Full Underbody Kit
 

Made a comment in anther thread to gauge interest and instead up muddying up that thread started a new on. Long story compacted super short is i have a miata, Solidworks, and a supplier with laser tables and breaks and all sorts of good stuff we use for work. I have been mocking up a full flat under-body in Solidworks from the front splitter all the way to the rear diffuser. As of now I am planning to have the splitter cut from 3/8 alumalite, the under-body and diffuser of .074. I will also have stainless frame rails made at the same time but the thickness it TBD. The end result will be a full underbody kit front to back with proper ducting for trans and diff and ducting for the radiator. If this is something you guys are interested in ill get the design posted up here in a week or so and we can modify it to our liking and get a group buy going. (My laser cutting guy gives a huge price break at 10 units,)

The problem with efforts like this is the same as all of other niche miata performance products. Being that, in the price range that this car plays in... the consumer base that wants something like this, has the means and motivation to fabricate it themselves. Especially for what this will inevitably end up costing...

Not trying to burst your bubble, and you've got to start some where. However this is a common problem that plagues the miata aftermarket and it's an inescapable reality of an aftermarket for a car with an initial buy in cost under 5k.

I would like to see the drawing.

Fully aware of that. About the only thing I have going for me to make this cost effective is my purchasing power with the laser cutting company. This year we were 70% of their total sales which is projected to be close to 3.5mil this year just to them. The only other part is i can provide the convince of having everything from front to back.

But like you said these cars are cheap in the racing word and these parts arnt that hard to make on your own at home with enough time and planning

Some of us don't have facility to accommodate such custom work but also don't want to pay a shop. I'd be interested in drawings, but just like any other thing...it may have to be tailored or adapted since everyone runs different exhaust and subframe setups. I imagine it'd be beneficial to market some pre stamped and bent radiator ducting, but alas, different intercooler and A/C setups.

Agreed. The radiator ducting i would leave closed of and allow for people to cut their own intercooler/brake duct holes into it. I know you are running over the top charge pipes and i plan to do the same. as for the exhaust im going to make sure it will utilize the stock exit location or straight out the back for those who prefer that.

Friking love your car too. its what spurred my VVT motor build

Aww shucks.

Damn, I was in Seattle/Bremerton for nearly a month last October. Should hung out.

Also if anyone needs anything laser cut let me know and we can come up with a drawing and get one made

Can we work on radiator duct?

Assuming no ac condenser

Sure can. What did you have in mind? Oil cooler mounting ncluded in shroud?

sub'd

I also have 3D modeling software available to me to make various projects. My main issue I have is finding someone willing to make the parts for a decent price.

I can get you a quote if your pm me a dxf of the drawing.

I didn't even think about an integrated oil cooler mount. But modular is good; options and holes for later that can easily be plugged. I have my oil cooler mounted behind the radiator right now.

I may have the bumper off in the next week or two to take some photos and eventually start doing some CAD. (Cardboard Aided Design). But like you said, something generic enough that folks can modify accordingly for intercooler piping or brake ducting. Right now, I'm just thinking simple box to the mouth. I wish the bumper itself wasn't so bulky and space consuming, but I don't think I'd give it up for a bash bar.

Got a fan shroud all modeled up. It is configurable to run either dual Spal 30101522 (1328 cfm @13A) or a single spal fan with a 25 row setrab or earls oil cooler. Still need to make a cutout for the coolant lines and add in the bulb seal to seal on the radiator.


https://cimg1.ibsrv.net/gimg/www.mia...aaf6673ef1.jpg
https://cimg2.ibsrv.net/gimg/www.mia...b88b5de880.jpg

Oh I misunderstood. I was thinking oil cooler mount integrated to ducting not shroud.

That's essentially how mine is mounted now, sans shroud and sealed to the radiator independently.

I was thinking of moving the cooler forward of the radiator. Single fanning it. But need to make a duct pretty badly.

I know what you meant. The oil cooler is way more efficient in front of the radiator. But I've seen many people on here mount it like you have it so this would give some flexibility on mounting. The undertake will have provisions for an oil cooler in front of radiator.

What's the thickness capacity of your laser people. Specifically 1018 cold rolled plate.

.135 10g is the thickest they can get in a sheet or up to 4x6 flat bar
They can cut 2" on the laser then jumps to the waterjet.

Your lower pic with the fan and 25 row oil cooler is actually how I am planning on setting up car only I'm using the 14" 30102042 fan (1864 cfm 17A) and the factory Setrab brackets for the 25 row. Street car so I was going to fab up a shroud like that for my Supermiata crossflow rad. Looks good!!!

Pretty happy with this, might make the cutouts for the radiator hoses a bit tighter fitting. Weight as shown with 2 12" spal fans is roughly 8 pounds
https://cimg3.ibsrv.net/gimg/www.mia...b73ea23c2e.jpg

Rather than just making another dual 12" spal shroud, why not make brackets to mount a single volvo fan with no shrowd. I think the race crew would be more on board with that, OEM quality fan that flows as much as 1.5 12" spals and not blocking airflow from most of the rad when at speed.

Do you have a part number for a the fan you're speaking of. or mounting basic hole locations for mounting points. I could have that done by this afternoon with enough info.

Is it the 15" fan front the volvo 850s

https://www.partsgeek.com/xb8g2h7-vo...y+Fan+Assembly

is this the fan you want in a shroud

I forget, some crazy volvo guy has a sight where he compares all of them and figures out the best one, the one thats almost as crazy as the tarus fan.

From what I've read today the 93-97 is a 15" fan with a high and low speed with the high speed gerring like 3500cfm. Then after 97 went to a smaller lamer motor.

I'm picking up a fan on Sunday for $50 off cl and will draw up a mount kit Monday.

Anyone else interested in a single fan with huge cfm numbers

Doube post

I've always liked the idea of a full underbody thats mounted on quick release posts. Some day, I guess.

This sounds really promising re: the huge fan. If that shroud has space for an oil cooler then that would be an awesome place to put it, i.e. out of the way of getting damaged easily and in a place with good air flow.

What size oil cooler do you guys want the mount to be fitted for? Im assuming a 25 row setrab cooler.

Fan was in bad shape so ordered a dorman oe replacement fan today. Should be here on the 29th. Once the fan shows up I should have a mount within a day or two.

as far as an oil cooler I think it'll be a really tight fit with the fan but I'll do my best to get it all behind the radiator.

anything you guys want to see made in the meantime before I hop back onto the front ducting and undertray

25 row

I have a rough model of the fan with a 25 row setrab and it fills every bit of cooler we have. It might get better once I get the fan and can throw some accurate dimensions in.

The other part I'm on the fence about is how I'm going to seal the fan and oil cooler to the radiator. I'll get creative with this and post what I come up with. I want this to be a cheap and easy solution for cooling.

Here is a teaser of what is to come


Teaser deleted

i did something similar, albeit not that fancy and rather more homegrown: https://www.miataturbo.net/build-thr...3/#post1399530

https://cimg4.ibsrv.net/gimg/www.mia...de59773c82.jpg

works great, but fitment with the intercooler pipe going to the intake was tight

FM claims that the dual spal 12 inch setup is like 4700 or something.

FM kit claims 4700 m3/h. When converted it is about 2780 cfm

Using a full fan shroud on a track car is a bad idea. It will not flow anywhere near enough at speed. You want as few obstructions to flow as possible. I had the full FM stage 2 airflow kit and their crossflow radiator, and my car would overheat in 75 ambient temps with a 200whp rotrex. Pull the shroud, pull the second fan, and temps didn't go over 200.

Just mounting the fan and the oil cooler to the back of the radiator is what you want to do. Any shrouding is just going to decrease total airflow through the radiator. Fans are only needed for cooling in low speed situations, where not a lot of heat is being generated, or in high throttle low speed applications (like an ag tractor or a bulldozer) which no track miata should ever see.

Edit: for hot areas and AC use, a fan shroud may be useful to ensure fan draw is completely through the radiator.

Understood. Leafy steered me in that direction and i am already working on a solution with the volvo fan. Ill have the fan mount finalized today other than a few minor changes once the fan arrives. Ill post a pic of what itll look like later today

https://cimg6.ibsrv.net/gimg/www.mia...896bc43619.jpg
What do you guys think of this. Only thing left is the mounting holes for the fan and a few relay mounting tabs

If it's a cross flow radiator, the oil cooler might interfere

If you send me dimensions on the crossflow I can make sure it works or come up with another solution for it.

Specifically the core size and the mounting studs for the fans

It's pretty much the same dimension, but the inlet is outside adjacent to the welded mount on the operating right side. Just enough for the hose and clamp, not much else.

https://cimg6.ibsrv.net/gimg/www.mia...a236a4e842.png

i can move the oil cooler down an inch or so that would clear the hose neck then I could make the oil cooler bracket shorter so that it stops with the end of the cooler and has 3 points of contact instead of 4? It would still be sealed all the way around just only bolted in 3 of the 4 corners. What do you think

Just an update on the fan. It shipped and will show up on the 29th then should have first prototype done by the 4th.

If you move the oil rad lower, it might collide with the front roll bar. Especially when running an oversize one. It really is tight down there. I had to redrill the brackets that hold my alloy rad in order to bring the lower part of the rad a bit more to the front and to increase clearance to the roll bar

(the British roll bar, i.e. sway bar)

I'm aware of this. I have the tubular roll bar that I will be test fitting with. I'm going to make it as low as possible while still clearing the roll bar so I can remedy the top clearance for psyberoptix csf radiator.

I steered you to the single volvo fan because if you made a double 12" fan shroud you'd be going against at least two other established solutions for the same stupid shit. The single volvo with no shroud will probably be the hot ticket for street/track guys that want to keep AC.

Got the fan today and will be cutting it out after work today. As far as compatibility with the crossflow radiator ill cut the top right off the oil cooler bracket for hose clearance and run 3pts of contact or i will make a new fancy bracket to capture all the mounting points. You decide.
https://cimg1.ibsrv.net/gimg/www.mia...a37b6cd6c9.jpg

Got pricing on the fan shroud today and we are looking at $130ea if we order 5 or $115ea if we order 10 and $108ea if we order 15. You would have to source your own fan and wiring. The shroud will come with bulb seal to seal the fan portion of the shroud to the radiator to maximize efficiency. For another 175 I can source and ship the fan and wiring as well.

As far as the oil cooler mounting I'll be doing this in the near future once I get myself an oil cooler to verify fitment.

https://cimg1.ibsrv.net/gimg/www.mia...123ee560a9.jpg

Mocked up working on wiring and should have it in this weekend. The fan porting is fully sealed on the radiator. Ill post more pictures on Thursday.

Thats fucking sick. You're gonna blow the hood right off with that thing.

Trying to make up my mind on wiring I have 3 options

1. Dual relay for just hi/low
2. Same as above with soft start to not go past 22a draw ever
3. Variable speed based.. rpm based off water temp maxing at 22a on hi

So got a wiring plan. Going to do option 3. It costs a bit more but is by far the best way to control the fan. The controller that ill order to test controls the fans 1-100% power with a soft start feature so there should be little to no idle dip at all which will be nice for the people that arnt able to run idle control. Total price for me with the variable fan control puts me right at $400 which is higher than anything on the market but will probably be one of the most functional.

I do heaps of this oil cooler location for customers. had great success so far. Quality hose and high flow -10 fittings and it hasnt caused us any issues at all.

We use a large PWR 21 row 1.5" thick cooler.

https://cimg7.ibsrv.net/gimg/www.mia...e414b31a0a.jpg
https://cimg8.ibsrv.net/gimg/www.mia...e6307e23a9.jpg
https://cimg9.ibsrv.net/gimg/www.mia...1bdf85a7aa.jpg


Dann

Good to know it fits there. I should have an oil cooler after the new year to start fitting on the radiator. Ill probably have the fittings come out towards the center with a -10 180 fitting but well see how much space is left once it's all mounted in the car. Also working on a replacement undertray that seals that area up.

also if anyone else has any good ideas on formed parts they want let me know and I can draw something up.

Does anyone know what our coolant temp sensor is outputting gfor a signal? Is is 0-5v or 1-4000ohms

Fan is in. Had to trim for the sway bar but lots of extra material on the fan. Currently there is about 1/4'' clearance. I have a variable fan speed controller with soft start so amp draw is a minimum while running.

https://cimg7.ibsrv.net/gimg/www.mia...27ee1cb990.jpg
https://cimg9.ibsrv.net/gimg/www.mia...531ea64c34.jpg
https://cimg1.ibsrv.net/gimg/www.mia...67863d58d2.jpg

Which fan controller did you use?

https://www.summitracing.com/parts/d...SABEgLkofD_BwE

This controller but i will just tap into the temp sensor wire for a signal instead of the probe that comes with the controller. The signal for the controller is 1-4000ohms according to derale's tech department.