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For how much you love going into all sorts of threads with your own special take on whatever is going on with it, according to your own special view of the universe, you sure don't take well to others doing it to your thread.
Listen, you are relatively new here. So you missing the fact that you stating clearly that there is only your one way to skin a cat on a thread that has a turbo system originating from John kuhn, who is the master of the same "blinders on" science (kibort is the master though) - can be fairly hilarious.
It's like banging your head against a wall trying to figure out how to travel across country while walking around in the train station.
Oh, and Todd already did all this **** and got more power with less cubic words.
Originally Posted by ptuomov
E85 pollutes, too, in two ways. First, making E85 is very energy intensive. Second, and this is a much greater concern of mine, E85 continues to pollute many otherwise interesting Rennlist threads...
For how much you love going into all sorts of threads with your own special take on whatever is going on with it, according to your own special view of the universe, you sure don't take well to others doing it to your thread.
Listen, you are relatively new here. So you missing the fact that you stating clearly that there is only your one way to skin a cat on a thread that has a turbo system originating from John kuhn, who is the master of the same "blinders on" science (kibort is the master though) - can be fairly hilarious.
It's like banging your head against a wall trying to figure out how to travel across country while walking around in the train station.
Oh, and Todd already did all this **** and got more power with less cubic words.
People have some objectives and then means of meeting those objectives. I don't judge people's objectives. It's everyone own business what they want. No accounting of tastes! I do comment on people's means of reaching those objectives. I invite comments from others, as well, on how I am meeting my own objectives. I think that's a fairly internally consistent and sensible approach to life, universe, and everything.
It turns out that E85 isn't the right solution for my objectives. I want to be able to fill up the tank at any gas station and don't want to be filling the tank all the time. Therefore, E85 is not the means to meet _my_ objectives.
Todd Tremel wants to have a fun car to trash around that is as fast as a crotch rocket motorcycle. That's his objective, which he's achieving. E85 as the main fuel and selectively using nitrous to spool the turbo at launch are good ways for him to meet his objectives. If you talk to him, you should ask him if I've ever criticized his objectives as being "wrong" or that E85 is not a good way to meet his objectives.
When you write that "you guys are still thinking about this all wrong" I'd appreciate it if you'd clarify whether you are critical of my objectives or critical of my ways of meeting my objectives. Regardless, I am not going to get my panties bunched up my crack.
...
Moving on, it looks like we can stay on the compressor map with these new intercoolers as long as we keep the pressure drop to the minimum in every other part of the charge piping:
Todd already did all this **** and got more power with less cubic words.
Really? I must have missed that. When did Todd make more turbo power on pump gas, with a stock engine and within the limited space constraints of the 928 chassis? Todd's projects are really cool but you are comparing apples and onions.
He did at least 825 rwhp on pump gas, so far he's more than 100 rwhp ahead of us on pump gas. Credit where credit is due, it's an impressive build.
The goals are different enough though that you are absolutely right about the oranges and onions comparisons.
Originally Posted by Fabio421
Really? I must have missed that. When did Todd make more turbo power on pump gas, with a stock engine and within the limited space constraints of the 928 chassis? Todd's projects are really cool but you are comparing apples and onions.
He did at least 825 rwhp on pump gas, so far he's more than 100 rwhp ahead of us on pump gas. Credit where credit is due, it's an impressive build.
The goals are different enough though that you are absolutely right about the oranges and onions comparisons.
Yes, but he was using 951 pistons in that engine and he cut the floorboards out of the car to fit the turbo's. He also had spray bars mounted on the intercoolers although he may not have used them during the initial dyno run.
I have no problem with chassis modifications as long as they are well implemented and safe. Often those are pretty expensive, though, so some compromise workarounds are often preferable.
In terms of intercooler spray, my philosophy is that one should replicate the actual driving conditions as closely as possible on the dyno. I prefer two 1600 cfm fans replicating the intercooler ambient air flow and a huge fan replicating the radiator air flow. If those are not available, then spraying the heat exchangers is what I've done to simulate the actual intercooler temperatures.
It's really hard to go over 700 rwhp with a stock 87 s4 engine, so modifying the engine internals was the logical thing to do for Todd Tremel. We'll have modified engine in the cat this summer as well.
Originally Posted by Fabio421
Yes, but he was using 951 pistons in that engine and he cut the floorboards out of the car to fit the turbo's. He also had spray bars mounted on the intercoolers although he may not have used them during the initial dyno run.
I have no problem with chassis modifications as long as they are well implemented and safe. Often those are pretty expensive, though, so some compromise workarounds are often preferable.
In terms of intercooler spray, my philosophy is that one should replicate the actual driving conditions as closely as possible on the dyno. I prefer two 1600 cfm fans replicating the intercooler ambient air flow and a huge fan replicating the radiator air flow. If those are not available, then spraying the heat exchangers is what I've done to simulate the actual intercooler temperatures.
It's really hard to go over 700 rwhp with a stock 87 s4 engine, so modifying the engine internals was the logical thing to do for Todd Tremel. We'll have modified engine in the cat this summer as well.
I'm not trying to minimize or diminish Todd's achievements. I'm only saying that Brendan Campion's "been there done that" comment is unfounded. As I said, apples and onions.
I'm not trying to minimize or diminish Todd's achievements. I'm only saying that Brendan Campion's "been there done that" comment is unfounded. As I said, apples and onions.
I get it, and agree. There are so many awesome 928 builds out there today, I love them all. More the merrier.
On the technical front, John's been putting in some serious hours on optimizing the inlet system for the larger turbos and the low compression engine. I want to retain the stock intake manifold for now, and that makes sense for John's kit as well. Everything upstream of the MAF housing is being reexamined and if needed redesigned. There are tens if not hundreds of little computations and optimization problems to solve within the constraints. None of it is Nobel prize quantum mechanics, but all of it needs solid engineering physics background. (I don't have it, but I stayed in Holiday Inn last night.)
Take for example the question of whether one should fit a larger diameter shorter radius or a smaller diameter longer radius 90-degree pipe elbow in the intake system. Say the space allows for either 3" R/D 1.5 or 2.75" R/D 2 mandrel bent elbow. Step up with a cone to 3" or stay at 2.75"? The velocity pressure of 3" pipe is about 70% of the velocity pressure of a 2.75" pipe. The loss coefficient for different R/D 90-degree bends are (R/D=1, K=0.33), (R/D=1.5, K=0.25), and (R/D=2, K=0.17). What this means in practice is that 3" R/D 1.5 has about the same loss as 2.75" R/D 2. It probably doesn't make sense to build a diffuser and nozzle to step up the size for the turn and the step it down if this is just connecting two 2.75" pipe sections. However, if the other end of the elbow faces say intercooler end tank, then the pressure loss at the tank is going to be significantly lower for the 3" pipe which means that one probably should build that diffuser to step up into the elbow. Hypothetical example, but you get the gist of it.
Another example is the duct area to the intercooler. The intercooler is a cross-flow intercooler with about 45% flow area of the gross area. This means that the most efficient opening in the bumper is probably somewhat under 45% of the intercooler face area, depending on how one trades off cooling vs. drag. However, since the gross intercooler area is larger, the air must be diffused with the best possible pressure recovery before it flows thru the intercooler.
Not all shapes are efficient:
There's an efficient expansion shape designed way back when by Kuchemann & Weber. (I copied the figure from the web but I am a proud owner of the Kays & London book so I could have scanned something like that!):
What the WW2 aerodynamics research doesn't cover is how to retain about the ideal shape while still allowing for the 928 headlights to open and close. Consequently, there was more adaptation of the ideal shapes to the packaging constraints:
Could a car factory design something better? Sure. But this is frigging awesome duct shape. The amount of effort and understanding behind that shroud and how to compromise for the space available is significant.
It's a hobby for John, so he can blow in the hours on design that a purely commercial effort wouldn't allow.
Gee I love visiting this thread, great to see John and yourself continuing on the quest.
Yeh I guess with the way 3D printing is going, creating moulds for casting exhaust manifolds becomes so much more feasible. Very much looking forward to the continued development.
It is fabulous for the 928 community that you and John have embarked on this horsepower odyssey.
Gee I love visiting this thread, great to see John and yourself continuing on the quest.
In all honesty, John's doing all the heavy lifting now...
Originally Posted by Roy928tt
Yeh I guess with the way 3D printing is going, creating moulds for casting exhaust manifolds becomes so much more feasible. Very much looking forward to the continued development.
The manifolds are getting closer and closer to actually coming out of the foundry:
More than a couple of hours were spent on that part of the project, too! ;-)
Originally Posted by Roy928tt
It is fabulous for the 928 community that you and John have embarked on this horsepower odyssey. Good Speed Gentlemen
Thanks. There are a number of nice builds documented on the RL. The latest that I found is this: http://www.refresh951.com/index.htm Although not a 928, it's really thoughtfully built ...and it runs on E85, which is a perfect solution for his goals!
Some progress here. This "plus sized" system needs bigger pipes to produce a lower pressure loss at higher mass flow rates. As mentioned earlier, the space available is unfortunately the same. Thus, some fairly thoughtful optimization of the pressure loss within the space constraints is needed.
Here's an example of one solution. We can go thin wall with stainless steel, which although slightly more expensive should work well for this purpose.
The pressure pipe coming out of the intercooler can be upgraded to 2.5" OD. 2.5" OD will allow us to use R 5" 90-degree mandrel bend which has a very low pressure loss. This is a well flowing bend with a smooth surface:
A 2.5" OD pipe fill also fit nicely under the stock cross-brace, after which we can use about 3-5 degree cone diffuser to decelerate the flow with near-ideal pressure recovery before the 90-degree turn into the plenum box.
Redesigning the plenum box will also allow us to use standard large-pipe mandrel bend in that turn, reducing the number of welded seams and fabrication effort while simultaneously lowering the pressure drop. The lower velocity going into the plenum box will further reduce the pressure loss and makes it easier to deliver high-quality flow into the MAF sensor element.
This is how the passenger side pipe coming from the fender will look like, the pipe will go under the stock cross brace.
Here's the existing system for comparison:
Driver side with some new pipes shown just to give some scale, a sense of proportions:
The existing system is a great design for up to 700 rwhp, but it needs to be "plus sized" for this next iteration. Think of "Christina Hendricks and Sofia Vergara shopping for bras together" plus sized.
On the induction side, the goal is to have no sharp (low radius) bends, no bends of any kind with high velocity, and no abrupt contractions or expansions of cross-sectional area.
New intercooler and shroud cad model and physical model are all with the intercooler manufacturer now. The first entry end tank is the trickiest for them to manufacture, I suspect.
John is designing the new version of the plenum box this weekend. It's one of those space constrained situations where a box is likely a better performing option than a Y-pipe.
One of the questions that needs to be answered about this turbo system is why is there a plenum box in the system in place of the stock air box and the filter.
Most modern cars use a Y-pipe to combine the turbos. Look at Audi and Porsche for example. Many people here have worked on a 928 Y-pipe intake, too.
Here's what Hans posted some time ago:
Here's Jim Doerr's. Notice the cobra heads feeding the filters:
And here is of course the Blackbird intake by 928 Specialists:
So why a plenum box instead of a Y-pipe? The basic answer is that there's not enough room above the MAF sensor housing (along the line extending from the centerline of the MAF sensor housing) to do a great flowing Y-pipe. There is room for a great flowing air box, however, and the principal reason for this is that the air box outlet (inlet to the MAF sensor housing) can be designed to draw air from all sides.
These kinds of inlets like to draw air from all directions, and a surprisingly (at least to me) large fraction of it likes to come in from the sides. I just copied this photo from the internet, not because it's particularly applicable to this specific case but because it illustrates the general tendency of inlets to suck from the sides:
In a space constrained situation in which we don't have enough headroom above the inlet, I believe its critical to use as much area around the MAF inlet / airbox outlet as possible. An air box which is wide accomplishes this.
Now, in a less space-constrained setting the Y-pipe has one great advantage, namely that if the turn radius of the legs is long enough, it's very efficient. It's very efficient because it doesn't require one to slow down the air flow, just to turn it. As long as the turn is gentle enough, the flow loss is small. That's why most new Porsche cars use a Y-pipe. (For boosted applications, Y-pipe also has less surface area and doesn't have to be as heavy and strong as an air box.) However, if the turn radius is too short and the merge angle isn't shallow enough, turbulence and flow losses in a Y-pipe can be quite high.
An air box needs to first slow down the air with maximum pressure recover and then allow it to make the turn into the outlet at low velocity. If that slowing down of air is not done efficiently, the air box will create a pressure loss. Thus, the diffusion into the air box is critical if the pressure loss is to be kept in check, or the inlet pipes have to be very large such that the entry flow velocity and thus the velocity pressure is low.
Here are some photos of the existing air box design as far as the air box outlet / MAF inlet goes. Note the bellmouth and the guiding vane:
The existing design in above pictures works well at the power levels for which it was designed.
The new one is taking shape as I type. I expect it to flow better than the above old design at higher mass air flow rates.
The exhaust manifolds are now a definitely a go, John released the purchase order, the foundry has the models, and the delivery date is mid July. Here's the last rendering.
This version passes the casting requirements, thermal stress requirements, gas flow requirements, and sensor location requirements.
Note the five sensor bungs. The four individual runner bungs can be used for either pressure traces or for WBO2 measurements (both need heat shields for the sensor). The fifth is for a very convenient access port for either slow (cycle average) pressure sensor, WBO2, or EGT. The point of that port is that it's more convenient to access than the individual runner ports. The best place to measure WBO2 for the whole bank is of right after the turbine because the burn process continues in the turbine and the readings are more reliable because of a more complete burn - downpipes have those.
While John's been working on the exhaust manifolds, I've had very little time to even think about car stuff. Work has been very busy, and one of my hobbies even busier. Because of my curiosity, I am involved in this brain hacking project in a personal capacity (nothing to do with my day job). The company is Thync and their first product just launch.
*** OFF TOPIC WARNING ***
This is me testing a beta version of the Thync device about six weeks ago:
It's incredible that those guys got it to the market on last Tuesday!
Since this is a Porsche 928 dicussion group, I wont go on more about this here. It's just the main excuse for my recent absence from here. People who are interested in this (off) topic can go read the below links:
TechCrunch
Hands-On With Thync’s Mood-Altering Headset
By Kyle Russell
June 2, 2015 http://techcrunch.com/2015/06/02/han...dset/?ncid=rss
"During a recent visit to Thync’s beautiful offices (they’ve renovated an old opera hall), I got to strap the startup’s mood-altering wave generator to the ol’ noggin…. While I was warned that Thync might not work the first time, a few minutes into my first session (using the Calm setting) I felt a wave of sluggishness pass over me. I had some difficulty putting words into a coherent question for Goldwasser, and felt a strong urge to take a nap that lasted until I got home.”
Daily Mail
Zap out of it! $299 headband can change your mood using electrical pulses
By Mark Prigg
June 2, 2015 http://www.dailymail.co.uk/sciencete...al-pulses.html
"Dailymail.com was only able to try the headband for a short amount of time, but the results were surprisingly noticeable. We tested one of the calm programmes. Once the headband was applied, you use the app to get the correct levels - which you reach when you feel a slight buzzing. After just a few minutes, I did begin to feel an effect. I felt calmer, more relaxed - not unlike the feeling of having a beer."
New York Magazine
I Tried a Brain-Zapping Gadget and It Made Me Feel High
By Jessica Silvester
June 2, 2015 http://nymag.com/scienceofus/2015/06...feel-high.html
"The session is winding down when Pal asks me if I’m still stressed out about my meeting — and that’s when I realize that my words feel very far away. My neurons do not seem drunk so much as high as ****.”
Boston Globe / BetaBoston
With a jolt, Thync’s mood-enhancing gadget brings calm or focus to your brain
By Nidhi Subbaraman
June 2, 2015 http://www.betaboston.com/news/2015/...to-your-brain/
"If the device sounds like something out of science fiction, that’s the point. “There’s no equivalent out there,” said Sumon Pal, Thync’s “chief of vibes.”… The effects can be worth it: five minutes on the “Ease” vibe will take the edge off a stressful meeting, or soothe the nerves before going on stage for a talk.”
San Jose Mercury News
Wearable tech 2.0 aims to alter mind, body
By Heather Somerville
June 2, 2015 http://www.mercurynews.com/business/...lter-mind-body
"This newspaper tried Thync, finding the "calm" vibrations did indeed have an effect: Breath slowed, anxiety disappeared, facial tension relaxed and worries gave way to a still mind.”
Psych Central
What Thync Looks & Feels Like
By John Grohol
June 2, 2015 http://psychcentral.com/blog/archive...ks-feels-like/
"Would I part with $299 for it? If I were a person who experienced a lot of constant, chronic stress in my life and didn’t find other effective methods for helping to relieve it, yes, I might very well plunk down my money for it. The research is pretty darned good for a startup, and it shows a lot of potential for future applications that go beyond just stress and energy.”
Gizmag
Thync mood-changing wearable officially launches – we go hands-on (again)
By Will Shanklin
June 2, 2015 http://www.gizmag.com/thync-hands-on-2/37820/
"I left the latest meeting feeling about as ideal as one can feel going out into the world: a zen-like calm and presence combined with the inspired motivation a young adult might feel on their first day of college (and by the way, I'm nearly two decades removed from that day)… From where we stand now, Thync looks like one of the most exciting and unique products we've used this year.”
Digital Trends
Zap yourself awake: Thync’s mind-altering, brain-jolting band is now on sale for $300
By Andy Boxall
June 2, 2015 http://www.digitaltrends.com/sports/...-release-news/
"Imagine being able to physically relax in moments, wherever you are and at any time, or do the opposite, and get a multiple Red Bull-style energy boost without actually drinking any of the sticky, sickly liquid? The Thync Vibes offers both these effects, digitally, by combining cutting-edge neuroscience with the conveniences of a high-tech wearable device, and it was one of the most exciting pieces of tech we used at CES earlier this year.”
Wareable
Thync's new wearable is mind bending
By Paul Lamkin
June 2, 2015 http://www.wareable.com/wearable-tec...d-bending-1199
"Instead of reaching for a Red Bull, the idea is that you strap on Thync to give yourself a neurological jolt.”
Engadget
Thync's mood-changing wearable arrives for $299
By Jon Fingas
June 2, 2015 http://www.engadget.com/2015/06/02/t...hanger-launch/
"The hardware worked well enough in our early hands-on, so it might be worth giving Thync a shot if you're often out-of-sorts -- it may well beat drinking coffee or beer to achieve the same effects."
Boston Business Journal
Would you use this wearable device to change your mood? I did and it was bizarre.
By David Harris
June 2, 2015 http://www.bizjournals.com/boston/bl...ange-your.html
"We think of this as a new category of wearables that operates in synergy with your body," said Tyler. "Instead of reading what you're doing, we're acting in synergy ... it primes your body to be in a more relaxed state."
Ubergizmo
The Thync Mood-Changing Wearable Can Be Yours For $299
By Tyler Lee
June 2, 2015 http://www.ubergizmo.com/2015/06/thy...ging-wearable/
"We have smartwatches, fitness bands, virtual reality headsets, and even smart clothing. However if you’re looking for something that sounds potentially futuristic, you might be interested to learn that the Thync mood-changing wearable is now available for purchase for $299.”
BostInno
A New Boston-Built Wearable Could Help Energize You—or Calm You Down
By Rebecca Strong
June 2, 2015 http://bostinno.streetwise.co/2015/0...g-your-energy/
"When it comes to calming yourself down, there are only so many stress management strategies that actually work for you... Similarly, you probably only have limited options that are effective for boosting your energy—and most of them, like sugar-laden energy drinks or coffee—will also result in an unpleasant but inevitable crash. For years, Thync has been conducting neuroscience research to develop a device that could offer a better solution for both scenarios. Now, the Boston-based company is finally launching its new consumer wearable, which could allow users to shift mental states in mere minutes.”
Discovery News
Wearable Device Changes Your Mood
By Tracy Staedter
June 2, 2015 http://news.discovery.com/tech/biote...ood-150602.htm
"Wake up on the wrong side of the bed? Got a case of the Tuesdays? Well, have we got something for you. It’s Thync, a wearable device that zaps your brain with low levels of pulsed electrical energy to calm you down or energize you up. It could be, for all intents and purposes, the world’s first digital drug.”
04-17-2015, 09:26 PM
