Hi guys , any regrets using a NA year car
Vs buying a NB style car ? What are the
Difference and restrictions in the build ?

I have a mint 1991 Miata that I was going
To use but am I better with a NB car ?

I do want the LS3 coil covers on the car for
Looks so ??? And problem with the NA.

Any tips to look out for ?

That's for your input !

Cheers
TVP

 

Witch swap you want to do, Gm or ford?

 

GM LS3

Tvp

 

TVP
I built a NA with a LS3 and I just love it! The differences seem to be the styling issue as well a the amount of room under hood. I was able to deal with the room issue when I built mine but I own both MIG and TIG welders and I was able to fabricate parts as required. So if you have the tools and skills it really is not an issue
As a side note I would advise to save plenty of $'s and upgrade the brakes,suspension, wheels and tires.
Tom

 

My problem is i have a Mint condition 1991 Miata NA with only 80,000 KL
The car is almost perfect, has origial Battery, brakes, Clutch, and has never been drivin in the Snow etc....car is Supercharged and has Momo Ferarri Rims.

My Plan was to ship the car To Flyin Miata and do a complete reno on my 1991, However I want the engine area detailed and the Corvette LS3 Coil covers on the engine to complete the look !

Do I sell my rust free NA 1991 Miata lets say for $ 12,000 dollars and pic up a used NB to do the conversion .????....

I dont want to have any rubbing issues when the engine is reved up or twisting under load ....or the tolerences beening so tight you have to pull the engine to work on the thing. or any other issues ??

I do not plan on racing the car so its just for street fun and show !

So the question is : do I put $ 50,000 in a NA Miata or a NB Miata ??

My e mail is tvp@rogers.com....would love to call you some time to talk !

Thanks
TVP

 

there is plenty of room in the NA. I managed to stuff an LS in there and a couple small turbos just for good measure.

@rogers.com suggests you are in canada. Where about are you from?

 

Yea I'm in Toronto , the problem is that I want
To use the coil covers to clean up the engine
Bay and give it a car show Finnish .
I was told they would not fit under stock
Hood. And if you had to remove rad
To change the belt ?

Question is can I modifiy the hood braces
To make the coil covers fit without
Rubbing etc

Cheers
Tvp

 

I just had a look at the LS3 covers, and i dont see any reason why they shouldn't fit. Do you have some information from someone that says they will not fit?

 

I'm just going on what flyin Miata
Told me ?

Tvp

 

we'll make them fit

 

Dave,
Yes the coil covers will fit. I trimmed mine slightly in front to prevent the paint under the hood from rubbing off. I'll post pics tomorrow. FM has trimmed the under hood support braces to allow clearance. I think both look good.
I tried to heat the covers to remould them but the plastic just charred and didn't soften.
Tom

 

Hi gilpin27 love to chat with you .. Could
You please send contact info to
TVP@Rogers.com

Cheers
Tvp

 

One of the biggest reasons to go with an NA as opposed to an NB is your local emmisions laws. Since most NA's (those older than 1995) are OBDI the most they are ever required to do is have less tailpipe emmissions than the original engine had. This is very easy to accomplish with and of the current V8 offerings, expecially if you decide to go with fuel injection.

That said, if you live any where near the notheast do yourself a favor and get an NA from the south west to use as a donor. It's well worth the cost of a plane ticket and gas to drive it back.

-Jason

 

Hi Jason , well the hard part was trying to fit the LS3 in the NA

So the new transplant car is a 2004 Mazda speed Miata

This with the 480 hp Ls3 stock engine should not have any
Issue with coil covers and smog tests ..

What car did you use ?

Cheers
Tvp

 

I use OBD1 NA's only because of the structure of PA's emission laws. In other states you can pass an OBD2 test by meeting the standards set for the donor car of the engine as long as the engine is no older than the car it's in. When the law is written this way it’s pretty doable (not easy) to make say a 2004 Miata with a 2004 GTO LS1 pass the test as if it was still a GTO. The technician plugs the OBD2 port in, checks everything out, notes that the ECU thinks it's a GTO and makes sure the car is doing everything a 2004 GTO should be doing. In PA it's not so easy. If I were to drive the same car into a garage in PA for an emissions test the technician would:

1. Plug the OBD2 port into his scanner.
2. Happily note that no codes are being thrown.
3. Enter the VIN of the ECU into the PennDot system.
4. Note that the computer says the car is a 2004 GTO.
5. Blindly stare at the screen for a moment.
6. Look back at the 2004 Miata sitting in front of him and wonder why this GTO looks so strange.
7. Check the VIN on the registration card and realize the car is a Miata.
8. Blindly stare at the registration card for a minute.
9. Look back at the computer screen.
10. Look back at the Registration card.
11. Get his manager.
12. Manager stares at the screen, the registration card and then the car.
13. After a few moments both of their heads explode and I fail my test (I do still have to pay the $65 for the test though).

Unfortunately, PennDot has never even considered why someone would ever want to swap an engine from one car in another and has absolutely NO provisions for it in their emission code. When I ran this scenario past one of the lovely people working in Harrisburg (after waiting on the phone for about an hour) it was explained to me that I would not fail, I simply cannot take the test. Stupid.

So, in PA my only choice is to use a chassis that is so old that it does not have to take the OBD2 test. This leaves me with pre-1996 OBD1 Miatas. I still have to pass the OBD1 test, which involves driving the car up on a dyno, sticking a "sniffer" up its tail pipe and recording how dirty it is at 35 mph. If it's cleaner than the level set for the donor car (of the chassis) of the same year it passes. The technician simply "assumes" that all 1994 Miatas had 400 hp V8's in them.
There are people in PA with OBD2 swapped Miatas. They simply have to work out a deal whereby they pull into the garage with a case of beer or something in the trunk and somehow it mysteriously converts itself into a window sticker before the owner shows back up. It’s getting harder to find garages that have this mystical power to turn beer into emissions stickers.

-Jason McCully

 

Well from what i can find out In Ontario Canada , if I have a 2004 Miata it will be tested as a 2004 Miata,

So i Just have to make sure the 2012 LS3 engine will meet the worst range for a 2004 Miata..... and still Pass,

This mite work if the motor is a stock LS3 430 hp vs the LS3 480 hot cam motor

Also we mite have to reprogram the ecu to run very lean at 2500 rpm and then switch it back after the test ?

Just an idea ?

Cheers
TVP

 

That's the problem. If your car is an OBD2 "passing" means plugging the car into a scanner and making sure everything is working. When the scanner is plugged in it records the VIN that is IN THE ECU. Since you cannot run a 2004 LS motor with a Miata ECU you are going to have the GM one in there. When the scanner connects to the GM ECU it's going to show a different VIN than the one on the registration. It's this "technicality" that fails the test, not the actual pollution coming out of the rear of the car.

Since an OBD1 car has no ability to be plugged into a scanner the VIN in the ECU (if it's even recorded there) never enters the test.

The only hope, if you want to use a psot-1996 Miata, is to get the GM ECU reflashed with a Miata VIN#. I don't know if this is possible, or legal.

Under this type of system you could get away with a brand new 2011 LS motor as long as you put it in a 1996 or older (OBD1) chassis. Next time I build I'm picking one up from Florida or the South West.

-Jason