APS Cold Air Kit - Tuners views?
11 March 2005, 01:14 PM
#1
APS Cold Air Kit - Tuners views?
As above. I know it's been discussed before but not to any sort of a conclusion.
I know some have views it will decrease the engine output and others say its a good piece of kit that will flow enough air for 400bhp+
So whats the bottom line (assuming one gets a re-map)?
I know some have views it will decrease the engine output and others say its a good piece of kit that will flow enough air for 400bhp+
So whats the bottom line (assuming one gets a re-map)?
11 March 2005, 01:59 PM
#4
11 March 2005, 02:43 PM
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Testing Andy, T-uk & myself did (not all three of us were involved in all the tests, but some of us in all of them) in various 400-434 BHP states of tune on the 20G on 2.0 or 2.5 with or without fuel additives found no loss of power whatsoever (the Delta Dash plots were drawing over each other) between the APS CAK and various other permuations including a huge K&N on a short ram.
Additionally, on the iON turbo, on the same day, I could not find any difference in power between APS CAK with MAF sensor and large K&N on the end of an MRT inlet pipe. This tells me that on this setup with Optimax only, that the inlet tract that we were changing was not the bottleneck. My feeling is that the turbine wheel and housing, with consequent octane limitations were the bottlenecks.
One man's meat, another man's poison, or maybe different setups and measurement techniques?
Additionally, on the iON turbo, on the same day, I could not find any difference in power between APS CAK with MAF sensor and large K&N on the end of an MRT inlet pipe. This tells me that on this setup with Optimax only, that the inlet tract that we were changing was not the bottleneck. My feeling is that the turbine wheel and housing, with consequent octane limitations were the bottlenecks.
One man's meat, another man's poison, or maybe different setups and measurement techniques?
Last edited by john banks; 11 March 2005 at 02:47 PM.
11 March 2005, 02:54 PM
#7
Originally Posted by harvey
Fitting an APS cold air kit is a great idea if :
1) You wish to reduce your engine output.
2) You wish to increase the possibility of an engine mishap.
2) Chris Davies who was at G-Force, being an Australian had quite a lot of knowledge of APS products . I attended a rolling road day and wiped the floor with all other Subarus with something like 417 bhp. Chris suggested to me that the induction system might be strangling the engine.
A few days later I took the APS kit off, which incidentally was not a good fit in the first place, and after discussion with K+N replaced it with a larger filter, shorter inlet tract and segregated cold area for the filter to breathe in. I returned to G-Force and produced something like 434 bhp so 17 bhp for a filter change. Bob Rawle then mapped the car and I went back to G-Force to produce over 450 bhp. So something like 33 bhp from a filter change and remap. This all took place over a ten day period from my first to third visit to G-Force.
The filter that APS were using at that time was a GA RU - 3130. Believe it or not this is rated by K+N at only 185 bhp. I have no idea if this is the filter that APS still use but it does demonstrate what they are about.
Surely your best solution is to put the APS cold air kit in the bin, you could always sell the miniature filter to someone with a 150 bhp Nova and then do similar to what I have done for Alan Bell. You will get best power with a shorter inlet tract of suitable diameter, as straight as possible and on Alans car I used carbon fibre and insulation material to segregate an area between the chassis rail and inner wing so that it only could breathe cold air. Air was also encouraged into the inner wing and hence into the cold area. Why not have a word with Alan Bell.
If you want this sort of modification let me know.
If you are in any doubt as to the veracity of what I am telling you, why not contact K+N, Chris Davies or Bob Rawle. Andy will also be able to confirm most of this anyhow.
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12 March 2005, 09:01 AM
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You will find a number of people who like to develop their own bespoke components, and try to justify why their part is better than X-Y-Z parts.
However, in this instance, the filter on the APS pipe was well used, and was replaced with a brand new filter on a new inlet pipe. I've seen increases of as much as 15bhp when changing from a filter that is 9-12 months old to a new filter of the same type. This is where some of the dyno-proven 15bhp air filter claims come from - yet when you put the bits on the car there is no real difference.
I would tend to agree with John Banks findings. There are inlet restrictions in the system - but you are going to be at 430-450bhp before you find them.
If you fit the APS inlet pipe your mixture will run lean and you risk destroying your engine - absolutely 100% correct. Some APS dealers in the UK will be happy to sell you one and say there is no problem - as they would really like to take the 170 pounds off you. However this change to your inlet system flows a lot more air than the standard air-box, and you will run into problems immediately.
The truth about Subaru tuning is quite simple - the standard parts on the car are quite restrictive, and have been mapped that way by the manufacturer. So if you fit components to your car which don't dramatically alter boost and AFR limits and require a remap immediately, then the parts you are fitting are not much better than standard.
A simple change to exhaust, intercooling, induction and will reliably produce 100 bhp over standard (based on an '03 Sti). However if you don't remap the ecu at the same time it will end in spectacular fashion.
Cheers,
Chris Davies
WRC Technologies
However, in this instance, the filter on the APS pipe was well used, and was replaced with a brand new filter on a new inlet pipe. I've seen increases of as much as 15bhp when changing from a filter that is 9-12 months old to a new filter of the same type. This is where some of the dyno-proven 15bhp air filter claims come from - yet when you put the bits on the car there is no real difference.
I would tend to agree with John Banks findings. There are inlet restrictions in the system - but you are going to be at 430-450bhp before you find them.
If you fit the APS inlet pipe your mixture will run lean and you risk destroying your engine - absolutely 100% correct. Some APS dealers in the UK will be happy to sell you one and say there is no problem - as they would really like to take the 170 pounds off you. However this change to your inlet system flows a lot more air than the standard air-box, and you will run into problems immediately.
The truth about Subaru tuning is quite simple - the standard parts on the car are quite restrictive, and have been mapped that way by the manufacturer. So if you fit components to your car which don't dramatically alter boost and AFR limits and require a remap immediately, then the parts you are fitting are not much better than standard.
A simple change to exhaust, intercooling, induction and will reliably produce 100 bhp over standard (based on an '03 Sti). However if you don't remap the ecu at the same time it will end in spectacular fashion.
Cheers,
Chris Davies
WRC Technologies
12 March 2005, 09:19 AM
#9
Ecu Specialist
Personally I wouldn't use an APS CAK , the filter is too small, as soon as I removed it from my STi5 (three years back I think) things got much better.
John you probably didn't see any change because something else was limiting to that level I would think.
Chris the truth is that the 80mm dia APS pipe causes dangerously lean running, the smaller diameter one also has issues in this respect although not as great, its not all about pipe diameter though, there are other issues with its design which should preclude it being a bolt on upgrade without remapping.
The filter is a K & N one, there is no need to change these they can be cleaned easily, prepared to be suprised by how much caked on grime there is as the inner wing is not the cleanest area.
I've seen do it yourself setups that are better as well.
cheers
bob
John you probably didn't see any change because something else was limiting to that level I would think.
Chris the truth is that the 80mm dia APS pipe causes dangerously lean running, the smaller diameter one also has issues in this respect although not as great, its not all about pipe diameter though, there are other issues with its design which should preclude it being a bolt on upgrade without remapping.
The filter is a K & N one, there is no need to change these they can be cleaned easily, prepared to be suprised by how much caked on grime there is as the inner wing is not the cleanest area.
I've seen do it yourself setups that are better as well.
cheers
bob
12 March 2005, 10:04 AM
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Bob,
Had you remapped your STi 5 with the APS kit, or fitted it then removed it?
As mentioned in my post - you can't fit the APS kit without remapping the ecu - so I'm not sure what you're getting at regarding the 80mm pipe and lean running. There are other APS dealers who will try to convince owners that they are ok to use without re-mapping - but this is not the case.
I feel the caked on grime on the APS filter was the main reason for the big bhp increase when Harvey changed his filter - perhaps not entirely due to the modified induction kit re-fitted.
cheers
chris
Had you remapped your STi 5 with the APS kit, or fitted it then removed it?
As mentioned in my post - you can't fit the APS kit without remapping the ecu - so I'm not sure what you're getting at regarding the 80mm pipe and lean running. There are other APS dealers who will try to convince owners that they are ok to use without re-mapping - but this is not the case.
I feel the caked on grime on the APS filter was the main reason for the big bhp increase when Harvey changed his filter - perhaps not entirely due to the modified induction kit re-fitted.
cheers
chris
12 March 2005, 03:11 PM
#11
Bob's
Your not going to silly power so the APS filter is fine for you. Plus you are looking at remapping and other mods - so not in isolation
When I changed the APS to a large K&N in the wing we added quite a lot of extra fuel to the map - but on re-runs at both Powerstation and G Force (both on the same days the results showed losses compared to the APS pipe!)
With APS - 415 at PS and 419 at G Force
With K&N - 399 at PS and 407 at G Force
(Interesting that the so called prudent rollers at PS are comparable to the well respected G Force onces - and incidentally as I've done about 40 power runs in the last few years the number at PS on the first run equates to about 470 bhp at Well Lane! - but thats a different matter!)
It really depends on configurations - I had the TD05/06 which clearly was the issue in my system - i.e. limiting factor - its fine for people who want to achieve say 370-380bhp on Optimax and Booster on standard internals maybe but not on an uprated engine)
With the Turbo I run now I would probably not be comfortable running an APS filter as the likelihood is that it would be restrictive
But we are talking powers in excess of 400bhp
I have had two other airfilters on my car (in addition to k&n and APS)
1. Blitz - total ****e - it destroyed my VF22 Turbo - by allowing fine grains in
2. HKS - better than Blitz but too small
3. APS - better as it was in the wing and much cooler
4. K&N - from a NorthEast supplier - dont have any concerns other than its in the engine bay so is hot!! - I need to get some cold air to it ideally
(But need to sort out other engine problems out first!)
Your not going to silly power so the APS filter is fine for you. Plus you are looking at remapping and other mods - so not in isolation
When I changed the APS to a large K&N in the wing we added quite a lot of extra fuel to the map - but on re-runs at both Powerstation and G Force (both on the same days the results showed losses compared to the APS pipe!)
With APS - 415 at PS and 419 at G Force
With K&N - 399 at PS and 407 at G Force
(Interesting that the so called prudent rollers at PS are comparable to the well respected G Force onces - and incidentally as I've done about 40 power runs in the last few years the number at PS on the first run equates to about 470 bhp at Well Lane! - but thats a different matter!)
It really depends on configurations - I had the TD05/06 which clearly was the issue in my system - i.e. limiting factor - its fine for people who want to achieve say 370-380bhp on Optimax and Booster on standard internals maybe but not on an uprated engine)
With the Turbo I run now I would probably not be comfortable running an APS filter as the likelihood is that it would be restrictive
But we are talking powers in excess of 400bhp
I have had two other airfilters on my car (in addition to k&n and APS)
1. Blitz - total ****e - it destroyed my VF22 Turbo - by allowing fine grains in
2. HKS - better than Blitz but too small
3. APS - better as it was in the wing and much cooler
4. K&N - from a NorthEast supplier - dont have any concerns other than its in the engine bay so is hot!! - I need to get some cold air to it ideally
(But need to sort out other engine problems out first!)
12 March 2005, 06:57 PM
#12
Ecu Specialist
Chris ... LOL
I think you could say I had remapped it just a tad.
Don't think Harvey mentioned caked on grime did he ? That was me, and I didn't say I suffered from that effect, just that the kit does if not regularly inspected and cleaned. the 80 mm kit shopuld be sold with a public health warning, caused a few engine problems to the uninformed it has.
bob
I think you could say I had remapped it just a tad.
Don't think Harvey mentioned caked on grime did he ? That was me, and I didn't say I suffered from that effect, just that the kit does if not regularly inspected and cleaned. the 80 mm kit shopuld be sold with a public health warning, caused a few engine problems to the uninformed it has.
bob
Last edited by Bob Rawle; 12 March 2005 at 07:02 PM.
12 March 2005, 07:55 PM
#13
just had my car remapped with an APS CAK and an MRT induction hose, the filter on the APS is the exact size as the K&N induction filter so when i swapped i had the same size filter on 
but once mapped the difference in acceleration was extremely noticeable 
but once mapped the difference in acceleration was extremely noticeable
Last edited by stevebt; 12 March 2005 at 08:00 PM.
12 March 2005, 09:33 PM
#14
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My 434 BHP and 395 lbft was run through an APS CAK that had run two Scottish winters and nearly 20000 miles and had never been removed or cleaned, and was achieved at 1.25 bar with 90% optimax/10% methanol using parts from the Subaru parts bin as follows - turbine wheel, turbine housing, short motor, heads with some porting work, mostly assembled by a farmer, OEM ECU remapped by a doctor I didn't gain any power at all switching to a much larger K&N on a short ram, for good measure I squeezed this large K&N back in the wing on the end of the APS cast elbow because the original APS item looked dirty, not because there was any gain in performance. Looking at the other twists and turns from atmosphere to inlet ports, and measuring various parameters, I don't think this elbow is a problem at this level. The filter looks dinky, but in my case that was only a psychological objection. Maybe aiming for 500 BHP is a problem, but so is a bolt on turbo and pump fuel IMHO.
I didn't gain any power at all switching to a much larger K&N on a short ram, for good measure I squeezed this large K&N back in the wing on the end of the APS cast elbow because the original APS item looked dirty, not because there was any gain in performance. Looking at the other twists and turns from atmosphere to inlet ports, and measuring various parameters, I don't think this elbow is a problem at this level. The filter looks dinky, but in my case that was only a psychological objection. Maybe aiming for 500 BHP is a problem, but so is a bolt on turbo and pump fuel IMHO.
13 March 2005, 01:46 PM
#15
Fang: I'm sticking with the APS myself as I am satisfied with the comments made....
but just wanted to clarify for the general SN community whether or not it is a 400bhp+ filter as many respected people have said or whether it should be "put in the bin as it only fit for a 150bhp nova....
Bob
but just wanted to clarify for the general SN community whether or not it is a 400bhp+ filter as many respected people have said or whether it should be "put in the bin as it only fit for a 150bhp nova....
Bob
13 March 2005, 01:55 PM
#16
Bob's - no probs
Doubt you'll be disappointed
Interesting that I never cleaned the APS - never had to - you dont get too much crap on it within the inner wing arch - or rather you shouldn't
Also the K&N that I replaced is circa twice the size of the APS in wing kit
Doubt you'll be disappointed
Interesting that I never cleaned the APS - never had to - you dont get too much crap on it within the inner wing arch - or rather you shouldn't
Also the K&N that I replaced is circa twice the size of the APS in wing kit
14 March 2005, 02:07 AM
#17
Chris : It was your comments in the first place that caused me to try an alternative to the APS CAK following a run on the rollers, conducted by you at G-Force.
"You will find a number of people who like to develop their own bespoke components, and try to justify why their part is better than X-Y-Z parts."
That was clearly aimed at me but I have no need to justify any parts I have developed. Some work and some do not and are discarded but the knowledge is retained. Sometimes results are contrary to expected. My development work is for my own benefit, to achieve acceptable power figures and not motivated by any wish or need to sell parts. The finding out is the interesting part for me, even when the result is not as anticipated. I have simply shared my findings.
"However, in this instance, the filter on the APS pipe was well used, and was replaced with a brand new filter on a new inlet pipe"
The CAK had been on the car for some time but the filter had been replaced during its life in the inner wing at least once and I know it will have been cleaned, using K+N cleaning fluid on several occassions.
"I feel the caked on grime on the APS filter was the main reason for the big bhp increase when Harvey changed his filter - perhaps not entirely due to the modified induction kit re-fitted"
As the filter was in the inner wing you are not in a position to comment on its condition.
Anyway, thanks for the comment which resulted in the single biggest power increase for the least expenditure on that particular engine.
The fact that others did not get similar power gains indicates, IMHO, that they were restricted in other areas, exactly the opinion formed separately by Bob.(Rawle).
The APS CAK serves a purpose for moderately tuned cars, however it should be sold with a very clear warning. Failure to rescale the MAF signal on fitting the CAK CAN result in sufficiently weakened AFRs to result in serious engine damage. This warning should appear on the packaging, without the need for any dealer verbal warning. APS know the problem exists.
Bob'5 "but just wanted to clarify for the general SN community whether or not it is a 400bhp+ filter as many respected people have said or whether it should be "put in the bin as it only fit for a 150bhp nova....
Bob"
Rather than rely on the pundits and respected people on S/Net for an opinion on a K+N filter why not ask the manufacturer for their rating for the filter in question. Afterall, they have extensive test and R & D facilities and might just know a little bit more about filters than the "experts"
Fangoria/Steve. "(Interesting that the so called prudent rollers at PS are comparable to the well respected G Force onces - and incidentally as I've done about 40 power runs in the last few years the number at PS on the first run equates to about 470 bhp at Well Lane! - but thats a different matter!)"
A considerable exaggeration as your own results will show, if they were done in controlled circumstances and carefully documented.
"You will find a number of people who like to develop their own bespoke components, and try to justify why their part is better than X-Y-Z parts."
That was clearly aimed at me but I have no need to justify any parts I have developed. Some work and some do not and are discarded but the knowledge is retained. Sometimes results are contrary to expected. My development work is for my own benefit, to achieve acceptable power figures and not motivated by any wish or need to sell parts. The finding out is the interesting part for me, even when the result is not as anticipated. I have simply shared my findings.
"However, in this instance, the filter on the APS pipe was well used, and was replaced with a brand new filter on a new inlet pipe"
The CAK had been on the car for some time but the filter had been replaced during its life in the inner wing at least once and I know it will have been cleaned, using K+N cleaning fluid on several occassions.
"I feel the caked on grime on the APS filter was the main reason for the big bhp increase when Harvey changed his filter - perhaps not entirely due to the modified induction kit re-fitted"
As the filter was in the inner wing you are not in a position to comment on its condition.
Anyway, thanks for the comment which resulted in the single biggest power increase for the least expenditure on that particular engine.
The fact that others did not get similar power gains indicates, IMHO, that they were restricted in other areas, exactly the opinion formed separately by Bob.(Rawle).
The APS CAK serves a purpose for moderately tuned cars, however it should be sold with a very clear warning. Failure to rescale the MAF signal on fitting the CAK CAN result in sufficiently weakened AFRs to result in serious engine damage. This warning should appear on the packaging, without the need for any dealer verbal warning. APS know the problem exists.
Bob'5 "but just wanted to clarify for the general SN community whether or not it is a 400bhp+ filter as many respected people have said or whether it should be "put in the bin as it only fit for a 150bhp nova....
Bob"
Rather than rely on the pundits and respected people on S/Net for an opinion on a K+N filter why not ask the manufacturer for their rating for the filter in question. Afterall, they have extensive test and R & D facilities and might just know a little bit more about filters than the "experts"
Fangoria/Steve. "(Interesting that the so called prudent rollers at PS are comparable to the well respected G Force onces - and incidentally as I've done about 40 power runs in the last few years the number at PS on the first run equates to about 470 bhp at Well Lane! - but thats a different matter!)"
A considerable exaggeration as your own results will show, if they were done in controlled circumstances and carefully documented.
14 March 2005, 01:45 PM
#19
Have hosted it here:
http://i2.photobucket.com/albums/y4/.../KNFilters.jpg
Its all well and good looking at the manufacturers figures, which, if accurate would mean that APS supply the wrong filter with the kit. It has however been tried and tested to twice the manufacturers claims without being a bottle-neck.
Bob
http://i2.photobucket.com/albums/y4/.../KNFilters.jpg
Its all well and good looking at the manufacturers figures, which, if accurate would mean that APS supply the wrong filter with the kit. It has however been tried and tested to twice the manufacturers claims without being a bottle-neck.
Bob
14 March 2005, 04:56 PM
#20
Your logic somewhat defies me. I proved that the filter and CAK were a constriction when I went from 417bhp to 432 bhp with no other change whatsoever. That became 450bhp after Bob Rawle mapped the car. Again with no other changes whatsoever, on the same rollers, same fuel, all within a ten day period and all RR printouts, notes etc retained.
The fact that others could not emulate that result indicates to me and others that they had other issues restricting potential power delivery and did not have the same need for high volume air. For instance, what cams were they running.
It is obviously possible to produce more power than the rated filter output but at some point the filter becomes a constriction and the more power produced on the same filter/CAK the greater the constriction becomes.(Hence my 33 bhp gain)
The figure quoted for the filter is from naturally asperated testing and on a turbocharged set up the fiter capacity will be somewhat more. I did not know the filter rated capacity until it was suggested I look at possible improvements in that area.
From my own results, testing and notes, I believe that the APS CAK was a definate restriction from somewhere between 325 and 350bhp.
"Its all well and good looking at the manufacturers figures, which, if accurate would mean that APS supply the wrong filter with the kit."
APS supply a filter that is small enough to go on the end of their kit within the confines of the inner wing and suit their purpose.
APS are a company who denied there was a problem with their CAKs over three years ago.
APS are a company who knew, three years ago at least, that there were potential problems with their kits.
You have just purchased one of these kits. Is there a prominent warning on it, advising that the MAF needs rescaling at the time of fitment to avoid the engine damage that can occur because the signal to the ECU is erronious, resulting in weak running.
The only reason the CAK stayed on my car for so long was that with the Link I was not running a MAF unit. These kits might be OK up to the low 300s IF proper remapping is undertaken but beyond that level the engine inefficiency will increase.
I have simply reported my findings in the hope that I help unsuspecting fellow Scooby owners avoid a needlessly blown engine or an unnecessary cap on performance. If you prefer the sales blurb from APS (which you have bought) or wish to read into what you have read on here as proof "It has however been tried and tested to twice the manufacturers claims without being a bottle-neck." that is up to you but others may be a little more circumspect.
The fact that others could not emulate that result indicates to me and others that they had other issues restricting potential power delivery and did not have the same need for high volume air. For instance, what cams were they running.
It is obviously possible to produce more power than the rated filter output but at some point the filter becomes a constriction and the more power produced on the same filter/CAK the greater the constriction becomes.(Hence my 33 bhp gain)
The figure quoted for the filter is from naturally asperated testing and on a turbocharged set up the fiter capacity will be somewhat more. I did not know the filter rated capacity until it was suggested I look at possible improvements in that area.
From my own results, testing and notes, I believe that the APS CAK was a definate restriction from somewhere between 325 and 350bhp.
"Its all well and good looking at the manufacturers figures, which, if accurate would mean that APS supply the wrong filter with the kit."
APS supply a filter that is small enough to go on the end of their kit within the confines of the inner wing and suit their purpose.
APS are a company who denied there was a problem with their CAKs over three years ago.
APS are a company who knew, three years ago at least, that there were potential problems with their kits.
You have just purchased one of these kits. Is there a prominent warning on it, advising that the MAF needs rescaling at the time of fitment to avoid the engine damage that can occur because the signal to the ECU is erronious, resulting in weak running.
The only reason the CAK stayed on my car for so long was that with the Link I was not running a MAF unit. These kits might be OK up to the low 300s IF proper remapping is undertaken but beyond that level the engine inefficiency will increase.
I have simply reported my findings in the hope that I help unsuspecting fellow Scooby owners avoid a needlessly blown engine or an unnecessary cap on performance. If you prefer the sales blurb from APS (which you have bought) or wish to read into what you have read on here as proof "It has however been tried and tested to twice the manufacturers claims without being a bottle-neck." that is up to you but others may be a little more circumspect.
14 March 2005, 05:17 PM
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A little info to add into the blend...
To my knowledge the two highest TD05 and 20G cars that have run at Dastek so far were both running APS CAKs with the dinky filter.
At Star, APS CAK TD05 result was 358 (this is 2nd best TD05, best on TD05 here 369 Andy F), APS CAK 20G 434 BHP (this is 2nd best on 20G here 440 Andy F). It is no shame being second best to Andy F
To my knowledge the two highest TD05 and 20G cars that have run at Dastek so far were both running APS CAKs with the dinky filter.
At Star, APS CAK TD05 result was 358 (this is 2nd best TD05, best on TD05 here 369 Andy F), APS CAK 20G 434 BHP (this is 2nd best on 20G here 440 Andy F). It is no shame being second best to Andy F
14 March 2005, 06:02 PM
#22
No restriction with APS on mine - or rather - there may have been - as Harvey et al have stated I could not determine as the restriction was the td05/06 - had I had a larger turbo on then yes maybe this would have shown the aps to be a restriction
(I have been several times to Powerstation and then gone the next day to Well Lane
Differences in power varied from 45bhp to 61bhp (on the 4 occassions that I have done the comparisons - 3 have been the next day, with no modification changes at all) - of course temperatures can account for differences........
I have also experienced similar differences on a similarly powered (e.g. 420bhp)an Escort Cosworth between Well Lane and Interpro...............)
I am glad that occasionally I do go to RR's as recent runs at PE and G Force (more so at G force) confirmed I had issues with the engine
(I have been several times to Powerstation and then gone the next day to Well Lane
Differences in power varied from 45bhp to 61bhp (on the 4 occassions that I have done the comparisons - 3 have been the next day, with no modification changes at all) - of course temperatures can account for differences........
I have also experienced similar differences on a similarly powered (e.g. 420bhp)an Escort Cosworth between Well Lane and Interpro...............)
I am glad that occasionally I do go to RR's as recent runs at PE and G Force (more so at G force) confirmed I had issues with the engine
14 March 2005, 07:16 PM
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Rather than rely on the pundits and respected people on S/Net for an opinion on a K+N filter why not ask the manufacturer for their rating for the filter in question. Afterall, they have extensive test and R & D facilities and might just know a little bit more about filters than the "experts"
15 March 2005, 11:48 AM
#24
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Originally Posted by john banks
A little info to add into the blend...
To my knowledge the two highest TD05 and 20G cars that have run at Dastek so far were both running APS CAKs with the dinky filter.
To my knowledge the two highest TD05 and 20G cars that have run at Dastek so far were both running APS CAKs with the dinky filter.
The test we done (removing it completely and gaining zilch) on JB's car proved that beyond doubt to me.
Rolling roads can be misleading at times, my RA on a 20g still using a std exhaust manifold went from 417bhp to 432bhp at Well Lane just by letting some air out the tyres !!
Andy
15 March 2005, 03:07 PM
#25
From the comments made it is quite clear (to me at least) that the APS CAK is not a restriction to well past 400bhp.
If it can flow anything a TD05/06-20g can pull through it then it most certainly isn't a "185bhp filter, good for only 150bhp Novas....and should be binned...."
Harvey, I am however grateful re: maf re-scaling, as the APS distributors seem insistant that it is just a 'plug and go' and doesnt require a re-map (which obviously seems not to be the case).
Bob
If it can flow anything a TD05/06-20g can pull through it then it most certainly isn't a "185bhp filter, good for only 150bhp Novas....and should be binned...."
Harvey, I am however grateful re: maf re-scaling, as the APS distributors seem insistant that it is just a 'plug and go' and doesnt require a re-map (which obviously seems not to be the case).
Bob
16 March 2005, 11:37 AM
#26
The official line from APS re: the filters:
"Our comments are that K & N (obviously), have to rate their filters for
worst case scenario. i.e. normally aspirated.
We have run WRX engines to 400 flywheel H.P., with / without this filter.
So long as it is clean, no difference in power."
Bob
"Our comments are that K & N (obviously), have to rate their filters for
worst case scenario. i.e. normally aspirated.
We have run WRX engines to 400 flywheel H.P., with / without this filter.
So long as it is clean, no difference in power."
Bob
17 March 2005, 03:35 AM
#28
Andy : I am afraid we are going to have to disagree on this. I did not expect to pick up the gains I did. I did not know the rating of the K+N filter when it was suggested I change it and as filter manufacturers, I think K+N are likely to know a thing or two about air flow and filtration. I discussed what I was proposing to do with K+N at the time.
The only changes were as reported on the same rollers in as near similar conditions as possible in a brief timescale. These were specific results that had a signifigance at the time so the details were well documented and my observations were honest and accurate.
You yourself are using rolling road figures for comparative testing where far smaller gains will be signifigant.
I am not saying that the filter in question cannot pass more air than it is rated for. I am happy that it will be restrictive beyond its rated cfm/bhp flow as assessed by the manufacturer.
Removing the air filter and gaining nothing is hardly surprising. With no filter in place there would be a substantial weakening in AFRs and without a remap that test is far from valid.
What dinky filter produced what power at Dastek or Star is not relevant. I accept the figures above. The engine can suck in air beyond the rated filter capacity once it has started to become a restriction.
To be relevant you would need to try a larger filter along with a remap to suit the new conditions.
Referring to APS:
Bob5 " "Our comments are that K & N (obviously), have to rate their filters for
worst case scenario. i.e. normally aspirated.
We have run WRX engines to 400 flywheel H.P., with / without this filter.
So long as it is clean, no difference in power."
I do not put a lot of store in what APS have to say. Remember this is the same company that denied there was a potential engine damage problem when fitting their CAK without a recalibration of the MAF Sensor. This is a company selling a product with potential for substantial engine damage and by your own admission, their dealer does not admit that it is other than plug and go. APS have also denied any knowledge of specific engine damage relating to the fitment of one of their kits. You will understand my scepticism at the quote above.
Bob5: From your comment above do I take it that there is still no clear warning on the packaging for the APS CAK?
I am glad that you were alerted to the need to get your MAF sensor rescaled BEFORE it cost you a major engine build. Others have not been so fortunate.
So here is the word from the filter manufacturer direct.
" The filter in question is rated at 185bhp in naturally aspirated applications. For turbocharged cars we would expect it to operate satisfactorily at up to 80% more than the N/A figure. The higher the airflow above the rated capacity the greater the pressure drop"
So by my maths, on a Subaru, that filter becomes restrictive around 333bhp. I think that is around my assessment on my own engine.
If that is around your power aspiration Bob you should be OK if the recalibration has been done. Sorry if I have alarmed you but I stick 100% by the accuracy of my own findings and I have regard for K+Ns technical competance.
Clearly you guys that think these filters are good for 400 + bhp have no need to change them. Obviously we can all see what filters everybody else is running at RR days etc.
The only changes were as reported on the same rollers in as near similar conditions as possible in a brief timescale. These were specific results that had a signifigance at the time so the details were well documented and my observations were honest and accurate.
You yourself are using rolling road figures for comparative testing where far smaller gains will be signifigant.
I am not saying that the filter in question cannot pass more air than it is rated for. I am happy that it will be restrictive beyond its rated cfm/bhp flow as assessed by the manufacturer.
Removing the air filter and gaining nothing is hardly surprising. With no filter in place there would be a substantial weakening in AFRs and without a remap that test is far from valid.
What dinky filter produced what power at Dastek or Star is not relevant. I accept the figures above. The engine can suck in air beyond the rated filter capacity once it has started to become a restriction.
To be relevant you would need to try a larger filter along with a remap to suit the new conditions.
Referring to APS:
Bob5 " "Our comments are that K & N (obviously), have to rate their filters for
worst case scenario. i.e. normally aspirated.
We have run WRX engines to 400 flywheel H.P., with / without this filter.
So long as it is clean, no difference in power."
I do not put a lot of store in what APS have to say. Remember this is the same company that denied there was a potential engine damage problem when fitting their CAK without a recalibration of the MAF Sensor. This is a company selling a product with potential for substantial engine damage and by your own admission, their dealer does not admit that it is other than plug and go. APS have also denied any knowledge of specific engine damage relating to the fitment of one of their kits. You will understand my scepticism at the quote above.
Bob5: From your comment above do I take it that there is still no clear warning on the packaging for the APS CAK?
I am glad that you were alerted to the need to get your MAF sensor rescaled BEFORE it cost you a major engine build. Others have not been so fortunate.
So here is the word from the filter manufacturer direct.
" The filter in question is rated at 185bhp in naturally aspirated applications. For turbocharged cars we would expect it to operate satisfactorily at up to 80% more than the N/A figure. The higher the airflow above the rated capacity the greater the pressure drop"
So by my maths, on a Subaru, that filter becomes restrictive around 333bhp. I think that is around my assessment on my own engine.
If that is around your power aspiration Bob you should be OK if the recalibration has been done. Sorry if I have alarmed you but I stick 100% by the accuracy of my own findings and I have regard for K+Ns technical competance.
Clearly you guys that think these filters are good for 400 + bhp have no need to change them. Obviously we can all see what filters everybody else is running at RR days etc.
Last edited by harvey; 17 March 2005 at 03:44 AM.
17 March 2005, 08:54 AM
#29
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Originally Posted by harvey
Andy : I am afraid we are going to have to disagree on this. Removing the air filter and gaining nothing is hardly surprising. With no filter in place there would be a substantial weakening in AFRs and without a remap that test is far from valid.
The point i was making about well lane rollers is that I have found them inconsistant on my own car. Also the last car I mapped on a 20G went there recently and had a number of different results anywhere between 360 and 407 bhp ??? All on the same day, same spec.
On Johns car he has on board wideband O2 monitoring, there was no change in AFR value, with or without the filter, also no change in boost response which you would expect if you had removed a restriction in the inlet.
Andy
17 March 2005, 09:17 AM
#30
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Originally Posted by Andy.F
Rolling roads can be misleading at times, my RA on a 20g still using a std exhaust manifold went from 417bhp to 432bhp at Well Lane just by letting some air out the tyres !!
Andy
Andy
martin