Topic

What is the current thinking about air filters?

There are a lot of old posts about air filters but nothing very recent.
A while ago there was a lot of enthusiasm about K&N cone type air filters and rerouted pipework whilst others said the same could be achieved by using an uprated filter in the standard air filter box and keeping the rest stock.. Some others were scathing about the tangible improvements and claimed it made no difference so best to stick with the standard air filter setup so long as it is changed regularly.

When I obtained my 2004 TF 115, it had been messed about with in several ways, but the change of air filter to a cone type was the only 'performance enhancement made, The rest were typical bodged sparkly additions.
I've always believed that a clean air filter was good for economy, performance and air/fuel ratios, and that any restriction to the airflow would detract from these. When I serviced my car, I bought a new cone filter, as the original air box had been removed, so I have to stick with what I have, unless I buy a new airbbox.
My personal opinion is, the cone filter does allow for better airflow, so performance etc should be improved. (In theory!)

Engine breathing is one of those topics which rolls around like Halley's Comet only less spectacular & more frequently. The thinking when I bought my f was to dispense with the resonates box & fit a cone filter. This drifted into a cone filter in an air box which had the effect of cooling the air, this I could never fully grasp, but it made some folk happy. I reasoned that as the 160 was developed as the performance version of the range then the breathing on that should be optimum. That is what I recreated, acquiring a 53mm throttle body & an air box & pipe work from a 160. One convoluted tube with its ram pipe goes to the near side air intake & the second along the chassis rail behind the engine. And did these upgrades improved performance & stretch space & time?
There was a little more urgency, no more. If your hat wasn't prone to blowing off before the modifications you weren't going to loose it now.
M

Back in the ‘50s, ‘60s and to a lesser extent the ‘70s when engines were simple and had modest power outputs, a gain of a few hp made quite a big and noticeable difference, so doing various modifications that would offer small gain in HP here and there would produce distinct results.
In the ‘50s if your 1.8 litre engine left the factory with 50HP every extra HP you could squeeze out of it was a winner, and there was a lot of low hanging fruit.
Now time has marched on, as has technical development, so by the time our cars with 1.8 litres could leave the factory with 160 HP the manufacturers had pretty well picked all that low hanging fruit, and that what was left, would only offer incremental gains.
If you have 160HP then a gain of a few HP probably won’t be noticeable.

In my case I only have 135 so a few extra wouldn't go amiss as low hanging fruit, wouldnt want to step into the rabbit hole of diminishing returns.

I love my TF but have always had an interest in anything mechanical and will read anything I come across about the subject, over my many years I have seen fads come and go and also some down right scams. I remember when we first went unleaded you could buy some metallic balls throw them in the fuel tank and not worry about hardened valve seats etc, yeah right.
I think if you strip the engine, lighten and balance the flywheel, crank and conrods then rework the head and match the ports, change out the injectors and have a remap done on a rolling road you would be an idiot not to change the induction system but up until then its basically bling.
I only intend to fit a Pipercross filter, I doubt it will make a noticeable difference but it wont hurt and apparently it makes the induction sound more noticeable, audible bling!
Probably the easiest and cheapest performance enhancement you could make is always drive with the hardtop on and reduce drag, any takers?

When the Longbridges were delivered of a Tahiti blue VVC they must have been proud parents. It measured up well with its 143bhp sleek lines & fine acceleration. The next one wasn’t as they had hoped, the runt of the litter with only 115bhp but still the fine lines to show it’s lineage & when it shot up the road after it’s bigger brother it surprised all.
We’ll, they said unless their both entered in the same race very few would notice the difference providing we don’t put badges on any of them.
And so it came to pass that unless you want to screw the balls of it around a track why worry. The underpinnings are more or less the same & I’ve driven one of these children of a lesser god over my test run & I didn’t find it wanting.
When I did my mods eBay parts were borderline free & the air box had a K&N filter in it. To do my mods now would come under the heading of diminishing returns.
All the low hanging fruit have now tumbled into the rabbit hole. Be happy with what you have from what I recall it looked a corker & why would you want to drive pass quickly when you can show your car off better slowly.