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MG MGF Technical - PTP / ITG air box induction kit

I have just been reading the data on this air box induction kit on PTP's website ( states "as much as a 9% increase in power and also has the figures from an independent Rolling Road session to prove the point. I have had the K&N 57I kit for some time but have heard good things about this kit, looking at the data displayed im very tempted but has anyone had hands on experience of this before I purchase the kit.

Your advise is appreciated

Steve Green

I would be sceptical about any dyno/rolling road data

It can be manipulated - ie does it show air temp / height above sea level etc - denser air gives higher output
There can be huge differences between data and also between different rolling roads

ie K&N with and without fresh air tubes


There are a few of us on this BBS with the ITG system. It has an enclosed cold air feed from the passenger side air intake. The results are better than the K&N 57i, although this comes, of course, at a significantly higher cost. In particular, when I had the K&N I felt that there was a lag in pick-up at low revs. The ITG doesn't suffer from this and seems to provide smoother power all the way through the rev range. The only person likely to have some independent figures for you would be Rog Parker.


The r/r figures from ITG were undertaken by a independant tester,the 9% increase was on the r/r ,slightly more will be achieved during driving as cool air will be 'forced' in. Apart from the price it is the best induction kit available,IMO.

enclosed filter systems will always function better than 'open' systems because of the isolation from the engine's heat. In fact, on a RR it is *bound* to perform better than an open system, even one equipped with cold air pipes because there is no circulation of air in the engine bay!

That said I have no doubt that the ITG is the most efficient system out there- and the improvements that Dave recounts are absolutely real.

But you can get similar results by enclosing a K7N or Pipercross filter... a much much cheaper option.

I'd agree though it would be most enlightening to RR compare a home made air box enclosure with an ITG...
Rob Bell

If ITG brought their price down to about 150GBP how many would be interested in making the switch (and ditch the K&N). Although you must admit K&N customer support is very good ... (cue ... Lesley ...)


Quite a few I suspect Gaz...
Rob Bell

I can make some enquiries about discount on a bulk order ... any takers?


Count me in.
Rob Bell

There have been several that have tried the ITG on the Elise BBS and no one has substantiated a +9% power gain.

I approached PTP/ITG with a view to them supplying one and carrying out a back to back RR test session with other air boxes, the results to be published on the BBS... they were not interested ... nuff said!


I've seen results from various RR tests, and the PTP/ITG comes out best. Whether the gain is worth it's price is another question...

From previous encounters with ITG with respect to performing back-to-back RR tests of their products compared to the competition Nick, the attitude you encountered comes as absolutely no surprise whatsoever!
Rob Bell

Its often quoted here that a K+N 57 will give about 8bhp on a 1.8mpi thats around 6.66%.
The ITG gives about 9% so the diff gained by the ITG is only roughly 2%,how accurate is the ITG figure,it does not if 9% is true a vast gain over the K+N.
What are the other benifits of an ITG.

DOH! Joe grabbed my point first. I stand to be corrected, but I'm sure I've heard figures of 15bhp extra from a K&N on a VVC. This equates to roughly 9%. So theoretically, there's little or nothing in it frm a power gain perspective.


Kieren Gibson

seems folks are missing the point here ... the ITG smooths the low-midrange lag that the K&N (due to its open design) suffers from. Its not necessarily the most bhp increase that ultimately counts.


Thanks guys,

So many different opinions but the way I see it is everyone who has bought one is over the moon with the results. I know its dearer than the other kits but the RR results are the only ones I have seen published by a manufacturer which goes along way in my book. I understand the principle of an enclosed air box which is a bonus over the K&n57I Thanks for all you help and my order is in with PTP for their kit.

Steve Green

I only bought the k&n for the noise - my advice is go with what you like the look of - but ignore the claims - power gains are all good while the filter is new/clean - once the PD across the filter increases you will lose the gains made - sometimes in a very short time period

I think Robs point about zero air circulation on a rolling road is spot on. As cold air seems to be pretty crucial i'm guessing that when the car is travelling forward the ram effect with the cold air pipes should increase the power gain on the 57i? Will there be a similar effect with the enclosed filters?, especially as i think we have agreed that there is little or no ram effect from air sucked in through the side vent. Looking at the discussed power increases on the rolling road could it be fair to assume that with the car moving forward at a reasonable speed the performance gain of the ITG system over the 57i set up will be reduced (or will the gain be cancelled out hot air rising from the engine)?

To try to reduce the warming effect from the engine I have made a wrap around heat shield cum enclosure for my 57i filter from an area of pollished aluminium sheet. This is wrapped round the filter in an oval shape when viewed end on (squashed down top to bottom). The length of the enclosure is about an inch longer than the filter at each end and the ends are open (though 50% of each end is the engine feed pipe itself and the actual end of the filter respectively). The cold air pipes vent into the enclosure via a tightfitting elongated hole. The enclosure is fixed to the car around the filter and the pipes are fixed to the enclosure by large cable ties.

This arrangement was inspired by photos of Rob Bell's first flexible duct enclosure and was an attempt to reduce the mid range lag apparent in the Filter tests. Seems to work ok.

I have a couple of photos if anyone is interested.

Ram air is a snakes nest - In my opinion the pressure of forced air induction isnt high enough to make a difference

We ran a bike manufactured with ram air and acheived 187 BHP corrected at the rear wheel 102lbs torque - no compressed air input

We then fed compressed air into the ram air inlet in relation to the speed - the final figures gave the same BHP and 2lb torque extra - this on a bike that was designed for Ram air - so its my belief that there is nothing to gain -
or not enough to warrant the expense and effort

Anyway - by the time you have put two bends in the inlet tubes you have lost any pressure gains - just look at the inlet tubes - ribbed - arghhh - air flows like water - imagine the turbulence by the time the air hits the throttle bodies - air pattern as it enters the combustion chambers is essential!

You may gain something with re mapping FI system - remember the ecu is set to give best performance with standard filter / box /airflow etc etc - but you would need to remap for say every 200rpm - not a blanket remap every 1000rpm

Beware feeding pure cold air during the winter unless you like frozen throttle bodies or can afford throttle body heaters!

The way to go is turbo charging and full re map

These filters are purley for noise !! But o boy it sounds good :)

May be of interest.
MGF fitment of cone filters seem to give a reasonable gains in performance, or is it just the 'noise' that makes you think this? If the increase is 'real' all this says is that the original equipment filter system must be really restrictive.
If you have an 'F' and want to fit a cone filter but don't want to splash out a lot of cash, stalk the autojumbles where you can find these at unbelievable prices. I picked up a "Green" cotton cone filter induction kit (meant for Peugeot 106) which retailed at 57 for just a fiver (brand new and boxed - admittedly the box was ripped open, so what!). With a bit of jiggery pokery and new induction tube it can be made to fit many vehicles.
Whilst running MGs (not F) I have fitted several makes, Pipercross, K&N etc, but the best I have come across is the Japanese one I have fitted to a Monty, superbly made dual cone, chromed, and large in size. It cost me 24, it was brand new, again this was at an autojumble.
By the way, did you know, if you just want the noise you can get this in many cases by just drilling a load of holes in your standard air filter induction box (where the air is drawn in, of course).


8BHP for MPi, 15BHP for VVC. This is not from the manufacturers but from regulars on this BBS on a real test on real cars. This test was published in MG World and included several of the leading filters and induction kits. So the power increase is real and not just in the mind. I found my braking points and gear change timing changed after fitting the filter, so, not just in my head, yours maybe, but not mine.
Tony Smith

>>This arrangement was inspired by photos of Rob Bell's first flexible duct enclosure and was an attempt to reduce the mid range lag apparent in the Filter tests. Seems to work ok.<<

I'd be interested in the pictures Paul- as an alternative to my rather 'Heath Robinson' arrangement shown on my web page! I was surprised to the extent that this 'bodge' worked, and would recommend to everyone to construct some form of heat shield.

I am a little concerned regarding claims that sticking a pipe into the airflow around a vehicle results in 'ram effect'. I don't think that this is the case at all. Okay, the K&N pipes duct air into the engine bay with welcome results, but fast moving air has a lower density than stationary air- which will reduce the potential power output from the engine. For this reason, the K&N pipes need to be mounted some distance from the filter- not so it blasts cold air at the filter element, but to reduce ambient temperature.

The situation with an enclosed filter is quite different. In fact, the location of the air filter intake is important and wants to be in an area of stagnant high pressure air. In this case, from video pictures that Paul, Tom, Scarlet and I took of the engine bay air vent, this is an ideal location for an enclosed filter air intake.
Sticking the air intake in turbulent, low pressure air (as is found under the car) would be detrimental to charge density and therefore ultimate power.

Just something to bear in mind- different filter solutions require different air intake positions...

PS Before anyone mentions the F1 ram-air intake, notice that it is high up above the driver's head and in stationary air flow rather than close to the body work in the 'dirty air'...
Rob Bell

One other thing - we found that no gain was made in any ram air system under 100mph - i do agree re the heat shield/cold air being required for hp gains

I specify air filters for the Gas turbine stations - eg DIDCOT and the one specific thats affects power output is filter Pressure differential - ie how hard the engine needs to "suck" to pull in the required air to burn the fuel


we found that no gain was made in any ram air system under 100mph - i do agree re the heat shield/cold air being required for hp gains

I specify/supply air filters for Gas turbine stations - eg DIDCOT B and the one specific thats affects power output is filter Pressure differential - ie how hard the engine needs to "suck" to pull in the required air to burn the fuel

The best option is always a two stage filter - just like the OEM rover part - as it gives the required particle filtration together with a low Pd across the filter - and doesnt "blind" too quickly!


A problem with a SOLE foam filter is that it will suffer particle migration/transferance - that is where a particle hits the outer side of the filter and knocks a trapped particle already in the filter through into the engine - so creating high engine wear!

Filters do not work on a mesh principle where a particle is trapped by a certain size hole - trapped forever - - they actually work by the fibres catching particles on strands - these particles can be knocked off the strands so its essential that a filter efficient enough for the job is selected

Although this is not a fundamental problem on a car engine as airflows are much lower it is something to bear in mind - high airflow is good - high dust migration is bad - although power output will be higher engine will suffer higher wear


Ram air is indeed a non starter until well in excess of three figure speeds is achieved and then the problem comes from being able to correctly map the fuel slope. In fact there is more potential from ramming in water and suffering hydraulic lock on your engine and grenading it!

The one quite clear point of the ITG kit is that it works quite effectively by using airflow to best advantage and not relying on any external ram effect at all. Cold air pick ups are sought in places where cold air can be drawn, but not water.

The results actually provide an increase in torque throughout the whole rev range, and in fact the torque and power peaks are actually at lower rpms. This is shown in the released test sheets, but I can concur the benefits in two cars, a standard MPi, then treated to a modified head, and my own car with it's other mods.

The cost is a sore point and is a matter I have brought up with ITG. They have a very narrow band between production cost of this kit and the retail cost, much less than you think. However the aspect of real volume has been raised and is currently a topic under discussion. I doubt that a target of 150ukp will be in reach, but to be under 200 would be a much more attractive proposition.

Roger Parker

This thread was discussed between 06/11/2001 and 09/11/2001

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