Air filters and MAF setups.

I've had this car for about 11-12 years now and been through loads of different air filter setups on it.I started with a crappy custom Jetex a local place made me(badly) and moved onto a huge universal Blitz filter that me and my dad made an adapter for.I had this in the standard position a while then had a stainless inlet made at a local exhaust fabricator and combined it with a fibre glass airbox meant for an evo.



After this I wanted to run a z32 maf and bought a greddy skyline single turbo adpater from Japan which came with 2 z32 mafs and 2 blitz filters.I sold the adapter itself and one of the mafs and filters and used the other myself with a 3" inlet I bought off Billy187 and then adapted to how I wanted it, including having a bit welded on so I could recirc the hks sqv.



I thought the blitz looked a bit lost in the engine bay as I've cleared so much stuff out of the way and also thought it might be a bit small for my ultimate goal of around 450bhp/400lbft so again went the way of finding something to suit my needs and settled on a large K&N filter.For it to fit though I had to chop the end of the z32 maf off though, losing the screen and the car didn't like this one bit.I think it was because the mesh is there to straighten out the air before it hits the maf and after removing it, the car would want to stall at junctions.It was fine for normal driving though but not ideal.



I started reading up on blow through maf's and I liked the benefits of them-better tickover and throttle response.Plus if you bow off a boost pipe it will still drive.So I started gathering the bits I'd need to run it and thought I'd make a better job of the inlet too, swapping 2x 3" 90 degree bends for 2x 3" 45 degree ones and was able to put the k&n back on exactly where I wanted it as there was no maf in the way anymore.I put the z32 maf on the straightest bit of the forge intercooler piperun I could find and fitted 2x 76mm>63mm reducers.I posted a few pics on the gtiroc and it was pointed out that this would still probably cause running issues.


So I thought feck it, and rerouted the intercooler piperun coming up in front of the radiator, using one of the reducers here to allow a 3" pipe to be in place.The reason being I could then have a much longer length of straight 3" pipe going into the maf to try and eliminate any problems.



This is where I am up to now.I just had a new z32 maf delivered to swap over the one I cut the mesh off and upon starting up the car was very hesitant to rev at tickover with any throttle.I switched the MAF for a none OE z32 i have and it ran better on that for some reason.Anyway, switched back the genuine z32 in and took it for a gentle test drive.The car wanted to stall once at a junction but didn't as i blipped throttle.It doesn't pull anything like it should and the power comes in what I can only describe as pulses with it pulling better at higher revs than lower.
I didn't give it any stick as the car is obviously in need of a remap to suit the new configuration.When I got back home though and the egine was warmed up, the tickover was sitting nicely at 950rpm whereas in the past its always been 1k+.It also reved more freely at tickover once warmed up.

I also decided to sort out the outlet off the gt3071 as it was a bit of a bodge job to get it to fit the forge pipework.


Before, with a chopped forge turbo outlet and a silicone coupler.The silicone was being forced to the left so not doing flow any good.


After, with a 63mm long stainless bend fitted.Much smoother.I relocated the pressure tap in the silicone joiner about 20cm left of where it was originally.

Added some exhaust lagging to the turbo outlet and some heat reflective blanket to help insulate it from the exhaust manifold.Also now has a bespoke Z32 maf pipe I bought from Danny and rerouted intercooler piping.
I also had to move the forge oil seperator so made up a new bracket for it and cut the hoses to suit.
The eagle eyed(not) among you will notice the Mk 27 heatshield.This time its some foam I had kicking about.It's used in furniture so should be ok heatwise and it makes for a very good shield.Plugs all the gaps and gets a nice seal on the bonnet while still allowing the cold air feed form the bonnet scoop to blast onto the K&N.Looks a bit daft in yellow, I might get some black foam or even spray it black and see how shit it looks.
I also moved the thingymebob that used to sit under the OE coil away from the block to prevent any future problems with it.I attached it the the Z32 tube mikalor for now, might move it again yet.

i like where uv put the coolant, how'd u get it there and is that a oil catch can next to it?

It just slots in between the grill and radiator, no need for a bracket.I can't put it in the original place as that's where my alarm siren is.Its a forge oil seprator, had it for years.

good thread - how do you rate the different approaches you have tried over the years ?

have you noticed gains in power delivery ? has one method shown more results ?

It's hard to say as I have changed it so often that getting RR results before and after would have cost a fortune.I don't think any of them particularly gained power, I just don't lose the power most other people are as they fit a cone filter and don't have any shielding or a decent cold air feed to it.
Not sure about the power delivery either as its curently running a map for draw through MAF on the old intercooler piping setup, so will be a bit out.Not really been booting it(or driving it much at all) just in case.Will be getting it mapped again soon but also having cams dialled in so won't be a true comparison as I should get improved spool from having that done(think there is too much overlap atm).