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Cool. Thanks for the explanation. Looks similar to another brace I saw posted here. I like your xmember braces too. I did the hole through the passenger side floor, but I like your version better.
Glad that my build helped you. I had a long thread here somewhere where I asked questions along the way. Lots of good info there provided by the great folks here.
Can’t wait to get mine out of storage. We’re suffering through the last little bit of winter here.
Thanks for the pics. I’m planning on making a heat shield for the slave, so maybe I’ll try this too.
I’ll be chatting with you when I build my next motor (possibly next year). You seem to be pretty smart about the 5.0.
Thanks for the pics. I’m planning on making a heat shield for the slave, so maybe I’ll try this too.
I’ll be chatting with you when I build my next motor (possibly next year). You seem to be pretty smart about the 5.0.
Sure thing, I have built heaps of them in my time. They are a good engine, they just need good cam, heads and intake. Happy to help you put together an engine plan..
In addition I have engine modelling software (dynomation). I can even spin one up with the combo you are thinking and see what it will do in the simulation. On my engine it predicted 340Hp at the wheels..I made 335hp with a bit of wheelspin...so 340Hp is bang on the money
The more I look at your pictures the more impressed I become with your build.
Little details like the Mazda emblem on the valve covers just show that you spent that last little bit of time and trouble to make it as perfect as possible.
With your transmission & rear end gearing & tire size what speed are you getting at redline in each gear and what rpm are you getting at highway cruising speed?
Since I am debating and planning my next Miata swap with one consideration being to use a different transmission it is of interest to me. Will definitely staying with an LS engine but the transmission and differential you are utilizing is a possibility.
Speaking of engines, what were your reasons for going with the engine you chose?
Presumably thing are different in the land down under but I do know that the Holden V8 engine is an LS so they are available but for all I know they could be a big cost premium.
Here in the USA the LS based engine is super inexpensive and available due to the wide range of vehicles using them.
Pretty close to half the pickup trucks on the road are General Motors products with LS derived engines under the hood.
Sure wish we had the Ute here cause I would have one of those instead of a hotrod Miata.
Something else that I have been wondering is if you have any plan to keep your intake air cooler than the under hood temperature?
As best I can tell from the picture your air filter is just open to the rest of the engine bay.
Thanks for the kind words. I did try my hardest to make everything as OEM standard and looking as possible. I did not want it to be better than OEM, just factory level detail and quality. It is pretty hard to make everything perfect when you are on a limited budget, but there are many things that can be done to make things look "OEM clean and neat". That is what i did essentially. I made sure I used as much of the factory stuff as possible, grommets, brackets, cables, connectors etc. It makes a difference when you add everything up. The Mazda logos on the rocker covers were not hard to do...but were a little tedious as they are Trickflow cast rocker covers. They are embossed with a the Trickflow logo from factory and I had to grind it all off (very messy, cast alloy went everywhere!). I then used metal reinforced fibreglass to make a small flat mounting platform for the Mazda Symbol as the surface is not flat there and the logo therefore wont stick. After i made the little flat area and sanded them back a little, I covered them with black VHT Wrinkle paint.
I am pretty happy wit the outcome, it fools a lot of people who look under the hood, as they cant really tell what engine it really is (Perfect!)
As I drive the car everyday it is not worth the extra effort or expense to make it look better than OEM. Plus the OEM look appeals to almost everyone, its a universal kind of presentation that works.
So I am very happy that you like the outcome and I really appreciate the kind words of support...
As far as the gear ratios, Diff ratio, Tyre Size and RPM goes the table is as follows:
On the Highway I am getting about 2000 rpm at 70MPH. This is a really nice cruising speed for the engine provided that the camshaft is matched. My cam is just on the start of its power ramp at this RPM which makes it feel crisp for overtaking as you squeeze on the throttle to pass other cars. There is no need to change gear, the full torque of the engine is there from about 2500 rpm to 5000 rpm so you just squeeze the throttle and ride the torque wave.
The reason for me going with a Ford 5.0L is four fold. First, I love Fords, enough said there!. Secondly, I know these engines very well and can build them with my eyes closed, so I built this one. Thirdly I had the full Trickflow top end available to me form another identical engine that I sold (so heads, Intake, TB etc), so its cost. Fourth is the most important reason, Legislation. The engine size of the Ford engine makes it possible for this conversion to be legal in Australia (only just!). Maximum engine size allowed in this vehicle is 5.5L, thereby removing many other engine options (i.e LS).
LS engines in Australia are plentiful and priced well. If I had a choice I would get an LS engine without question, its newer in design and lighter. Plus it would have been cheaper to get one with low miles than build the new Ford engine. However the fitment of the Ford engine is easier (no tunnel mods...which are a big no no if you need the car to be legal) and they afford you more room in the engine bay. Australia is in many ways quite draconian with its laws around vehicle modifications so things like modifying tunnels and inadequate clearance are frowned upon. Things have improved but it is still a minefield for the uninitiated. Most people give up as they do not know how to approach things, something as simple as not putting wiring through a grommet or having adequate clearance in some places can invalidate a car from being legally registered.
As a Mechanical engineer, I worked for the car companies (GM, Ford, Toyota) as a steering and suspension designer, I know what the registration authorities will look out for as I have gone through the legislation carefully for each and every modification that I have made. It is a long, convoluted and in many parts of legislation it is unreasonable and lacking any kind of physics in its approach. This is very frustrating as if you want to do something ever so slightly outside the exact legislation the process can be too hard. In the USA you are all quite lucky not to have this sort of Nanny State antics making your project a painful experience
So that's why I settled for the little ol' Ford 5.0L, it is also easy to fit, quite cheap, reasonably reliable and readily available. Also servicing is a DIY breeze...With a decent set of heads, cam and intake they can be made to deliver power. However the one thing that hurts them is the cast iron block it is heavier than the alloy block LS engines. There are Ford Alloy blocks available (Dart, Ford Racing) but they cost a lot of money and if I was richer, then yes I would get one for my builds...it only weighs 85lbs !
And yes the Australian "Ute" is a great variant, it drives like a normal car but gives you the versatility of a small pick up truck. Check out the Holden HSV variants for some good reading!! They are very popular here in the modified car seen, some are supercharged, turbocharged..its an Australian culture thing! As Australian as a Koala!
Yes you are very observant and have spotted my exposed air filter (yuk!) !! I am in the process of making an Airbox/Shroud to stop the hot air from hitting it. I will also try and get a cold duct into the airbox shroud from somewhere. There is not a lot of room in there and as such I am still developing that solution. I initially tried to get a mustang cobra air filter pod box but I wasn't able get it to fit..it was too big. The air temp is something that needs to be addressed, as the engine is high comp it needs to stay as cool as possible. I might measure the temperature at the air filter there one day to see what it is and I will then remeasure it with the airbox in place to see if it has made a good deal of difference. So far I have not had any detrimental performance or engine behaviour with the expose pod, BUT best practice dictates a sealed airbox for smooth airflow entry to the maf for accurate readings.
Cheers
I will post up some pics once I get the airbox thing sorted out.
Thanks for the response.
All of your discussion points make sense.
Here in the US the small pickup V8 Chevy engines are 4.8 & 5.3 so they would ne usable within your size restrictions.
The 5.3 can even be gotten with an aluminum block from some Cadillac SUV's.
I even know of one guy who destroked a 5.7 to get an engine that revs like an exotic.
Don't know his redline but based on the sound it must be somewhere above 8000 rpm.
You have lots of restrictions that don't make sense but hopefully they are consistent within Australia.
Here in the US each state has different restrictions with California being one of the worst.
I am lucky being in Oklahoma because the state does not even know or care that I have done a swap.
For insurance and registration purposes it is still a slow little 4 cylinder.
For the cold air intake you might take a look at the Yellow Submarine LS build.
Originally he routed his intake so that the air cleaner is in the area in front of the front fender where the fog lights would normally go.
The bonus is that you get consistent cool air because the opening in the front that used to house the fog light works very well.
He notched the very front of his box frame to get clearance for the round tube but when I was considering doing it my idea was to fabricate a rectangular duct that would flow a decent amount of air and lay right against the box frame on the driver's side without the need to do any trimming. https://www.v8miata.net/general-moto...ar-2911/page9/
As a variation on that you could probably work up a duct to feed cool air into a box located inside the engine compartment but it seems to me that would be doing double work over simply figuring out a direct duct configuration.
The Tare weight listed for the NC Series is somewhere between 1062kg-1101kg according to Redbook. If you wanted to do a 6.0L LS the Tare mass would need to be 1200kg in order for it to be compliant. Unfortunately I think that this is too far away from the mark to be signed off as a 6.0L. The 5.3L LS could be an option for you and they can be made to make decent power too..
I've got an online brochure here for a series 3 NC and the heaviest listed weight is 1179kg, still not 1200kg so I'd have to talk to VASS engineer to see if options or anything can tip it over 1200 or not.
Congrats on the build too, looks great!!
Just make sure that you are referencing the TARE weight and NOT the KERB weight. Heaviest NC TARE weight i could find was 1140kg. Multiplied by 5 gets you a maximum engine cc value of 5700cc. So a 5.7l LS engine will be ok, provided everything else in vsb14 is compliant and legal.
I hope you can get it over the line. It's a fun thing once its legal and running .I love mine..😁😎👍
Good Lord, never really appreciated how lucky we are in the States. Great conversation on being legal down Under.
Good Luck,
RonR
Hi Ron,
You have no idea how draconian the Australian laws can be. there is a reason for this in that they want to ensure that the cars that are modified are safe for people to drive...i.e. stop, steer, don't pollute, not noisy, too low, pose a fire hazard, dangerous in a collision etc.
It is a good system...but it is utterly unforgiving to anyone who is uninitiated with it.
Some of the stories that the certifiers told me about were quite hair raising i.e. cars attempting legal compliance with horrid brakes that locked the rears first, rubber fuel lines that run right next to exhaust systems, etc etc. So the safety net needs to be there for those cases.
I am happy to have done it the right way in the end...but boy o boy they do NOT make it easy, even for me and I knew what to expect. A sample…
1) Full Emissions test (not easy to pass with a modified engine)
2) Full Brake and manoeuvrability test
3) Full Noise Test
4) Full Chassis Torsional Rigidity Test
5) Complete modifications listing and approvals needed from brakes to grommets for wiring
6) Finite Element analysis report for chassis structure (yep..bet you never guessed that one!)
The list goes on...I get bad memories just thinking about it haha
Overall I got through without too much drama in the end but that was because I had done 14 months of research and provided a massive report to the certifier with everything that he needed to issue the authorities with.
The USA does not have this level of governance...but I think a happy medium point would satisfy both ends of the equation.
It is all over now and I am just happy that my dream to drive a V8 MX5 is now my daily reality!
I haven't posted on here for a year in my thread but I wanted to give everyone a little update on the build and what I have been working on and what tweaks have been done. I hope that someone finds the information useful...
1) Diff Ratio: I have changed the read end ratio to 3:73 (was 3:27, then I went 3:45). I feel that with the tall overdrive on the T5z (0.63) that the 3.73 ratio makes the car much perkier but hardly affects the highway cruise experience (only 150 rpm difference from 3.45 ratio). I need to note that I have a tall wheel and tyre combination...17 inch with 215/45/17 tyres. A 3.73 in a 14/15 inch wheel car would likely be different..
2) Starter Heat: I noticed that heat around the starter motor is an issue with these cars. I saw some heat damage on the cables on the starter after 12months of summer time cruising. I have now used Kevlar/reflecting heat tube around all cables going to starter and have used self adhesive heat shield around starter itself to stop this. Occasionally after a long run and when car was hot it was always bit hard to start...but all good now, starts first go.
3) Tunnel Heat: Although I added heat shield in the tunnel area to reduce the radiant heat, I felt it was not quite enough and I added another layer recently to try and slow the heat down even further. Especially around the handbrake/seatbelt buckle area...it would get hot there.
4) Battery Cables: I upgraded the battery cables from he original Miata cables..they were pretty much dead and corroded in sections. A must do for everyone.
5) VSS Signal. I had trouble replicating the EECV VSS signal from my Dakota Digital speedo module. So I have reverted to utilising a instrument cluster from the correct vehicle which fees the ECU the right signal. I have the cluster hidden in the boot in the cavities down the fender. It was the only way to stop the VSS Error codes from appearing and from having the car drop rpm too quickly when pushing in clutch whilst moving or even at idle. Correct VSS signal helps this situation.
6) Valve Spring: I had some bad luck in that I broke a valve spring...no idea why it happened. I changed all of them just to be sure. They are a PAC racing spring so theory says they should be good, but I guess there is a first time for everything. I had slightly erratic and lower than ideal vacuum. It was a dual spring and only the outer spring broke..the inner spring kept the valve going. I would only notice it sometimes stumble. It had broken very early on in the piece, I did 10000 miles like that...LOL.
7) PCV Valve: I installed an adjustable PCV valve from mewager.com. This allows you to exactly adjust the vacuum at idle and cruise for correct PCV operation. These engines tend to suck a fair bit of oil through the PCV into the intake so getting the right operation point for the PCV valve keeps this oil ingestion to a minimum.
8) T5z Gearbox: I had to rebuild the T5z because it didn't change want to change gears one day. Although the box shifts very smooth, is quiet and works well it feels marginal from a strength perspective. if I had my time again I would get a T56 or TKO 600...I considered it but clutch, tail shaft, exhaust, mounting and shifter all need to be modified to work with it...for the conversion cost involved I could rebuild the T5z another 4-5 times. So I will stick with it.
9) CAM: Whilst I was doing the valve spring I also upgraded the cam to a larger Ed Curtis custom unit currently its 222 @ 50 with 0.6 in lift (Was 214 @50 with 0.6 lift). Idle excellent and is pretty much the same as before if not smoother! (with all valve springs now working properly!). Sound is slightly heavier and engine sounds much better and throatier. I am still running the clutch in so I will find out when it hits the dyno...aiming for 370 rwhp.
Apart from that the car has been running perfectly. It is a great machine and I look forward to enjoying it over autumn!!
Hi Engineer
Congratulations on your V8 MX5 build.
My project (Melbourne Victoria) has stalled on the rules for ADR69/00 offset frontal crash. The VASS engineer requires me to prove that a V8 Mazda will perform identically in the crash test compared with OEM and apart from crashing my car in front of him nothing satisfies. This includes crash computations which he could not understand so these were rejected summarily. There seems to be no intention of allowing V8 Mazda to be approved in the ‘nanny state.’
How did you get your vehicle approved under this ADR rule? Do you think your car would comply with Victorian application of the rules.
regards CivEng
Thank you for the kind words on my build. It was a really long haul to get her built and legal but I am happy now that I can drive it
The ADR60/00 rule would typically be applied to a manufacturer that is looking to produce vehicles on mass for ADR compliance for legal sale in Australia, thereby a sample is mandated to ensure all is OK with the end product. This is a normal process that is reasonable when applied at the "manufacturer" level.
Now in your case..you are NOT a manufacturer and your vehicle... if I am not mistaken is being certified as a modified car OR is it being classified as an ICV car ?? There is a difference in how the certification process and certification requirements work with each process.
If its certified as a modified car with an "engine change" then it is NOT in any way reasonable for the VASS engineer to mandate an ADR 69/00 crash test. If they insist on you doing this...then they need to understand the following:
That ANY car with ANY engine change according to this logic MUST be crash tested as there is no way that ANY engine swapped car can meet the original ADR69/00 test. The VASS engineer's logic if applied, will mean that ANY engine swap in ANY car needs a full ADR crash test. This is of course not only absurd for a one off vehicle, but also not necessary as you are not a manufacturer. Additionally, if they apply this logic law to your application and car, then they must apply it to all engine swapped cars. I am sure they don't ADR crash test every car that has been approved or applied for an engine swap !!!
However I feel that that the VASS engineer is simply AVOIDING your project. They don't really want to do it, so they try to scare you off with ADR crash tests. They simply do not want to risk their license by putting their name to the car...this is obvious. I know this myself as I had so many of them almost hang up on me after I told them what I wanted to do...ROFL They told me "that's dangerous, I would never certify something like that" or "That is not legal, cant be done" or "mate you cant do that and maybe you should build something else".
I have heard it all it before...and most people would say "oh well...I tried". But unlike most people I read all the VSB and ADR regulations, I understand the engineering, the requirements of that law and how we could meet both. I spent a lot of my time (14 months) on this but it paid off..
Any VASS engineer worth a dime, would sit down with you and see how things could be reasonably worked out. If they cant or wont do it...use another VASS engineer.
This is a very tight rope to walk...but it is walkable.
Another couple of new additions to the car that I think are noteworthy for all:
1) Added the 5th Gear countershaft retainer plate to the T5z. This plate was designed by Paul Sagliosi from 5speeds.com (https://www.5speeds.com/t5.htm) and it is very very very worthwhile addition to any T5 rebuild. It did two things for me...it eliminated almost all of the "clunking" noise that happened in my T5z when the car was bunny hopping. The transmission sounded like it was loose. Now it sounds very tight and nice. Also I found shifting was smoother with it as well. It simply stops the entire 5th gear countershaft from rocking on the bearings. An excellent mod and its less than $50
2) I added a trunk lift kit and I lined the inside of the trunk lid with dynomat and covered it in black carpet. The car is noticeably quieter now when driving and additionally it looks great with the trunk open ( I will take a pic and post it) and the lift kit makes it sooo much easier when getting stuff out of the trunk. I highly recommend it! Also less than $50 !
I thought that I would post a pic of my heat shield setup for reference. I ran a 3 inch flexible ducted pipe from the front of the bumper opening through the factory hole in the body (just ahead of the wheel arch inside the engine bay). I enlarged it slightly to get the ducting through. So now there is a very strong stream of air that comes through and blows air all around the air filter which is encased by the heat shield. The heat shield attaches to an aluminum bracket which is attached to the Air flow meter mounting holes. I also shaped the heat shield to follow the contour of the body.
I have tested it with a thermocouple and it drops the air temperature almost as soon as the car is rolling to the ambient temp. Without the shield and ducting running an exposed air filter element will make you air intake temps soar over 50 deg C. With the duct and shield the intake temps are almost ambient when the car is moving even at slow speeds. Simple but effective
Enjoy Stainless steel heat shield with dynomat style reflective sheet Rear shot showing a lack of being totally sealed...but it doesn't make any real difference. As soon as the car rolls it gets cold air. I used a 2 inch feeder pipe to add additional air into the main 3 inch pipe that goes to the filter. This pipe neatly fits inside the lower cavity of the front bumper and runs across the mouth to the other side. Top view of engine
Just a quick review of some minor mods I have made recently:
1) Brake Master Cylinder brace: I also added a brake master cylinder brace which attaches tot he strut tower. I can honestly say it has made a very noticeable difference to the initial bite of the brakes. It just digs in a lot better. Well worth the 5 minutes it takes to fit. You can see it in the pics above..
2) Mishimoto Oil Catch Can: This was another easy little mod that helps keep the intake system clean. I noticed that it collected more oil than I expected. Well worth the effort as it keeps the intake clean. Quality of Mishimoto product was excellent.
3) LED Number Plate Bulbs: This was a necessary mod as my plate bulb blew so I changed to LED and WOW are they heaps brighter or what!. Pretty cool!
4) LED Trunk lamp: I designed my own trunk lamp using a couple of LED lights. It works a treat, as soon as you pop the trunk it grounds the connection and you get a bright trunk! no more darkness....AND when you combine the light of the interior trunk with the number plate lights...its super bright. You could study for the BAR exam under that light until well into the early morning!!
5) Ken Auto Dosukai brace: I got this brace and fitted it up but I think as I have a roll cage it probably didn't make that much difference. Still its a well made brace, very light. In a standard car it would help I guess, but I couldn't tell if it was there or not
6) Clock Spring: OK I was getting intermittent air bag errors in the car for the last 5 years I have owned it, flashing error code 6 (Drivers Airbag on an NB). New OEM Mazda clock spring and 20 mins later...it was replaced. Now there are no more errors!
7) Nardi 5 Speed gear ****: I was able to find a unicorn! A Mazda Nardi wooden gear **** with a 5 speed pattern! Never seen one before or since. It was immaculate...So now I have the correct 5 speed pattern on the gear **** for my T5z
8) LED Headlight bulbs from Flyin Miata: I replaced all of the main bulbs in the headlight clamp with the Flyin Miata Diode Dynamics kit. They are USA made and are excellent, they provide so much more light than the standard halogen globes. The MX5 has average lights at best but these make them pretty decent.
Just thought i would post up the last 2 mods that I have made to the car..which may be of use to someone with similar issues:
1) Charcoal Canister Purging solution (to remove fuel smells) Recently I have been toying with the Miata EVAP canister system as I get a fuel smell coming from the canister which then wafts under the hood and then eventually finds its way through the air vents and into the cabin. It will happen when its a hot day and the car has been idling a lot in traffic. This is due to the V8 getting the tank and fuel lines very hot and expanding the vapors to the point where they flood the charcoal canister and overwhelm it, thereby letting the gasses "leak" out from the open air vent on the canister. This happens on the standard MX5 as well but nowhere to the degree of the V8 converted cars. Many people delete the evap canister but thats not a smart thing to do as it has an important role to play. From what I could find out, the SCT tuner software that I use to tune my car does NOT have a parameter that allows me to control the duty cycle of the purge solenoid. So I was stuck with whatever the factory duty cycle was for purging, which is no where near frequent enough to evacuate all the fuel vapor gases from the tank and canister. So what I have done to solve this is to use a really cool Multi function Timer that I bought from here:
This timer allows me to setup cycling of the purge solenoid (independent from the ecu) so that the vapors can be sucked into the intake manifold at a more frequent rate. I have currently got it setup to work as follows:
Upon Ignition ON
Delayed Start for 10 mins (allows for engine warm up)
After 10 mins it will activate the purge solenoid
The Purge solenoid will work for 8 secs when activated then turn off
The Timer sleeps for 10 mins
Purge solenoid is reactivated for 8 secs
The Cycle will then repeat every 10 mins until ignition is switched off.
I thought I would share it as its been a bug bear for me for a while now....as people have often complained about my car smelling like its got a fuel leak, and the garage would stink of fuel after I parked the car (when hot) in it and closed it up.
So no more fuel fumes headaches after 2 hours of being stuck in traffic
2) Vacuum Canister for Brakes (Helps improve brake power)
The brakes I had on the Miata seemed a little weak due to he fact that the booster sees reduced vacuum from Mazda OEM spec due to the larger cam in the V8 engine. I was getting about 13 in Hg of vacuum at idle, a booster will need about 17-19 in Hg vacuum to get a good charge for full power. I did have a vacuum pump on the car initially to help, but it was a heavy and noisy thing and as a result I didn't like it. So I decided to install a brake vacuum canister to assist the brakes to get more power by storing more vacuum so it can fully charge the booster. On downhill runs with engine braking the engine will pull over 21+ in Hg of vacuum, that gets stored in the canister and booster (and locked in with a one way valve) thereby letting me get full brake power on my next stop(s). The install was easy, I just had to make a bracket to mount it just in front of the shock tower and above the chassis frame rail. What I noticed immediately was that the pedal felt like it was "higher" and "cushion like". Essentially I am getting more bite earlier and the power assist is now higher from the increased vacuum so it feels "cushion like".
I am pretty happy with the improvement, more braking power and no moving parts or noisy pumps
03-19-2018, 09:07 PM
