Really interesting article on the MX5, obviously some of it is not relative, but the methodology they used seems quite insightful. Wonder if we could do something similar?
Anyways points out that the majority of the performance loss occurs in the top of the airbox (33%). This is likkely to be pretty similar to the MR2, and calls into question the benefit of a drop in filter.
Anyways have a read see what you think
m http://www.autospeed.com/cms/article.html?&A=0892 (http://www.autospeed.com/cms/article.html?&A=0892) m
If someone has a spare airbox that they dont mind getting back with a couple of 3mm holes drilled in it, I have just spent £6000 of my firms money on a Beamex MC5 fitted with a 0-100mBar differential pressure sensor and data logging capabilities. Hooked up to the filter and the relevant signal on the ECU, it could quite easily log rpm vs. diff pressure across all the relevant points.
I did butcher an old side air intake for much the same reasons, in order to log pressure and potential flow vs. speed, but I never had a pressure cell sensitive enough until now.
I've just chucked one away you could have had Grant, wouldn't have been much use though as the bottom was like a block of cheese after a mouse had been at it.
Next week I'm going around a few scrappies after bits If can find a OEM Filter housing I'll pick one up for you, I'd really like to see the results of your new toy! s:lol: :lol: s:lol:
Have you logged any data for the side vent given you've already butchered it?
Quote from: "MRMike"Have you logged any data for the side vent given you've already butchered it?
No, its kicking around somewhere with all the other MR2 bits I seem to have accumulated. Apparently there is some similar data on SC for the side vent, but I dont recall having seen it myself.
If anyone turfs up any info on air pressure in the side vent region then let me know. I have just replaced the stock inlet tube with one of the same diameter but of a longer length so that it runs right up to the side vent. The inlet is thus totally sealed from the engine bay and in theory should only draw in air from outside. The probelm is after a couple of PMD runs, it appears to have impaired performance rather than improved it. The tube is only about 8" longer than std. Wondering if it has anything to do with: a) The side vent being a low pressure region and thus actually reducing flow. b) The increased length of the tube changing the harmonics of the inlet tract and maybe buggering up the physics of the std Heimholtz resonator etc.
Obviously I need to ascertain the reason before any remedies can be made but if low pressure in the side inlet is the problem, the obvious solution is to get some kind of c-one scoop type thing to scoop in air and create a high pressure area.
Grant,
I have spare side intakes and air box if you want them! You know where i am s:) :) s:)
Ok, ok... it would seem that there is quite a demand for some definitive data on this subject... So I'll "borrow" adams airbox and nearside vent sometime soon and start work... I really do need to shut up occasionaly s:roll: :roll: s:roll:
Cheers Adam!
I read the article on the link. The stock airbox that the guy was talking about seemed to be very restrictive by his description of the holes at inlet and outlet. I opened my airbox yesterday for the first time to put a K&N panel filter in and noticed that the holes for both inlet and outlet did not appear to be smaller than pipework each side and therefore not restrictive in that sense. Okay I don't know about all the finer parts of gas flow theory and such, leave that to the brainier members, but our airbox just seemed a bit better than the MX5 one described.
I looked yesterday and, as has been reported by a few people, the stock airbox is good, hence the reason it has taken Beanie so long to perfect an improvement. s:wink: :wink: s:wink:
a lot of stock air boxes are quite good, as once you start messing around modifying them (e.g cone filters) youre just letting in nothing but hot air