brettus and others to fully appreciate; the EFR 7670 0.83 A/R turbine housing is approximately equivalent to the Garrett G30 0.61 A/R housing wrt peak turbine flow capacity. Even the largest EFR 7670 1.05 A/R EWG turbine housing would only equate to ~0.92 - 0.95 A/R on a G30 turbine housing. . |
Originally Posted by Brettus
(Post 4985910)
Pretty obvious that it's a T3 single scroll from the pics so it follows it must also be a 0.83. What did you actually order?
Putting in some estimates into Matchbot with that turbo gives me slightly less (24) than your measured 26psi EMAP so it's within expected range IMO. Improvements could be made with a more free flowing exhaust possibly. Also, here is picture of my data from Dyno log. EMAP int (14.4) is the wastgate pressure. https://cimg1.ibsrv.net/gimg/www.rx8...87f3d523c9.jpg |
I assume that the manifold was made by someone else who just made it to suit the turbo provided?
According to Matchbot changing from 0.83 to the 0.92 will only reduce EMAP by 1psi. You could gain more by going for a custom free flow exhaust. IMO |
It was a complete kit; Turbo manifold, turbo, downpipe, intercooler & piping was purchased from turbosource as a bolt on and go kit.
How would you make this more free flowing like increase to next diameter size? Would you do custom cat back, turbo back, or even the turbo manifold design. I am running a 3" downpipe to 3" BHR resonated mid pipe (no CAT) and exotic speed R1-T 3" racing muffler with resonator deleted. https://cimg6.ibsrv.net/gimg/www.rx8...62b19ed38e.jpg |
maybe you should search some since it seems like that may not have been the case originally … :suspect:
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Originally Posted by Smikella
(Post 4985929)
I am running a 3" BHR resonated mid pipe
After that ..... The catback system doesn't look too bad for flow but again - it was designed for NA flows, so would look at selling that and making a custom setup. Unbolting it and running without it as a test will tell you if it needs replacing. |
the catback has dual 3” straight thru mufflers, I doubt that’s an issue even with the one tight 180 being cheated some in the middle, likely being overkill for NA since that’s a lot of flow area.
Possibly consider making the midpipe straight thru. A turbo itself tends to act as a rasp dampener of minor sorts. . |
Originally Posted by TeamRX8
(Post 4985947)
the catback has dual 3” straight thru mufflers,
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my apology, just looking at them in the exhaust system photos all the pipes appeared to be the same size, but as you stated and corrected me on, the website is listing the muffler pipe as 63mm (2.5”).
Originally Posted by ExoticSpeed Website
I’d again stress that it’s the EFR 7670 turbine housing’s limited flow capacities that are the primary source of the back-pressure as per my previous comments. . |
some context putting what I propose are the EFR 7670 Turbine A/R flow points on the Garrett G30 turbine map for comparison
when I looked at a more probable PR rather than max capacity, it wasn’t quite as bad as previously stated due to the difference in curve shapes https://cimg6.ibsrv.net/gimg/www.rx8...4692d33de.jpeg . |
Here are some pictures; the muffler is nearly 4.5" in diameter with the pipe going in around 2.5" so I would image the website muffler ID of 63mm has to be accurate.
Looking at the ExoticSpeed vs the BHR midpipe under the car I would say the midpipe would be a good place to start as it has an un-desirable step down in OD and the resonator definitely is smaller than I remembered. Its unfortunate a 3” straight test pipe would be a great start in replacing my wife’s anniversary gift from 2018 :scared: lol I am still working on getting ahold of Turbosource since our initial conversation on why I did not get the .92AR size as ordered. https://cimg3.ibsrv.net/gimg/www.rx8...5db41041ce.jpg https://cimg5.ibsrv.net/gimg/www.rx8...dbe08a33f2.jpg https://cimg6.ibsrv.net/gimg/www.rx8...d87d100d02.jpg |
basically they mostly all do; to work with both the original manifold and original catback. There may be (or, have been) an exception or two since my own experience has been to make my own as full true 3” size rather than off the shelf stuff just for that very reason, but I also have mine split to smaller dual at the rear. It could even be dual 2.25” because that works out to roughly a single 3.2” pipe size; not being less than the single 3” pipe feeding it being the key. point, the more so being the better to either account for or offsett losses in the transition split.
cutting back on the original response, too wordy and cluttering the thread. . |
Originally Posted by Smikella
(Post 4985990)
Its unfortunate a 3” straight test pipe would be a great start in replacing my wife’s anniversary gift from 2018 :scared: lol
To me that change is a no brainer and I'd expect to see a decent improvement in emap. After that ......... probably not much to gain. Changing AR at this point would be a wasted effort IMO. |
it’d just be the principle of the matter, and they are dimensionally different so there’s that too, but just for reference there is a larger aftermarket EFR 7670 turbine housing option, but cast iron and EWG.
1.25 A/R divided T3 1.27 A/R open T4 edit: it had slipped my mind that the T3 housing above is actually a T4 flange with T3 port openings. t’s just a matter of porting the openings out to a T4 gasket size. . |
Originally Posted by TeamRX8
(Post 4986002)
it’d just be the principle of the matter, and they are dimensionally different so there’s that too, .
Really don't understand why Borg Warner bothers with housings that are such a small jump in flow as can be seen in your chart above........... |
edit: you have to consider the range of turbos offered; 7064 just before and 8374 just after, but more recently the addition of the 8370. It definitely needs a larger turbine housing option, especially after they added the larger 83 compressor with the 70 turbine.
otherwise cutting the original response back. I also ran the matchbot numbers and was able to match the dyno log values closely. For me emap improvement was close to what Brettus said; only 1 - 2 psi better with the 0.92 depending on the factors. Only another 1 psi drop with the 1.05 housing. And that was at the 8200 rpm point and other data shown in the dyno log photo. It’d be better to stay below 8000 rpm as VE was dropping off substantially. You’d also probably be better served working on lowering the IAT. . |
bump :suspect:
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Sadly, not too much to update on and might not be until next year. This was my last communication with my turbo kit supplier:
https://cimg5.ibsrv.net/gimg/www.rx8...5fc683c504.png I'm going to let go of the T4 housing issue and focus on a 3" straight midpipe (instead of BHR resonated) and wiring the Haltech ECU into the car this winter. I am also considering an electronic wastegate upgrade to provide better control especially since we will have to re-tune. https://www.full-race.com/full-race-...conversion-kit |
Originally Posted by Smikella
(Post 4987403)
I'm going to let go of the T4 housing issue and focus on a 3" straight midpipe (instead of BHR resonated)
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