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Re: Tik Pipe kit Roadster 82cv
Tolsen,
perhaps if you were to logically explain why you are so convinced the most common approach will spell death and destruction, people will listen a little more closely. Consistent, peer-reproduceable results are the building blocks of fact, not presumption and blind faith... that's more a description of religion than science!
Measuring pressure drop across a filter with almost no mass flow is not relevant. Ignoring entry losses to a duct because you consider nothing but flow area is only partially relevant. Declaring a reduction of duct section immediately before the compressor inlet is detrimental to the health of the turbo with no evidence, or theory, and data which are only remotely related to the issue is not so easy to swallow. Perhaps that's why people are having "difficulty grasping" your arguments. I'm very sure that in your mind you have unequivocal evidence to back your statements, but you have to convincingly communicate why you reached this conclusion before anyone else will be in the same position. Just telling people isn't enough (see comment on religion). Yes, of course a step should be avoided to reduce an inevitable entry loss, but the argument really boils down to: is this entry loss going to be better or worse than passing the flow down a narrower-bore, corrugated-wall tube?
The answer could come from several directions. CFD modelling would be good if you want to truly, even parametrically, understand the best solution. 'Fag-packet' calcs will work to a certain extent, but to get an answer you'll have to make several sweeping assumptions; it may not be accurate enough. Empirically there are many ways to address this from a basic flow bench right up to engine testing on a dyno. I've yet to see any relevant empirical data other than from chassis dyno testing... and a lot of that is compounded with additional modifications, test-to-test repeatability issues, and variable doses of optimism. Some sources can be trusted, others not so much, and moreover all tests really need to be done on the same dyno, by the same operator in close succession of each other to have true pertinence.
Someone out there probably has such data. I've not seen it yet and I haven't the facility, time or need to generate it myself.
If you want to truly prove your point I suggest you need to generate some appropriate and valid data. Perhaps a simple and very direct way of doing this is to make intake mass flow measurements. This could be done on-vehicle, doesn't need any assumptions and sums all dynamic pressure losses. All you need is a mass-flow meter from a dead scrapyard car, some appropriate tubing, a stable power supply (use dry cells), and something to record the meter output voltage... or even just a multimeter and a willing passenger. Drive up your favourite hill at full load and in a gear such that you accelerate slowly through peak torque speed and record your data continuously (write down the biggest number if you must, but it will be less convincing... I'd really like to see a curve reflecting the variation of VE). Make your changes to the TIK hose, filter, intake, underpants or anything else, then repeat the exercise. Try to do it on the same day so you don't need to worry too much about ambient variation. If you come back with fully justifiable data that show a "high flow" filter or a larger, smooth-bore TIK is worse than the OE parts, I'll eat said underpants.
It's data that really count here, not opinion. If you can unequivocally demonstrate, you'll find more people may be able to grasp your arguments.
That is all.
Cheers... Paul
Originally posted by tolsen
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perhaps if you were to logically explain why you are so convinced the most common approach will spell death and destruction, people will listen a little more closely. Consistent, peer-reproduceable results are the building blocks of fact, not presumption and blind faith... that's more a description of religion than science!
Measuring pressure drop across a filter with almost no mass flow is not relevant. Ignoring entry losses to a duct because you consider nothing but flow area is only partially relevant. Declaring a reduction of duct section immediately before the compressor inlet is detrimental to the health of the turbo with no evidence, or theory, and data which are only remotely related to the issue is not so easy to swallow. Perhaps that's why people are having "difficulty grasping" your arguments. I'm very sure that in your mind you have unequivocal evidence to back your statements, but you have to convincingly communicate why you reached this conclusion before anyone else will be in the same position. Just telling people isn't enough (see comment on religion). Yes, of course a step should be avoided to reduce an inevitable entry loss, but the argument really boils down to: is this entry loss going to be better or worse than passing the flow down a narrower-bore, corrugated-wall tube?
The answer could come from several directions. CFD modelling would be good if you want to truly, even parametrically, understand the best solution. 'Fag-packet' calcs will work to a certain extent, but to get an answer you'll have to make several sweeping assumptions; it may not be accurate enough. Empirically there are many ways to address this from a basic flow bench right up to engine testing on a dyno. I've yet to see any relevant empirical data other than from chassis dyno testing... and a lot of that is compounded with additional modifications, test-to-test repeatability issues, and variable doses of optimism. Some sources can be trusted, others not so much, and moreover all tests really need to be done on the same dyno, by the same operator in close succession of each other to have true pertinence.
Someone out there probably has such data. I've not seen it yet and I haven't the facility, time or need to generate it myself.
If you want to truly prove your point I suggest you need to generate some appropriate and valid data. Perhaps a simple and very direct way of doing this is to make intake mass flow measurements. This could be done on-vehicle, doesn't need any assumptions and sums all dynamic pressure losses. All you need is a mass-flow meter from a dead scrapyard car, some appropriate tubing, a stable power supply (use dry cells), and something to record the meter output voltage... or even just a multimeter and a willing passenger. Drive up your favourite hill at full load and in a gear such that you accelerate slowly through peak torque speed and record your data continuously (write down the biggest number if you must, but it will be less convincing... I'd really like to see a curve reflecting the variation of VE). Make your changes to the TIK hose, filter, intake, underpants or anything else, then repeat the exercise. Try to do it on the same day so you don't need to worry too much about ambient variation. If you come back with fully justifiable data that show a "high flow" filter or a larger, smooth-bore TIK is worse than the OE parts, I'll eat said underpants.
It's data that really count here, not opinion. If you can unequivocally demonstrate, you'll find more people may be able to grasp your arguments.
That is all.
Cheers... Paul
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