[Brody]

Recently changed my automatic transmission fluid. While under the car I noticed that there are four threaded holes in adjacent bracing that look like they might be for a shield or brace under the transmission. I bought the car used with a few thousand miles, so I don't know if there's a component missing or if it was just never there from the factory.

Does anyone have any pictures of this area of the vehicle, particularly anyone with an automatic?

 

[ameridan]

My understanding is that the brace is only installed for MT. Might have been a fit or NVH (rattle) issue?

 

[Brody]

My understanding is that the brace is only installed for MT. Might have been a fit or NVH (rattle) issue?

Thanks for that insight. I figured that something goes in that location but wasn't able to locate a parts diagram showing either the forward cover, rear X brace, or "missing" center cover.

 

[mtnghost]

That are all like that, nothing attaches there. Thought I was missing something on my first Abarth as I bought it used, then bought my current one new and same thing. Mine have both been standard shift. It may be something used on the Miata platform that doesn’t have a place on the spider.

 

[Brody]

Thank you, good to know!

 

[Kentsmudger]

My understanding is that the brace is only installed for MT. Might have been a fit or NVH (rattle) issue?

This pic - from your very helpful website - shows the extra brace for the manual car, going across the gearbox, between the two plates marked on the OP's picture

 

[Walshy6677]

My understanding is that the brace is only installed for MT. Might have been a fit or NVH (rattle) issue?

@ameridan is right, the MT has a brace there, the auto doesn’t because it is deeper.

 

[Brody]

It still seems a bit odd that provisions were made for additional covers but never implemented. Even forward and rearward of that manual brace you can see mounting points.

 

[Walshy6677]

It still seems a bit odd that provisions were made for additional covers but never implemented. Even forward and rearward of that manual brace you can see mounting points.

Not really, they use as many common parts as possible, just economics. I have a manual, my friend the auto, we recently changed the transmission oils on both, it is exactly as outlined to you.

 

[Brody]

Not really, they use as many common parts as possible, just economics. I have a manual, my friend the auto, we recently changed the transmission oils on both, it is exactly as outlined to you.

I’m talking about these unused mounting points circled in red below. The MX-5 is a dedicated platform. Are you saying these are parts bin components from another vehicle like a Mazda3?

 

[Augerhandle]

Those holes are part of Mazda's "gram strategy".

 

[Good-Win Racing]

I’m talking about these unused mounting points circled in red below. The MX-5 is a dedicated platform. Are you saying these are parts bin components from another vehicle like a Mazda3?
View attachment 94324

There are some aero covers that attach to the additional points shown. My recollection is that they were europe only (faster autobahn speeds made them actually useful) and manual transmission only. I don't recall if they were Miata only. At least in theory they gained very slight advantage in miles per gallon. There are aftermarket versions, we sell the Velox brand though out of stock today they look like this picture below on Manual transmission ND Miata.

Note that there are some potential issues with sealing the bottom of the Fiat entirely. With the Fiat you have an exhaust driven turbo, with the Miata we do not. Result is that everything with Fiat involves MORE HEAT. Sealing the bottom means more of that heat is trapped with result you get higher transmission and differential temperatures. We also noted they won't fit with bigger diameter exhaust systems. Thus, for all those reasons, we don't run them on our Fiat 124 that we race and we don't list them in the Fiat 124 section of our website.

 

[Brody]

That's really definitive and authoritative info, @Good-Win Racing! Thanks for solving many mysteries simultaneously. I think that's a great point regarding heat with the 124 if it were too buttoned up.

 

[Walshy6677]

This pic - from your very helpful website - shows the extra brace for the manual car, going across the gearbox, between the two plates marked on the OP's picture

Hi @Kentsmudger, this isn’t quite right. The UK/ EU spec on the MT car has covers/ connectors between the braces. I haven’t got a picture on the car, but you can see it here when I took it off to fit my System One exhaust. Actually, when you remove the fixing bolts it comes off as one piece.

 

[mtnghost]

Hi @Kentsmudger, this isn’t quite right. The UK/ EU spec on the MT car has covers/ connectors between the braces. I haven’t got a picture on the car, but you can see it here when I took it off to fit my System One exhaust. Actually, when you remove the fixing bolts it comes off as one piece. View attachment 94356

Yeah we don’t have that in NA.

 

[Brody]

@Walshy6677 At first I thought that was your car laying on its side next to the road.

 

[Walshy6677]

@Walshy6677 At first I thought that was your car laying on its side next to the road.

Well it was a fair amount of it that’s for sure! 😂 😂 😂

 

[madfiat]

The heat issue is legit. I'm like "who the hell would want seat heaters" because anytime I drive more than a few minutes, the trans tunnel and most of the floor pan is radiating heat at me anyway.

 

[Walshy6677]

There are some aero covers that attach to the additional points shown. My recollection is that they were europe only (faster autobahn speeds made them actually useful) and manual transmission only. I don't recall if they were Miata only. At least in theory they gained very slight advantage in miles per gallon. There are aftermarket versions, we sell the Velox brand though out of stock today they look like this picture below on Manual transmission ND Miata.

Note that there are some potential issues with sealing the bottom of the Fiat entirely. With the Fiat you have an exhaust driven turbo, with the Miata we do not. Result is that everything with Fiat involves MORE HEAT. Sealing the bottom means more of that heat is trapped with result you get higher transmission and differential temperatures. We also noted they won't fit with bigger diameter exhaust systems. Thus, for all those reasons, we don't run them on our Fiat 124 that we race and we don't list them in the Fiat 124 section of our website.

Brian, I’d never thought about the heat issue, I don’t feel any undue radiated heat when I drive my car, even on log runs. We recently had some days of 6 hours in the car for instance. I fitted a System One and would say there is a lot of insulation between the exhaust and body. Would your suggestion be to remove the plastic bits and leave just the brace to encourage heat dissipation?

 

[Good-Win Racing]

Brian, I’d never thought about the heat issue, I don’t feel any undue radiated heat when I drive my car, even on log runs. We recently had some days of 6 hours in the car for instance. I fitted a System One and would say there is a lot of insulation between the exhaust and body. Would your suggestion be to remove the plastic bits and leave just the brace to encourage heat dissipation?

Insulation between exhaust and the body is there for a reason and you should leave it alone. Not clear to me what you are referring to as 'plastic bits' but if just a street car I wouldn't worry much if you have the extra panels. In race use we found there are limits to how much we can seal the bottom, heat levels for transmission and differential can get too high and we have exploded both on track when we sealed the bottom too much.