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Well the SS has been sold and it's now time to find the MX for me. I have been trying to decide between SP and SE for some time with both having pros and cons. I have dríven a few SE's but as yet haven't found a local SP to test drive.

My question relates to the SPmotorsport kit for the SE. They claim with the cold air and intercooler kit combined with the 2.5 inch exhaust that 140KW is made at the rears.

Does anyone have experience with this kit? With some limitted mechanical knowledge (know sweet FA about turbos) is it feasible to fit this kit myself or is there someone in Melbourne who deals in it?

Are there other alternatives that are available in Melbourne?


I know I am asking alot but this field is pretty new to me. I have always had V8's etc. but as I am getting older I am getting wiser and am looking for a car which I can use to join in on some of the motrsport events. It's a reasonable outlay and want to make sure I go the right way.

Cheers
Mark

Larger intercooler ($200-$250 off ebay)
DIY air intake behind the passenger headlight ($not much - DIY)
SP Motorsport or other exhaust (custom or any other mandrel bend exhaust that will fit). Around 2.5 - 3 inch woud be good (<$1000)
Any exhaust shop to mate exhaust to the dump pipe - ($100)

Could be done for far less than the $3,000 kit.

You can DYI for cheaper then the SPM kit and produce more rwkw in the process. However, if you dont get air flow and fuel right your car wont run well or you may end up with an expensive bang.

If you choose a DYI CAI (cold air induction) kit utilisng the stock AFM (air flow meter), the stock AFM must be placed as far as way as possible from the blow off from the recirculated BOV (blow off valve). Failure to do so will lead to turbulent air flow confusing the AFM leading to further changes in the AFR (air fuel ratio) bringing about surge and idle issues.

You cannot use the AFM unless you replace it with MAP (manifold airway pressure) sensor which requires a after market stand alone ECU.

When you change the stock induction on the SE with a CAI you will see a 1-2 psi gain on the boost gauge with a slightly leaner AFR on a wideband 02 meter without physically dialling up boost. A few have choosen to remain with the stock induction and add MBC (manuel boost controller) and dial up an extra 3 pounds and get a real noticeable improvement, however the net gain in rwkw isnt as much as a MBC with a CAI.

As far as the exhaust is concerned if your planning on staying with the stock turbo and not running an aftermarket EMS, then a complete 3 inch systems or a dual gas downpipe will lead to boost creep. Which means you will hit boost cut (factory 10.5psi cut on the SE) and spike seriously lean on your AFR as the OEM injectors are at \"duty cycle\" ie max flow and cannot compensate with more fuel.

Why does it boost creep @ 3inch ? Too free flowing in combination with CAI, small wastegate hole and preload tension on the actuator isnt set correctly for that flow.

Last time i looked the SPM exhaust has a 2 3/4 dump followed by 2.5inch from cat back. 2.5 is more then adequate. The biggest restriction on the SE as far as exhaust is concerned is the downpipe and muffler, so if noise and outright power isnt your forte you would only have to change that.

The stock intercooler problem is that it restrictive and suffers from heatsoak after the first few pulls, by changing it with an appropriate sized intercooler (too big and you will loose flow and hence boost) you will reduce outlet temps and improve flow leading to more power.

If you were do it all yourself.

Ebay intercooler with clamps and reducers $200
2.5 stainless downpipe with HFC (hi flow cat) and muffer $ 1000 (installed)
CAI (ready made ones can be bought from the US ie AEM or FM) $300
MBC $80-120
BOV $250-300 (you will need it as the factory BOV leaks when you surpass stock boost)

For $2k you should get 140 to 150rwkw.

Great post Blackster. I learnt alot from it.

Bevan wrote:Great post Blackster. I learnt alot from it.

Absolutely,

Thanks for the very informative feedback. Sounds very realistic that SP performance is obtainable without very much outlay. 2k for that kind of percentage increase is pretty cheap horsepower.

Sounds like I will now have to find myself a mint SE (I'll settle for a SP if one comes along). Just got to find a bow to put on it so I can tell the missus it's a present for her

blackster wrote:MAP (manifold airway pressure) sensor

spike seriously lean on your AFR as the OEM injectors are at "duty cycle" ie max flow and cannot compensate with more fuel.

Not quite: Manifold Absolute Pressure. That's just semantics though.

Duty cycle is usually expressed as a percentage, in that the higher the percentage; the more times the injectors are opening and closing to allow fuel to flow. Max duty cycle is usually around 85%, any higher than that and you risk "locking" the injectors, which is obviously bad (AFAIK this is a problem for turbocharging an NA6 with stock injectors, they just can't flow enough fuel and they lock up). All you need to add to your statement to make is correct is the word "max".

eg. as the OEM injectors are at "max duty cycle"...

Other than that, I agree, very informative and helpful post. 150kw is decent power, at what RPM do you feel the kick in the pants, and does it taper off towards the top end?

Boags

Boags'MX5 wrote:

blackster wrote:MAP (manifold airway pressure) sensor

spike seriously lean on your AFR as the OEM injectors are at "duty cycle" ie max flow and cannot compensate with more fuel.

Not quite: Manifold Absolute Pressure. That's just semantics though.

Duty cycle is usually expressed as a percentage, in that the higher the percentage; the more times the injectors are opening and closing to allow fuel to flow. Max duty cycle is usually around 85%, any higher than that and you risk "locking" the injectors, which is obviously bad (AFAIK this is a problem for turbocharging an NA6 with stock injectors, they just can't flow enough fuel and they lock up). All you need to add to your statement to make is correct is the word "max".

eg. as the OEM injectors are at "max duty cycle"...

Thanks for the correction, if your looking at duty cycle figures

with 440cc injectors @ 10 psi with the OEM fuel pump and standalone EMS on an SE/mazdaspeed.

Max 66% duty cycle ~11.2 AFR.

The OEM injectors that are on the SE are about 265cc so hitting max duty cycle above 10psi is not hard to see.

Other than that, I agree, very informative and helpful post. 150kw is decent power, at what RPM do you feel the kick in the pants, and does it taper off towards the top end?

Since doing the mods spool starts at 2000rpm with minimal lag. The FM 02 mod has helped alleviate the big kick in the pants at 4500-5000 as there is "lean tip in issue" with the OEM ECU. There's still a kick at 4500-5000 rpm but not as big as before.

Bevan wrote:Larger intercooler ($200-$250 off ebay)
DIY air intake behind the passenger headlight ($not much - DIY)
SP Motorsport or other exhaust (custom or any other mandrel bend exhaust that will fit). Around 2.5 - 3 inch woud be good (<$1000)
Any exhaust shop to mate exhaust to the dump pipe - ($100)

Could be done for far less than the $3,000 kit.

Bevan have you got a photo of how the DIY air intake behind the passenger headlight is achieved?

blackster wrote:The FM 02 mod has helped alleviate the big kick in the pants at 4500-5000 as there is "lean tip in issue" with the OEM ECU. There's still a kick at 4500-5000 rpm but not as big as before.

Is this the issue ASE05 was having with his? He did complain that the power was kinda like a tap around the 5000rpm mark.

Jules

sliq wrote:

Bevan wrote:Larger intercooler ($200-$250 off ebay)
DIY air intake behind the passenger headlight ($not much - DIY)
SP Motorsport or other exhaust (custom or any other mandrel bend exhaust that will fit). Around 2.5 - 3 inch woud be good (<$1000)
Any exhaust shop to mate exhaust to the dump pipe - ($100)

Could be done for far less than the $3,000 kit.

Bevan have you got a photo of how the DIY air intake behind the passenger headlight is achieved?

I don't have a turbo unfortunately. BUT if I did, this would be easily accomlished by a couple of silicone or steel 90deg bends put together to fors an 'S' pattern to come out of the front of the turbo, bend up towars the bonnet, then bend again towards the headlight. Attach MAF and pod on the end and you'r away!

I don't know if it's related, but the 4-5k rpm issues you guys are mentioning effected me in teh past on my turbo NA6, we had to pull timing at about 4300rpm and then add it back in at 5000rpm, very odd, and never seen an engine that required such an ignition curve...

Remeber a lot of teh extra power guys are making with big exhausts on thier turbo cars is not just due to the exhasut, a bigger exhaust will also equate to more boost, even weithout a boost controller.

Magrat wrote:
I can't understand the second paragraph with regards to the AFM. Seems to contradict itself.

I dont see a contradiction, perhaps this explantion will help.

The SE/mazdaspeed runs MAF (mass air flow) sensor which is basically an air flow meter. The MAF sensor is used to determine the mass of air entering an EFI engine and the ECU uses the MAF sensor information to determine how much fuel is required to run the engine.

A MAP sensor also calculates mass air density by using engine speed and air temperature, the ECU uses this information to calculate the appropriate fuel flow to run the engine.

A problem with hot wire MAF sensors (what the SE has) is that they require laminar flow across the hot-wire. If recirculated turbulent air from recirculation valves is too close to the MAF sensor or a CAI that is not designed properly delivers mass turbulent air. Issues such as poor idle, poor power, poor fuel economy, hesitation, pinging or surging may arise as the MAF sensor becomes confused from changes in flow dynamics.

To run a MAP sensor on the SE and get rid of the MAF sensor you require a aftermarket ECU, usually a standalone ECU.

E-bay intercooler. Is this one of the ones from USA on e-bay?

No it can be found on AU ebay, take a look at SE intercooler upgrade thread.

The exhaust pipe and muffler is sourced from? Everything I can find seems to be above $1,200 uninstalled (1240 from MX5 Mania).

If you want to do a full exhaust upgrade that is bolt and ready to go you have the option of SP motorsport exhaust which can be found at SP motorsport or mania.

If you are not chasing every single Kw, you do not have to change the full exhaust, the restriction primarily lies in the down pipe and muffler. Any decent exhaust shop, should be able to fabricate a custom stainless down pipe and muffler for under 1k.

I have been looking at the Flying Miata CAI package for US$460, has intake, recirculated GFB (BOV???), O2 sensor mod, manual boost controller. Would this be ok, seems similar in price to list above?

The FM CAI is a nice system however it wont work on the aussie SE, the air filter sits where our ABS unit lies.

The air intake seems to be in the passenger corner of the engine compartment. Wouldn't this be a rather warm place to suck from?[/color]

There is plenty of cold air there, there are deflectors in the air dam that draws air into that area. When you upgrade the intercooler, there is a greater temperature reduction in air to the throttle body.

Ebay intercooler...

http://cgi.ebay.com.au/CoolingPro-550x1 ... dZViewItem

If you want the 140 just give them a call..I think they had quite a few of them.

They are universal intercoolers - not specifically for the MX5.

www.justjap.com

Magrat wrote:Haven't found the intercooler on e-bay as yet. Probably have to wait for a while.

Look here

Would an AEM CAI be ok, it seems to tuck into the area front of the passenger side wheel. Have only found suppliers in USA.

The AEM will fit, however you need to manipulate a few brackets.