induction kit for classic
15 May 2009, 08:57 AM
#1
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
induction kit for classic
whats the best induction kit for a classic 93-96 , id like to do away with the resernator box and have it as close to the inner-wing air intake as possible.
tell me what your using !!
cheers carl
tell me what your using !!
cheers carl
15 May 2009, 09:38 AM
#6
Scooby Regular
Join Date: Jun 2006
Location: Scotland
Posts: 154
Likes: 0
Received 0 Likes
on
0 Posts
Unless your going for BIG power upgrades, turbo remap etc... you will not gain anything from ditching the existing airbox.
Ditch the resonator from the wing & slap in a decent panel filter as suggested & you'll gain a nice but slight increase in induction noise ( & percieved power ! ) with no downside.
even with extra vents in your bonnet & an ally heat shield the mushroom style induction kits are really only for looks, & the mean temp of you inlet air is still going to be higher than the air in the wing, but if thats your bag then go for it !
! but make sure you MAF is well supported or the additional vibration will probably kill it. which aint so pleasing.....
all above IMHO of course ( tried both, went back to standard airbox mostly cause the mushrooms looked too "MAX POWER" for me ). but then I am ancient....... & should probably know better !
Ditch the resonator from the wing & slap in a decent panel filter as suggested & you'll gain a nice but slight increase in induction noise ( & percieved power ! ) with no downside.
even with extra vents in your bonnet & an ally heat shield the mushroom style induction kits are really only for looks, & the mean temp of you inlet air is still going to be higher than the air in the wing, but if thats your bag then go for it !
! but make sure you MAF is well supported or the additional vibration will probably kill it. which aint so pleasing.....all above IMHO of course ( tried both, went back to standard airbox mostly cause the mushrooms looked too "MAX POWER" for me ). but then I am ancient....... & should probably know better !
15 May 2009, 11:39 AM
#7
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
ok what about using the standard airbox with good pannel filter as i am and running at the moment then running a cold air feed pipe from the front of the car and cutting a large hole say 70mm diammeter in the air box , i have a spare to try it . surely the more air getting in the better !!.
its nothing to do with induction noise as im getting on for ancient aswell
its nothing to do with induction noise as im getting on for ancient aswell
Trending Topics
15 May 2009, 10:54 PM
#12
Using aluminium to make a heat shield is not the best move as aluminium is a good conductor of heat. Use a sheet of carbon fibre or even plastic.
The APS CAK filter is rated at 309 bhp by K+N so if you want much more than 320 bhp the APS CAK will be restrictive.
On 97-00 cars best stay with the OE airbox to around 340-350 bhp.
On 93-96 cars it is worth going with a cone filter a bit earlier and you can make a heat divider.
Note the bonnet vent is usually blanked off and that is for a reason. If you remove the blank you can actually increase under bonnet temperatures, not reduce them.
The APS CAK filter is rated at 309 bhp by K+N so if you want much more than 320 bhp the APS CAK will be restrictive.
On 97-00 cars best stay with the OE airbox to around 340-350 bhp.
On 93-96 cars it is worth going with a cone filter a bit earlier and you can make a heat divider.
Note the bonnet vent is usually blanked off and that is for a reason. If you remove the blank you can actually increase under bonnet temperatures, not reduce them.
16 May 2009, 12:49 AM
#13
Scooby Senior
iTrader: (1)
Join Date: Nov 2000
Location: Wildberg, Germany/Reading, UK
Posts: 9,706
Likes: 0
Received 73 Likes
on
54 Posts
Using aluminium to make a heat shield is not the best move as aluminium is a good conductor of heat. Use a sheet of carbon fibre or even plastic.
The APS CAK filter is rated at 309 bhp by K+N so if you want much more than 320 bhp the APS CAK will be restrictive.
On 97-00 cars best stay with the OE airbox to around 340-350 bhp.
On 93-96 cars it is worth going with a cone filter a bit earlier and you can make a heat divider.
Note the bonnet vent is usually blanked off and that is for a reason. If you remove the blank you can actually increase under bonnet temperatures, not reduce them.
The APS CAK filter is rated at 309 bhp by K+N so if you want much more than 320 bhp the APS CAK will be restrictive.
On 97-00 cars best stay with the OE airbox to around 340-350 bhp.
On 93-96 cars it is worth going with a cone filter a bit earlier and you can make a heat divider.
Note the bonnet vent is usually blanked off and that is for a reason. If you remove the blank you can actually increase under bonnet temperatures, not reduce them.
16 May 2009, 08:41 PM
#14
so I am not convinced your facts are correct
Some years ago when I started developing my STi 6 Wagon I had been persuaded the APS CAK was the best thing since sliced bread. In these days the perceived knowledge was that every day Subarus could not run at 400 bhp and as far as we know my Wagon was the first 400 plus bhp Subaru daily driver in Europe. I went to a Southern rolling road day at G-Force and it was the only car to exceed 380 bhp from memory. Actually 417 bhp. I was tipped off by Chris Davies who ran the rolling road and was an Australian with extensive APS knowledge that my APS CAK was likely to be a restriction. The following week I junked the APS CAK in favour of a large filter and shorter inlet tract. At this time the car was still running MAF. The following Friday ie. 6 days after my initial RR run at G-Force, I went back to Aylsbury with no further modifications and the car produced 434 bhp. I went on from there to stay with Bob Rawle in Swindon and we spent a fair bit of time over the weekend mapping the car.
I returned to Aylesbury which is 200 odd miles from my home during the following week because I was determined to get representative figures that were consistent and the car produced 451 bhp from memory.
Other than junking the APS CAK, fitting a large filter, shortening the inlet tract but retaining the MAF sensor and Bob Rawle's mapping, nothing else had been done.
I still have the graphs here.
These are the facts reported accurately but obviously you are at liberty to disblieve them. As far as I am concerned (and many other people) the APS CAK is intended for semi-standard cars and not cars putting out substantially more power than Subaru intended.
These kits were sold on the back of glossy advertising not factual information and for a long time APS did not issue warnings to purchasers of these kits regards the potential for engine damage unless the MAF was rescaled or the car was remapped when the CAK was fitted.
16 May 2009, 09:17 PM
#15
Scooby Regular
iTrader: (4)
Join Date: May 2003
Location: Doncaster, UK
Posts: 2,567
Likes: 0
Received 0 Likes
on
0 Posts
Stick to a cotton or foam filter like a K&N or Apexi
Cant believe your doubting what Harvey is saying.
16 May 2009, 09:24 PM
#16
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
bonnet vent
Note "the bonnet vent is usually blanked off and that is for a reason. If you remove the blank you can actually increase under bonnet temperatures, not reduce them."
just interested on how getting more cold air in would increase heat , give me a bit of info mate please
just interested on how getting more cold air in would increase heat , give me a bit of info mate please
17 May 2009, 08:37 AM
#18
As regards increased under bonnet temperatures, I have actually measured this and found it to be the case which surprised me so much so that I have done the experiment on a number of occasions and always found that under bonnet temperatures can rise 6-12 C. with one or other or both of the vent blank plates removed.
I think it is a misconception that removing the blank plate allows more air in.
Here is what I think happens. Subaru have designed the engine bay for cooling air to enter at the front, predemonanty through the radiator but also through the gap above the headlights and the air flow is over the engine and then sucked down the transmission tunnel aided by some air from the scoop. Now if you remove a blanking plate you are opening that grille to a low pressure area on top of the bonnet so air is now pulled out through the grille and that must disturb the air flow through the engine bay to the extent that warm air can remain confused within the engine bay.
I have also noticed that when you fit a 6 speed box which is that much wider than a 5 speed, under bonnet temperatures increase again, presumably because the transmission tunnel is that much more full of gearbox casing.
If you make a carbon fibre divider and run it along the drivers side chassis rail and it is made well enough to act as a good blanker, high enough to get to the bonnet and probably with rubber door seals along the top then there is a case for removing the blanking plate in the section that forms the cold air area. You then encourage air into this area from the orange wedge or from the space between the FMIC and headlights where I cut out unnecessary pressed steel work and by removing the section of the blanking plate within the cold air area you then encourage flow into the cold air area, across the filter and up through that section of the open vent.
I think it is a misconception that removing the blank plate allows more air in.
Here is what I think happens. Subaru have designed the engine bay for cooling air to enter at the front, predemonanty through the radiator but also through the gap above the headlights and the air flow is over the engine and then sucked down the transmission tunnel aided by some air from the scoop. Now if you remove a blanking plate you are opening that grille to a low pressure area on top of the bonnet so air is now pulled out through the grille and that must disturb the air flow through the engine bay to the extent that warm air can remain confused within the engine bay.
I have also noticed that when you fit a 6 speed box which is that much wider than a 5 speed, under bonnet temperatures increase again, presumably because the transmission tunnel is that much more full of gearbox casing.
If you make a carbon fibre divider and run it along the drivers side chassis rail and it is made well enough to act as a good blanker, high enough to get to the bonnet and probably with rubber door seals along the top then there is a case for removing the blanking plate in the section that forms the cold air area. You then encourage air into this area from the orange wedge or from the space between the FMIC and headlights where I cut out unnecessary pressed steel work and by removing the section of the blanking plate within the cold air area you then encourage flow into the cold air area, across the filter and up through that section of the open vent.
17 May 2009, 09:08 AM
#19
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
what i was thinking of doing was modding the blanking plate with a flange and running some duckting and a shroud around the aftermarket air filter so its forcing cold air around it. just playing with ideas as theres no where to run a cold air duct pipe from the front of the car . is there any other ways in !!
17 May 2009, 09:24 AM
#20
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
at the end of the day take the box off and cleaned it out with petrol
and the engine would be ok for 12 track days before a freshen up light rebuild for the next year !!
Last edited by westybikes; 17 May 2009 at 09:26 AM.
17 May 2009, 10:00 AM
#21
Re: What Harvey is saying about K&N Filter elements.
Isn't the issue we are talking about the maximum flow capacity of the filter element itself? This being dependent upon the construction of the element and surface area. The easy answer to this is to just stick a larger K&N cone filter onto the APS (or other CAIK) as required surely? Seeing how "restrictive" the original piping is for the OE airbox, I can't imagine the CAIK pipework to be a significant restriction unless you are running frankly stupid power, at which point you are going to have ditched most OE parts of the inlet side of the engine anyhow, so in my mind it becomes a little bit irrelevant.
I'm currently using a K&N Typhoon kit, and while I am open minded about what restrictions it may give at higher power levels (which currently being somewhere over 300bhp I haven't noticed yet), the vast improvement of air temperatures [seen at MAF] is worth more to me than maximum power figures.
The sums regarding required surface areas for K&N filters are towards the bottom of this page - formulae is for American engines so in Cubic Inches. K&N Air Filter Facts You Should Know. I would assume they are different for other filters as their capacity to flow air will be different dependent on the filter medium.
This has just sparked my curiosity!
I've followed Harveys posts and threads about under bonnet and air temps quiet closely, and they've always been very interesting.
Isn't the issue we are talking about the maximum flow capacity of the filter element itself? This being dependent upon the construction of the element and surface area. The easy answer to this is to just stick a larger K&N cone filter onto the APS (or other CAIK) as required surely? Seeing how "restrictive" the original piping is for the OE airbox, I can't imagine the CAIK pipework to be a significant restriction unless you are running frankly stupid power, at which point you are going to have ditched most OE parts of the inlet side of the engine anyhow, so in my mind it becomes a little bit irrelevant.
I'm currently using a K&N Typhoon kit, and while I am open minded about what restrictions it may give at higher power levels (which currently being somewhere over 300bhp I haven't noticed yet), the vast improvement of air temperatures [seen at MAF] is worth more to me than maximum power figures.
The sums regarding required surface areas for K&N filters are towards the bottom of this page - formulae is for American engines so in Cubic Inches. K&N Air Filter Facts You Should Know. I would assume they are different for other filters as their capacity to flow air will be different dependent on the filter medium.
This has just sparked my curiosity!
I've followed Harveys posts and threads about under bonnet and air temps quiet closely, and they've always been very interesting.
Last edited by Prasius; 17 May 2009 at 10:06 AM.
17 May 2009, 03:45 PM
#23
Scooby Senior
iTrader: (1)
Join Date: Nov 2000
Location: Wildberg, Germany/Reading, UK
Posts: 9,706
Likes: 0
Received 73 Likes
on
54 Posts
I am simply sharing my knowledge with you and it matters not whether you care to believe me or not but if you get the part number of the filter on the end of your APS kit you can find out for yourself what the CFM rating is.
Some years ago when I started developing my STi 6 Wagon I had been persuaded the APS CAK was the best thing since sliced bread. In these days the perceived knowledge was that every day Subarus could not run at 400 bhp and as far as we know my Wagon was the first 400 plus bhp Subaru daily driver in Europe. I went to a Southern rolling road day at G-Force and it was the only car to exceed 380 bhp from memory. Actually 417 bhp. I was tipped off by Chris Davies who ran the rolling road and was an Australian with extensive APS knowledge that my APS CAK was likely to be a restriction. The following week I junked the APS CAK in favour of a large filter and shorter inlet tract. At this time the car was still running MAF. The following Friday ie. 6 days after my initial RR run at G-Force, I went back to Aylsbury with no further modifications and the car produced 434 bhp. I went on from there to stay with Bob Rawle in Swindon and we spent a fair bit of time over the weekend mapping the car.
I returned to Aylesbury which is 200 odd miles from my home during the following week because I was determined to get representative figures that were consistent and the car produced 451 bhp from memory.
Other than junking the APS CAK, fitting a large filter, shortening the inlet tract but retaining the MAF sensor and Bob Rawle's mapping, nothing else had been done.
I still have the graphs here.
These are the facts reported accurately but obviously you are at liberty to disblieve them. As far as I am concerned (and many other people) the APS CAK is intended for semi-standard cars and not cars putting out substantially more power than Subaru intended.
These kits were sold on the back of glossy advertising not factual information and for a long time APS did not issue warnings to purchasers of these kits regards the potential for engine damage unless the MAF was rescaled or the car was remapped when the CAK was fitted.
Some years ago when I started developing my STi 6 Wagon I had been persuaded the APS CAK was the best thing since sliced bread. In these days the perceived knowledge was that every day Subarus could not run at 400 bhp and as far as we know my Wagon was the first 400 plus bhp Subaru daily driver in Europe. I went to a Southern rolling road day at G-Force and it was the only car to exceed 380 bhp from memory. Actually 417 bhp. I was tipped off by Chris Davies who ran the rolling road and was an Australian with extensive APS knowledge that my APS CAK was likely to be a restriction. The following week I junked the APS CAK in favour of a large filter and shorter inlet tract. At this time the car was still running MAF. The following Friday ie. 6 days after my initial RR run at G-Force, I went back to Aylsbury with no further modifications and the car produced 434 bhp. I went on from there to stay with Bob Rawle in Swindon and we spent a fair bit of time over the weekend mapping the car.
I returned to Aylesbury which is 200 odd miles from my home during the following week because I was determined to get representative figures that were consistent and the car produced 451 bhp from memory.
Other than junking the APS CAK, fitting a large filter, shortening the inlet tract but retaining the MAF sensor and Bob Rawle's mapping, nothing else had been done.
I still have the graphs here.
These are the facts reported accurately but obviously you are at liberty to disblieve them. As far as I am concerned (and many other people) the APS CAK is intended for semi-standard cars and not cars putting out substantially more power than Subaru intended.
These kits were sold on the back of glossy advertising not factual information and for a long time APS did not issue warnings to purchasers of these kits regards the potential for engine damage unless the MAF was rescaled or the car was remapped when the CAK was fitted.
17 May 2009, 03:48 PM
#24
Scooby Senior
iTrader: (1)
Join Date: Nov 2000
Location: Wildberg, Germany/Reading, UK
Posts: 9,706
Likes: 0
Received 73 Likes
on
54 Posts
Why? is no one on here allowed to disagree with the likes of Harvey or any of the other big guns.
As I said I am running round 370 PS with my APS and haven't noticed any restrictions and neither have the other 2 mapped MY01 STi 7s that can't keep up.
As I said I am running round 370 PS with my APS and haven't noticed any restrictions and neither have the other 2 mapped MY01 STi 7s that can't keep up.
17 May 2009, 04:07 PM
#26
Scooby Regular
iTrader: (7)
Join Date: Apr 2009
Location: DIESEL POWERED BORAT! SLAMMED, R32 WHEELS, MAPPED, DE-CAT, TINTS. LOVE IT!
Posts: 2,032
Likes: 0
Received 0 Likes
on
0 Posts
i run a large K&N with no dramas what so ever. i have a modified rez box on the inner wing so cold air is rammed directly onto my cone filter. my cone sits pretty much between the 2 plastic pipes that pop out the wing from the rez box and is far enough away from the engine to not suffer from heat sink! simple common sence dont cost £££s.
17 May 2009, 04:31 PM
#27
Scooby Regular
Thread Starter
iTrader: (6)
Join Date: Apr 2009
Location: reading
Posts: 315
Likes: 0
Received 0 Likes
on
0 Posts
i run a large K&N with no dramas what so ever. i have a modified rez box on the inner wing so cold air is rammed directly onto my cone filter. my cone sits pretty much between the 2 plastic pipes that pop out the wing from the rez box and is far enough away from the engine to not suffer from heat sink! simple common sence dont cost £££s.
19 May 2009, 12:31 AM
#28
Alright keep your wig on!! As like you I am only quoting the facts about my car with an APS CAK, no MAF and mapped by Bob Rawle.
Why? is no one on here allowed to disagree with the likes of Harvey or any of the other big guns.
19 May 2009, 12:32 PM
#29
Scooby Senior
iTrader: (1)
Join Date: Nov 2000
Location: Wildberg, Germany/Reading, UK
Posts: 9,706
Likes: 0
Received 73 Likes
on
54 Posts
Feel free to disagree, especially if you have observations that will stand up but just because you produce 370 PS you cannot claim there is no restriction from the filter unless you measure the pressure drop with a manometer or Magnahelic guage or do some other thought out checks.
19 May 2009, 02:11 PM
#30
I suggest you specifically discuss the ability of the APS/K+N filter and APS CAK with Bob next time you have the opportunity. I seem to remember a long time ago Bob ran an APS CAK but he will NOT recommend one now for anything with medium power upwards.
This thread is a good example of how reported information on Scoobynet is changed slightly, the story spreads like wild fire and another Scooby myth is created.
At no point have I said 309 bhp is the LIMITof an APS with no noticable restrictions.
The filter is RATED by the manufacturer at 309 bhp and beyond that power output it will gradually have an ever increasing water manometer depression. This means the turbo is having to fight against an increasing vacum in the inlet tract which is not good for developing max power as I demonstrated previously.
I have actually invested in Magnahelic guages so I can examine air flow, constrictions etc and know what is happening. The best inlet system would be where positive pressure and not negative pressure was created. Then the turbo does not have to overcome it.
I appreciate you are a sceptic but I have measured this so many times I know what is happening. No doubt you are conditioned by the glossy advertising and false reputation for these CAKs. My advice is that you remove the APS CAK and fit a trumpet and largest cone filter you can get into the space available.
Done properly, you will be pleasantly surprised if you can measure the change accurately.
This thread is a good example of how reported information on Scoobynet is changed slightly, the story spreads like wild fire and another Scooby myth is created.
you quoted 309 is the limit of an APS with no noticable (by me) restrictions.
The filter is RATED by the manufacturer at 309 bhp and beyond that power output it will gradually have an ever increasing water manometer depression. This means the turbo is having to fight against an increasing vacum in the inlet tract which is not good for developing max power as I demonstrated previously.
I have actually invested in Magnahelic guages so I can examine air flow, constrictions etc and know what is happening. The best inlet system would be where positive pressure and not negative pressure was created. Then the turbo does not have to overcome it.
OK so just for arguments sake lets say that my APS is restricting my engine breathing, what would I do to rectify it bearing in mind I can not fit a panel filter as I have an FMIC.
Done properly, you will be pleasantly surprised if you can measure the change accurately.