Chicken Drumstick Posted October 23, 2020 Author Share Posted October 23, 2020 4 hours ago, Snagger said: In this neck of the woods, my tyre pressure can go from 32 psi when I first get into the car to 38psi during a moderate drive on the motorway in the early afternoon. That will have a big effect. Then, as you said, the atmospheric conditions make a big difference to engine performance and a measurable effect on drag on the vehicle. Add in different transmission temperatures affecting oil viscosities and bearing preloads, there is an awful lot that can affect driving tests on different dates or even just different times of the same day. I know theory says all this is true. And you can feel it in some cars from one extreme weather condition to another. But day to day I think it is almost of little to no significance. I regularly drive a section of road where I can log by eye a performance benchmark, which I do as often as possible (3-5 times a week, most weeks). While the conditions may change, what I see on the speedo is always almost 100% the same. I'm sure with proper timing gear and measuring down to the tenth or one hundredth of a second or mph there would be variance. But in reality this means almost nothing. Quote Link to comment Share on other sites More sharing options...
Snagger Posted October 23, 2020 Share Posted October 23, 2020 2 hours ago, Daan said: Interestingly, international also had a go at the manifold when they upgraded the tdi to 2.8L: Without having seen one up close, I wouldn’t want to make a guess as to whether that was for airflow reasons or for clearance from other engine ancillaries like the bigger VNT and any pumps or accessories that may have been moved from the 300Tdi positions. Certainly, the big step inside the manifold inlet, under the badge, is going to cause disruption to the airflow. It may be that the disruption has positive effects on the engine running by causing a sudden drop in air velocity, which would increase air pressure. Quote Link to comment Share on other sites More sharing options...
TSD Posted October 24, 2020 Share Posted October 24, 2020 On 10/23/2020 at 10:41 AM, Snagger said: Without having seen one up close, I wouldn’t want to make a guess as to whether that was for airflow reasons or for clearance from other engine ancillaries like the bigger VNT and any pumps or accessories that may have been moved from the 300Tdi positions. Certainly, the big step inside the manifold inlet, under the badge, is going to cause disruption to the airflow. It may be that the disruption has positive effects on the engine running by causing a sudden drop in air velocity, which would increase air pressure. That intake manifold was redesigned to suit the Ford installation, where the turbo outlet to the intercooler would clash with the LR intake position. TGV had some head rework though, larger intake and exhaust valves, and I think bigger ports. You can see in Daans photo the outer head bolts are smaller diameter than the 300tdi ones (they are M8 instead of M12). So the manifold would have got some rework in any case. International produced several different intake manifold designs for the HS2.5 (300tdi) at the same time, according to the parts catalogue. The one of the left looks pretty bad, but the one on the right would be ideal for confusing people who think my Ibex is a GWagen... 2 Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted October 24, 2020 Share Posted October 24, 2020 Some interesting comments and remarks on this, which reminded me that my Buell motorbike came fitted with a 'breadbox' for the air intake which in fact was a Helmholtz Resonator which allowed a wodge of still air to be present for intake, and which apparently contributed to quieter and more efficient running. That intake on the 200Tdi looks like a passable car version, which might account for the reduced noise and smoother running. Or of course I could be talking utter nonsense and am completely deluded! 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 25, 2020 Share Posted October 25, 2020 @Jocklandjohn - not nonsense at all, lots of modern cars the plastic intake pipes have resonators built into them, and I assume the boffins with supercomputers and fluid dynamics simulations have worked out it's worth doing. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted October 25, 2020 Share Posted October 25, 2020 16 hours ago, Jocklandjohn said: Some interesting comments and remarks on this, which reminded me that my Buell motorbike came fitted with a 'breadbox' for the air intake which in fact was a Helmholtz Resonator which allowed a wodge of still air to be present for intake, and which apparently contributed to quieter and more efficient running. That intake on the 200Tdi looks like a passable car version, which might account for the reduced noise and smoother running. Or of course I could be talking utter nonsense and am completely deluded! Looks like “Streethawk”! Quote Link to comment Share on other sites More sharing options...
Ex Member Posted October 25, 2020 Share Posted October 25, 2020 On 10/24/2020 at 5:45 AM, TSD said: That intake manifold was redesigned to suit the Ford installation, where the turbo outlet to the intercooler would clash with the LR intake position. Ummmmmm. That pipe is the turbo inlet. Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted October 25, 2020 Share Posted October 25, 2020 2 hours ago, FridgeFreezer said: @Jocklandjohn - not nonsense at all, lots of modern cars the plastic intake pipes have resonators built into them, and I assume the boffins with supercomputers and fluid dynamics simulations have worked out it's worth doing. Worth having a watch through the chat Cosworth had with a reporter about the Valkyrie engine. They've designed the intake plenum specifically to get a flow of air back and forth across the pistons. About 9m30 in. I did some reading the other day of an article written by one of the Garrett engineers and that technique is useful on a NA engine but when it comes to supercharged (of which a turbo is one) engines then you're better off just ensuring it gets fed lots of air and has an easy exhaust route to allow the turbo to spool up freely as you'll see far more gains that way. 1 Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted October 25, 2020 Share Posted October 25, 2020 On 10/24/2020 at 12:45 PM, TSD said: International produced several different intake manifold designs for the HS2.5 (300tdi) at the same time, according to the parts catalogue. The one of the left looks pretty bad, but the one on the right would be ideal for confusing people who think my Ibex is a GWagen... Does this mean that the "Mercedes" manifold could (be made to) fit the 300Tdi head? Quote Link to comment Share on other sites More sharing options...
TSD Posted October 25, 2020 Share Posted October 25, 2020 I'm certain it would fit out of the box, but finding one is likely to be difficult. I think it would only have been sold in South America, and probably not very common even there. I don't know what vehicle it was fitted into, probably not a Sprinter though? Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 26, 2020 Share Posted October 26, 2020 15 hours ago, TSD said: I'm certain it would fit out of the box, but finding one is likely to be difficult. I think it would only have been sold in South America, and probably not very common even there. I don't know what vehicle it was fitted into, probably not a Sprinter though? It's a 'Navistar International 2.8 Powerstroke' and is fitted to sprinters in foreign parts 1 Quote Link to comment Share on other sites More sharing options...
TSD Posted October 26, 2020 Share Posted October 26, 2020 I knew I should have added a smiley for the hard of thinking 1 1 Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted October 26, 2020 Share Posted October 26, 2020 19 hours ago, Ed Poore said: Worth having a watch through the chat Cosworth had with a reporter about the Valkyrie engine. They've designed the intake plenum specifically to get a flow of air back and forth across the pistons. About 9m30 in. I did some reading the other day of an article written by one of the Garrett engineers and that technique is useful on a NA engine but when it comes to supercharged (of which a turbo is one) engines then you're better off just ensuring it gets fed lots of air and has an easy exhaust route to allow the turbo to spool up freely as you'll see far more gains that way. Fascinating! Thanks fior the link - thats a rabbit hole to fall down....! Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted October 26, 2020 Share Posted October 26, 2020 21 hours ago, Snagger said: Looks like “Streethawk”! That's not actually mine - my M2 is a later model with a few more shiny parts on it! Currently fabbing up a frame to fit a small fairing (Imola style) to stop my head getting ripped off when I try to go above 60! Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 26, 2020 Share Posted October 26, 2020 "Worth having a watch through the chat Cosworth had with a reporter about the Valkyrie engine. They've designed the intake plenum specifically to get a flow of air back and forth across the pistons. About 9m30 in." If only they had let Cosworth loose on the 300tdi Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted October 27, 2020 Share Posted October 27, 2020 14 hours ago, cackshifter said: If only they had let Cosworth loose on the 300tdi I reckon with a little rework to the headers that engine would fit in the engine bay of a Defender... Or maybe the 250hp 3 cylinder one... Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 27, 2020 Share Posted October 27, 2020 22 hours ago, Jocklandjohn said: That's not actually mine - my M2 is a later model with a few more shiny parts on it! Currently fabbing up a frame to fit a small fairing (Imola style) to stop my head getting ripped off when I try to go above 60! I had a White Lightning. Still don't know why I sold it... Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted October 27, 2020 Share Posted October 27, 2020 6 hours ago, Nonimouse said: I had a White Lightning. Still don't know why I sold it... 3ltr bottle ? Sitting alone in the park ? Mo 😉😁 2 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 29, 2020 Share Posted October 29, 2020 On 10/27/2020 at 4:55 PM, Mo Murphy said: 3ltr bottle ? Sitting alone in the park ? Mo 😉😁 On my bench, stinking of wee 1 Quote Link to comment Share on other sites More sharing options...
HampshireHog Posted October 29, 2020 Share Posted October 29, 2020 I think if the older members were honest , we've all been there Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted October 30, 2020 Share Posted October 30, 2020 On 10/27/2020 at 10:20 AM, Nonimouse said: I had a White Lightning. Still don't know why I sold it... Lovely bike. I can understand your pain! Mines is 2000 MY and I bought it new and don't intend getting rid of it. Not the bike to ride if you don't like talking to people! 1 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted November 1, 2020 Share Posted November 1, 2020 On 10/30/2020 at 9:42 PM, Jocklandjohn said: Lovely bike. I can understand your pain! Mines is 2000 MY and I bought it new and don't intend getting rid of it. Not the bike to ride if you don't like talking to people! I've a list of bikes I should never have sold. The Jota and the Buell are top of the list Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted November 25, 2020 Share Posted November 25, 2020 On 11/1/2020 at 8:32 PM, Nonimouse said: I've a list of bikes I should never have sold. The Jota and the Buell are top of the list My mate had a bright orange Jota which I borrowed one day - and terrified myself! The right foot gear change caught me out in an overtaking manoeuvre approaching a corner when I got an unintended lower gear rather than the braking effect I was expecting! Here it is with a Montjuic for company... 2 Quote Link to comment Share on other sites More sharing options...
Badger110 Posted November 25, 2020 Share Posted November 25, 2020 On 10/24/2020 at 11:43 PM, Jocklandjohn said: Some interesting comments and remarks on this, which reminded me that my Buell motorbike came fitted with a 'breadbox' for the air intake which in fact was a Helmholtz Resonator which allowed a wodge of still air to be present for intake, and which apparently contributed to quieter and more efficient running. That intake on the 200Tdi looks like a passable car version, which might account for the reduced noise and smoother running. Or of course I could be talking utter nonsense and am completely deluded! Well this takes me back, someone who actually owned a Buell! I worked for HD in thier service department for a few years and trained on Twin cam and Evo engines Those bikes were a blast to ride, do you still have it? 1 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted November 25, 2020 Share Posted November 25, 2020 I think that's a Jota 180, mine was a Jota 120. Lovely bikes. The Monjuic was a lunatic machine - utter lunacy. I had a 1981 Ducati 900SS after the Jota. That was fun. But so unreliable... Then a number of Motor Morini Quote Link to comment Share on other sites More sharing options...
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