How to DIY shielded cowl intake.
Moderators: timk, Stu, zombie, Andrew, The American, Lokiel, -alex, miata, StanTheMan, greenMachine, ManiacLachy, Daffy
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
How to DIY shielded cowl intake.
Hey everyone,
Some of you have seen this from my garage thread but wanted to chuck it over here to hopefully help someone and add to this great community in a positive way.
Please keep in mind that this whole thing took about 5 hours but with these instructions they would take you less and if you are time poor one of our sponsors mx5 mania stocks a sexy carbon one.
The intake has been fitted now for about a month and is working fine and looks to have improved my fuel consumption when dríven normally so bit of a bonus there.
I would love a loch intake but are rare now days and I needed a little project.
Anyway the how to with some pics.
From the get go I wanted to have a 76mm hole in the cowl like others have done because if I didn't like it I could fit a mania one easily. Every one who has tried to make a small saw hole larger knows what I mean.
However what I did do differently to others was instead of using 75mm pipe as the main pipe I wanted to use 100mm. The reason for this was for a larger volume of what would essentially be the air box and figured I could over come the usual rattle associated with these intakes. More on that later.
So as this is mainly PVC plumbing pipe you will need from the plumbing supply place.
*pvc 75-100mm adaptor $9
*pvc 100mm joiner $5
*pvc 100mm pipe Free off cut. 300mm would be plenty.
I didn't want the intake looking like a dunny pipe so the adaptor in the photo has already had the threaded end cut off and been sanded as I was going to paint it.
Next part required was a silicone joiner 3inch internal diameter.
I picked one up from super cheap for $10 (other colours available I wanted black)
So now we have this.
Trial fit.
As stated I didn't want a dunny intake so I cut down the join to 50mm, 25mm either side of internal seat In Joiner.
You could get away with 10-15 either side of seat.
Sanded all casting marks, part numbers lips ect off and now have this.
So time to join it all together, do not use plumbers glue....... I SAY AGAIN DO NOT USE PLUMBERS GLUE!. I hate to think what it would do to sensors ect. I used this as I had it laying around.
Join it all up.... More to come
Sent from my iPhone using Tapatalk
Some of you have seen this from my garage thread but wanted to chuck it over here to hopefully help someone and add to this great community in a positive way.
Please keep in mind that this whole thing took about 5 hours but with these instructions they would take you less and if you are time poor one of our sponsors mx5 mania stocks a sexy carbon one.
The intake has been fitted now for about a month and is working fine and looks to have improved my fuel consumption when dríven normally so bit of a bonus there.
I would love a loch intake but are rare now days and I needed a little project.
Anyway the how to with some pics.
From the get go I wanted to have a 76mm hole in the cowl like others have done because if I didn't like it I could fit a mania one easily. Every one who has tried to make a small saw hole larger knows what I mean.
However what I did do differently to others was instead of using 75mm pipe as the main pipe I wanted to use 100mm. The reason for this was for a larger volume of what would essentially be the air box and figured I could over come the usual rattle associated with these intakes. More on that later.
So as this is mainly PVC plumbing pipe you will need from the plumbing supply place.
*pvc 75-100mm adaptor $9
*pvc 100mm joiner $5
*pvc 100mm pipe Free off cut. 300mm would be plenty.
I didn't want the intake looking like a dunny pipe so the adaptor in the photo has already had the threaded end cut off and been sanded as I was going to paint it.
Next part required was a silicone joiner 3inch internal diameter.
I picked one up from super cheap for $10 (other colours available I wanted black)
So now we have this.
Trial fit.
As stated I didn't want a dunny intake so I cut down the join to 50mm, 25mm either side of internal seat In Joiner.
You could get away with 10-15 either side of seat.
Sanded all casting marks, part numbers lips ect off and now have this.
So time to join it all together, do not use plumbers glue....... I SAY AGAIN DO NOT USE PLUMBERS GLUE!. I hate to think what it would do to sensors ect. I used this as I had it laying around.
Join it all up.... More to come
Sent from my iPhone using Tapatalk
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
Starting at the cowl end.
Small smear around join and then slide it into 75mm end of adaptor this is a tight fit but doable and will seat perfectly.
Next smear around PVC joiner.
Now you should have this. Wipe off excess.
Now let it dry overnight. Beer time the beer is for the courage to drill a 75mm hole in your car. I then cleaned it up and slightly enlarged it with a dremmel, no pics sorry but I taped the area right up to save any paint chipping and used a hole there as a guide between the two washer bottle holes. I also made a 3 inch template to check location and size and stuck it there as a guide.
More to come.
Sent from my iPhone using Tapatalk
Small smear around join and then slide it into 75mm end of adaptor this is a tight fit but doable and will seat perfectly.
Next smear around PVC joiner.
Now you should have this. Wipe off excess.
Now let it dry overnight. Beer time the beer is for the courage to drill a 75mm hole in your car. I then cleaned it up and slightly enlarged it with a dremmel, no pics sorry but I taped the area right up to save any paint chipping and used a hole there as a guide between the two washer bottle holes. I also made a 3 inch template to check location and size and stuck it there as a guide.
More to come.
Sent from my iPhone using Tapatalk
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- hks_kansei
- Speed Racer
- Posts: 6154
- Joined: Tue Feb 03, 2009 10:43 am
- Vehicle: NB8A
- Location: Victoria
Re: How to DIY shielded cowl intake.
Looks essentially the same as my old one, just I didn't use a silicone connector at the cowl end, mine was just the PVC tube, and I put a bit of U section rubber around the edges of the cowl hole (looked quite tidy as it covered the obviously cut edges)
for an NB you can simply drill a 15mm (from memory) hole in the cowl tube to accept the rubber bung to hold the temp sensor.
for an NB you can simply drill a 15mm (from memory) hole in the cowl tube to accept the rubber bung to hold the temp sensor.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
Ok so that's the hard bit done and past the point of no return. I should also mention I cleaned up all the metal shavings and actually had a bloody large magnet under the hole saw to catch them. I then painted the hole with colour coded touch up paint and let it dry overnight. I also had to cut a small piece of plastic trim that sits over the fresh air vent. Basically I marked it out through the hole and trimmed it back a couple mm. It isn't noticeable against the black silicone and looks factory. I believe black penguin had a photo on his build doing it with his mania intake, thanks for the heads up Pete.
Next night and time for a trial fit.
Now this is where that little silicone join plays a major part as this goes through the firewall and because of this there is no metal on plastic, fibreglass, carbon ect rattle associated with these intakes.
But I warn you it is a very very tight fit so easiest is bend a corner down feed it in then reach into cowl and pop corner up. Trust me it's tight!!
At this time I took a measurement from the lip inside the join to the start of the tapered section of the the simota filter housing. Cut the pipe and did a trial fit.
Now I should mention here that the 100mm pipe WILL NOT fit over the simota filter housing but there are two ways around this. One is buy another adaptor but it's ugly and I didn't like using one to be honest let alone two. Second way around it is sand down the inside of the 100mm pipe.
I used 100mm stormwater so not sure if drain pipe would have the same thickness wall but essentially what I have has PVC, some blue plastic, then PVC again.
I used the blue plastic as a depth guide and when I had a nice blue ring inside the pipe it slid into the simota filter housing tight but easy. (I also chanfered all edges on this build except filter to help assembly and make the finish neater)
At this point I put two rivets in to hold the filter housing to the pipe. I did this by sliding the pipe down into position perfectly marked two points horizontal and drilled through the filter and the pipe. I then inserted a blind alloy rivet to just hold it in place (just sitting in hole) while I drilled the other side, I then pulled the rivet out and again used the blue gasket silicone to seal the pipe to the housing and properly inserted the two rivets. Now the whole assembly is properly sealed and won't twist on the filter. It makes it more rigid overall.
Sorry no pics of this.
Now my car does not have extractors but will be seeing a full Nitrodann system shortly so I have kept this in mind. Many people criticise these intakes for heat soak when running past extractors and I looked at ways to perhaps reduce this including shields however I found the best stuff to be this.
It is reflective aluminised fibreglass tape with an adhesive back. So not only reflects heat but insulates. You can get gold which would work better (gold reflects heat better) but I didn't want a fully sick gold intake and on the MX we might be talking 0.00000001hp difference.
For what it's worth the stuff in gold is used in F1 to shield there intakes so yes it does work.
Now applying the tape I figured I would wrap it around however with the diameter size change it was going to look ordinary with folds and creases ect. I instead cut strips and laid it length ways.
The adhesive is very good but over time I'm sure it would lift so I fitted a stainless hose clamp each end to stop this and hide ugly frays and uneven cuts.
So now it looks like this.
After a test fit I also used the tape on the side and underneath of the filter housing closest to the exhaust to help shield it from heat there as well.
I didn't put tape on the rest of the filter housing because........it's pretty and Shiny!! Lol.
Now it was fitted up I rotated the AFM 180 degrees to move the plug to the cold side and just neaten up the wiring.
It also allowed me to make a bracket to go from an existing air box stud to AFM. It isn't really needed but couldn't hurt. I also made a temporary washer bottle bracket to do the job till I get a nopro one.
So all done.
Final thoughts.
IT IS VERY LOUD!!! But I like it.
There is definitely a crisper throttle everywhere in the rev range. power increase (butt dyno) is mild but felt especially over 5,000rpm which was probably the air box snorkel and bends acting as restriction before but the cold air would help. I had a K&N panel in my air box before.
Would I do it again? Yer I probably would.
Cost was.
*Plumbing supplies $14
*silicone join $10
*simota filter $55 delivered
*heat reflective tape $50 delivered.
*gasket silicone, hose clamps, metal for bracket ect was all FREE as I had it laying around
*time 5 hours
So cost me $129 but call it $150 if I had to buy gasket silicone, clamps ect.
Now the down side I did develop a rattle from 3/4 to full WOT and after searching for ages it turned out to be the flap for the fresh air rattling when full recirc was on so if I slide the knob back 10mm from full recirc and it's gone. I'll put some foam in there when I'm in that area next.
Enjoy and any questions chuck them up.
Hope this helps someone.
Sent from my iPhone using Tapatalk
Next night and time for a trial fit.
Now this is where that little silicone join plays a major part as this goes through the firewall and because of this there is no metal on plastic, fibreglass, carbon ect rattle associated with these intakes.
But I warn you it is a very very tight fit so easiest is bend a corner down feed it in then reach into cowl and pop corner up. Trust me it's tight!!
At this time I took a measurement from the lip inside the join to the start of the tapered section of the the simota filter housing. Cut the pipe and did a trial fit.
Now I should mention here that the 100mm pipe WILL NOT fit over the simota filter housing but there are two ways around this. One is buy another adaptor but it's ugly and I didn't like using one to be honest let alone two. Second way around it is sand down the inside of the 100mm pipe.
I used 100mm stormwater so not sure if drain pipe would have the same thickness wall but essentially what I have has PVC, some blue plastic, then PVC again.
I used the blue plastic as a depth guide and when I had a nice blue ring inside the pipe it slid into the simota filter housing tight but easy. (I also chanfered all edges on this build except filter to help assembly and make the finish neater)
At this point I put two rivets in to hold the filter housing to the pipe. I did this by sliding the pipe down into position perfectly marked two points horizontal and drilled through the filter and the pipe. I then inserted a blind alloy rivet to just hold it in place (just sitting in hole) while I drilled the other side, I then pulled the rivet out and again used the blue gasket silicone to seal the pipe to the housing and properly inserted the two rivets. Now the whole assembly is properly sealed and won't twist on the filter. It makes it more rigid overall.
Sorry no pics of this.
Now my car does not have extractors but will be seeing a full Nitrodann system shortly so I have kept this in mind. Many people criticise these intakes for heat soak when running past extractors and I looked at ways to perhaps reduce this including shields however I found the best stuff to be this.
It is reflective aluminised fibreglass tape with an adhesive back. So not only reflects heat but insulates. You can get gold which would work better (gold reflects heat better) but I didn't want a fully sick gold intake and on the MX we might be talking 0.00000001hp difference.
For what it's worth the stuff in gold is used in F1 to shield there intakes so yes it does work.
Now applying the tape I figured I would wrap it around however with the diameter size change it was going to look ordinary with folds and creases ect. I instead cut strips and laid it length ways.
The adhesive is very good but over time I'm sure it would lift so I fitted a stainless hose clamp each end to stop this and hide ugly frays and uneven cuts.
So now it looks like this.
After a test fit I also used the tape on the side and underneath of the filter housing closest to the exhaust to help shield it from heat there as well.
I didn't put tape on the rest of the filter housing because........it's pretty and Shiny!! Lol.
Now it was fitted up I rotated the AFM 180 degrees to move the plug to the cold side and just neaten up the wiring.
It also allowed me to make a bracket to go from an existing air box stud to AFM. It isn't really needed but couldn't hurt. I also made a temporary washer bottle bracket to do the job till I get a nopro one.
So all done.
Final thoughts.
IT IS VERY LOUD!!! But I like it.
There is definitely a crisper throttle everywhere in the rev range. power increase (butt dyno) is mild but felt especially over 5,000rpm which was probably the air box snorkel and bends acting as restriction before but the cold air would help. I had a K&N panel in my air box before.
Would I do it again? Yer I probably would.
Cost was.
*Plumbing supplies $14
*silicone join $10
*simota filter $55 delivered
*heat reflective tape $50 delivered.
*gasket silicone, hose clamps, metal for bracket ect was all FREE as I had it laying around
*time 5 hours
So cost me $129 but call it $150 if I had to buy gasket silicone, clamps ect.
Now the down side I did develop a rattle from 3/4 to full WOT and after searching for ages it turned out to be the flap for the fresh air rattling when full recirc was on so if I slide the knob back 10mm from full recirc and it's gone. I'll put some foam in there when I'm in that area next.
Enjoy and any questions chuck them up.
Hope this helps someone.
Sent from my iPhone using Tapatalk
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
I did all that with Tapatalk so if anything doesn't make sense please let me know as i hate typing on my phone.
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
-
- Speed Racer
- Posts: 3471
- Joined: Sun Jan 19, 2014 9:52 am
- Vehicle: NA6
- Location: Lugarno, Sydney
Re: How to DIY shielded cowl intake.
Now it just needs a sound clip
NA6 turbo - 140kw atw - not the most powerful but so much fun
- LiteIsRite
- Fast Driver
- Posts: 424
- Joined: Mon Apr 08, 2013 8:16 pm
- Vehicle: NA6
- Location: Northern Rivers NSW
Re: How to DIY shielded cowl intake.
speed wrote:Now it just needs a sound clip
+1
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 [sold]
"Cherry" - Classic Red 1990 NA6 [sold]
Re: How to DIY shielded cowl intake.
I just don't see where it is getting the air from.. Is that inside the car cabin?
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
- StanTheMan
- Forum legend
- Posts: 6824
- Joined: Thu Apr 24, 2003 11:00 am
- Vehicle: NA6
- Location: Balgowlah
Re: How to DIY shielded cowl intake.
cherrymx5 wrote:I just don't see where it is getting the air from.. Is that inside the car cabin?
Sent from my iPhone using Tapatalk
There is a hole in the fire wall.
the air comes from the gap between the bonnet & windscreen.
Satans Ride called F33nix the resurrected NA6
- aka_juffa
- Racing Driver
- Posts: 1005
- Joined: Wed Dec 14, 2011 2:40 pm
- Vehicle: NA8
- Location: SE Melbourne.
Re: How to DIY shielded cowl intake.
Well done Alex.
There is also our very own forum members version.
http://www.autospeed.com/cms/article.ht ... 5&A=110680
There is also our very own forum members version.
http://www.autospeed.com/cms/article.ht ... 5&A=110680
Motor Neurone Disease chose me, I choose Voluntary Assisted Dying.
- StanTheMan
- Forum legend
- Posts: 6824
- Joined: Thu Apr 24, 2003 11:00 am
- Vehicle: NA6
- Location: Balgowlah
Re: How to DIY shielded cowl intake.
speed wrote:Now it just needs a sound clip
when I first experienced the CAI I thought that's how the car should have sounded out of the box.
if you get a louder than standard exhaust....it kind of drown this out.
If you get cams it gets much louder with bigger overlap.
when you get the stand alone ECU & remove the AFM ( more so with the NA6).... it gets ridiculously loud. LOL
Satans Ride called F33nix the resurrected NA6
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
cherrymx5 wrote:I just don't see where it is getting the air from.. Is that inside the car cabin?
Sent from my iPhone using Tapatalk
Hey mate, have a look here it goes into detail about the benefits and how a cowl intake works (it also has another DIY) http://www.mx5driver.com/thread/6151/ra ... take-na-nb
Also i can confirm better fuel consumption with the install before i was getting 9-10L per 100km and on the trip up from Bega through kangaroo valley, Thirlmere, Mulgoa ect on the weekend for the brass monkey run the car returned a fuel consumption of 7.9L per 100km on 98 octane fuel. now obviously most of the drive was just cruising along at 80kmh but was having fun on the mountains in kangaroo valley.
On the Sunday at the brass monkey run we cruised along between 80kmh and 110kmh, around Mt Panorama i was having fun on the tighter corners and powering out of them but at the end of the day it is a public road, the speed limit is 60kmh on the mountain and plenty of young families walk around the track so really it is not safe to treat it like a race track so in short i didn't use that much throttle. however i returned a fuel consumption of 8L per 100km again on 98 octane. both days were 90% roof down, 10% soft top up. (left hardtop at home)
As a side note the brass monkey was a great run and good to meet Regie and see his NC in the flesh, sounds as good as it looks.
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
https://vimeo.com/175469067
Here is a sound clip everyone it's a little lame, I'll get something better when I get it on the track.
Only iPhone taken. This is second gear out of the corner bout 3/4 throttle up to 5,000rpm roof down. Speed at back off 60kmh. As stated before public road and lap before had mother pushing a pram up that corner so obviously taking caution.
Sent from my iPhone using Tapatalk
Here is a sound clip everyone it's a little lame, I'll get something better when I get it on the track.
Only iPhone taken. This is second gear out of the corner bout 3/4 throttle up to 5,000rpm roof down. Speed at back off 60kmh. As stated before public road and lap before had mother pushing a pram up that corner so obviously taking caution.
Sent from my iPhone using Tapatalk
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
LiteIsRite wrote:speed wrote:Now it just needs a sound clip
+1
speed wrote:Now it just needs a sound clip
just for you guys there is one there now .
StanTheMan wrote:speed wrote:Now it just needs a sound clip
when I first experienced the CAI I thought that's how the car should have sounded out of the box.
if you get a louder than standard exhaust....it kind of drown this out.
If you get cams it gets much louder with bigger overlap.
when you get the stand alone ECU & remove the AFM ( more so with the NA6).... it gets ridiculously loud. LOL
Its all coming Stan
also for people who haven't been there the mountain is a two way road hence why im hugging the left side.
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
- Alex 2550
- Racing Driver
- Posts: 561
- Joined: Mon May 11, 2015 12:01 pm
- Vehicle: NA8
- Location: Far south coast NSW
Re: How to DIY shielded cowl intake.
aka_juffa wrote:Well done Alex.
There is also our very own forum members version.
http://www.autospeed.com/cms/article.ht ... 5&A=110680
thanks mate actually it was that article that made me go the way i did as originally i was only going to make a cowl intake snorkel and heat shields for the standard box but after i read that i doubt i would of gained anything except noise. thanks for putting the link up as i think it really is a good read to have here.
Life is busy at the moment so MX will be seeing little time over the next few months but a roll bar is next on my list of major purchases, looking at a MX5+ tall boy diagonal and a Nitrodann full exhaust system. but after that the head will be coming off for a clean up, port, valve unshrouding, port matching, shave and a set of cams all run by a MS2PNP. once that is done ill look at a mania enlarged intake or similar but with heat tape on it as well to free up the intake path a little more which will probably be the end of power increases for this car around the 100-110kw mark maybe more. however depending on what the motor sport front brings power may get capped at 90kw for a couple years with a focus on suspension and seat time.
this car is just for fun so it doesn't get a priority as far as funds allocation goes however i am really liking the MX5 experience so ill be selling some other toys to boost the funds shortly.
Retro NA8
build viewtopic.php?f=57&t=71923
build viewtopic.php?f=57&t=71923
Return to “MX5 Engines, Transmission & Final Drive”
Who is online
Users browsing this forum: No registered users and 63 guests