Riley's LE NA8

[RileyR]

Thanks for all the helpful replies,

The undertray is in (very fast delivery from MX5 Plus) and I think under-bonnet temps have dropped a little. Im kicking myself for not realizing that it was missing in the first place as its obviously pretty important for cooling

I had no idea about the negative effects of positive pressure in the engine bay. My logic was that the more air going into the engine bay the better, so thanks for clearing that up.

Thanks for that info rascal, 90L of air per second is a lot more than I would have thought was going through it! Im surprised the intake doesnt feel cooler compared to other things around it. In any case, I wont be throwing money at shielding the intake any more

I may however look into getting a proper temp gauge so that I can be aware of any problems early on

[pepejesus]

The engine is cooled by water, and that water is cooled by the air flowing over the radiator.

So you don't want more air going into the engine bay to cool the engine, you want more air going through the radiator to cool the water to cool the engine.

The best way to do that is by ensuring the air coming into the engine bay has nowhere to go except through your radiator - this is why people spend a good bit of time making sure any gaps around the radiator are sealed, and creating ducts that ensure the air has nowhere to go except straight through the radiator. The factory undertray will assist with the latter. See this thread for example: http://mx5cartalk.com/forum/viewtopic.php?f=30&t=71173&p=874025#p874025

I wouldn't worry about under-bonnet temperatures (or the perception of under-bonnet temperatures) - what I would worry about is the water temp, the oil temp, and whether your air intake has a good source of (relatively) cold air.

It seems like with your current intake that's a resounding yes to the last question, so no issues there.

The other questions to answer then, are your water and oil temps ok, and you've not mentioned anything indicating either of those is too high.

From what I know about your car on this thread, I would be incredibly surprised if you had issues with either of those things.

The feeling of radiant heat from your exhaust manifold is not an indication of anything other than the fact that hot gasses flow through there (a good thing - that's what it's there for).

[RileyR]

Thanks for the info pepejesus.
I like the idea of being able to DIY some ducting cheaply. It might be over kill for me to start down that path as its not a highly modified engine etc, although it might help me out for hill climbs or even sprints.

I havent had any issues with cooling, but thats just going off what the stock gauge is telling me.

[pepejesus]

Even with stock engines the stock cooling can be marginal at the track on a hot day. Doing a bit of DIY ducting would be a good insurance policy. Plenty of people reckon that ducting will give you the biggest benefit to the cooling system, more so than even putting in a massive radiator (and it's a lot cheaper too!)

Re: the under-bonnet temps - it's an issue if you're melting things in the engine bay, but apart from that, shouldn't be a worry.

[RileyR]

Ok good to know. I have had a bit of a look and cant find too much that I could do to improve it (now that i have the oem undertay). I am running with AC so the radiator for that is in front of my actual radiator, so its going to be a bit harder to properly seal it all off. But I could fix up a couple things ie the gap on the top underside of the bumper.

There are some hoses running pretty close (only a few mm) to the extractors and I might look at protecting them as I dont want them to burst. Can they take the heat?



Also, this happened on the weekend



I found 2 sparco jnr's for sale on 2 sides of Brisbane and managed to nab them both. I have 2 harnesses as well (need the eye bolts/ mounting points)
One comes with drivers side rail already attached making that easy to install (need a new seatbelt stalk to mount to trans tunnel though).
However, passenger side is going to be difficult - from what I have read. And I want these mod plated so I might look at getting it done properly (possibly on a set of na6 rails to prevent hacking up my stock na8 rails).

[Magpie]

So coming out to Morgan Park to test out all the changes?

[pepejesus]

Be interested to see how you go with the harness on the left - I've just installed a similar Sparco 6pt along with a Sprint seat in my SE.

I've found that the adjuster on the pull-up style lap restraints fouls the opening on the seat, which is less than ideal.

Although if you were sat further forward (I'm as far back as I can get) it might not be an issue.

I'm currently considering whether to try and replace with a a pull-down style harness (adjuster is close to the buckle rather than close to the carabiner/eye bolt) or just put up with it...

[RileyR]

I got some good news today which will put all this off for a week or two. But I certainly do intend on testing it all out at the track as soon as possible
Ill let you know how I go with the harness when I get around to sourcing and the bits I need to mount it up

[RileyR]

I found the time to bolt in the drivers side seat but encoutered some problems .
(I started a new thread in regards to this as its too big for this build thread)
viewtopic.php?f=28&t=71241

[RileyR]

Both seats are finally in









The seats are great, I got a fair bit lower, they are pretty comfy, obviously very supportive through corners, they look great and are only a bit harder to get in and out of with a bit of practice.

[RileyR]

Some other small niceties

[RileyR]

I made it to the QR midweek sprints yesterday on the clubman track.

The mx went great and I was surprised at how well it came back from hairy moments.

My best time for the day was 1.09.45 (clubman circuit) which I am pretty happy with to be honest for my first sprint event on tarmac.

Im keen to get back out there and improve



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[RileyR]

Heres a video of that lap. I can see some things I can improve on, but am happy to get any advice etc from some of the old hats.

[pepejesus]

I've never dríven this track so can't really give you any specific pointers on certain corners etc but these are my general thoughts.

The car appears to be under-damped, what springs and shocks are you running? Seems to be causing a bit of roll oversteer mid to late corner in particular as the oscillations you generate on turn in are not being properly controlled.

Driving wise I think you should just focus on being smoother, far too many abrupt inputs and too many inputs on the wheel in general, particularly on entry. I think you also need to get your heel toe shifting down pat as it looks like you're a little late which combined with your abrupt inputs is unsettling the car quite a bit mid-corner.

With your lines, you're not using all of the track particularly on exit. Let the car run through the corner all the way to the exit. At the moment you're giving it too much steering mid corner and scrubbing off speed. It's all about momentum with these cars. You want to concentrate on having a nice smooth arc from entry all the way to exit. Mid-corner should be all about letting the car just run it's line without scrubbing off speed, then unwinding the steering lock as you feed the throttle back in and just ruuuuuuunnnnn the car all the way to the edge of the track on exit.

It also looks like the car is too loose but it's hard to tell whether that is because of your driving or an inherent balance problem with the car.

All in all though looks pretty good, tidy everything up and you'll be well on your way.

[RileyR]

Thanks for the tips pepejesus they are much appreciated,

Im running stock shocks with lowered king springs Not ideal I know.... But budget and priorities will mean that it could be a while off before I can upgrade them. It did feel a bit 'rolley' and I constantly had trouble through the bumps through the dipper (turn 3) - as seen in the vid. I have considered just getting some decent 2nd hand shocks but I think it would only be a temporary solution and need to be replaced with decent coilovers anyway.

I did notice I was very abrupt on the steering, especially on this lap (but somehow it was my fastest?). - Definitely something to improve on in any case.
When down shifting I am not applying even pressure on the brakes, as in when I blip the throttle I am also pressing the brakes harder. This shouldn't be too hard to remedy as I can practice that anytime.

Yes I was losing speed mid corner, but I couldnt work out why! Your comment makes sense. Quite often at turn 5 I was struggling to hit the apex but I didnt feel I was going fast enough on the track out, so I tried a late apex (as in vid) but I still didnt feel I was fast enough on the exit.

Hopefully its not too long till I can get back out there on the same track and try and improve.

My clutch slipped a few times on the more urgent gear changes - So im thinking on its its way out and in need of replacement