NA6 Intake/Exhaust Mods

zephyrus17 · Postby **zephyrus17** » Fri Dec 02, 2011 3:20 pm

I got a Simota air filter and I'm ready to drill the hole for the firewall CAI. What's a recommended size for the hole to drill? Would it be possible to have a 100mm (that's the size of the filter inlet) hole if I drill to the very side of the firewall? Or is there better air pressure if I go straight back from the AFM?

Postby **NitroDann** » Fri Dec 02, 2011 3:56 pm

The throttle body is only 56mm so anything bigger than that

Dann

zephyrus17 · Postby **zephyrus17** » Fri Dec 02, 2011 4:01 pm

Yeah, that's why I got the MAF adaptor and the filter. I'm just wondering if I need a reducer, that's all.. I'll go play with it over the weekend

zephyrus17 · Postby **zephyrus17** » Fri Dec 02, 2011 11:12 pm

Got itchy and installed the new airfilter and removed the original airfilterbox and 90deg bend. Didn't cut a hole in the firewall yet, though. No noticable power increase, but by golly the throttle response is fantastic! Revs so keenly now

93_Clubman · Postby **93_Clubman** » Sat Dec 03, 2011 3:13 pm

zephyrus17 wrote:I got a Simota air filter and I'm ready to drill the hole for the firewall CAI. What's a recommended size for the hole to drill? Would it be possible to have a 100mm (that's the size of the filter inlet) hole if I drill to the very side of the firewall? Or is there better air pressure if I go straight back from the AFM?

Usually circular 75mm diameter hole, but before drilling, do a mock up of how you're going to have the whole thing setup to visualise it. Usually a spacer reducer is used with the Simota, & if you ever want to fit a front suspension tower brace you'll need to go back perpendicular to the windscreen cowl area. However, keep in mind that the windscreen cowl area drains water so don't cut the hole too low.

zephyrus17 · Postby **zephyrus17** » Sat Dec 03, 2011 3:20 pm

Thanks for the advice. I'll do that. Should I need to put a semi-fine mesh at the intake opening at the cowl to prevent leaves and stuff getting in?

93_Clubman · Postby **93_Clubman** » Sat Dec 03, 2011 4:03 pm

zephyrus17 wrote:Should I need to put a semi-fine mesh at the intake opening at the cowl to prevent leaves and stuff getting in?

Not really, as the airfilter is going to stop it anyway - just try to avoid parking under trees or bushes for long periods of time that might allow rubbish to collect in the windscreen cowl.

zephyrus17 · Postby **zephyrus17** » Mon Dec 05, 2011 3:53 pm

Went to Adelaide Belt and Hoses and supercheap auto, both didn't have the pipes/reducers I needed. Bunnings doesn't have the flexi stuff, only stuff for plumbing. What other places can I try?

I might have to get the 65 - 100 reducer from bunnings instead. I'd prefer it to be as close to 100 as possible, but if it has to be done, then, ah well.

93_Clubman · Postby **93_Clubman** » Mon Dec 05, 2011 11:36 pm

Mania used to just sell the carbon fibre tube (which goes from 100mm to 75mm) without the filter if you asked them:

Loch Stewart CAI.jpg

zephyrus17 · Postby **zephyrus17** » Mon Dec 05, 2011 11:49 pm

I went to Bunnings and found the stock severely lacking. The filter neck is 77mm (3"). They didn't have a 100 - 75 adaptor, but only a 100 - 90, and a 90 - 75. I think I'll go back to Bunnings are exchange for just the 100 - 65 mm one. But the benefit of this is that the 75mm pipe fits exactly into the adaptor. If I get the 100 - 65 adaptor I'd need two sleeves, a 100 mm sleeve and a 65 mm sleeve. And who knows if Bunnings has stock for them. But, yes. I'll ask Mania too

93_Clubman · Postby **93_Clubman** » Tue Dec 06, 2011 12:13 am

Are you setting it up similar to this, of course noting that yours is an NA6 & this is an NA8:

Mania CAI.jpg

zephyrus17 · Postby **zephyrus17** » Tue Dec 06, 2011 12:26 am

I am. I tried to bend it to the very far corner, but found the windscreen wiper motor was in the way. So that's the best compromise I could do.

93_Clubman · Postby **93_Clubman** » Tue Dec 06, 2011 12:32 am

And using the same order of components, i.e. engine cross pipe to AFM to adaptor to Simota filter to tube to firewall?

zephyrus17 · Postby **zephyrus17** » Tue Dec 06, 2011 7:51 am

Basically, yes... I have a feeling you're going somewhere with this

93_Clubman · Postby **93_Clubman** » Tue Dec 06, 2011 11:36 am

Only going somewhere in that I hoped that was what you'd say, as it has its advantages, which isn't to say it's the only way. On the NA8 at least, the bottom half of the airbox can be left in place, which provides support to the filter, as well as not directly exposing it to the headers. Same could apply to the NA6, hence the suggestion to do a mock-up or two before drilling, so that you get the best setup for your vehicle taking into consideration future mods.