1998 NB and the Mania CAI?

hughlb · Postby **hughlb** » Sat May 02, 2015 1:58 am

Hi guys,

I live in Adelaide and own a 1998 NB, which is entirely stock, but I was looking at buying a Mania Cold Air Intake system, mainly for the sound, but also for any other happy surprises it might bring. I just have a few concerns/questions, I know there is a lot of discussion about Cold Air Intakes, but I have some specific questions in relation to the 98 NB.

I guess, first and foremost, according to the MX5 Mania website, I can fit this system on an early NB model, as I don't have the ABS system blocking the necessary hole through the firewall. But is this system better suited to NA models?

Would adding a Mania CAI in any way lead to increased wear on engine components in the long run? It's my daily drive, and I wouldn't want to affect its otherwise bulletproof reliability.

Is there any risk to drilling through the firewall, ie. is the system more susceptible to dust or water intake?

Will there be any drop in power output on an NB? I've heard there can be slight drops in bottom-end power with aftermarket intakes, and given I'm mostly keeping it below 4500rpm, I would like to retain the small amount of power it has below its power band.

Is there anyone in Adelaide that you would recommend to fit the system? I get my car serviced by Marque at Viva Auto Repairs and couldn't be happier as he owns and races an MX5, I just thought I'd see if anyone had suggestions.

Thanks for any feedback you can give!

Hugh

Postby **NitroDann** » Sat May 02, 2015 2:26 am

"1998 NB and mania CAI"

Will it blend?!?

Yeah its fine, put it on.

rascal · Postby **rascal** » Sat May 02, 2015 9:01 am

If you are mostly keeping it below 4500rpm then adding the cai will be of noise benefit only.
The gains from a freer flowing intake are predominantly felt in the higher rpm ranges.

KevGoat · Postby **KevGoat** » Sat May 02, 2015 11:51 am

I would see if you can get a ride in an NA or NB with one fitted before committing. Many people remove them due to the noise.

Viva would fit it, but I don't think it would be difficult to do it yourself.

hks_kansei · Postby **hks_kansei** » Sun May 03, 2015 1:08 am

they fit fine.

engine longevity really depends on how good the filter is, from memory the filters in them are pretty good (not sure how compared to the OEM paper ones) but I think the mania ones are an oiled filter (personally I dont like them too much stuffing about to clean them)

I had a diy version of a mania on mine and while the noise was fun I ended up taking it off, it looked meh, and it constantly filled with leaves because of the position of the intake in the firewall.
I'd basically have to take the damn thing off once every 2 weeks and shake the leaves out of it other wise they;d build up and choke it down.

Really depends where you park your car though, at that stage mine was parked outdoors

Blesif · Postby **Blesif** » Sun May 03, 2015 5:58 pm

I have one on my 99 NB8A. Its only noisy at heavy throttle, otherwise I barely notice it. The filter is a K&N oil bathed and seems to work well. It will collect leaves if the car is parked outside or under trees and it is a pain to disconnect and shake them out. As for extra performance - strictly at the upper rev limit eg above 5000. I doubt it gives a lot extra - just sounds like it does.

hughlb · Postby **hughlb** » Mon May 04, 2015 2:11 am

Thanks for all your input. I'd say at this stage an intake modification isn't worth it. I've looked at other ways to improve the engine sound; exhaust modifications don't sound as good as intake modifications to my ears, with one possible exception and one question;

Would changing the headers without changing anything else in the exhaust system work?

I thought it might open the sound up a bit, without it sounding like a typical exhaust modification - louder engine sound is what I'm getting at.

Thoughts?

hks_kansei · Postby **hks_kansei** » Mon May 04, 2015 1:49 pm

Would be a minimal sound change if anything.

If you just want intake noise, and don't want the cost/hassle of constantly cleaning the filter I can suggest the following:

Drill/cut holes on the dirty side of the airbox, adds intake noise, no power gain.

Remove airbox and add a pod filter to the AFM - adds noise, tiny power loss (if you can shield it from heat though you can get it back to even)

Ideally i'd just buy a second airbox from a wrecker, hack open the dirty side and see if you like it. you get noise, and you still have a nice easy to replace OEM filter.

Snowmotion · Postby **Snowmotion** » Mon May 04, 2015 3:01 pm

I made a replica of a DDM stage 2 intake that I think is a good compromise. More induction noise on open throttle but not obtrusive and what ever power gains can be achieved by removing the flex joints of the standard intake.

hks_kansei · Postby **hks_kansei** » Mon May 04, 2015 3:20 pm

^ that would be ideal.

I've been meaning to make one too, but i'm just help up by finding time.

That and I want to try and design it so that I can still use a panel filter. (cbf cleaning pod filters)

SuperMazdaKart · Postby **SuperMazdaKart** » Mon May 04, 2015 7:53 pm

I DIY'd my own version of the Mania CAI (which is actually a copy of the original Loch Stewart version) using bits from eBay/Bunnings & stuff in the shed. Was quite proud of it in the end & saved myself a heap of money compared to buying a pre-made one. Plus the added benefit of choosing a color for it. I didn't really like the idea of using oiled filters so mine was a dry Simota filter which came with it's own heat shielding.

I removed the largest clamp afterwards though, the filter casing isn't really meant to accept a clamping force & pushing on the rubber reducer tightly was enough for it.

If you're happy with Viva Auto Repairs then I wouldn't be concerned with having them do the work if need be (maybe stay away from the camper van/caravan rental stuff though). Sometime ago I researched what happened to Mildren's Race Engineering, a well known Mazda rotary engine performance workshop who also had the the side business Miata Sport. Turns out Viva bought that business & have some of their mechanics working at Viva now. MRE isn't around anymore though.

Snowmotion · Postby **Snowmotion** » Mon May 04, 2015 8:59 pm

hks_kansei wrote:^ that would be ideal.

I've been meaning to make one too, but i'm just help up by finding time.

That and I want to try and design it so that I can still use a panel filter. (cbf cleaning pod filters)

You could look at running a stock filter diagionally across the box but would need to fit a side and bottom rail for it to sit in.
Bear in mind that the K&N filter I fitted in 50% larger in surface area than the stock panel filter.

I will PM you a photo of the box with the top off.

madkeen · Postby **madkeen** » Thu May 07, 2015 3:59 pm

Hi there. I recently picked up an old Loch Stewart airbox on Gumtree and love the difference it's made to my stock NA8. Certainly sounds better - and you only hear it under throttle, so no drone or complaints from my anti-exhaust wife either! :p It's a meaty, rumbly roar. Feels like it give some extra kick in the mid-range too... but I may be delusional.

Seriously though.. don't hesitate. Great mod, even if the part is something like 15 years old!

I should note I got some pro help with the install from Automotive Plus in Brisbane. Turned out the airbox I bought was a direct fit to an NA6, so a bit of tweaking was needed to get it into my NA8 (plus relocation of washer bottle).