Twin turbo upgrade
#176
Just pointing out that some assumptions were made, and they could be (and probably are) wrong.
were the stats on the website 100% correct?
were they the same at both locations?
and better yet, were they the same outside the shop as they were inside the shop?
(in a heated shop the temps would be a little higher, therefore the humidity will be lower)
All perfectly rational questions that should be answered before questioning someones ability or credibility.
#177
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Wow !!!
Damn, I feel somewhat responsible for all this...
I don't think Chadwick is manipulating dyno conditions at all.
He's simply relying on the dyno's atmospheric sensing module which measures absolute pressure, temperature and relative humidity for SAE correction.
He said it best, its a tool to help with tuning and troubleshooting.
Could something be faulty? Yes.
The only time I've seen a correction factors greater then 1.20 (20%+) are from cars dynoed from places like Denver (over 5000ft altitude).
Your own link with your conditions...
http://wahiduddin.net/calc/calc_hp_abs.htm
puts you @ 6540 ft density altitude.
Sea level is 29.92 in/Hg
Your 24.34in/Hg measurement cannot be correct since it places you @ 5000+ feet above sea level.
See: http://www.engineeringtoolbox.com/ai...ure-d_462.html
I personally don't agree with using SAE corrections on forced induction engines since the numbers are usually inflated with the increse of altitude and temperatures. Its mainly useful on normally aspirated engines.
Sorry for all the commotion...
JD
I don't think Chadwick is manipulating dyno conditions at all.
He's simply relying on the dyno's atmospheric sensing module which measures absolute pressure, temperature and relative humidity for SAE correction.
He said it best, its a tool to help with tuning and troubleshooting.
Could something be faulty? Yes.
The only time I've seen a correction factors greater then 1.20 (20%+) are from cars dynoed from places like Denver (over 5000ft altitude).
Your own link with your conditions...
http://wahiduddin.net/calc/calc_hp_abs.htm
puts you @ 6540 ft density altitude.
Sea level is 29.92 in/Hg
Your 24.34in/Hg measurement cannot be correct since it places you @ 5000+ feet above sea level.
See: http://www.engineeringtoolbox.com/ai...ure-d_462.html
I personally don't agree with using SAE corrections on forced induction engines since the numbers are usually inflated with the increse of altitude and temperatures. Its mainly useful on normally aspirated engines.
Sorry for all the commotion...
JD
#178
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Keep us updated.
JD
#181
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Ok, Im glad this sounds like it has been resolved. When I read this thread I am interested in awesome power made by the BNR's with a good tune! I am not interested in reading a court case, like its turtned out to be (and hopefully over please DO NOT restart it).
My two cents worth (but please do not restart the issue, if you feel the need just start a new thread about Dyno HP flucuation) having said that:
I thought everyone knew that numbers will change depending on atmospheric conditions. And the fact that someone would try to pin so hard that the numbers are not 'perfect' is appaling. Oh no it only made 380~400 rwhp! For a twin set up that is still pretty damn badass, Who cares about a little HP flucuation, this should be about the potential of the BNR's whatever that may be.
Now with that out of they way, is it possible to post a dyno graph with the best turbo transitions? I would like to see this for my own learning needs, and what to expect when ordering BNR's .
Thank you
My two cents worth (but please do not restart the issue, if you feel the need just start a new thread about Dyno HP flucuation) having said that:
I thought everyone knew that numbers will change depending on atmospheric conditions. And the fact that someone would try to pin so hard that the numbers are not 'perfect' is appaling. Oh no it only made 380~400 rwhp! For a twin set up that is still pretty damn badass, Who cares about a little HP flucuation, this should be about the potential of the BNR's whatever that may be.
Now with that out of they way, is it possible to post a dyno graph with the best turbo transitions? I would like to see this for my own learning needs, and what to expect when ordering BNR's .
Thank you
#182
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"If" the dyno sheet was altered, there are still MANY cars floating around in the 420's RWHP with the 3's. I don't think another 15 or 20 RWHP is out of the question with less split and more advance. Most of the cars I have built are tuned conservative so I don't push them to the limits. If you guys want me to build the twins to do 440 I will and I'll do it on my personal car.... But you guys would probably pick the sheet apart even if the corrections were right.
Bryan@BNR
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#183
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Bryan, I would love to see your car make 440rwhp. If this can be done with out a transition powerdrop, and you can post a dyno run, Ill order a set of Stage 3's before Dec 31st.
As far as scrutinizing the dyno to death goes... I live at sea level in a rather cold climate, so what ever correction factors there are, my climate offers just about best case scenerio.
Its the people that focus on the couple of ugly twigs that miss the scenery
As far as scrutinizing the dyno to death goes... I live at sea level in a rather cold climate, so what ever correction factors there are, my climate offers just about best case scenerio.
Its the people that focus on the couple of ugly twigs that miss the scenery
#185
Lets compare costs for a second. These are not exact figures but you should get the idea...
Good Single Turbo Kit $5000 BNR's $2500
Fuel Kit $800 Fuel Kit $400
FMIC $1200 SMIC $600
Exhaust System $1000 Exhaust $1000 possiby?
PFC $650 PFC $650
Good Tune $500 Good Tune $500
Total $9150 Total $5650
Pretty big difference there...
Good Single Turbo Kit $5000 BNR's $2500
Fuel Kit $800 Fuel Kit $400
FMIC $1200 SMIC $600
Exhaust System $1000 Exhaust $1000 possiby?
PFC $650 PFC $650
Good Tune $500 Good Tune $500
Total $9150 Total $5650
Pretty big difference there...
Originally Posted by Bryan@BNR
Its pretty funny when you compare a T67 single turbo to bolt up twins... Hold on lets dig up a GT42 or a GT45 and compare them! First off, on that dyno sheet, what is the timing set at? Whats the split? Whats the AFR? That car is making close to 360 RWTQ, and the dynosheet was made at 19 psi of boost.... Why do you even compare the 2? BTW why don't you compare the top end TQ between the 2 sheets...
I spent several months with a low and slow transition on my car after I added flow mods and upped the boost and found it unacceptable. I managed to get it into acceptable-but-not-great territory (13-9-14 with a 0.4 millisecond transition) with dual MBCs and a lot of experimentation but I am not at all convinced that I could get, say, 17-14-17 in a very high flow system. I have a nagging suspicion that the stock sequential control system is simply not capable of producing a decent transition in a high boost high flow configuration.
I'd like to be proven wrong because I have a set of M2 dual ball bearing sequential twins sitting in my garage waiting to go on.
#186
Banned. I got OWNED!!!
I believe that alot of it has to do with the programming of the sequential system. It's my belief that if you want to achieve a smooth transition after upgrades it's going to require going outside of the mazda programming. My answer is Rob Baileys Solenoids and a Motec M820. The M820 and the new software should allow us to program it to say that @ x pressure, this happens then when y = z do that. The theory is to equal out as much as possible and hopefully get the transition down to a flat spot and nothing more. Then the right gear ratios to keep shifting above the transition. We have inputs for MAP, exhaust manifold pressure, and secondary boost pressure between the secondary compressor and the charge control valve. Hopefully all that information will allow us to achieve a somewhat smooth transition. I'm experimention on factory twins before I send them to Bryan. So let the crucifing begin because this is going on a 13B-RE and being stuffed in an FC
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#187
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I have no idea where the FMIC/SMIC thing comes from, the fuel system does not vary with turbo configuration for a particular power level, and a nice single kit can be had for less than $3k (e.g., here). Getting to 400+ whp or so is going to be plenty expensive with either system. The price difference between both is not significant.
The particular configuration details are not the point. The point is that even a fairly large turbo can have pretty much the same low end power as this sequential setup, and - crucially - without the transition problem. As you suggested, the picture may be somewhat brighter with better low end boost - but I'd like to see that picture and not theorize about it. In particular, I'd like to see that it is possible to have an acceptable transition dip with a high flow sequential system.
I spent several months with a low and slow transition on my car after I added flow mods and upped the boost and found it unacceptable. I managed to get it into acceptable-but-not-great territory (13-9-14 with a 0.4 millisecond transition) with dual MBCs and a lot of experimentation but I am not at all convinced that I could get, say, 17-14-17 in a very high flow system. I have a nagging suspicion that the stock sequential control system is simply not capable of producing a decent transition in a high boost high flow configuration.
I'd like to be proven wrong because I have a set of M2 dual ball bearing sequential twins sitting in my garage waiting to go on.
The particular configuration details are not the point. The point is that even a fairly large turbo can have pretty much the same low end power as this sequential setup, and - crucially - without the transition problem. As you suggested, the picture may be somewhat brighter with better low end boost - but I'd like to see that picture and not theorize about it. In particular, I'd like to see that it is possible to have an acceptable transition dip with a high flow sequential system.
I spent several months with a low and slow transition on my car after I added flow mods and upped the boost and found it unacceptable. I managed to get it into acceptable-but-not-great territory (13-9-14 with a 0.4 millisecond transition) with dual MBCs and a lot of experimentation but I am not at all convinced that I could get, say, 17-14-17 in a very high flow system. I have a nagging suspicion that the stock sequential control system is simply not capable of producing a decent transition in a high boost high flow configuration.
I'd like to be proven wrong because I have a set of M2 dual ball bearing sequential twins sitting in my garage waiting to go on.
Usually if your fitting a Large / Good sized single you would need a good intercooler setup. Now im not saying that SMIC arent good but either FM or VM flow better and are more efficient.
Fueling wise you can manage with just a good secondry fuel rail with 1200cc injectors as opposed to all singing all dancing primary and secondry rails with 850cc & 1600cc etc etc
Also to get good spooling from a large single you need supporting mods that aid it...
Its quite simple when you really think about it. Any way you look at it the twins have more torque lower down the rev range compared to the single...
Last edited by Rixio_Scon; 12-18-07 at 11:18 AM.
#188
I believe that alot of it has to do with the programming of the sequential system. It's my belief that if you want to achieve a smooth transition after upgrades it's going to require going outside of the mazda programming. My answer is Rob Baileys Solenoids and a Motec M820. The M820 and the new software should allow us to program it to say that @ x pressure, this happens then when y = z do that. The theory is to equal out as much as possible and hopefully get the transition down to a flat spot and nothing more. Then the right gear ratios to keep shifting above the transition. We have inputs for MAP, exhaust manifold pressure, and secondary boost pressure between the secondary compressor and the charge control valve. Hopefully all that information will allow us to achieve a somewhat smooth transition. I'm experimention on factory twins before I send them to Bryan. So let the crucifing begin because this is going on a 13B-RE and being stuffed in an FC ![Big Grin](https://www.rx7club.com/images/smilies/biggrin.gif)
![Big Grin](https://www.rx7club.com/images/smilies/biggrin.gif)
~Ramy
#189
Banned. I got OWNED!!!
Good points and I did think of most of them but decided against it becuase
the twins are being strapped on a 13B-RE and I wasn't confident that there would be enough adjustment in the software to accomodate the differences between the two engines.
Also from what I understand about the PFC, you cannot alter the transition itself only the point at which it happens.
I don't have a proper harness and would have to build one, I felt building a harness for a Motec would be much easier than one for a PFC or trying to frankenstein something together from 2 or three other harnesses
I just felt that the Motec would allow the most control over the entire setup and allow me to get the most out of the turbo's
the twins are being strapped on a 13B-RE and I wasn't confident that there would be enough adjustment in the software to accomodate the differences between the two engines.
Also from what I understand about the PFC, you cannot alter the transition itself only the point at which it happens.
I don't have a proper harness and would have to build one, I felt building a harness for a Motec would be much easier than one for a PFC or trying to frankenstein something together from 2 or three other harnesses
I just felt that the Motec would allow the most control over the entire setup and allow me to get the most out of the turbo's
#190
Yea I'm not second guessing *your* decision. Sounds like you did your homework
Oh and I didn't realize you left out the "W" in "13B-RE" on purpose lol. My bad ![Big Grin](https://www.rx7club.com/images/smilies/biggrin.gif)
As for whether or not you can alter the transition itself, I honestly don't know. I'm sure someone more verse in the PFC could chime in w/ that.
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![Big Grin](https://www.rx7club.com/images/smilies/biggrin.gif)
As for whether or not you can alter the transition itself, I honestly don't know. I'm sure someone more verse in the PFC could chime in w/ that.
#191
Banned. I got OWNED!!!
Yea it was intentional
Bigger runners, simpler intake, easier to mount in the chassis and the REW twins BARLEY cleared.
It's been a while since I did the research on the PFC but my recolection is that the rpm point could be altered, not the individual solenoids which I would need to do. I would love it if someone could chime in about it though
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It's been a while since I did the research on the PFC but my recolection is that the rpm point could be altered, not the individual solenoids which I would need to do. I would love it if someone could chime in about it though
#192
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I have no idea where the FMIC/SMIC thing comes from, the fuel system does not vary with turbo configuration for a particular power level, and a nice single kit can be had for less than $3k (e.g., here). Getting to 400+ whp or so is going to be plenty expensive with either system. The price difference between both is not significant.
The particular configuration details are not the point. The point is that even a fairly large turbo can have pretty much the same low end power as this sequential setup, and - crucially - without the transition problem. As you suggested, the picture may be somewhat brighter with better low end boost - but I'd like to see that picture and not theorize about it. In particular, I'd like to see that it is possible to have an acceptable transition dip with a high flow sequential system.
I spent several months with a low and slow transition on my car after I added flow mods and upped the boost and found it unacceptable. I managed to get it into acceptable-but-not-great territory (13-9-14 with a 0.4 millisecond transition) with dual MBCs and a lot of experimentation but I am not at all convinced that I could get, say, 17-14-17 in a very high flow system. I have a nagging suspicion that the stock sequential control system is simply not capable of producing a decent transition in a high boost high flow configuration.
I'd like to be proven wrong because I have a set of M2 dual ball bearing sequential twins sitting in my garage waiting to go on.
The particular configuration details are not the point. The point is that even a fairly large turbo can have pretty much the same low end power as this sequential setup, and - crucially - without the transition problem. As you suggested, the picture may be somewhat brighter with better low end boost - but I'd like to see that picture and not theorize about it. In particular, I'd like to see that it is possible to have an acceptable transition dip with a high flow sequential system.
I spent several months with a low and slow transition on my car after I added flow mods and upped the boost and found it unacceptable. I managed to get it into acceptable-but-not-great territory (13-9-14 with a 0.4 millisecond transition) with dual MBCs and a lot of experimentation but I am not at all convinced that I could get, say, 17-14-17 in a very high flow system. I have a nagging suspicion that the stock sequential control system is simply not capable of producing a decent transition in a high boost high flow configuration.
I'd like to be proven wrong because I have a set of M2 dual ball bearing sequential twins sitting in my garage waiting to go on.
I don't know if you are familliar with running that much boost on a large single. When you turn up the boost, your mid range will drastically change. Why dont you do a single turbo comparison, with the same timing map and run the same AFR at 17 psi on each turbo and see what ya get. You'll see that your bottom end TQ and HP will be less at 17 psi than it is on 19-20 psi which was ran on the sheet you gave.
I did not design the stage 3's to beat every single turbo out there. I designed them so they wouldn't be so damn brittle to boost. You get over 15-16 psi with the stockers and you don't know when that time bomb goes off... Shaft nuts come loose, shafts snap, thrust bearings wear, previous apex failures that hurt the turbine wheels ect ect. The 3's make good power, they are bolt up and they are reliable at higher boost levels...
There is going to be a dip in transition no matter what you do (stock or 3's). The difference between non sequential and sequential is that 80 RWHP dip during transition if the boost is up. I always told customers that you'll loss in the transition and the top end you'll be hinderend 15-20 RWHP with all the sequential system valve assemblies in line.
I have had professional road racers that tinker with the sequentials that optimized the system and run 17-19 psi successfully on the race track. They win events and don't call me complaining about transition!
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If your car has solenoids that have 150K on them and all the diaphrams are also that aged, maybe its time to replace them. The cars are still beautiful, but they are getting aged...
Bryan@BNR
Last edited by Bryan@BNR; 12-18-07 at 01:48 PM.
#194
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As i said before watch this space...Rob is sending out my solenoids tmrw so hopefully as soon as i get home i'l fit them & by the 1st of jan it should be DYNOGO TIME!
#196
#197
I'm actually a big fan of the sequential system. If I had not found a set of M2 twins (thanks, Fritz) I'd be buying your 3s. On my stock turbos with the standard flow mods, I'm hitting 14 psi at 2500 rpm, which is very nice. However, I don't think there is a large body of knowledge out there about transition tuning on highly modified cars with sequential turbos. In the past few years people have started to rediscover the benefits of sequential configuration (thanks largely to your turbos) but I think there is still a knowledge gap. An 80 hp transition dip is not trivial, however - it would be nice to think that there is a way of fixing it.
#198
So while mileage may be low, one must also take age into consideration as well. There's a reason why manufacturers state year AND mileage restrictions on their warranties: because they know BOTH can lead to failures.
~Ramy
#199
Banned. I got OWNED!!!
This point may be stating the obvious, but really, why are we wasting time with 15 year old parts? When my FD is going under the knife, I'm making sure that NOTHING 15 years old remains on the car. If left on, sooner than later, those parts will fail, and will only be a headache not only to diagnose, but also to repair as Mazda continues to discontinue parts for the FD on a regular basis. And the prices of those parts that remain will only continue to rise as availability decreases.
So while mileage may be low, one must also take age into consideration as well. There's a reason why manufacturers state year AND mileage restrictions on their warranties: because they know BOTH can lead to failures.
~Ramy
So while mileage may be low, one must also take age into consideration as well. There's a reason why manufacturers state year AND mileage restrictions on their warranties: because they know BOTH can lead to failures.
~Ramy
Another place I *think* fails and no-one really pays attention to or checks (And I think thins becuase I read alot of boost issues here) are the vac/pressure tanks. I built my own out of some aluminum tube just becuase like Ramy says... I don't want nutin on my car that's old.
-Brian