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Why don't you drop the "world misunderstands me" routine and do something productive for us. Please sketch us a manifold with pencil and paper (or whatever) that uses Hans's flanges, fits under the hood, uses as many stock components as possible (but not more), and meets your high standards of optimality in terms of air flow.
I still fail to see the "witch hunt" here......... just the witch looking to be hunted. i don't think upfix, that anyone dissed your ideas/techniques in this thread until you chimed in. if you can't sit back and let others create stuff that differs from yours, then troll elsewhere.
Post up a for sale thread of your works with a cost/benefit comparison vs stock?
Your broadcast statement that none of the RL forum users understand anything about airflow and what you have done is quite frankly absurd at best.
If you are frustrated by comments on this thread to your posts, that is one thing. But to blatantly spew broadcasts about the lack of knowledge by people who choose not to reply to your post puts you and what you say into the category of mass insulter here.
It is physically and theoretically impossible for you to know what knowledge of airflow theory and practice all RL users have. Especially the ones who choose or simply don't comment on your thread. (Irrespective of the value of your contributions)
Key is ALL users..
If you're so knowledgeable, I invite you to describe in full ALL the aerodynamic, airflow and charge management principles were used in my CAD model of my supercharged inlet system.
If you are indeed that knowledgeable please have at it. Prove to the forum that you know what you are looking at. (As you claim to have the theoretical and practical knowledge, FYI, I have posted lots of cutaways on RL of the CAD, so a search will provide you with lots of images.)
On another note, even if I disagree with Hans, or another manufacturer of 928 parts, does not mean I have to insult the entire forum or that manufacturer. That is just silly 5 year old behavior. The civil adult thing to do would be to agree to disagree and explain why for the benefit of all on the forum..
As far as cost per HP, you have clearly demonstrated that for some of us who can afford to finance our ideas without regard to cost or harm to anyone clearly escaped your grasp. We do it because we can.!
Hi Andy. You are correct in a general sense. I did not consciously set out to hijack the thread, but it does overlap the aera in which I've been working viz improved intake breathing, and, where I've achieved demonstrated improvements.
I applaud Hans' work, but I'm both saddened and somewhat irritated, in that beginning with a clean white sheet lies the opportunity to come up with a no-compromise, top shelf design, but instead I see only a repeat of the old beliefs and understanding of intake airflows.
So what do I do? Do I just spectate, or do I get in somebody's face with proven, up-to-the-minute airflow principles so that every 928 owner who buys a Hans' manifold will have the best base on which to add performance items such as cams, headers, chips etc?
Even just using my modified S4 manifold these items will yield greater improvement than with the stock manifold.
You comment that: "it's not about you and what you designed". Well then what is the point of this forum if it's not a place to share 'designs' with other Rennlisters?
Is it a Hans Forum? Or a Kibbort Forum? Or a Greg Gray Forum? Or a "I've been doing it for the longest and I have the biggest shop filled with the best CNC stuff so I must be an expert" forum?
Excuse me, but here in Australia we are known for having good BS antennae, and right now mine are flailing about at light speed re your argument.
Greg Gray commented on my obvious ability to use epoxy filler and bits of sheet metal and a tiny Dremel grinder (which I'm having difficulty in not taking as condescending), he forgot to mention the the most important ingredient: knowledge of the subject. And I'll state it unequivocally right here and now (again): NONE OF YOU UNDERSTAND THE SUBJECT. And all the most amazing workshop machinery won't help you with performance improvements until you do.
Which is why, after who-knows how many hours of analysis and effort, no one on this forum has produced a 400+ hp 5-litre normally aspirated street motor, as have the Europeans. Yes - the rpm limit must be raised (titanium rods and valve gear. And slippery coatings and ceramic coatings and vortex generators and use of surface turbulence is needed). None of which will be but a fleabite of use unless the motor can breathe. But you know that.
You can see my comments either as insults, or pointers towards useful information. You be the judge.
Look at today's superbike performances: they all meet European (EU) pollution and noise limits, but we have plenty of 1200-1600cc machines producing 180+ rwhp. There are plenty of Kawasaki 1300 Hyabusa machines (180 rwhp out of the box) running happily at 200,000 miles. Many have gyros that change ECU performance mapping as lean angles increase. BMW's 1600 Six has gyros that point the headlight around corners, adjusting for lean angle and speed. It's a true 250km/hr GT bike.
So c'mon people! Is there not something you think we can learn from this machinery?
Getting back to my situation: the message in "The World's Fastest Indian" is that with an understanding of the principles at work, great results can be had from the use of the simplest of materials. Check out Bert Monroe's achievements. Better still, watch the movie. Take particular note of the moment where Bert recognises both the cause of a high speed wobble and it's simplest of solutions.
On a similar theme, a friend of mine - a tatty-looking one-man machine shop owner (both Fred and his shop) were approached by a sub-contractor to a NASA component supplier to find a way to make a particular type of UHF cavity resonator. Only happened because Fred was a well known as a far-outside-the-box solution finder. Fred worked out a successful machining method and produced the goods. Unless NASA has retired a lot of satellites in recent years the odds are that some of Fred's resonators are still in service.
As far as I know, and acknowledging some of Greg Bird's observations, I'm the only person to have made sizeable performance gains with S4 manifold changes, so if everyone stops and thinks about it for a moment, I must understand something that they don't, and I must know how to put it to use. So to use an old expression, it's money for old rope if one cares to take it.
As for starting my own thread: I did, but it got hijacked, not by a single post but by a few day's worth of posts. So I started another ...
As I've stated often, I did what I did as a fun experiment. The results exceeded my expectations (and I'm not finished yet).
My car has come alive, to the extent that it's a buzz to drive, even just down to the corner shops. I arrive home with a every time. It has a much faster throttle response, and even with the A/C on and a 70lb dog on board the performance is still better than the pre-mod car with the A/C off.
So who would not want to know about this? After all ppl are happy to spend $000's to get a lesser performance gain.
Maybe that's the problem: all this extra performance can't be so easy. Must be BS. Yeah well - their loss. I'm the one having the fun.
One more point: what is the aim of a forum of this type?
To share new knowledge and improvements (I would have thought), or is it a place where well established sacred cows can't be questioned?
Seems to me it leans towards the latter. Mostly I believe, because there is insufficient understanding of the topic by all involved.
I have a BMW R110S sports bike. I made similarly simple changes to the intake runners and airbox. This is the result (again what is not shown by the dyno curves is the snappy throttle response and the 20% mileage improvement):
I'm trying to comprehend what / why owners don't seem to be seeing.
As in this forum, ppl in the R1100S forums seem happy to pay $2k to $4k for all the same type of mods that show very average dyno chart improvement. ?????
Is it an ego thing? A badge of honor thing?
"Look at all the $$$$ I spent on all this performance bling. Without doubt I'm now the fastest guy on the track". Then he is overtaken by a drab looking car tuned by an owner who understands the key principles involved in say cornering/grip or engine performance or roll couple ... and so on.
People can be funny old cattle at times.
Anyway I've said my piece. As another saying goes: Don't give advice: the wise don't need it and the foolhardy won't heed it.
Thanks.
BTW, while I've not been to Texas I have heard of the Texan reputation for courtesy and good manners. It does not mean however, by implication, that every Texan is courteous and well mannered.
You may well find some of my comments to be rude. I would say they might seem a bit confrontational but 'we' seem to be known for getting to the point without unude ceremony. Sorry.
Sometimes, to get the attention of a cantankerous Longhorn, you need to crack it firmly between the eyes with a lump of 4 x 2. Which I have done. Not a Longhorn but a Brahman. What else are you to do when he 'corners' you in open country without a tree in sight?
Maybe this is what I've done here and maybe it's what was needed on behalf of other 928 owners looking for improved performance.
Ciao.
Again, happy for your enthusiasm. And I'm glad that you believe your time spent was so significant.
And I didn't want to point this out, but you are so far "over the top" on what you think is a radical improvement that you really need to stop and apply some simple logic and realistic data interpretations.
I see your results as being virtually the same....before and after.
Certainly nothing statistically significant.
Dynojet results/general guide for all people:
1. I've got a file with hundreds and hundreds of Dynojet tests. Literally hundreds. I always have a minimum of 3 tests done, for each change I make. Those results vary by 1-2+%. The transmission temperature changes. The tire temperature changes. The fuel temperature changes. The engine temperature changes. The outside temperate changes.
I can show you literally dozens of dyno tests that vary this much, taken minutes apart!
2. Dyno operators generally (almost always) are trying to show customers what they want to see....improvement. They will inevitably print the worst run from the original test with the best run from the second test and compare these.
If each one of these tests vary by 2+%.....well you do the math.
Print your first results (all) with you second results (all).
3. Your dyno results are virtual copies of each other....at different starting places on the paper.This points towards "dyno variance", not real life improvement. Look at the two graphs....lay them over each other. If these results were actually about an improvement in airflow, wouldn't you expect there to be changes in particular areas (high rpm) while there not being any change in other areas (low rpm)? I would!
I seriously doubt that at 1500 rpms, the shape of the entrance to the runner, is even remotely an issue. The airflow speed is simply too low to matter!
The fact that the two graphs are exactly the same, from 1500 to 6,000, tells everything. Your statement "And I'll state it unequivocally right here and now (again): NONE OF YOU UNDERSTAND THE SUBJECT." seems to lead people to think that you know what you are talking about, yet even a novice person doing the very basic port work knows that power increases from airflow improvements are never linear....it just doesn't work that way!
4. The longer between tests that are being compared....the less valid the results. Weather changes. Temperature changes. The fuel companies change the vapor pressure of the fuels as these things occur. Power results are affected by these changes. When I am trying to compare things (and really want to know what is going on), I generally run tests within days of each other. I have what I want to test ready to go, make my first test, go back and make the changes I want to do, and immediately return.
I'm assuming that you removed your manifold, made the changes, and went back and retested months later? This affected your testing results.
5. Tests must be exactly the same...with only one change made.
Did you change anything else, when your manifold was off? Replace the knock sensors? Replace leaking vacuum hose? Clean the injectors? Replace the spark plugs? Change a fuel pressure damper or regulator? Change anything else?
Anything "extra" you do completely invalidates any individual component tests.
Understand I'm not trying to negate or put your effort "down". I'm just trying to point out that sometimes conclusions are not valid.
You put on a stock manifold one day, go test it and print all three results. You then go home, change that manifold and retest it the next day (no other changes) and print all three results. At that point, if you've got a 6% change....from the "best" run compared to the "best" run.....and you've got some valid data!
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
Greg, thanks for your patient reply (given the circumstances). I'll get back to it in the very near future.
Quickly:
Had I achieved only a very minor improvement (or even gone backwards lol) I wouldn't have bothered with the cost of a dyno test.
As it happens there as this moment when I pushed the accelerator. And still is. I didn't need a dyno run to know there was an improvement and it was to satisfy my curiosity that I went ahead.
The charts don't show it but the engine response is now so quick and sharp. To me it gives the car a 3 x fun drive factor.
Yes - the charts appear show just a solid S4 performance - but it's more than that.
Can't wait to see what serious cams will do. BTW - manifold was the only item changed.
Cheers
UpFixen
Last edited by UpFixenDerPorsche; 01-25-2015 at 09:59 PM.
Greg, thanks for your patient reply (given the circumstances). I'll get back to it in the very near future.
Cheers
UpFixen
One point I forgot to mention in there. That 1-2+% change (point #1 and point #2) can also be "additive" to the results, not always a negative thing!
It's possible that if you took the highest "first test" (before the modification) and the "lowest" second test (after the modification), that the results might actually be more impressive!
One point I forgot to mention in there. That 1-2+% change (point #1 and point #2) can also be "additive" to the results, not always a negative thing!
It's possible that if you took the highest "first test" (before the modification) and the "lowest" second test (after the modification), that the results might actually be more impressive!
The door swings both ways!
Thanks Greg. Yes, the fun and games of measureing errors.
I don't think it's altogether surprising that both charts are virtually identical (I was surprised as well, when I saw them btw) because I've done nothing to change resonant frequencies nor added any new shapes. My changes simply made it easier for air to flow by reducing the level of restriction within the manifold.
The dyno operator / owner is John Gill (a Rennlister) who lives nearby. He's a take-no-prisoners dyno operator so you get no favours, and more to the point I didn't want any, as the result had to stand on it's merits.
One change I forgot to mention: from a K&N air filter to the OE paper filter, and well before the manifold changes.
But I must keep returning to what I think can't be seen in the charts: the 'personality change' in the engine: instant response to the smallest touch on the accelerator and the eagerness to get up and go.
I don't think it's altogether surprising that both charts are virtually identical (I was surprised as well, when I saw them btw) because I've done nothing to change resonant frequencies nor added any new shapes. My changes simply made it easier for air to flow by reducing the level of restriction within the manifold.
I don't think that's true. You did change the resonant frequency of the manifold, in the flappy closed mode at least, by filling in part of the plenum with epoxy. The stock size is about 1.9L per side. If you reduce the plenum volume, then you move the resonant frequency up. I tried to estimate the effects in some other thread and they aren't huge but they are meaningful.
Thanks Greg. Yes, the fun and games of measureing errors.
I don't think it's altogether surprising that both charts are virtually identical (I was surprised as well, when I saw them btw) because I've done nothing to change resonant frequencies nor added any new shapes. My changes simply made it easier for air to flow by reducing the level of restriction within the manifold.
The dyno operator / owner is John Gill (a Rennlister) who lives nearby. He's a take-no-prisoners dyno operator so you get no favours, and more to the point I didn't want any, as the result had to stand on it's merits.
One change I forgot to mention: from a K&N air filter to the OE paper filter, and well before the manifold changes.
But I must keep returning to what I think can't be seen in the charts: the 'personality change' in the engine: instant response to the smallest touch on the accelerator and the eagerness to get up and go.
Cheers.
Over the years I have communicated with John, at length, and appreciate his methods and tenacity. I'm not questioning the accuracy of his dyno results....he's as "standup" a guy as I've ever communicated with.
I'm simply pointing out that people (not only you) need to be careful when drawing conclusions from dyno results. People need to make sure that they are comparing apples with apples and not apples with oranges.
Everyone wants positive results on everything they do....it's human nature.
People will spend hundreds of dollars on pieces that don't work and claim that they "feel" a tremendous difference...even though the dyno results show minimal gains or no gains.
Certain "performance chips" immediately come to mind.....there's "snake oil" by the gallons involved there.
One thing that is always worth noting....dyno testing only tells so much....that's why people race.
There's no racing series for 928s, which is one of the reasons why some of the bull**** that we hear and read floats on the surface seemingly indefinitely. In the normally aspirated 944 world, there at least was some racing that would filter out some of the chunkiest misconceptions.
I'd be happy if people with their 928s would show up at dyno days to compare results. A modest proposal, could we achieve that?
I don't think that's true. You did change the resonant frequency of the manifold, in the flappy closed mode at least, by filling in part of the plenum with epoxy. The stock size is about 1.9L per side. If you reduce the plenum volume, then you move the resonant frequency up. I tried to estimate the effects in some other thread and they aren't huge but they are meaningful.
That is true, but as you say the effect is not great.
I was thinking about this while making the alterations and estimate I've reduced the volume by about 500cc per side. I also wondered how much the TB plenum volume plays in the Helmholtz resonance calculations given the size of the opening to the TB plenum, which is partially closed by the butterfly plate for much of the time.
As I was doing it all for fun and interest I didn't delve any further and took the view that if everything went pear shaped I'd just hve to get back in there and play dentist again.
There's no racing series for 928s, which is one of the reasons why some of the bull**** that we hear and read floats on the surface seemingly indefinitely. In the normally aspirated 944 world, there at least was some racing that would filter out some of the chunkiest misconceptions.
I'd be happy if people with their 928s would show up at dyno days to compare results. A modest proposal, could we achieve that?
Over the years I have communicated with John, at length, and appreciate his methods and tenacity. I'm not questioning the accuracy of his dyno results....he's as "standup" a guy as I've ever communicated with.
I'm simply pointing out that people (not only you) need to be careful when drawing conclusions from dyno results. People need to make sure that they are comparing apples with apples and not apples with oranges.
Everyone wants positive results on everything they do....it's human nature.
People will spend hundreds of dollars on pieces that don't work and claim that they "feel" a tremendous difference...even though the dyno results show minimal gains or no gains.
Certain "performance chips" immediately come to mind.....there's "snake oil" by the gallons involved there.
One thing that is always worth noting....dyno testing only tells so much....that's why people race.
.. he's as "standup" a guy as I've ever communicated with.
LOL. We talk about forthright people as those "who call a spade a shovel". John calls a spade a @#^%%*?> xyz shovel.
People will spend hundreds of dollars on pieces that don't work and claim that they "feel" a tremendous difference...even though the dyno results show minimal gains or no gains.
My work background has made quite dispassionate re evaluating changes and I call it the squinty eye effect - you know, where if you you really squint hard as a certain rpm is reached .... yes... you're sure there was a bit extra there. Definitely.
I don't have to squint with this one; it's as obvious a pie in the face.
The changes I made to my Beemer (bike) cost $35 for second hand intake runners and took about an hour to implement. When I posted the results on a forum I got all manner of vague reasons why it probably would not work for them. Yet the same crowd boasted about the $2000+ they spent on I performance bling. After a while I felt like someone trying to give away free money.
Maybe if I duplicated those runners in carbon fibre, added some bling, and charged $750 I would probably have been rushed off my feet.
01-25-2015, 09:16 AM
BMW's 1600 Six has gyros that point the headlight around corners, adjusting for lean angle and speed. It's a true 250km/hr GT bike.
Take particular note of the moment where Bert recognises both the cause of a high speed wobble and it's simplest of solutions.
BTW - manifold was the only item changed.