tuning myths...

pikey motorsports

Track Warrior
Points
222
Location
hampshire
Car
69 Mustang Coupe
Ok, so iv seen in numerous places on this forum people talking about cone filters and back boxes making extra bhp... WRONG!

On the vast majority of "normal" (read none performance) vehicles, a cone filter will LOSE you power. This is due to the heat in the engine bay being sucked directly into the intake via the cone. On HIGH performance engines, ie skylines,impreza sti's, evo's (you get the idea) a cone filter can be used without a loss in power as the engine management is preset to take this into account.
your average car (clio,corsa,polo,escort,golf etc) is not. they are set from the factory to run slightly lean so as to provide better mpg/less emissions.

even high performance engines benefit from an enclosed airbox design, such as the k&n typhoon. but look at it this way, if you fully enclose a cone filter what have you got? an AIRBOX!

put a performance panel filter in if you want to help your car breathe better!
and if you really cant live without the induction sound, drill some holes into the wing and front sides of the airbox, under the panel filter.


next, back boxes adding 5bhp etc....WRONG AGAIN!

a backbox will add sod all BHP. even a full cat back exhaust system will only add an average of 5bhp. removing the Catalytic converter will probably give you around the same gain.
the only exhaust option your going to see any real gain from is a FULL manifold back exhaust system.
choose a 4-1 manifold for mid to top end power or a 4-2-1 for low and midrange improvement. also, dont overdo it with the bore of the exhaust. there is no point running a 3" pipework straight through on a 1.2 etc. as an example, a standard or mildly tuned 2.0 16V should be running around 2.25" pipework, 2.5" if well tuned,3.0" for a SERIOUSLY tuned engine.

some exhaust manufacturers claim a full matched manifold and system can gain you as much as 15% of the engines power, so in theory a 150bhp engine could see as much as 22.5bhp gain. This is however VERY unlikely, even a 10% gain is hard to achieve on a relatively standard engine.

what does gain power is combining modifications and remapping the cars ecu to adjust the fuelling and ignition curves to suit your mods.

Ebay special ECU chips are not worth the risk BTW, you just dont know what has been programmed, if it will be compatible with your engines state of tune etc. either get a proper remap, or dont bother!

The bottom line with engine tuning is "you get what you pay for".

BHP doesnt come cheap, proper engine mods like porting and polishing the head along with bigger exhaust valves costs strong money, but it is worth every penny!

i have a spare 16v head thats going to be getting a full stage 4 port and polish, black carbide coated oversize exhaust valves and multi angle valve seats. thats close to £600. the gain in bhp will be around 15bhp. but thats going onto an already tuned engine.

Sorry for the rant, but it really gets my goat up that people believe/talk this kind of crap!
:sad2:
 
Do you feel better for that now? ;)

Also rather than talking peak power gains we should be looking at the overall effect on the Torque curve. 10bhp more is nice but not if it only hits that gain at 7000rpm and you lose some low down power at 2-3000 rpm!

I still see Induction kits as a "style" mod for most cars, and most people fit these for the sound rather than the power gain but I totally agree that without a cold air feed they are next to useless as power mods.

The overall gains are always cumulative, just doing one mod will not add much at all but doing a few mods on different parts of the engine releases more power than the sum of all the other mods (if that makes sense!;))
 
Agree with most of it except the bit about induction kits.
Getting round the heat is no problem.
A good heat shield and a cold air feed will suffice.
Also just to point out Tuned Impreza's work better with a panel filter.
And also the point about ECU's is wrong.
Most cars ECU's nowadays take into account the air flow and temp and they do adjust themselves to a certain extent.
 
Agree with most of it except the bit about induction kits.
Getting round the heat is no problem.
A good heat shield and a cold air feed will suffice.
Also just to point out Tuned Impreza's work better with a panel filter.
And also the point about ECU's is wrong.
Most cars ECU's nowadays take into account the air flow and temp and they do adjust themselves to a certain extent.

All MAFS will compensate for airflow as that's exactly what they measure. Most now work on the pair of hot wires principle and will therefore deal with temperature and barometric pressure as well.
 
But they are still designed to run as lean as possible! your average family/shopping car is not designed in such a way as that it dumps loads more fuel in if the air intake is higher. it will self adjust, but not to any kind of extent as to be beneficial to performance. also, hot air is less dense than cold air, therefore less fuel is used to the equivalent amount of cold dense air, and thats physics, it is not an opinion!

also on the induction kit debate (and this is my last statement about them, the arguement has been had a million times on every car forum and the proof speaks for itself) even a heatshielded and cold air fed induction kit will not work as well as an enclosed panel filter with good cold air feed. FACT.
And i think you'll find i did indeed mention that even cars such as imprezas work better with enclosed filters.

:)
 
But they are still designed to run as lean as possible! your average family/shopping car is not designed in such a way as that it dumps loads more fuel in if the air intake is higher. it will self adjust, but not to any kind of extent as to be beneficial to performance. also, hot air is less dense than cold air, therefore less fuel is used to the equivalent amount of cold dense air, and thats physics, it is not an opinion!

also on the induction kit debate (and this is my last statement about them, the arguement has been had a million times on every car forum and the proof speaks for itself) even a heatshielded and cold air fed induction kit will not work as well as an enclosed panel filter with good cold air feed. FACT.
And i think you'll find i did indeed mention that even cars such as imprezas work better with enclosed filters.

:)

I totally agree with you. I've never bothered with induction kits on any car.

All enclosed intake panel filters are fed with cold air unless startup controls dictate otherwise. This is only done so that the engine reaches operating temperature swiftly. Once temps stabilise then there is nothing to be gained from drawing anything other than cold air.

Colder air is denser air, which means more mass oxygen per unit volume of air.

Once we get into the realms of forced induction the negligible benefits of an induction 'kit' seem even less likely.

So, what is it the message that you are trying to convey?
 
Ok, so iv seen in numerous places on this forum people talking about cone filters and back boxes making extra bhp... WRONG!

On the vast majority of "normal" (read none performance) vehicles, a cone filter will LOSE you power. This is due to the heat in the engine bay being sucked directly into the intake via the cone. On HIGH performance engines, ie skylines,impreza sti's, evo's (you get the idea) a cone filter can be used without a loss in power as the engine management is preset to take this into account.
your average car (clio,corsa,polo,escort,golf etc) is not. they are set from the factory to run slightly lean so as to provide better mpg/less emissions.

But they are still designed to run as lean as possible! your average family/shopping car is not designed in such a way as that it dumps loads more fuel in if the air intake is higher. it will self adjust, but not to any kind of extent as to be beneficial to performance. also, hot air is less dense than cold air, therefore less fuel is used to the equivalent amount of cold dense air, and thats physics, it is not an opinion!

also on the induction kit debate (and this is my last statement about them, the arguement has been had a million times on every car forum and the proof speaks for itself) even a heatshielded and cold air fed induction kit will not work as well as an enclosed panel filter with good cold air feed. FACT.
And i think you'll find i did indeed mention that even cars such as imprezas work better with enclosed filters.

:)


So am I reading wrong then because the first statement that is underlined says that impreza's and the rest work with a induction kit.
The point I am trying to make is that OEM airboxes are useless. And upgrade is what is needed. And all cars with an ecu and afm can compensate the same as say an Impreza and thats a Fact.
Most cars are detuned from the factory so the is room for improvement on most.
 
So what we need are performance airboxes without those vanes in them. The Carbon airbox would be a good fit then!
 
So am I reading wrong then because the first statement that is underlined says that impreza's and the rest work with a induction kit.
The point I am trying to make is that OEM airboxes are useless. And upgrade is what is needed. And all cars with an ecu and afm can compensate the same as say an Impreza and thats a Fact.
Most cars are detuned from the factory so the is room for improvement on most.



Love the way you've quoted and underlined the sentences that "prove" your point.... but YES, You are reading it wrong. Read the paragraph underneath where it says

"even high performance engines benefit from an enclosed airbox design, such as the k&n typhoon. but look at it this way, if you fully enclose a cone filter what have you got? an AIRBOX!"

And again you are missing the points im making,
yes SOME engines are de-tuned from the factory, but not all have scope for performance tuning. some engines, like the vauxhall corsa sport, have MASSIVE scope, as they were puposefully restricted by fitting restrictive inlet manifolds, this is NOT the case with the vast majority of small engined production cars.

OEM airboxes are not useless, people like yourself just dont understand how to improve them. As Xavier has said, removing the vanes inside of the airbox (smoothing) increases air flow. also, fitting a larger cold air feed again, increases air flow. what the standard box does BETTER than a cone, is shield the air being drawn into the engine from engine bay heat. the ONLY way to fully heatshield a cone filter is to ENCLOSE it, which like i said basically means you have created an airbox... cold air feeds are all well and good, but they do not guarante that it is only cold air that is drawn into the induction,the only way to do this is to...oh wait, enclose the induction system around the cold air feed.... cone filters do not do this!

Also, once again missing the point here TN, im not saying an ecu wont compensate for differing air conditions, what i am saying is that the ecu on a car such as a clio is aimed at running lean and providing low emissions and better MPG, not performance. fitting an induction kit sucking in warm air will not suddenly make the ecu think its a sports car. the ecu is set from the factory to work within certain parameters, these do not change without a remap. if the ecu was so adaptive from the factory, why would people need to remap them?

Like i said in my last post, im not going to get involved into another debate about induction kits.

If you want to believe that your induction kit really adds lots of power, you believe that.
 
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I think you are both agree to a large extent. I don't think TN is trying to "make you look stupid", he's not like that! As I read it he merely pointed out the part of your post he misread or didn't understand and found contradictory.

You both agree that an upgrade from OEM is preferable although the details will vary a lot from application to application.

Different cars in different states of tune will respond differently. The question is what is the best upgrade and the answer depends on the car and what has been done to it already and can't be discussed in such a general thread as this one.
 
not really, unless we are talking forced induction, an enclosed design is ALWAYS better. Its a Fact! why do you think someone like K&N spent so much money developing fully enclosed induction kits like the viper?and why does the viper or BMC's enclosed carbon make so much more power than a normal 57i type cone? its because they are enclosed, ie, NO hot air gets into them at all.

At the end of the day, opinions are like you know whats, everyones got one. but mine are born from facts and experience, not theorys or what some magazine said.
 
Courtenay Sport have it worked out perfectly to get the best from an air filter. Panel filter, cold air feed and drill the bottom half of the air box on the side thats away from the engine. I've gone down the route of cone filters in the past and definatly have to say that Panels with modded boxes are the better. My Calibra 2.5 about killed itself with too much air when I fitted a cone filter from K&N. It wasn't until I had the entire exhaust uprated to 3" staright through and sealed the Air filter in a box with cold feed from the front of the, that it then beifitted the gains. So agree toatally with the comments above.
 
So what we need are performance airboxes without those vanes in them. The Carbon airbox would be a good fit then!

or a cheaper way is to cut out the vanes and smooth the box yourself.

forced induction is different as the temp differences are only slight after being squeezed through the turbo.

will admit that i did look at full CAI for the Bora however doing lots of reading the gains were very similar to having smoothed the airbox and fitted a large cold air feed to the box
only real difference is the induction noise and unfortunately alot do subscribe to the belief that noise = power.

back boxes no, cat back yes but it depends on how restrictive the OEM exhaust is. and of course the cat is pretty restrictive as the emissions are getting harder to pass
 
This how I made my K&N work in the end on my last Calibra V6. I had to seal it with cold air feed from the front bumper and had custom piping made to enable to air to stay cooler from heat soak from the engine. I had to spend loads on the exhaust to get it all run right. Definatly stick with a panel filter and cold feed, loads less hasstle.

Sealed57i.jpg
 
Love the way you've quoted and underlined the sentences that "prove" your point.... but YES, You are reading it wrong. Read the paragraph underneath where it says

"even high performance engines benefit from an enclosed airbox design, such as the k&n typhoon. but look at it this way, if you fully enclose a cone filter what have you got? an AIRBOX!"

And again you are missing the points im making,
yes SOME engines are de-tuned from the factory, but not all have scope for performance tuning. some engines, like the vauxhall corsa sport, have MASSIVE scope, as they were puposefully restricted by fitting restrictive inlet manifolds, this is NOT the case with the vast majority of small engined production cars.

OEM airboxes are not useless, people like yourself just dont understand how to improve them. As Xavier has said, removing the vanes inside of the airbox (smoothing) increases air flow. also, fitting a larger cold air feed again, increases air flow. what the standard box does BETTER than a cone, is shield the air being drawn into the engine from engine bay heat. the ONLY way to fully heatshield a cone filter is to ENCLOSE it, which like i said basically means you have created an airbox... cold air feeds are all well and good, but they do not guarante that it is only cold air that is drawn into the induction,the only way to do this is to...oh wait, enclose the induction system around the cold air feed.... cone filters do not do this!

Also, once again missing the point here TN, im not saying an ecu wont compensate for differing air conditions, what i am saying is that the ecu on a car such as a clio is aimed at running lean and providing low emissions and better MPG, not performance. fitting an induction kit sucking in warm air will not suddenly make the ecu think its a sports car. the ecu is set from the factory to work within certain parameters, these do not change without a remap. if the ecu was so adaptive from the factory, why would people need to remap them?

Like i said in my last post, im not going to get involved into another debate about induction kits.

If you want to believe that your induction kit really adds lots of power, you believe that, but im afraid the simple fact is, your wrong.


Now what is that suppose to mean?
I give out an opinion in response to your opinion.

I never said a cone filter is better. I said OEM boxes are useless and need upgrading.
Now upgrading doesn't mean replacing the whole lot.I know how to improve an airbox and have done so many times in the past.

There is no need to get all wound up. All I am doing is voiceing my opinions.
 
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Opinions are what we thrive on. Please let's not get into a personal flame war here. Things sound much more harsh when typed in and it is easy for misunderstandings and disagreements to blow out of all proportion.

Rather than telling anyone off here or taking sides it is my aim to keep this as a positive discussion on the merits and drawbacks of induction kits. I've edited out what I consider to be potential attacks or flames in the name of keeping the peace.

One mans Fact is anothers opinion and it depends on the car it is applied to. I've seen cars gain power with induction kits just as I have seen them lose it. There are always going to be exceptions and this is where open debate comes in.
 
Agreed Waynne. We don't want to get like Pistonheads, now do we? It seemsto me that TN and PM are talking the same language, but one is American and the other English :)

As a slight aside, if we are using air boxes which take their air from outside the engine bay so are breathing the air we breathe, is a filter actually required? My Elan back in the 70s and my Robin Hood now both ran/run Weber DCOE 45s with trumpets and no filters with no (obvious) ill effects. I'm guessing that with forced induction engines the turbine is the vunerable part that needs protecting from even minute particulates. But what about N/A engines?
 
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Interesting thread, I guess this is aimed at the younger inexperienced owner/drivers on the forum and not so the ones who have the 'T-shirts' ;)

I spent some time working on induction designs and those developed ended up being sold to the BTCC, so know a thing or two. However, motorsport induction is a totally different animal where designs can be accomodated as the powerplant and ancillary equipment in a race car are somewhat different in layout to a road car.

An induction system for a production car is always a compromise as this tends to be one of the last items to be squeezed into the engine bay. Most aftermarket manufacturers and suppliers look for ways to improve the breathing and route into the engine. Again these are not always optimum but compromise.

As said any open cone in most cars is just a waste of time, it makes the youngsters happy. Those in the know will spend some time choosing a system that fits and works, doesn't need to be pretty.

As for ecu's, not all types can cater for small mods but some do have the ability to retard the timing but not advance it. Some can also alter the AFR by a small amount as this takes into account varying weather conditions.

For optimum induction a 'ram air' effect (or VECTIS) is the best, but in a real situation there is not enough room to execute this design. Even if you could accomplish this in a road car I doubt you could afford the ecu and extra sensors to monitor the burn conditions as this is similar to turbo charging in effect. I have seen the after effects of this on a 750 superbike after it expired, Cosworth had the remains of the psitons to analyse and the owner was told to wind the boost down....................only to be told it did not have a turbo fitted!

When modding a car to a point where it needs the ecu stretching it must be remapped or changed for a controller that can be custom programmed to suit the mods done and indeed have the scope for more. Afterall, what chip company offering of-the-shelf chips know what your car has with regards mods? A remap will be tailored to suit the mods and get the best out of it.

OG, I'm with you and ran my HSX Chevette on open trumpets at times with no ill effects, sounded awesome on those twin 48's :bigsmile:
 
good points guys. and yes stamford. i was aiming it at the younger dare i say it ill informed max power generation. not that i am much older myself!

as for running with no filter, i have done this too, and i didnt notice any ill effects either.
to be safe though, i ran with a piece of mesh covering the intake, with some tights behind it. no restriction, but no crap can get in either...
 
In defense of OEM air filters it all depends on the car in question. I have 106bhp engine in my Civic (D16Y7). I have the OEM air filter with the box on. IMO it would be pointless upgrading the air filter in favour of some sort of induction kit. 1. The engine is not capable of gaining much from the 'upgrade'. 2. The money spent on the modification will not give anything over 5 extra bhp. Money that could be put towards a B18! :D

The problem with induction kits is that they a commonly installed incorrectly. I.E. Too close to the engine. All this will do is suck in warm air, but commonly these types of installations are done purely for the noise made.
 
My MG for example had a figure of around 175 as standard. With a free flowing cat back exhaust, BMC CDA with good cold air feed and a decat upped this to 191. After a days running on a dyno this was maxxed to 200 by remapping the ecu to get the optimum AFR with those mods. I could have gained more but decided to stick to standard pump fuel and not the optimax type.

No two cars are ever the same and respond differently to certain mods. Indeed some standard equipment induction systems are probably no worse than an aftermarket version. Some manufacturers do not offer a kit as the OE one is that good. The only offering is an upgraded panel filter that just requires cleaning.

Any mod is uselss if not executed correctly and better still, if you have not declared it to your insurance company then why have them?

Right I'm off to buy a bank of electric superchargers and few resistors to get another 50bhp, then fold my rear seats down and up the stereo to gain another 10 ;)
 
good points guys. and yes stamford. i was aiming it at the younger dare i say it ill informed max power generation. not that i am much older myself!

as for running with no filter, i have done this too, and i didnt notice any ill effects either.
to be safe though, i ran with a piece of mesh covering the intake, with some tights behind it. no restriction, but no crap can get in either...


I'm gonna do this next year. Leave the airbox off and put a pair of tights over the end just to stop all the crap gettin in.
 
2 x :lol:

The only thing I would worry about getting in the air intake are metal fragments or particularly abrasive dust. These won't burn in the engine and can cause scoring, pitting and premature engine wear. I guess pretty much everything else will just burn up.
 
Some panel filters are a waste of time. They have a thick plastic lattace on the top which can restrict the surface area by around 20%. Don't get a cheap one.
 
i agree with pikey motersports.with what hes said. a cone filter and back box dont add any power what so ever they just make noise for show. also a cone filter can strangle the engine if there is not enough air going into the engine. ive done it before on one of my mates cars and would rev to 4000 then start splutering. when i put the stanard air box back on it worked fine. also it can destroy the air mass meter which will need replacing if it happens.
 
I wouldn't worry, a cold air intake feed would give more gains and be less hassle. On a highly tuned engine which is running hot it makes sense to wrap the exhaust to my mind. If there is not the problem there then don't fix it.
 
Most half decent cars have half decent cold air induction anyway. At least, the ones I've owned have been pretty well set up.

A cone filter under the bonnet is not remotely comparable.

I'd leave the drop in performance panel filters well alone, too. With OEM pleated paper ones being circa £5 (apart from VW, who I imagine want about fifty quid for one of these) it's better just to change them every 5000 miles or so.
 
tnx obi_waynne. i have been snooping around for a tuner for the ford fiesta mk7.5 2013 1.5 sport powershift ti-vct petrol n/a 112ps asian spec. all to na avail. you guys have any ideas?
 

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