Mk1 performance air filter
Discussion
Mazdamender said:
Mellow Matt said:
I've been wondering about this too. As far as I can see, it won't have much, if any, effect on power, but it'll make a nice noise.
Not sure if a nice noise is worth the money & hassle though!
pick up response is better.Not sure if a nice noise is worth the money & hassle though!
Mellow Matt said:
Mazdamender said:
Mellow Matt said:
I've been wondering about this too. As far as I can see, it won't have much, if any, effect on power, but it'll make a nice noise.
Not sure if a nice noise is worth the money & hassle though!
pick up response is better.Not sure if a nice noise is worth the money & hassle though!
Mazdamender said:
Mellow Matt said:
Mazdamender said:
Mellow Matt said:
I've been wondering about this too. As far as I can see, it won't have much, if any, effect on power, but it'll make a nice noise.
Not sure if a nice noise is worth the money & hassle though!
pick up response is better.Not sure if a nice noise is worth the money & hassle though!
I got 19mpg on the way back from collecting mine 
Mellow Matt said:
Mazdamender said:
Mellow Matt said:
I've been wondering about this too. As far as I can see, it won't have much, if any, effect on power, but it'll make a nice noise.
Not sure if a nice noise is worth the money & hassle though!
pick up response is better.Not sure if a nice noise is worth the money & hassle though!
As for power. Well lets be reasonable about it. A MK1 is either 1.6 or 1.8 litres making not a huge amount of HP. Yet still fairly high specific output for a stock engine (bhp/litre).
So any 1 single simple mod (short of FI or Nitrous) is not going to suddenly find 20hp. On a 6.0 litre 400hp motor it might be a different story.
So in percentage terms the gain will be similar, but in actual HP it won't. Expect 0.5-3hp sort of gain on most n/a cars of small displacement.
I don't know the design of the MX-5 airbox, but as a rule a free flowing larger volumne filter with a direct cold air feed will produce better results than most stock setups.
Combine this with removing any baffling and sound suppression sections of the intake box/tract and gains will be seen.
Air box resonance has also been proven to be benefit too in some applications.
But it's more the compound affect of mods. e.g. just and exhaust, just an air intake, just a ported inlet manfold, just a bigger TB will offer up limited results on their own. Combine them together and sort out the A/F ratio and it can truly change how a car drives.
Actually, on an MX5 the general consensus is that although it may feel sharper and of course sound a lot better it doesn't add any power at all. In fact the reports I've read have all said that it might actually lose a bit of power and it makes it run a little richer and that in turn causes it to be a bit less economical though I suspect the loss of economy is more a result of the induction noise causing a heavier right foot 
I'd still fit one myself though
I'd still fit one myself though
MX-5 Lazza said:
Actually, on an MX5 the general consensus is that although it may feel sharper and of course sound a lot better it doesn't add any power at all. In fact the reports I've read have all said that it might actually lose a bit of power and it makes it run a little richer and that in turn causes it to be a bit less economical though I suspect the loss of economy is more a result of the induction noise causing a heavier right foot
I'd still fit one myself though
Most small engined n/a owners claim similar on pretty much every make I've ever read about.I'd still fit one myself though
Again it comes back to expected gains. i.e. 300hp V8 might see a 5% power increase with such a mod. Which is 15hp and usually enough to be noticed in most cars.
A 5% gain on a MK1 MK-5 (112-138hp) is only 5-7hp at most. So will be a lot less noticeable. But chances are smaller higher tuned cars to start with will see less gains anyhow, even in percentage terms.
That said, if such a mod is able to alter the a/f ratio enough as you claim above, then it is worth doing. But you will need to re-tune to see the benefit.
Swapping in some highlift cams without tuning doesn't really work either. Lesser mods may have less impact, but it doesn't mean the theory is truly any different.
I agree with what you say but in practise, according to every dyno run I've seen, there is never any increase in power and often a loss though not many MX5 engines make the quoted power anyway so whether it's the intake that causes the loss or just an old engine is open to debate (other than the late UK Mk1 1.6s which usually make more than the quoted figure oddly enough, often over 100bhp - some 114bhp engines end up with less than that!). It's just possible that Mazda actually did a good job designing the stock crossover, filter box and intake
I personally did an experiment with both of mine one being a Mk1 1.8cc 1993 import and the other a Mk 2 1.8cc 1999 import early last year after Andrew at Autolink got hold of me to try a Mk 2 one he had.
I ran both with the standard airbox set up for two weeks watching fuel and speed,from 70>90mph(more 90) on the motorways,I then watched them for two weeks with after market air cone filters on(good make ones) with the same speeds.
I have a really heavy right foot and like making the ozone hole as big as i can,now with the after market jobbies on i had more response so put my foot down even more, also to hear that lovely rumble from the back,so even though i was even heavier with my driving style and gear changes on the motorways in the two weeks of clocking this, i used less fuel???
The reason i did this was to see for myself if they did make a difference,after years of reading all the rubbish about them on the internet and thinking "nah not for me" and i personally can and have seen that they do.
Now i can not personally answer the question to why this is,but i have seen it with my own eyes and the facts that i watched did not lie.
Because if you look at this logically i should be using more fuel,because I'm putting my foot down more???
I ran both with the standard airbox set up for two weeks watching fuel and speed,from 70>90mph(more 90) on the motorways,I then watched them for two weeks with after market air cone filters on(good make ones) with the same speeds.
I have a really heavy right foot and like making the ozone hole as big as i can,now with the after market jobbies on i had more response so put my foot down even more, also to hear that lovely rumble from the back,so even though i was even heavier with my driving style and gear changes on the motorways in the two weeks of clocking this, i used less fuel???
The reason i did this was to see for myself if they did make a difference,after years of reading all the rubbish about them on the internet and thinking "nah not for me" and i personally can and have seen that they do.
Now i can not personally answer the question to why this is,but i have seen it with my own eyes and the facts that i watched did not lie.
Because if you look at this logically i should be using more fuel,because I'm putting my foot down more???
Fair enough. Can't argue with personal experience 
I suspect though that any performance diference would be down to changing the way you drive when it sounds so much better. Why you got better economy with the cone filter who knows. Was the old panel filter clean or in need of replacing anyway?
I suspect though that any performance diference would be down to changing the way you drive when it sounds so much better. Why you got better economy with the cone filter who knows. Was the old panel filter clean or in need of replacing anyway?
Even if the A/F ratio isn't optimum you are still improving a restriction on an engine. Remember a filter is only there to clean the air for engine reliability and longevity not to promote performance. Running no filter and airbox maywell be even more efficient too if you don't care about engine life.
Lastly, it's amazing how much effort car makers put into sound suppression on the induction system. I've seen it on 2 of my cars, one a V12 with direct airflow restrictions and one a V8 with a baffled airbox lid and two large harmonic sound suppression chambers. On the later dyno tests show 11-18rwhp gains by replacing the airbox lid and removing the suppression chambers. Even while retaining the stock air filter!
Lastly, it's amazing how much effort car makers put into sound suppression on the induction system. I've seen it on 2 of my cars, one a V12 with direct airflow restrictions and one a V8 with a baffled airbox lid and two large harmonic sound suppression chambers. On the later dyno tests show 11-18rwhp gains by replacing the airbox lid and removing the suppression chambers. Even while retaining the stock air filter!
GravelBen said:
I can't remember exactly, but don't you get a quite significant flat spot around 4000rpm if you get rid of the apparently pointless resonance chamber on the 1.6 intake pipe?
I can well believe it, even more so if it's not tuned to account for the change in flow rate.Ages back I tabbed up a CAI for a mates 1275GT cluman ruining an SU carb. It increased airflow so much it completely knackered the stock tune. So much so that the carb really needed re-jetting.
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