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MG MGF Technical - K+N air filter.......disapointed....ECU?

Please help!!!
With reference to a disapointing result after all the hype of fitting a K+N air filter,I failed to feel any performance improvement:(
Could I reset the engine management system by disconecting the battery for 24hrs?
When the ECU is first activated the engine management system advances the ignition, this setting stays in its memory and it will only alter itself to further retard the map if a fault occurs.This is a safty feature and is common to almost every modern engine,
or so I am told.
After a fault is repaired(in this case new K+N air filter also changing to higher grade fuel 99RON)the engine will gradually become better, but unless the memory is wiped, it would take an infinate number of re-sampling or re-mapping cycles for the effect on the average to be overcome.
A modern ECU can reduce engine efficiency by delaying the spark or reducing the volume of AIR and fuel going in.
The knock point of 95RON is much lower than 99RON:
CONCLUSION;
To overcome the problem of the parameters learnt from running the car on normal unleaded and a new K+N air filter can the ECU be "re-initialised" with a full tank of pure super ( shell optimax here in Germany) and the re-setting of the ECU by disconnecting the battery?
Any comments would be welcome as I am a little disapointed in my K+N air filter!!

Thanks STUART
F-MG-818
STUART

how did you fit the K&N??? Where are the pipes..;
You must be the first to notice nothing! The difference on my VVC & my bro's MPi was tremendous.

And the extra RON won't change anything on performance, only your wallet will feel the difference...

reset ECU: I guess unplugging it is less complex than disconnecting the battery, but I'm sure other MGF-whizzmen on this BBS can supply the details.
Dirk Vael

To be honest I didn't notice any difference when I fitted a K&N to my VVC. Well maybe a slight difference towards the end of the rev range. I found the noise irritating after a while and took it off. The engine seems to rev more smoothly with it off too. I guess it just wasn't what I was hoping it would be ?
Maybe I'm missing out.

Dave
Dave

We've assumed that you've fitted a 57i kit, not a panel filter, right? Panel filters produce negligable power gain.

As quoted in the archive, you can reset the ECU by 5 presses of the accelerator in quick succession.

Whilst my car, at 33k, is "well run in", it was noticable that on the parade laps of Silverstone I caught cars each time (I'm sure some of them were VVC's), so I believe it really is generating more power, though I agree its not that "feelable" on the road.

For a VVC we're talking maybe 15BHP gain. Given that the differences in power output due to the weather are several BHP (cold air vs warm etc) its not a lot more than "on a good day".

Neil
NNW49
Neil

Perhaps we have over-hyped the K&N.

I know that I felt a huge difference after fitting it to my MPi - it allows the engine to breath mor freely and therefore is much quicker through the revs and now hits the the limiter very, very quickly.

Ted
ted Newman

The air filter is a 57i cone, my F is a 1.8i,and the K+N was fitted by Brown + Gammons while i was in the UK for silverstone. so the pipes are conected every thing is correctly fitted!! I wanted to fit them myself but as I was in the UK and I could not wait until I got home to Germany so I had it done while-u-wait.

Regards Stuart
STUART

Stuart

I am wondering if the fitting has been done correctly?
As I said I noticed the difference straight away and without resetting the MEMS.

BTW the the 5 flicks of the gas pedal only resets the stepper/idle of the ECU.

Dave

You say you find the noise irritating, was this all the time? I have to say I like the noise which only becomes obtrusive when giving it some 'welly'.

Ted
Ted Newman

Stuart - there is no knock sensor on the K-series. It doesn't 'learn' ignition timing settings, it just uses the maps that are stored in it. Putting a higher octane fuel in will make the engine 'safer' in that it'll be less likely to 'knock' (could be a worthwhile precaution for hot track use) but it won't affect the performance.

The ECU cannot do anything about the volume of air going into the engine, it would need 'fly by wire' throttle control to do that. The exception to this is at idle, when the ECU controls the IACV (Idle Air Control Valve) to give the idle speeds that are stored in the map (against temperature). It probably tweaks the ignition timing at idle too as a fine control of idle speed.

The only 'learning characteristic' of the ECU is fuelling, where it will 'learn' some modifications to the fuel map when running in a steady state (constant rpm, constant throttle position) by reading the air/fuel mixture from the lambda sensor.

Hope this helps.

Mike
Mike Bees

Thanks Mike,it was only a thought as a friend of mine
tried the same thing with his impreza after disapointing results with a performance air filter and it worked,I thought maybe the same philosophy might apply to the MGF. still it was worth a try!!

Regards Stuart
STUART

A 57i cone on a 1.8i will give a 8 bhp gain at 5850rpm- it isn't the greatest gain of power in the world, but it should be noticable.

I found that throttle response was far better, and from 3500 rpm the engine breathed far more freely, giving palpably more power. Furthermore the engine was more than happy to rev right up to the rev limiter- something that simply did not occur with the standard filter.

If you've not noticed the same, then there is something wrong. One possibility is that the cool air ducts drawing cold air from under the car and directing i at the filter itself is not working. Temperatures in the engine bay are more than adequate to totally wipe out any potential power advantage from a filter installation like this. Check that the pipes are properly secured both under the car pointing forward, and inside the engine bay, point back towards the filter but a good 10cm away from the cone itself.

Dave, I am surprised you found the noise intrusive- the filter is near silent under constant throttle openings. It can only be heard when the car is accelerating which for me is a major plus point: it adds to the 'sportiness' of the car! But we all have differing priorities, and it sounds as though a K&N panel filter with an improved cold air supply would be right up your street. If you are interested, Rog, Nick and Bruno have all modified their cars in this fashion...

Rob
Rob Bell

Ho Hum, here we go again!

It's true, you can't simply lob a K&N in, be it cone or panel, and expect it to work wonders with your power output. As already said by others, and i totally agree, you have to take a look at the bigger picture; intake temp, awkward air passages etc. Personally, and as you all know by now, i am more than happy with my little filter and ducted intake.

Back to the subject of my wifes' Corsa (which also leads onto another thread..) After two complete shifts over 12 days we have the fuel results using the Panel filter in place of the paper job.

Four round trips to and from Heathrow to Gillingham=576 miles. Before costing £60.00 per shift

Now only £45.00 per shift

In a nutshell it's paid for itself aready.

I still haven't got the filters for our vans yet though!


See ya.
Nick

Stuart

I have to agree with you I fitted a K&N Cone plus an SP exhaust in one day. All I noticed is that at 5500 + revs the engine seemed to not decline in power as quickly as standard. Unless you drive like this every day you will not notice any difference. I had fast road cams fitted and noticed a difference straight a way. Car pulling better. I personally do not believe that the K&N Cone gives 155 to VVC. I know that Rob and the other went to K&N for the tests but as far as I know there has been no independent tests. I believe that all you will get from the VVC or the 1.8I is about 10BHP from Cone plus exhaust and around 1,2 bhp from the CAT. Test were done on Lotus Elise in a CCC magazine and all the VVC with Cone plus Exhaust yielded was 153BHP. My views on mods are:

Good cone filter 5 bhp
Good sport exhaust 4-5 BHP
Icon unit 2 BPH
Power boost valve 1-2 bhp
CAT 1-2 bhp
Fast Road Cam with verier pulleys for hydrolic valves 15 bhp
Gas flow heads 10-15 bhp
Bigger valves ??
Throttle bodies ??
Steve

>>....Lotus Elise in a CCC magazine and all the VVC with Cone plus Exhaust yielded was 153BHP<<

And that's exactly what Caterham quote for their VVC engined '7' - which has a similar air filter (but no rubber hose between filter and plenum), and a decent exhaust (no cat, I believe).
i.e. - about +8bhp more than the standard MGF VVC

Steve
Steve

I confirm that when I fitted my K&N cone filter 2 years ago, I noticed the engine revved more freely, I was surprised to go as fast into the red zone.
This year, I fitted an SP exhaust and I didn't noticed any power improvement (but that doesn't mean there wasn't any).

Fabrice
Fabrice

>>I know that Rob and the other went to K&N for the tests but as far as I know there has been no independent tests<<

Steve, I can reassure you that these WERE independent tests although they were performed at K&N R&D. We went to great lengths to ensure that the operators at the rolling road were totally unaware as to which filter was fitted, and the fact that the results demonstrate that the K&N had no advantage over the Ram air filter (other than cost) would suggest that not everything went K&N's way.

However, other tests have been performed. JT for one has rolling road tested his car with the K&N 57i and found a near identical power gain on his 1.8i as we found on Richard Eaton's 1.8i: 8 bhp.

Point is what does a 10 bhp gain going to feel like? On a vehicle weighing in at about a tonne, a 10 bhp is not going to have a massive impact on acceleration- probably only a couple of tenths of a second to 60mph?

An SP exhaust probably gives around 3-4 bhp max. Given that Fabrice could not feel the difference is not surprising given that this is half of what can be expected from a filter (which incedently costs only a fraction of the price of a new exhaust system).

To really feel a big difference in performance you probably need at least an extra 20 bhp, and a comenserate increase in torque. In fact the perception of 'power' is in fact the influence of engine torque, not engine power! Rog has made this point time and again, and one can see exactly where he is comming from here.

>> Unless you drive like this every day you will not notice any difference<<

This is the point: driving the car near the engines power peak - high up in the rev range for a 1.8i - means making use of the whole rev range. This applies (only more so) to the VVC. The filters release more top end power by free-ing up the engine breathing. This can be clearly seen from the graphs on the filter page http://ourworld.compuserve.com/homepages/robmidgleybell/filter.htm.

In fact, have a look at http://ourworld.compuserve.com/homepages/robmidgleybell/mpi_cfilters.jpg

Notice that the torque curves for all cone filters are pratctically the same as the standard new paper element until about 4000 rpm. Therefore until you exceed 4000 rpm, you aren't going to notice much of a difference. Put bluntly, a filter is never going to markedly increase torque. If you don't exceed 4000 rpm very often, then perhaps this is not going to be the modification for you.

The cams that Steve has bought sound ideal for a more 'relaxed' approach to getting more perceptable power from your engine. I suspect that this is an approach that is going to become far more popular in the future!

Personally, I like sports cars where you have to use some revs to get the most from them and make a pleasant noise in going so. I have no problem in recommending any replacement filter to anyone. And I certainly have no connections to the K&N company!

Rob
http://go.to/mgfgallery
Rob Bell

You lot, Really!.


The cars you drive are simply JUNK!

It doesn't matter what you do to them, they will never win any races. So to play about with air filters and any other trivia, is just wasting your time.


Get a DECENT car.

Visit the Ferrari sites and BB's for information on these supremely exquisite cars.

Better by far than any old MG tripe!
Ferrari Owner

To Ferrari Owner

Why are you acting like an idiot. People who can afford a ferrari would not visit others peoples BB to act the way you do. I recommed that you visit a doctor. Rob can you recommend treatment for this idiot.
Dave

Well I think he has point.

Ferraris are pretty neat cars
Rob Bell

Actually, Ferraris are very nice cars- but a Porsche 911 GT3 will eat them for breakfast...

MGFs do race successfully- and many of us enjoy tasking our own road cars to the tracks for competitive motorsport. These MGs are great cars.

I doubt that 'Red' would dare do that with his automotive mode of transport, and it isn't a Ferrari...

Rob

Rob Bell

OK hands up who thinks 'Red' has got a picture of a Ferrari as his PC wallpaper. And has a big poster over his bed. Now, does Red have the top bunk or the bottom one?, Beer Bottle glasses perhaps? No girlfriend? Sad isn't it.
Nick

Red, stop thinking, it just overheats youy little brain that is already strained by dreaming of a Ferrari.
Fabrice

We'll have no comments from Belgium.

Nice sprouts though.
RED Ferrari

Red

Some very nice things come from Belgium - including sprouts.

What ever came out of Akansas? They can't even spell it correctly or is it pronounce it correctly.

Kite
Cpl Kite

about airfilters..... I've learned from an earlier thread that changing the length of the tube between filter and engine, changes the rpm where the power gain is situated.

Erik
(trying to prove he's smarter than a ECU, he learned from a previous thread!)
Erik

On Eriks point I have achieved a happy balance by halving the length of the tube on my MPi

Ted
Ted Newman

Erik - lengthening the induction 'tube' can give an increase in mid-range torque. It would be interesting and not too difficult to do some practical tests on a rolling road.

Mike
Mike Bees

After reading all the highly informative posting, I made the decision to look at purchasing the K&N 57i kit for my VVC. I rang my insurance company (Direct Line) and they asked for a percentage power gain over the standard air filter fitted. They wanted to know standatd BHP and BHP gained from fitting the new filter. I told them 143BHP Standard. What is the 'Official' BHP gain when fitting this kit because you could argue that different cars will produce slightly different results. I don't want to end up stating a figure to them and then (hopefully not) if it came to the point where I had to make a cliam then I may end up losing out cause the figures I quoted were wrong. They said by the way, that it would cost me an additional 84GBP per annum on my insurance (1275GBP per annum, 23yrs old, 2yrs NCB, No convictions or accidents). Anyone else had any experience having to quote figures or had to deal with Direct Line and modifying there MGF ? Info would be greatfully recieved as I dont seem to be able to find 'Offical' Figures from K&N as yet.

Kieron.
Kieron Sykes

Hello all, long time no BBS!

Been away on 'holidays' to lovely Port Stanley in the Windy Falklands. No MGF, No girlfriend, lots of penguins and cheap beer!

Anyway to the matter in hand. Kieron I think you may find what you are looking for on Kinors pages.

http://www.knairfilters.com/marque/mgfthumb.htm

Although Rob Bell will probably be able to help you more, he seems to be the induction man! Correct me if I am wrong.

Hope this helps,

Regards

James.
James

To prove that like stocks and shares things can go down as well as up I have recently been doing various things with a Rover 200 BRM, which has a standard VVC engine. Before delving into some head work a series of comparisons were done with an ITG and a K&N Cone filter, more of a side issue in seeing if the results with the MGF can be mirrored in the FWD application.

It didn't!!

The results on Pete Burgess's rollers over very many runs averaged out with 125bhp at the wheels with the standard car and standard (new) paper element, 130bhp with the ITG panel and a very disapointing 120 bhp for the cone. The 'feel' of the engine mimicked the changes also. Of note is the results on the same rollers with my own car would, if the tests were repeated on the same day, show my 1.8i was only 12 bhp behind the K&N equipped BRM with my K&N panel filter and cold air pick up mods.

These are the summary of a wide range of tests done over a day with a number of variations such as a large bore and very long pipe to draw cold air from outside the unit to open intakes and different angles. There was very small changes not worthy of note.

There are a number of possible conclusions to be drawn from this test, but one thing clear from driving the car is that the ITG set up was clearly the best for this car.

It also goes to show that performance parts are sold on claims, which reflect the product in the best possible light. (i.e. one car where specifically good results were achieved, perhaps above the average.) When it comes to insurance I would be somewhat reluctant to start quoting claims as what will actually be achieved. After all what if you possibly find yourself paying more insurance for less power?

Rog
Roger Parker

Echo Rogers remarks. And with similar setup, I made a point of getting figures from a rolling road test before going ahead with insurance changes. And it was worthwile to do so as PB came out tops. Renewal due next month, i wonder what's instore??


BTW still no Panel Units for my vans ;-(

Nick
Nick

Thanks for the input guys, anybody know of a rolling road near warrington ? and do you know how much they normally charge for such a service ?
Kieron Sykes

Well my K&N needs cleaning still :-) I have noticed a the effectiveness of the K&N goes down when it needs cleaning. Also since I fitted Tom cold air bracket last year I have not been bothered to rerout my cold air pipes and I think this is having an effect on the performance, mybe next weekend :-)
Tony Smith

This thread was discussed between 13/07/2000 and 21/07/2000

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