Riley's LE NA8

[RileyR]

Hi,
where did you get the service parts- mania or mazda etc?

Nice extractors - dont throw away the standard old na8 one as I just bought a na8 engine and need a front pipe to get it into the na6 ;)

I got them from a few local places in Toowoomba. I got the t-belt kit, water pump and tappet cover gasket from parts for cars. I got the coolant pipes from bursons and wippels mazda and the drive belts from bursons. I found that wippels to be very helpful, professional and had fast delivery.

Haha ok I will hang onto them

[RileyR]

I lusted over that car so bad when it went up for sale.
BRG/Tan was my fall back plan if I couldn't find a blue one for the right $$$
I know the whole argument over steelies but those just filled the guards perfectly and make your car look like a real daemon.
Keep up the good work.
Following!

Luke.

Thanks Luke! I reckon the steelies look pretty good too. But they might be replaced one day by a lighter more attractive wheel that can fit some wider tyres. But I just cant justify that at the moment.

[RileyR]

I also bought an Xforce 2.25" exhaust system which I managed to get at cost price!
The Xforce extractors finish at 2.25" so the Xforce 2.25" exhaust should work well
The exhaust and extractors are waiting for me to get home to bolt them on.



I just need to get a hi flow cat and that will be the entire exhaust done

[RileyR]

The extractors and exhaust finally went in along with a 200 cell high flow cat
Im pretty happy with it all. My butt dyno says there is more power, especially in the mid range. It sounds quite nice as well, not too loud and doesn't completely drown out the intake noise from the mania intake.

While the extractors look great in the engine bay there has definitely been a substantial rise in under-bonnet temps




Im looking into ways to reduce the under-bonnet temps and possibly further reduce heat soak through the intake. I am wanting to avoid heat wrapping the extractors as I have read that it can often damage the extractors.

Track dog racing have a good heat shield, but could be fairly costly coming from the states. - Price is over $100 USD without shipping.




Otherwise, supercheap sell a heat shield product which can be cut to shape and moulded. Cost is around $60 and could be diy'd.




There is also heat reflective tape which can be used on the intake to reduce heat soak. At the moment the mania cai is getting pretty hot sitting that close to the extractors. The reflective heat tape would look ugly but could be effective.






Im just weighing up options at the moment, if any one has some good suggestions that would be awesome

[Magpie]

The key to reducing under bonnet temps is getting airflow through the engine bay. Why do you think the under bonnet temps have increased? There should have been no increase in EGT's?

Is the undertray installed?

You could ceramic coat the headers or install the OEM (or similar) heat guard.

[RileyR]

The key to reducing under bonnet temps is getting airflow through the engine bay. Why do you think the under bonnet temps have increased? There should have been no increase in EGT's?

Is the undertray installed?

You could ceramic coat the headers or install the OEM (or similar) heat guard.

Thanks for the reply Magpie, I havent taken any temp readings, but the engine bay is noticeably hotter when I lift the bonnet. The intake etc is also much hotter to the touch. Though, no noticeable difference on the stock temp gauge. The stock headers had the heat guard, which I assume did its job fairly well.

No undertray :/ didnt come with one when I bought it. After a quick look and read it looks like they are worth while and might help with my problem. Maybe a headlight intake would also help?

[Magpie]

Get the undertray as a priority!

Indicator intake may cause more harm than good as air can be sucked out of them. Air will always find the path of least resistance. Hence if you have an indicator intake, the incoming air hitting the radiator can go out the intake instead of through the radiator. This means less air going into the engine bay hence less cooling possibilities.

You need to force all the air coming into the front of the car to go through the radiator and into the engine bay. The undertray channels this air to exit out the back of the engine.

[RileyR]

Ok ill get an undertray asap. Should I look into expensive aftermarket aluminium types of just go for OEM?

I was considering the intake for the cover of the popup lights. But it would probably wont be overly effective like the indicator intakes that you have mentioned.

[Magpie]

Just the plastic one will do. Try Automotive Plus, MX5 Mania or somebody parting out a car on the forum.

I have a vented headlight cover (mariner blue) if you want to test it out, as well as indicator intakes. The indicator intakes need to be wired but that would not take too long to do.

[RileyR]

Ordered an OEM undertray through Automotive plus
Thanks for the offer, I might take you up on it. Have you found the vented headlight cover to be effective?

[Magpie]

They look good Try the undertray and sealing around the radiator first. Happy to lend it out if you want to test it.

Since you have the MX5 Mania intake the headlight vent will not do very much as the headlight intake is more designed to feed air to the OEM airbox.

[speed]

I also believe that my engine bay temperature increased with extractors and no heat shield but with the supercharger sitting directly above it, I don't have much space for the heat shield

[datfreak]

Its probably too much effort (the fab work) for a street car but I like how Madjak's car uses the half rad from a Honda.
It leaves a huge hole for cool air to get at the airfilter and also flood the whole engine bay without the restriction of the rad fins.
His rad does look too small but if it can cool his awesome engine it will be fine on any 1.8 nonturbo.

[pepejesus]

Not making any comment on madjak's car because it's awesome and he knows exactly what he's doing, but you do not want to flood the engine bay with air. The only thing that will do is make your cooling less effective by pressurising your engine bay.

You want to push as much air as possible through your radiator (and other heat exchangers) and out of the engine bay (through a hood vent for example).

Why are you worried about under bonnet temps? What issue is it causing? Water, oil temps etc are fine yes?

I suppose what I'm getting at is, do you even have an issue, and if you don't, mucking up the way the cooling system works to solve a non-existent problem seems like a very bad idea.

I'd suggest having a read of this thread before you do anything: http://www.miataturbo.net/race-prep-75/miata-cooling-system-thread-79930/

Particularly this part:

-Adding more cooling intakes
This never works. The opening in the OEM bumper skin is already larger than it needs to be to meet the area requirements of the radiator. What we see too often is these “cooling intakes” bypassing the radiator and actually dumping into the engine bay. The thought is “ I’ll cool the engine”. What actually happens is that high pressure air mass packing into the engine bay makes it harder for the high pressure air trying to make its way through the radiator to well, get through. The result is reduced airflow. The engine itself is a sucky radiator. Let the coolant and radiator to the thermal conduction.

[rascal]

Im looking into ways to ..... possibly further reduce heat soak through the intake.

There is also heat reflective tape which can be used on the intake to reduce heat soak. At the moment the mania cai is getting pretty hot sitting that close to the extractors. The reflective heat tape would look ugly but could be effective.

Im just weighing up options at the moment, if any one has some good suggestions that would be awesome

My suggestion is that heat soak on the intake tube would make such a miniscule difference to intake temps that it isn't worth worrying about.

Some simple maths;
An 1800 cc 4 stroke engine at WOT at (eg) 6000rpm consumes about 90l of air per second. (1800*6000/2/60/1000)
Assuming a 60mm intake tube x 800mm long (just random guesses) the volume is 3.14*3*3*80 = 2260cc or 2 1/4 litre.
Therefore the engine is consuming the entire contents of the intake tube every 0.025 seconds. ie the air is only staying in the intake tube for just over 2/100ths of a second.
The air would not be heated up by any significant amount by 0.025 sec exposure to a 30-50degree warmer intake tube.

Therefore the effort to shield the intake pipe itself is largely a waste of time.

Ensuring the air that it is entering the pipe is cooler in the first place (ie a proper cold air intake) is a whole different ball game and makes a massive difference.