Increasing the diameter of the intake tract will not increase the engines air intake capacity on a linear scale, therefore not increasing power on a linear scale. The engine can only pump so much flow and the turbos can only deliver so much volume. The difference is a pressure (boost), which is a factor of temperature, dependant on volume. So if the intake and pressure tubes are found to be limiting, you will see an increase in pressure and temperature with no additional power (flow). If you increase the diameter of the pressure tubes, and if the tubes are found to be a system limit. Then the boost will decrease, along with temperature and there will be an increase in flow. Keep increasing the pipe diameter until the pressure starts to decrease more than linear, and you have found the outter limit of the max pipe diameter, where also the power band would move to the right and a higher flowing head is more beneficial. Just guessing.
I realise the relation is not linear and agree with your thoughts, I was trying to dumb down my thoughts as I dont have the actual numbers and volumes and ratios to give specific accurate measurements. I am a plumber by trade and have spent a lot of my life dealing with basic fluid dynamics in relation to flow rates pipe sizes and pressure loss etc. the flow of air through our inlet tracts while not identical inthe way it is effected by specific factors still follow the same laws in similar fashions. I accept a lot of people have better knowledge of whats happening than I, and I am not trying make statements as to what is happening more presenting hypthesis based on my knowledge for people to show me what is correct or incorrect. I do this mainly for selfish reasons. I want to know stuff, this is one of the ways I learn, and if someone else learns something in the process then great. With what you have said (Whiteknight) I admit you are 100% correct every bend and deflection in the inlet tract will have an effect on flow rates the very shape of the cross section has an effect, these things I know and understand. I could not quantify how much and the effects individually are negligable I feel in relation to the effect of the overall size increase. Also I am very surprised as well that there was an increase in the earlier threads I said I thought any increase would be minimal I am now trying to discover why I was so incorrect and I feel this is the whole point of this sort of thread. as such I am looking forward to other theories and results.
Have to laugh, thread about testing the pipes not too far in to it "stop talking about dynos!" Now we have a thread about dynos not too far in to it and we are talking about pipes :rofl: I've had an after thought: what I SHOULD have done was started a thread for my results and findings and hypothesis etc AND another thread for the discussion. This would have kept it nice and easy to follow for people When I move to the next stage of testing I might do something along those lines, maybe create a simplified test results only thread and leave the original open for endless debate and discussion If I can prove my theory with facts and figures etc it will answer a lot of questions and more or less confirm what some people have said on both sides of the argument for some time. I'm possibly sounding a little like the Riddler but I'm not prepared to go into details just yet, some people just wont get it so it will cause a stir.
yeah off topic I suppose I am.... but that is your pipe charts is it not. and I have suggested other alternatives eg fuel formula although that is a bit oof a big leap. unless someone does back to back on 2 dynos and shows us different charts (and I am not wanting this its just BS waiting to happen) then the only thing this thread can be about is understanding the mods done and the effects shown on the sheets.
When we made 456rwkw or 612rwhp back in 2005 way before anyone else, even in USA I think? Anyway we used 2 inch intercooler pipes, I doubt very much if it would make anymore peak power with 2.5 inch, might make more torque and change the torque map. As for dyno's. Mungy using GT2860R with .64 rear housings rated at 360ph max x 2 this is 720 hp at the engine less 25% power drain loss actual (rolling dyno ) or estimated equasion using a hub dyno equals 545 rwhp or 406.4rwkw. Consistent with SR20's on our dyno with the same turbo makes around 210rwkw.
Im not strying to steer this thread away from JP's original intention but this issues comes around regularly and its relevant to the topic. Concentrating purely on the diameter of the pipe completely clouds the issue and is close to irrelevant. jeez, if you want to know if the pipe diameter is restricting it just meaure your pipe system, work out its flowrate agains the flowrate of a powerful engine already measured. Comparison DONE! However, it just not that simple. The DESIGN of the routing of the system is just as important as the diameter and imho THIS is where the differences in results is largely stemming from. Unlike sonic waves which happily travel around twists and turns, air has mass, and will NOT travel along the length of twisting and turning pipe in one nice and even "slug" of air. The pipe has 2 different inner lengths (radius) in a turn and constantly varying inbetween and so the "slug" of air travelling around the inner radius will not magically slow down and the outer radius just as magically speed up so the given "slug of air emerges nice and even like. The slug travelling along the inner radius will emerge from the turn well ahead of the air on the outer radius! This then creates a tumbling or rolling turbulence inside the pipe. And THIS hasnt even taken into account the mass of the air and its inertia. Turbulence = restriction and at the end of the day, unless you magically create a turbulence to counteract a turbulence as dolphins do with their skin to reduce drag underwater, ech time the air changes direction then you create even more turbulence!!! In some cases, Im guessing that THIS is what has happened and all of a sudden a particular restriction is reduced. You have ALL universally ignored this fact and im sure would assume the air would travel down its long and winding road in a nice and cohesive "slug"... Nope Im afraid gentlemen! Bearing this in mind, have a look at the tortuous path the air in the air piping has to take. Turns left, right up and down and compound............ and your all mesmerised by diameter alone????? Even a small change in bend radius V's diameter, entry angle into/out of the coolers can have marked impact on flowrates. Can have quite an effect on airflow potential. This is borne out in the design and placement of airflow meters and a simple redesign of the piping location of the afm can affect afm operation considerably and consequently render a given tune useless! I am dealing with this EXACT issue as i type with a CA18det in an S13. IMHO, the ONLY relevant testing would be where the fundamental system design remains completely unchanged and ONLY the piping diameter alone is altered. Sorry to JP for the hijack, but i feel this very important and influencing issues has been ignored for too long. E
You know as well as I do these are things I am looking into and will try and prove further down the track I was just talking (actually talking not key board smashing) with JP yesterday & explained my theory on the situation & a possible improved product based on this - so long as I prove myself to be correct :rofl: Most people wont have even noticed when I mocked up the pipe kit on the outside of the car the pipes were plumbed in reverse through the intercoolers It was what was required to do the job at the time, further testing will not have this error and as I have said multiple times I've not finished so still working through the process. I will send you a message with my theory E you will love it and it will melt some brains around here trying to get their heads around it :rofl:
.86 turbine housings not .64 Z1 claims 600hp at the wheels easy: http://www.z1motorsports.com/popup_image.php?pID=94&imageNum=2 And states 700HP is possible "With the addition of camshafts, intercoolers, portwork, upgraded manifolds, and proper tuning abilities, these turbos are capable of producing 700 whp". We are not going to be able to point at one particular item and say "there it is the magic HP maker!" contributing factors have got to be: A good batch of fuel - we have seen as much as 10% power drop due to crap fuel, maybe we got a good batch. Cool air temp - The 498KW runs were done in the morning, air temp went up by about two or three degrees in the arvo and we couldn't repeat the 498Kw runs. Something in the installation of the pipe kit - I have my suspicions & theories. Condition of drive train - the car has about 70K on the clock as compared to most at 160K plus. All the nick nacks - multiple little power adders all added up giving an excellent result. Same dyno today just ran another Z32 and did 360Kw on 14PSI with 555cc injectors at about 80%, this car has similar engine work as mine but GT28 turbos with bushes not ball bearings & full custom exh manifolds. The dyno plays fair, this car just does the job & that's all there is to it - now if I can replicate the excellent results scaled back to my set up I'm picking mine will be over 400Kw but under 450 .... or maybe we might juuuuust push it far enough ..... :rofl: (might be a thread on my next eng rebuild soon :rofl: ) While tuning the other Z32 today they found a interesting little quirt with the ECU that we hadn't yet picked up on and IF (ifs buts and maybes) we had that quirk sorted it should have made the difference to get the record. So close but not close enough - next time maybe
edit my post was the same comments I made earlier... I know there is more to this than straight volume and I am not after specific HP figures for a given mod. I am just trying to get ideas on how things are working together and individually to give improvements. an example shown in this thread is the inlet tract, on itself this may give minmal improvement but with more boost we get a (enter whimsical number here) improvement we can then use as a guide, stating that on its own its pointless but matched with this mod, this mod, and blah we can now see the worth of it.
Ok so .86 rear will help alot, what compressor wheel size is it 47mm ? Still 60% duty cycle side feed injectors, to make 498rwkw doesn't add up to me. Which turbo exactly are Z1 talking about, and what fuel used? Are USA dyno's on the same scale to Aussie Dynodynamics???
Max inj percentage of 60% was for 450Kw runs. As per previous post you may not have seen 60% of 850 = 510 Using the old rule based on rolling road so power at the wheels, I assume 25% loss on rolling road so that's ~ 635hp at flywheel only ~70HP loss on hub dyno so 565Hp at the hubs or 420Kw Now we all know things improve and going by the maths above as rough or incorrect as it might be we are in the ball park at least and with only a ~7% gain over the days of old with old computers and intakes, turbos etc ..... The injector rule of thumb doesn't rule the power output out by a long way.
I thought you said 60% at 498kw even 450kw I would expect more like 70% or higher. Also the dyno graph power curve doesn't match .86 rear unless it is over 3 and stoked to 3.2 litre engine? What do you mean 60% of 850+510 is that 850cc and 510 kw or? Also if you can clarify what you mean only 70hp loss on hub dyno? Also I found the info on Z1 site, this is it isn't it 28psi and RACE FUEL to make 600 or 700+ wheel HP?? http://www.z1motorsports.com/product_info.php?cPath=6_16&products_id=94
So what is the relevance of the ambient air temp? We seem to agree that it is the engines actual air temp which is relevant. Try tuning an engine when the ambient air temp is 30*C, keeping the intake temp below 40 is a pretty good result, means the IC is doing it's job, but it's crap for power output.
Old rule of thumb equation: size of injector in CCs = Hp at wheels SO 850CC injectors at 60% gives ~510HP at wheels on rolling road. Add 25% for losses on rolling road + drive train loss to give engine power = ~635HP at engine V8 Super tourer engine on engine dyno made 50Hp more than when fitted in the car and run on the hub dyno but this is modern race gearbox and diff and less power so I assume ~70HP loss through box and diff and CVs etc on Z32. 635HP minus the loss as above gives approx 565HP at the hubs or 420Kw If you go back and find how old that rule of thumb is it's no surprise cars are going beyond what that rule indicates is possible Originally I said 66% at 498kw BUT this is what I thought the tuner had said and have not confirmed this was the correct number and have nothing on paper or program to back it up so could very easily be wrong.
FFS, is this argument still going on ... Adapted from Montgomery Scott: The notion of 2 dynos reading the same is like trying to hit a bullet with a smaller bullet, whilst wearing a blindfold, riding a horse. Use the same dyno as a method of comparing impacts of changes - for everything else, buy yourself a crown ... :bash:
Please go back and have a read of: Posted on the 7th July 2012 when people started talking about dyno to dyno cock swinging. It's pointless and nothing but an invitation for a punch up. There is still an open invitation for anyone who wants to see this car on the dyno doing exactly what I have said it did any time you like, I can even arrange running it on a rolling road - entirely at your risk! any damage done to the car is entirely your responsibility! There is an extremely strong tone of disbelief from some members here yet no one has the decency to take my word for it far enough to come and see it for themselves So easy to knock what you can't achieve yourself, people need only search the other forums for other cars with similar mods at present to see knocking and doubting the power this car has made only shows your a bit slow keeping up. No offence intended - it happens, things move on and people take time to catch up. "it will not make 498kw on a roller" but what brand!? soooo open for error, I bet $500 I can take it to a rolling road next week and put down near as damn it the 450kw the tune was set at on the hub dyno. I can't do the 498 without Dave putting the 498 tune back in so don't start that crap.
It WILL make that power on a properly operated roller depending on the fricking brand!! THAT has been the whole issue all along, some of you do NOT understand the simple fact that not all dynos are created equal and not all of them read the same regardless of being a rolling road or hub dyno. Is it really THAT hard to grasp this simple as hell concept? Am I really trying to deal with people who simply do not understand this or am I dealing with people who are using lies and deception to try and discredit something someone has done? I firmly believe the later. I was asked what it would run on a rolling road I gave the ficking answer then you guys brought the brand of Dyno dynamics in to it and I responded with we need to do a comparison. Then you guys start accusing me of being the thick person :rofl::rofl::rofl::rofl: It's not my fault or problem if your beloved machines read lower than some of the others - I don't care, I do understand this and always have, there is nothing for you to teach or prove to me or anyone else WE GET IT!!! YOUR MACHINE READS LOWER WHO FRICKING CARES!!!!! Damn small dyno syndrome at its worst There is absolutely NO point in all of this, the car was run on a hub dyno and gave a 100% correct and honest reading end of story, that's it, no cheating, no lies, no photoshoping, no dodgey tuner, no race fuel , nothing done to cheat or lie in any way shape or form. The reading given from the hub dyno is 100% fact and truth from the hub dyno. Please give it up on trying to GUESS at what it would on your machine in another country, that's a pathetic waste of everyones time and just shows people aren't man enough to deal with facts as facts. We know for a fact what it runs on the Dynapack end of story any speculation on what it would run on your machine is just that speculation.
Yes but mungy it is a bit like musical chairs with your statements of features of this mysterious engine, facts and figures. Now you say Why would you tune it at 498kw then remove the tune? I think we all agree dyno's vary, especially Aussie rolling roads compared to New Zealand hub dyno's.
In New Zealand we have to fit cat convertors to the cars now when they require a engineers cert for road use, the car doesn't currently have cat convertors (they are ordered and on the way) so the tune was pulled back a little for safety factor from any added back pressure due to the cats. It's not musical chairs, what it is is people not paying full attention to what has been said & only taking certain parts of certain posts then arguing that I'm not telling the whole story or I have changed my story etc. It's nit picking attempting to dismiss the power recorded IMO, the owner of the car doesn't say much on the forums & I bet he is glad he doesn't at the moment. If this is the sort of public interrogation people get for being as honest as they can it's a wonder anyone ever posts anything at all. Give me a mth or so and you will have something else to cry about anyway :rofl:
