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I bought my first Miata a couple years ago as my first track car to learn with from a local track instructor. The car had a roll bar, bride seats, FM Vmaxx suspension, Track pads, and big 15X9 NT01 Shoes. Since I couldn’t fit in the Brides, he kept them and I added some Kirkey Intermediates bolted to the floor, and a 330 Momo steering wheel for leg space (best upgrade ever! Who would have ever thought that?!?!)
With that, I signed up for my first track day and had a blast. By my 3rd track day, I quickly found the two Achilles heels of the Miata for track days.
1. The car runs hot even stock, especially in the South
2. Guys in big V8’s anything not a Miata don’t understand what lifting is when giving a point by.
I quickly solved the running hot with a nice aluminum radiator and coolant reroute. For power I made the rookie mistake and tried doing bolt-ons. (Header, exhaust, intake) and quickly realized that was getting me nowhere fast. <--HA! (In the bolt-ons method defense, I really needed a MegaSquirt and tune, but I knew I wasn’t going to be happy once I had that.)
So the quest for more power began in earnest. Well, the research phase did at-least.
I even gave serious thought to a few different cars (a C5 vette & e46 M3 were both very high on the list) but the Miata is so supported as a track car and so much cheaper to run it kept winning out. Now the question became, how to make the Miata faster for the track.
Now, before I go over all the options I looked into, and boy there are a TON of options for the Miata, let me state my “goals” for the car.
Goals:
· Reliable on the Track (There is enough maintenance to do on a track car, I don’t want to be wrenching on the car more than driving it.)
· Enough HP to actually pass someone (that’s 250+ WHP to me)
· Easy to work on / fix
· Cheaper running costs
· Safe & Comfortable
With those goals in mind, I started looking at all the different options. Below are my thoughts and guesstimate on cost (I’m only talking drivetrain in cost for parts. Suspension, brakes, seats, etc. have to be upgraded no matter what.)
KMiata – I’m a huge fan of high revving engines and the K24A2 engine is what should have been offered as the High Performance version back in the day. Talk about the perfect engine for a little lightweight two seater! With those accolades, you would have thought I would be building the KMiata, unfortunately, for a track car, I feel you need to replace the trans (weak if you add any more power) and diff (need a lower ratio) or swapping those out and you are at guesstimate of 12K in costs and 220 HP & 180 Torque. I also wasn’t crazy with the Frankenstein car…Honda Engine, BWM Trans, Chevy Diff. I felt like this could be hard to find parts for.
JV6 Swap – I really didn’t like the idea of supporting the engine from just the back. Also it used the Miata trans & diff, and I felt they would not be reliable enough on the track with this sort of power. I like this swap for street, but didn’t look robust enough for the track to me. (305 HP & 275 Torque (engine) Guesstimate of 6K in cost with no changes in Diff or Trans)
Ecotec – I didn’t research this as much. The Ecotec has nice low end torque, but in real life guys seemed to be only getting 170hp and the engine runs out of steam before it redlines at 7k. Granted this swap is relatively cheap, but for the power of the Ecotect, I’d just find a nice used supercharger and save some cash and a bunch of the time. (170 HP & 170 Torque (wheel) Guesstimate of 3.5K in cost with no changes in Diff or Trans)
Exocet – I saw a few of these at HPDE’s and thought they would be a blast. I also always wanted to build a kit car. I was seriously thinking about an Exocet for a bit, but, their Achilles’ heel is aero and they get Miata slow once you hit a long straight. So in the end, I’d still want more power, which means turbo or engine swap in the Exocet…now you have the cost of the Exocet & the power upgrade.
302 V8 swap - I didn’t give this combo much thought. The five point oh, didn’t really appeal to me and I’ve heard there can be handling issues with this swap (but I’m sure there are ways around it. Again, didn’t really check it out.) (225 HP & 300 Torque (engine) Guesstimate of 10K)
LS Swap – An honest LS3 swap would be pure madness for the track…AWESOME! 430hp (before going full retard with the 525hp cam upgraded version) has to be intoxicatingly fast if you can ever find a place to stretch all those ponies’ legs out. But (don’t shoot) the LS engines aren’t really “fun” engines to me. I know they are super fast, but they feel lazy to me. (I guess since they aren’t really a reving engine and all that torque, no need to shift.) Lastly, the LS swap is expensive (much less so if you use an iron block truck motor, but I wouldn’t do that for a track car) and you could have a nice C5 Z06 for the same price with a lot less wrenching. (430HP & 425 Torque (engine) Guesstimate of 18K)
EFR 6258 Turbo – I had basically decided this was the route I was going to take. I did a bunch of reading for a few months, and I never heard a bad word about the EFR 6258. It spooled super quick and I saw guys making over 400 wheel horse power with them…at least for a very short time before blowing something up. I was pretty much going to follow the Super Miata / Track Speed formula. So why didn’t I choose the EFR? Every build I read always had something blowing up. Either the engine (After putting 5k in stronger parts in it…Ouch!) or the trans would go. I even was reading about one guy that kept breaking his half shafts. It always seemed like everything was fragile. Not to mention you are always battling the heat. Living in the south, heat is a real issue. I know a lot of you have built and track turbo’s successfully, but the learning curve is steep, the cost is high, and everything in my opinion, is still on the fragile side. (280 HP & 250 Torque (wheel) to stay semi reliable Guesstimate of 12K)
Rocketeer – I only saw this recently. Adding it more for others incase they are researching. It’s a V6 Jag motor that looks great in the example they have. (240HP & 220 Torque (engine) couldn’t find cost of kit)
LFX – I remember originally looking at the V8Roadsters website, seeing that the LFX swap kit cost more than the LS swap kit and asking myself, why would anyone want to pay more money for less horsepower? Well, the part I was missing at the time was that a used LFX can be had for a lot less than an LS motor or a built BP motor. The LFX can be had for about 1 grand, it weighs the same (some say less) than the Miata BP it’s replacing and it’s a splash of E85 away from 300+ wheel hp. Additionally the trans is built to handle the power and the diff comes in ratios that are useable. I won’t have the heat issues of a turbo, and it’s not fragile since it was originally built to handle this power in a much heavier car. The learning curve is also not as steep for me, since I won’t be learning to tune the engine or how to build a motor with the LFX swap. So, what’s not to like about the LFX? I’ve found two things. First, is it’s direct injection and the valves get dirty quick. This is solved with a very good oil catch can. Second, people seem to have clutch issues. (Almost everyone is running an aftermarket clutch, so I’m going to try the heavy (over 50lbs) stock clutch to begin with and hope for the best. (290 hp & 260 Torque (wheel) Guesstimate of 12K)
So there you have it. The LFX swap is my Goldilocks swap for the Miata.
My present track car isn’t the prettiest with hail damage and such. I knew I’d be unhappy spending a bunch on my present car and it still looking rough once done. Additionally, if I bought another Miata I can still do track days while I’m building. That’s the best of both worlds!
I started my search around Christmas break, and ended up finding this car a week later with a blown motor. It was sitting at a mechanics shop in a big puddle with the engine half apart and everything was wet. That said, the body and paint looked good and I figured I could sell some parts to cover most of the cost. She came home on Jan 1st. Starting the New Year off right!
Home at last! With her roller skates on.
A couple weeks later I picked up a hardtop. It needs paint and a little work, but will make a great top for a track car. (That said, if I find a lightweight aftermarket top, I might buy it and sell this one. Either way, I now have a top for the car too.)
Finding the engine & drivetrain took about a month. This was a bit more work than I originally was expecting. I searched ebay, craigslist, camaro5 forum, called some local yards, LKQ, and Car-Part.com. In the end it was Car-Part.com that I used to find my drivetrain.
I was looking for a complete dropout motor from a Camaro so I didn’t have to buy a bunch of brackets, bolts, and other parts. (If you’re doing this swap, I highly recommend you do the same, otherwise you will spend a bunch of time and money looking for miscellaneous bolts / parts and you will get nickled-and-dimed to death) Additionally, even better to get a drop out from a manual transmission car, since the wiring harness you need is from the manual, and you might be able to use the flywheel and a few other manual specific parts.
Unfortunately, you are going to find that most engines have been pulled already and stripped, thus why the long search.
The LFX swap from V8 Roadsters gives you the choice between two transmissions…the MV7 & MV5
Originally, I was looking for the MV7 transmission (which is about impossible to find, since only 3 Caddy owners in the world wanted a manual transmission and the MV7 was only put on an ATS Caddy for a few years.) Anyway, the MV7 is “the” transmission to get if possible since the gear ratios are a little bit more evenly spaced.
Since the MV7 is unobtainium, I decided to just go with the MV5, which is the tranny used on the Camaros and much easier to find.
Once I decided upon the MV5, I figured out a trick to help find a manual LFX, verses an auto. The "trick" I ended up using to find my “complete” motor is the transmission. If you search by the engine the majority of cars you find will be auto, but by searching on the transmission, you know the engine (if still there) is what you need. This limited a lot of the noise, and once I started looking this direction I found what I was looking for pretty quickly.
I ended up getting a complete 2014 engine (except the power steering pump & AC compressor) and trans with 25k miles. The gentleman I was working with also found me the 3.42 limited slip diff. All of this was put on a pallet and shipped to a buddies house (easier for semi to drop off) from Florida for just under 2500.
At this point, I’m only missing a handful of “chevy” parts. 2012 ECU, Power Steering Pump Assembly, Gas Pedal, MAF sensor, and some bolts for the starter & alternator (they had removed them already to sell separately.) I found a guy parting out a Camaro on the Carmaro5 forums and bought all the other parts I needed. (Except the ECU, more on that later.)
I originally bought an engine stand, but after seeing what others did, I returned it and bought 3 small dollies from Harbor Freight. They have worked great. I did have to cut up a 2x4 (Taken from the pallet) to reinforce the dollies so they wouldn’t break. I ended up using one dolly for the 1.8 I pulled from the Miata and the other two dollies for the 3.6 engine & trans.
Always nice to see another LFX build. Yeap - stay away from SPEC clutch + flywheel - good news though is LuK now has a clutch+flywheel replacement kit that's not outrageously expensive. You will need an engine stand to (easily) replace the shortened oil pan. NB has a bit more room in the engine bay, I'm sure this is gonna be a fun build.
This has taken me a lot longer than I originally thought it would. I figured I could disassemble the car in one weekend. Granted, I have bagged and tagged everything as I took it off the car (which takes a lot more time) and I haven’t just cut hoses or snipped wires, I’ve pulled everything out in a manner that I could still reuse it if I wanted. Additionally, I also tagged every electrical connection. (Just used blue masking tape) so I can more easily chase wires later on. (Not sure if this will be a huge help or not, but it’s done just in case.)
I also didn’t realize how much I needed to strip the car down to just its shell. In the back of my mind, I thought I really was just pulling the engine & transmission, but in reality, you have to pull EVERYTHING off the car. (I lie…not everything, you can leave the windshield wipers on the car and the rear tail lights.) None of this was really hard; just a lot more time consuming than I thought it was going to be.
Out with the old! The engine is just the start, so much more to pull from the car...
Now for the front subframe & control arms etc. & then the fenders and everything else...(Ignore that beautiful LFX teaser...I couldn't find a photo with everything pulled.)
Can't forget the interior...Here's the dash pulled... and then everything else...(Good Riddance to the STINKY carpet!)
So far I've left the Rear Subframe in the car. I'll show some pictures of that once it's pulled later.
Note 1: If you don’t own a proper ½” impact gun, do yourself a huge favor and go buy one now. I don’t know what took me so long, but it made removing the exhaust and the PPF so much easier. It saved me a couple hours of work already.
Note 2: If you are buying the Harbor Freight 1 ton engine lift, it's barely long enough to reach the engine, If I didn't have the bumper cover off, I'm not sure it would have worked. With the cover off, this will work, but I wish I bought the 2 ton.
Thanks for the clutch info! I've seen everyone having issues, and I'm fairly certain I'm going to have to swap mine too. As far as the engine stand...LOL...I have found that out the hard way. More to come, but I wish I had for the oil pan.
To fit the LFX, you have to cut the corners off from the engine bay and do a little hammering on the firewall.
Corners
I was a bit worried about cutting the corners, but cutting them ended up being easy. I think it took me an hour in total to cut them off and that was only because I broke a few cutting wheels in the process.
Corner before cut....
The top cut...(The blue tape was used as a guide for a straight line)
Almost all done. (as everyone else has said, be careful that you don't cut the bottom part otherwise you have a hole you will need to deal with.) This was the hardest area to cut, since the blade on the grinder doesn't fit as easily. Also, probably smarter to remove the rubber steering shaft piece before cutting.
I decided to make my own corner supports. I wanted to cover the entire area so it looked smoother, where the V8 Roadsters is more like a piece just welded on top. (That said, once the engine is in, nobody will every see this part of the car.)
I used 11 gauge steel (1/8" thick) for these corners. I did some CAD (Cardboard Aided Design) for these pieces and it took a few times of test fitting and then grinding but they came out pretty well. If you are doing too, start with the firewall then the fender. There is a lip on the fender side that will help hold the firewall piece in place. You can just slip the metal behind it.
Firewall piece made and tucked in behind the fender lip
With the Fender side in place.
Ugly Welding...(This was before I started welding with Gas. Just like with cooking, Gas is SO MUCH BETTER / EASIER. Flux core welding was so much harder, especially on thin sheet metal. If you are learning to weld like I am, I highly recommend you use gas over flux core. All that said, my welding still looks like crap, but its much better than with flux core.)
Firewall Modification
I couldn't find a lot of pictures (or they weren't very clear to me on where exactly I needed to "dent" the firewall before putting the engine in. So I ended up test fitting the engine, marking and then hammering the area a bit.
These two picture shows the engine touching the firewall before I did any massaging of the area. I was able to get the front 4 bolts for the subframe on, but the back 4 bolts wouldn't were not even close.
I dropped the engine again and hammered around the area. Here is what it looked like after the first pass. Everything fit now, but it still needed a little more persuasion for engine movement before calling it done. You can see where most of the hammering/bending was with the paint chipping off. It looks a lot rougher than it really is.
I hammered it a bit more for good measure. (I wanted 3/8" to 1/2" room between the engine and the firewall.) Here is a shot of the engine in place. (I've actually hammered it a little more after these shots too, but I think this gives a good idea of room needed.)
I also ground down this lip, that was next to the steering pump to give a little more room and any other lip around the engine to give a little more room.
Left to do in the engine bay...
1. I want to weld up the holes in the firewall I'm not going to use.
--Those two square holes where the throttle and cruise control cables use to come out
--The two heater core holes next to them.
--The two holes for the AC.
--Possibly the whole where the Miata engine harness went through the firewall, I need to figure out where I'm running the new wire harness.
I started by stripping the engine down, removing the wire harness and hoses that were in the way. Then I installed the subframe to the engine while it was all still on the dolly.
Engine before stripping it down
Engine stripped & with Subframe Installed Note the coolant tube I left on, it needed to be removed for me to test fit the motor
As other's have said, it's much easier to install the engine from underneath verses going in from the top. Just raise the front of the car and roll the engine in place. Lower the car back down, and then raise the engine up and bolt the subframe to the car. If you are clever like in the Portabull thread, build your dolly so that the subframe / engine is high enough that you don't need to lift the engine up, just lower the car, bolt the subframe up, and then lift the car a little again to get the dolly out from underneath. (That method works best when you have a lift...Oh, what I would do for a lift right now!)
Raise the front of the car UP!
Roll the engine & Trans under the car
Lift the engine up and bolt the subframe to the car
Frame Rails Install
My subframes were pretty straight, but I did need to hammer them a little bit to be nice and straight. It's a bit shocking how easily you can bend them back to straight. It just takes a couple taps from the hammer. I can easily see how the frame rails will help stiffen the car up.
Once I was able to get the frame rails over each side, I bolted the transmission cross member to the frame rails. Since I knew all of this was going to be taken off, I bought some nuts to use for the test fitting. V8Roadsters sends nuts with nylon inserts so they lock. I had a hard time getting the frame rails on with the cross member fastened. They wouldn't just go straight up, so I ended up having the bolts loose and got one frame rail on. I used a floor jack to hold it in place. Then I sort of rolled the other frame rail on, verses just going straight up. From there, I tightened the bolts on the crossmember to the frame rails and started drilling holes and temporarily bolt up the frame rails.
Unfortunately I don't have a bunch of pictures of all of this. (Probably because I was under the car on my back.) Here is a picture of the rails semi attached / all the holes drilled.
One issue I did have is the bolts that attach the new cross member to the transmission are too long. These are the stock bolts, and you can see they are an inch or more too long. I used some smaller bolts for temporarily installing everything, but I'll need to fix this when I install for real.
With everything in place I could measure for the shifter modifications. As you can see there is very little room for the shifter. Only 1.75" of space. The shifter rod is an inch, so you only have 3/8" between the transmission / shifter and 3/8" between the shifter and the trans tunnel.
When I realized how close everything was & that I needed to pay someone to tig weld the aluminum up for me anyway, I decided the best course of action was to punt on the shifter and have V8Roadsters modify it for me.
I pulled the shifter all apart and cut off the legs that attached the shifter to the transmission and sent the following off to be modified.
In a couple weeks, those parts should look like the one below
Thanks! I'm hoping it's a good choice! The progress has felt slow, I have a couple more items to write about and then we will be basically to where I am today. BTW...Your car is beautiful! I hope mine looks half as nice when done.
It's been over a year since I last posted (YIKES!) Life happened, then it happened again, and while I was gasping for air, life decided I needed more and kicked me hard in the boys...2019 it was nice knowing you. Something(s) had to give, and this build was one of those things. In the last couple of months I've started working on the car again, and it's time to start getting this build thread updated too. I'm going to try and update a lot over the next month and hopefully I can get the thread to current state.
So, where did we leave off?
Sound Deadening Removal
I had a couple hours last summer and it was super hot out. I decided to buy some dry ice and remove the sound deadening in the car...because ice is cold and it was so hot out.
If you have never used dry ice before...some info:
You can buy it at the grocery store
It's sold in 10lb bricks, I bought 2 of them, but only needed 1
It doesn't melt quickly like water ice does, it lasts a lot longer.
The slurry I made with alcohol took about an hour to melt the 10lbs.
One of the 10lb bricks left in a cooler over night was still close to 10 lbs the next day.
I crushed up the dry ice in a 5 gallon bucket and added some isopropyl alcohol to make an ice slurry. Dump the slurry on the tar and wait for it (5 min?) to freeze off from the metal floor. You can actually hear the metal shrinking and the tar popping off at times. From there its just a bit of scrapping to get it to come off.
This method works great for the horizontal parts. The vertical sections (firewall and tunnel) were a pain and the ice didn't work so well. I tried putting ice in a ziplock and propping it up so it sat on the metal vertically, but it didn't work very well and I ended up scrapping most of the tar off of these sections. You can even tell in the photo below where I scrapped a bunch, leaving tar residue all over the place, verses where it popped off nice and clean.
Since I was having issues with the tunnel, I decided to try using a can of compressed air upside down to freeze the firewall tar mat off. This didn't work very well for me, and I ended up scrapping the majority of the tar off the firewall. I also used a wire wheel on the end of my drill to take some of it off around the bolts. (Note if it was cold outside, I think the upside down air can would have worked, but it was around 100 outside and probably 85 in my garage, it just couldn't cool enough) I didn't take a picture of this area with the tar removed / or while I was removing it, but here is the area we are talking about. Also, it's bare metal under this tar mat, everywhere else was painted.
Once all the big is off, I tried a bunch of different chemicals to get the residue off. Most of the items didn't do anything, but Mineral Spirits worked fairly well. (Picture is not from when I cleaned up with Mineral Spirits, but you can see the final cleaned result in this pic)
I was thinking this was going to reduce the car weight by 20 lbs, when I started. The joke was on me, lets round up and call it 4lbs, and this includes the weight of the box. LOL
I'd guess I had 4-6 hours in doing all of this between going and buying ice, scrapping what wouldn't freeze off and general clean up afterwords. Lots of work for so little in weight reduction.
Because "Race Car" and because I'm naive and obviously like pain, I decided to try my hand at Seam Welding. Seam Welding sucks, its about equal to going to the dentist in terms of fun, there is no other way to put it. I don't know what professional welders charge to do this, but it can't be cheap. My guess is that they all start with a car that has been acid dipped and totally stripped of all paint & seam sealer. My car has not been dipped and totally stripped of all paint and seam sealer, and I purposely bought a car that didn't need paint or body work so I didn't have to mess with that. <--Famous Last Words right there!
I started under the fender. This seemed like a good spot since there wasn't as much seam sealer to remove and everything would be hidden (allowing me to practice welding a bit more).
Fender
And I immediately ran into my first issue, that gap across the top is too large, you can see Mazda spot weld this piece in 4 spots an inch down from the top.
So....out comes the hammer...(Actually, the wire wheel came out first, to clean off the paint, then I hammered it shut).
And after some really bad welding...Voila!
Rinse and repeat on the other side & onto the next area...Inside the front wheel wells.
Wheel Wells
I'm not sure we have really spoken about removing the seam sealer yet. The wheel well has seam sealer that is over an inch thick in spots. A wire wheel on the grinder seems (no pun here) like a very good idea, that is until you try it the first time. The wire wheel ends up melting the seam sealer and flinging it all over the place (i.e. your face...you are wearing a face shield while grinding right?) into a sticky web that even spider man would be impressed with. <--I should have taken a few photos. Another option on getting seam sealer out is with a torch. I pulled out the map gas and tried burning it out, but remember that nice paint on the car that I don't want to repaint? Not to mention the stench (and toxic-ness) of burning "rubber"? This was no bueno too. I'm already on a short leash with the HOA, I don't need to add having the fire department showing up. So what did I use? I ended up using a cheap 1/4" chisel to cut / chisel out the seam sealer. When I had the big out, then I would use the wire wheel on the grinder to finish it off. It still made a mess, but less of one.
A bit of chisel action to remove the big stuff...
Ground down and ready to weld
And after some welding...
Engine Bay
Next up was the Engine Bay...as if it hadn't already suffered under the knife enough from me.
Here you can see in the engine bay the welds from inside the fender and wheel well. (Just a bit more that needs to be cleaned up and painted.)
A lot of times while welding, I would still hit some seam sealer that I hadn't cleaned out enough and it would burn...I remember that happening a lot in this area.
Also did a little bit of the firewall. I should have done this to the ends, but it's tight and removing seam sealer no matter welding would have been a pain.
Onto the interior... Door Jams
I had a hard time welding the A-Pillar, since it's semi upside down at this point and gravity wasn't my friend. I ended up spot welding it verse running a bead.
Rear Cabin (Not sure what you call this area of the car exactly)
pictures need to be rotated, but I don't see how on here and I'm being too lazy to re-upload.
And DONE with the seam welding!
I would guess I spent over 40 hours 60 hours doing all the seam welding. The welding itself was the quickest part, cleaning up all the seam sealer and prepping to weld (which as you can tell, I didn't do but so well) was a huge time sink. A lot of the areas were in tight spots. It was hard to get everything as clean as it should have been.
As far as if this was worth it? I haven't driven the car yet, and honestly so many changes are being made to this car, I doubt I will ever be able to say for certain what all the seam welding did or didn't do. That said, it feels stiffer to me, the doors open and close while up on jacks / jack stands really smooth with no issue. My other Miata will pinch the door while jacked up or on stands only in the front etc. and be hard to open or close. I also had a friend come over and he was looking at the car. He also mentioned (without any nudging from me) that the doors opened and closed really well for being on the jack stands etc., saying his Miata wouldn't do that. Note: I have the frame rails and both subframes off the car too, so it's really just the shell, and nothing else stiffening it up.
Thanks, I really hope so! I originally was trying to do everything "while I was in there" but now, I've moved towards if it's something that can be done later with only an hour or so of rework, do it later and get the car running!
This isn't exactly the order that I did these, but figured we can stay on the engine bay metal fab trend for a little bit.
Since the stock sway bar mounts are known to bend / flex and eventual break under hard track use, I figured I'd upgrade them.
Purchased the V8 Roadsters mounts...Best part of these mounts (besides strength) is all the holes in the bottom allowing you to adjust the bar to where you need/want it.
First step is removing the old mounts. They are bolted and welded in place, so you have to drill out the spot weld between the two bolts to get them out.
After you remove the old, new ones get bolted in place in the existing holes for two of the corners. (I drew some lines around the mount to see where I needed to grind the metal to be clean for welding) These are much larger and you are supposed to weld up the two corners that don't have bolts in them.
You can't see it from this picture (and I can't find the pictures I thought I took while installing) but the bolts on each side are on opposite corners from each other, and the mount was about 3/16" too wide, so by tightening the bolts you would end up with a twisted and crooked mount from side to side. To fix this, I used a couple C-Clamps to close the 3/16" gap and hold them in place while I welded them up. This worked great and they came out pretty well.
Here is a picture after welded up
Mounts done. They just need to get painted & install the sway bar.
Firewall & Tunnel Modifications / holes to block off
I was unsure of what holes I needed to block off on the firewall & tunnel. Some of this was not fully knowing what I was going to do with heater hoses & with wiring harnesses, and some of it was not knowing what holes go to what. I'm a bit further along now and I wish that I had welded up some of these holes (before I painted) with metal and just drilled them out again if needed. Maybe the following pictures will help the next person figure out what they want to keep and what they want to block off.
Since my car is a track build, I will not have AC nor will I run heater hoses into the cabin. If you are going to keep AC, you should probably keep those two holes. Heater hoses will require new holes in the firewall with the LFX. Additionally, I am fairly certain you will not be using the oblong engine wire harness hole in any LFX build. I wish I had blocked this hole off earlier.
Firewall
I know earlier I went over the "massaging" of the firewall with a hammer to get the LFX engine to fit. Besides that modification, there are some holes that need to be blocked off.
Notes:
I'm guessing that the middle 3 green square holes are used to hold items behind the dash against the firewall. They are not used on the engine side at all. (I checked on my stock Miata) The two outer most green squares have rubber plugs in them from the factory.
The two big circles one on each side are for your wiring harnesses, that go down to your lights & run other engine stuff. (de-wiring the harness of junk wires is an entire different thread)
The only other item I didn't mark off, is the brake master cylinder.
All the other holes above the pinch line, are in the cowl and don't matter. They are used for windshield wipers and holes for push plugs that hold items (like brake lines)
The clutch hole needs to be enlarged. I forgot how much larger it needs to be made, I'll try to figure out and update this thread with the info.
As you can see here, I blocked off the heater hoses (they are blocked by the LFX, and you will need new if you keep your heater core) and the throttle cable / cruise control cable holes, since they are not used by the LFX and also blocked by the motor.
Trans Tunnel
I'm not too worried about the O2 sensor hole. I'm 90% sure I'm going to be putting a drop floor in this car, and that will make this hole go away. I can also block the parking brake hole at that time.
Also, while I had the grinder out, I cut off these two threaded studs. No need to have sharp objects poking out of the floor.
Oh boy. You're chugging through a lot of the garbage that I'm on the tail end of getting knocked out so I feel your pain. I need to order those sway bar mounts as well. That stuff definitely sucks, no other way than to just push through it. I even decided to weld all the tiny holes shut in the engine bay as well, looks great but what a dumb idea haha. Check out my build thread if you're curious. I'm also in the same situation where I hope this stuff is worth it, but there's going to be no way to tell on such a massive ground up rebuild with dozens of other major modifications at the same time. I get pulled into that "while it's apart" modification rabbit hole way too easily.
I checked out your build and left a reply there, but again, awesome job! Anyone reading my build and thinking about seam welding (or any metal fab) go visit Arca_ex’s build to see how it’s done.
FYI the AC drain hole I found useful to run sensor wiring to the transmission. Shorter wiring path to a cabin mounted ECU then running it though the firewall. Not sure where you plan to mount your electronics.
07-15-2019, 10:46 PM
Goldilocks...An LFX Track Build
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