Cold air upgrade/K&N intake system
#1
Racer
Thread Starter
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Considering a slight mod to the engine and see a couple things available. One is a cold air upgrade that installs under 20 minutes(says them), adds 11hp+ and increases airflow by 20%. The other is a K&N high-flow intake system with a 90 minute install(yeah right) adding 23hp+. Not mechanically inclined I am thinking the first option best although option 2 while only $75 more is a much more complicated install that might require my mechanic to do adding $$ to project. Any thoughts from owners who have experience with these products...suggestions.....
#2
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Ask yourself why Porsche didn't give you an additional 23 hp if it really worked.
Tuning intakes is not as simple as making air flow easier. It has to do with the speed of sound of air, distance between the valves and the inlet, rpm and resonance tuning. Less air flow resistance at low/medium rpm can result in lower torque.
The aftermarket solutions may have more power at some rpm, at some vehicle speed at some air density, but 11 or 23 hp is unlikely. You just want the look of a custom intake and that's ok. Otherwise a clean air filter may be just as useful.
Tuning intakes is not as simple as making air flow easier. It has to do with the speed of sound of air, distance between the valves and the inlet, rpm and resonance tuning. Less air flow resistance at low/medium rpm can result in lower torque.
The aftermarket solutions may have more power at some rpm, at some vehicle speed at some air density, but 11 or 23 hp is unlikely. You just want the look of a custom intake and that's ok. Otherwise a clean air filter may be just as useful.
#4
Instructor
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I bought a K&N ( used), installed it on my car. Had I CEL issue, turned not to be related to the K&N, but caused me grief. I ran with it for a while and decided to go back to stock. While the sound was there with the K&N I also have the Fister D mufflers so sound was not that big of a deal. I noticed no power increase at all, but then I didn't dyno it either.
#5
Rennlist Member
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I have the K&N kit. No issues. Install more like three hours. Not sure if getting any power but it sounds great with my Fabspeed cats. Make sure if you get it that you don't face the nut side of the bolts for the airbox towards the engine pulleys. There almost no clearance as it is. Don't oil the filter either. I read somewhere that that was a cause of some of the cel lights.
#6
Rennlist Member
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The oil from the K&N will increase your chances of a CEL.
This reminds me of a co-worker I had, who knew I was a "car guy". He got an intake for his Acura TL and used to always say something like "just got a new intake, my car is faster then yours now (my E46 M3)" I think I remember asking how much HP that amazing intake gave him, and he mentioned some crazy number like 45 HP or something. The guy was convinced... And funny thing was his last name was Faille (Ironic right?).
On many cars fitting an intake will actually lose power, unless your car has force induction and you can tune for it, best case scenario I'd say would be less HP than you can count on one hand. Most German cars already have very well designed intakes. The only cars I've seen benefit being N/A are larger displacement engines with lazy designs (think 90's American V8's).
As mentioned above make sure you go oil-less. One benefit I did not talk about is a moderate increase in sound. Don't expect to feel a power difference though...
This reminds me of a co-worker I had, who knew I was a "car guy". He got an intake for his Acura TL and used to always say something like "just got a new intake, my car is faster then yours now (my E46 M3)" I think I remember asking how much HP that amazing intake gave him, and he mentioned some crazy number like 45 HP or something. The guy was convinced... And funny thing was his last name was Faille (Ironic right?).
On many cars fitting an intake will actually lose power, unless your car has force induction and you can tune for it, best case scenario I'd say would be less HP than you can count on one hand. Most German cars already have very well designed intakes. The only cars I've seen benefit being N/A are larger displacement engines with lazy designs (think 90's American V8's).
As mentioned above make sure you go oil-less. One benefit I did not talk about is a moderate increase in sound. Don't expect to feel a power difference though...
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#8
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IMHO, the best solution is to keep the stock airbox (which is actually quite effective as a cold air intake) and use the stock filter. Replace the connector tube between the airbox and plenum with a silicon tube and cap off the resonator tube outlet with a 1.5" rubber cap and done. This gave me a wonderful intake noise at full throttle and if anything, smoothed out the power delivery just a tiny bit. See picture below...
These silicon hoses are inexpensive on eBay... About $20-$40 with the large hose clamps. Another $5 or less for the 1.5" cap and clamp. There are a few vendors selling the same setup for double and triple the price...
K&N filters themselves are pretty controversial. They definitely can increase air flow a bit, but have some problems. Primary problem is owners often don't know how much or how often to oil them... Over-oil them and they tend to leave deposits on the MAF sensor causing issues, under-oil them (or let them completely dry out) and they do a poor job of filtration. I'll run K&N's on moto's and older cars without MAF sensors, but don't run them on my 996.
![](http://photos.smugmug.com/photos/i-x35mzBn/0/L/i-x35mzBn-L.jpg)
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Hoguer62 (03-10-2021)
#10
Instructor
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Yes the oil in the K&N filter is to trap dirt. This issue is when you clean it for re-use and use too much oil when re-applying it. Use one if you like the look and the noise it makes.
#13
Nordschleife Master
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Benefits of the CAF are in the imagination of the beholder, rather than in reality.
My car came with one installed by the first owner. It was nothing but a pain in the *** for throwing check engine lights and trashing the MAF - that was with the factory oiling, and nothing I did.
In the end I got tired of the hassle and converted the car back to stock and discovered that it made zero difference to power or noise. Now, the noise thing might be because I also have an after-market exhaust system that sounds sweet.
If it's hassle you want, go for the CAF. If it's noise you want, go for a good exhaust. If it's power you want, go for a GT3.![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
BTW, I didn't even bother selling my K&N, I just threw it in the trash, as I didn't want any future owner being annoyed at me for selling them so much grief.
My car came with one installed by the first owner. It was nothing but a pain in the *** for throwing check engine lights and trashing the MAF - that was with the factory oiling, and nothing I did.
In the end I got tired of the hassle and converted the car back to stock and discovered that it made zero difference to power or noise. Now, the noise thing might be because I also have an after-market exhaust system that sounds sweet.
If it's hassle you want, go for the CAF. If it's noise you want, go for a good exhaust. If it's power you want, go for a GT3.
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
BTW, I didn't even bother selling my K&N, I just threw it in the trash, as I didn't want any future owner being annoyed at me for selling them so much grief.
#14
Race Director
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I love my V-flow intake. Does it make ANY extra power? Prolly not.
Have I had any MAF issues (except the one I had w/ the factory airbox and "vintage" 1999 MAF)? Nope.
Does it sound awesome? Yes, yes it does.
Have I had any MAF issues (except the one I had w/ the factory airbox and "vintage" 1999 MAF)? Nope.
Does it sound awesome? Yes, yes it does.
#15
Three Wheelin'
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I am skeptical of any significant horsepower gains, but a modified intake pipe can give you a wonderful intake sound. Especially full throttle at high RPM's.
IMHO, the best solution is to keep the stock airbox (which is actually quite effective as a cold air intake) and use the stock filter. Replace the connector tube between the airbox and plenum with a silicon tube and cap off the resonator tube outlet with a 1.5" rubber cap and done. This gave me a wonderful intake noise at full throttle and if anything, smoothed out the power delivery just a tiny bit. See picture below...
These silicon hoses are inexpensive on eBay... About $20-$40 with the large hose clamps. Another $5 or less for the 1.5" cap and clamp. There are a few vendors selling the same setup for double and triple the price...
K&N filters themselves are pretty controversial. They definitely can increase air flow a bit, but have some problems. Primary problem is owners often don't know how much or how often to oil them... Over-oil them and they tend to leave deposits on the MAF sensor causing issues, under-oil them (or let them completely dry out) and they do a poor job of filtration. I'll run K&N's on moto's and older cars without MAF sensors, but don't run them on my 996.
I agree about the horsepower, but Porsche also devotes quite a bit of engineering to regulatory compliance. Intake sound is a significant issue and the OEM airbox & plumbing is almost certainly designed to not only give good performance , but also meet sound and cost goals.
Great point... My intake sound was amazing before the muffler mod, but with louder fisterD style exhaust, it is mostly masked with exhaust note.
![](http://photos.smugmug.com/photos/i-x35mzBn/0/L/i-x35mzBn-L.jpg)
IMHO, the best solution is to keep the stock airbox (which is actually quite effective as a cold air intake) and use the stock filter. Replace the connector tube between the airbox and plenum with a silicon tube and cap off the resonator tube outlet with a 1.5" rubber cap and done. This gave me a wonderful intake noise at full throttle and if anything, smoothed out the power delivery just a tiny bit. See picture below...
These silicon hoses are inexpensive on eBay... About $20-$40 with the large hose clamps. Another $5 or less for the 1.5" cap and clamp. There are a few vendors selling the same setup for double and triple the price...
K&N filters themselves are pretty controversial. They definitely can increase air flow a bit, but have some problems. Primary problem is owners often don't know how much or how often to oil them... Over-oil them and they tend to leave deposits on the MAF sensor causing issues, under-oil them (or let them completely dry out) and they do a poor job of filtration. I'll run K&N's on moto's and older cars without MAF sensors, but don't run them on my 996.
I agree about the horsepower, but Porsche also devotes quite a bit of engineering to regulatory compliance. Intake sound is a significant issue and the OEM airbox & plumbing is almost certainly designed to not only give good performance , but also meet sound and cost goals.
Great point... My intake sound was amazing before the muffler mod, but with louder fisterD style exhaust, it is mostly masked with exhaust note.
![](http://photos.smugmug.com/photos/i-x35mzBn/0/L/i-x35mzBn-L.jpg)
pfbz what size are those clamps?