Kevork Posted October 8, 2002 Share Posted October 8, 2002 My car has Roller Barrel Throttle Bodies with an ITG filter, and in the quest for more power I noticed this "RAM-AIR" system at MogRacing Carbon Parts Does anyone out there have one of these fitted on their car, and if so what improvements have you noticed? Are there any other kinds of "RAM-AIR" Systems that you could recommend? Thanks in advance, Kevork Link to comment Share on other sites More sharing options...
Red SLR Posted October 8, 2002 Share Posted October 8, 2002 There is a similar version from Re-vere 🤔 It claims to give 5bhp. The main difference is the "scoop" is under the nose. Seen one on an R500 - looked nice and was lead to belive the 5bhp gain was about right as it was on the RR at the time. See X777CAT here Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 8, 2002 Share Posted October 8, 2002 Ahem. Jason Krebs research showed the Reverie one robs power rather than gives. Further investigation showed negative relative pressure in the airbox - it was originally designed for scoops in the side of the nosecone. The under nose scoop is only good for picking up idly deposited bags of cement... If any significant Ram effect goes on, the ECU has to take account of it by adjusting the fuelling - and it needs to be rigged with a strategy to determine whether ram is going on or not. If you don't correct for extra air, the engine will run lean.... which isn't good. Unless specifically designed for, ram air is a red herring. The more significant effect is the cold air feed - the MOG box looks like it will have no problem delivering cold air. Link to comment Share on other sites More sharing options...
murph7355 Posted October 8, 2002 Share Posted October 8, 2002 Also, AFAIA, the Reverie one was intended to get the noise of the induction down rather than achieve any power increases. It also costs 1200GBP or so. There are better ways to spend that sort of money if power is the aim. Link to comment Share on other sites More sharing options...
Red SLR Posted October 9, 2002 Share Posted October 9, 2002 It is now more like 600 quid inc VAT. I saw the car (A non road legal R500) being set up on the RR with one, the operator said it did gain power, but maybe this was also due to an ECU tweak? Its main purpose it to reduce noise. Upto 9dB. See X777CAT here Link to comment Share on other sites More sharing options...
Joachim Westermann Posted October 9, 2002 Share Posted October 9, 2002 We build the "Ram-Air" for a Swiss Comepetition. The owner ordered this part, so we build it. The idea was: The turbo engine need cool air. Now the air is definitly cooler. The customer is very happy. If you have a "Ram-Air" effect at a standard car can be doubt. Here another ram-air system: 😬 http://find-ich-scheisse.de/plastikbomber/teile/ram-air.html 😬 Regards Joachim Link to comment Share on other sites More sharing options...
Mole Posted October 9, 2002 Share Posted October 9, 2002 I have been experimenting with ducting "cold" external air to the area of the intake filter on my standard 1.8 k-series. I've also rigged up some temperature sensors to measure external temp and the temp close to the intake. It's early days, but in comparative testing, the ducting seems to reduce air temp at the intake by up to 10 degrees. My set up is very crude and it doesn't measure temp in the intake just close to, but subjectively, the engine seems to develop power better in the midrange and feels to accelerrate better - but this is just subjective. As per another thread, I am going to try an accelerometer to measure performance to get a more objective measure of the difference, but bearing in mind that the effects of the cold air ducting are probably relatively minor, I'm not hopeful of proving anything much - in fact I'm beginning to wonder why I'm doing it (apart from it being a good excuse for more blatting and more accelerrating 😳 😳. SV 52 CAT - the Mole is flying Link to comment Share on other sites More sharing options...
Red SLR Posted October 9, 2002 Share Posted October 9, 2002 That had better not be cheese flavour.... 😬 See X777CAT here Link to comment Share on other sites More sharing options...
V7 SLR Posted October 9, 2002 Share Posted October 9, 2002 There was a lot of RAM air talk on the Se7ens list recently (few weeks back). I believe it was determined that: 1. You get negligable air pressure increases below 100mph (actually, compared to a turbo, you get negligable charge effects from RAM air only at much higher speeds). 2. Bolting on a "scoop" cannot guarantee charge increase. Aerodynamics are complex and you'd probably need a wind tunnel to site your scoop. 3. You need some sort of air pressure monitoring for the ECU, inside your airbox. Easy enough as turbos have this, however, when mapping how in hell do you simulate the effects of running at 200mph on a rolling road? 4. Much more effective is the funnelling of cold air. This is likely to give real gains. For example, when my engine is mapped, Dave Walker keeps an eye on the ambient and engine temperatures and shuts down when things get hot. So the engine is mapped using "cooler" conditions. By ensuring the engine only receives cool air thereafter sort of guarantees you are always getting the best out of your engine. 5. Some bikes employ ram air scoops, but it is believed (by those who cared to comment) that they all run on carbs, which theoretically will react positively to charge pressure increases by design (carbs feed fuel in according to the amount of air that passes through), as opposed to ECU's which require pressure sensors and require mapping to account for such changes. 6. Can't remember whether you need an atmospheric baro reading outside of the airbox for mapped ECU... Think that was it... Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Graham Perry Posted October 9, 2002 Share Posted October 9, 2002 Mole,Sounds interesting I have been thinking about this for some time. Please let us know where you reckon the coolest place is. I was driving down the road using a thermometer on a wire and although all the temperatures I got were based around the cockpit area, I found the lowest temp was behind the door mirror close to the glass face rather than directly in the airflow at 60 MPH. The difference IIRC was about 8 degrees C. It might therefore follow that ducting the air from behind a headlight is effective (although not elegant) Link to comment Share on other sites More sharing options...
Lennie Posted October 9, 2002 Share Posted October 9, 2002 Gary and I tried a cold air box on a 1600 Rover 750 race car and also a German race car.We used the area where the heater would normally sit and sealed with the bonnet and scuttle. The air filter was put in the box and connected to the inlet manifold by flexible hose and used the heater vents to get the cold air. The car was diffinitly better we even ended up putting heat reflecting foil on the box. I dont know the answers but we also reasoned that there was a lot of turbulance around the standard air filter. Another question that arised over a brain storm down the pub was 'as there is massive positive pressure in front of the screen, with our air box sucking air from the heater vents would this reduce the pressure and hence the drag. As I said a few pints had been sunk by then. Link to comment Share on other sites More sharing options...
Miraz Posted October 9, 2002 Share Posted October 9, 2002 Mole - I'm considering moving my radiator to the left hand side of the car and ducting airdirectly from the nosecone into the airbox in order to get a good, cold air stream. There is enough room in the nose of an SV to dedicate about 15cm of the nose intake for the engine, without impacting airflow to the radiator. Ram air is a whole other set of issues though... Link to comment Share on other sites More sharing options...
V7 SLR Posted October 9, 2002 Share Posted October 9, 2002 Len, I've been thinking along the same lines. I'm looking for an airbox and can't decide whether to go for a forward facing one or a rearward facing one and utilise the intake normally used for the heater (which I don't have). Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Mole Posted October 9, 2002 Share Posted October 9, 2002 My ducting set-up is very simplistic - a length of 3" diameter ali ducting which can be stretched to a bit over a metre (cost about £10). I've attached this with cableties - the inlet is below the chassis near the right-hand engine mount (right-hand from the driver's pov). The outlet is on top of the pedal box facing the air filter. Had to squash the output end a bit because 3" dia only just fits under the bonnet line. The big disadvantage is that this arrangement only feeds cold air to one side of the filter. The temp sensor is on this side so the air going to the engine is likely to be warmer than actually indicated. I'm thinking of putting the sensor inside the filter to get a more accurate measurement. Miraz - I thought about putting something in the nosecone but I couldn't find ducting over a metre without paying a lot more , I didn't want a set-up that made removal/refitting of the nosecone more complex , I judged that the air flow under the car would probably be just as cool as that through the nose aperture and possibly cooler because there would be a shorter run of ducting through the engine bay . 3" ducting sitting below the chassis is still not as low as the sump and therefore not too vulnerable - nb 3" seems to be the largest size that can be routed without fouling the steering column etc. If anyone is interested, the air temp guage is a £14 job from Maplin (powered by a single AA battery and also has a digital clock) with remote sensors at about £3 a time (with a suitable switching arrangement you can fit as many as you like - I've fitted 2 - one by the air filter, the other externally to get ambient temp). I've made a neat little mount that grips onto the centre tunnel ahead of the gear stick - I'll post more details if anyone is interested? SV 52 CAT - the Mole is flying Link to comment Share on other sites More sharing options...
Matthew Wheatley Posted October 17, 2002 Share Posted October 17, 2002 RatRace Motor sport used to fit them for some of the racers they worked on. Didn't ask about details as I wasn't interested at the time. (Think it may have been aimmed at 1.4k's) Link to comment Share on other sites More sharing options...
Gridgway Posted October 17, 2002 Share Posted October 17, 2002 ooooh ouch PC, that cement comment was below the belt! Graham Link to comment Share on other sites More sharing options...
Klaus Loske Posted October 18, 2002 Share Posted October 18, 2002 Hi, interesting topic... I am looking to build an airbox for a X-flow running on Webers. Mainly to reduce induction noise. Has anybody done this? Experience with Airboxes and carbs? In general I think the ram-air effect is not so effective. I think that on an F1 car, ram air would give you an additional 4-5 % at max speed, but there, everything is optimised so i guess you would only get 1 or 2 % max on an less ideal set-up. Main effect should be cold air feed. Gruss Klaus Link to comment Share on other sites More sharing options...
DohNut Posted October 18, 2002 Share Posted October 18, 2002 I believe that the DCOE has a small connection above the float chamber which pressurises the float chamber. Connecting a small pipe from this point to the air box should provide any extra fuel due to an increase in air pressure. I believe this is how cars such as the Renaut 5 turbo could work (and the turbo pressure not blow the fuel back out of the carb) Nick Link to comment Share on other sites More sharing options...
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