Got Wice? You Shoulda Got A V8

[Fitz]

What do you get when you put one of these Into one of these?

Want to find out? Stick around!

[hopped up]

Go cart?

[Fitz]

Originally Posted by hopped up

Go cart?

Hardly. Let's do a comparison between this little rice burner and that legendary giant killer the Ford Cobra.



Wheelbase
Ford Cobra 90 in (2,286 mm) 1991 Mazda Miata 89.2 in (2,265 mm)

Length
Ford Cobra 151.5 in (3,848 mm) 1991 Mazda Miata 155.5 (3,950 mm)

Width
Ford Cobra 61 in (1,549 mm) 1991 Mazda Miata 65.9 in (1,675 mm)

Height
Ford Cobra 49 in (1,245 mm) 1991 Mazda Miata 48.4 in (1,230 mm)

Curb weight
Ford Cobra 2,315 lb lb 1991 Mazda Miata 2,070 lb (940 kg)

Horsepower
289cu in Ford Cobra 370 1991 Mazda Miata 1600 cc 95
427 cu in Ford Cobra 480 1991 Mazda Miata e-rod LS2 485-525


This is the stuff the mustang boys have nightmares about!

[dfrank]

Originally Posted by Fitz

Hardly. Let's do a comparison between this little rice burner and that legendary giant killer the Ford Cobra.

289 Ford Cobra

Wheelbase
90 in (2,286 mm) 1991 Mazda Miata 89.2 in (2,265 mm)

Length
151.5 in (3,848 mm) 1991 Mazda Miata 155.5 (3,950 mm)

Width
61 in (1,549 mm) 1991 Mazda Miata 65.9 in (1,675 mm)

Height
49 in (1,245 mm) 1991 Mazda Miata 48.4 in (1,230 mm)

Curb weight
2,315 lb lb 1991 Mazda Miata 2,070 lb (940 kg)

Horsepower
289cu in 370 1991 Mazda Miata 1600 cc 95
427 cu in 480 1991 Mazda Miata e-rod LS2 ~485


This is the stuff the mustang boys have nightmares about!

That's going to be cool, but 6.0L=366cu not 427.

[Fitz]

Out with the old stuff: Engine, transmission, driveshaft and differential make a trip to the Junkyard. The Mazda driveline components are all cast iron housings. What goes in to replace them is aluminum so the weight difference between the 1600 cc 4 cyl, 5 speed trans and Torsen diff and the LS2, T56 six speed and Cobra R diff is only 50 pounds! Not much weight gain.

[Fitz]

Originally Posted by dfrank

That's going to be cool, but 6.0L=366cu not 427.

I have a 20,000 mile LS2 and T56 six speed in my garage. It's what's left of a friends 2006 GTO after it was torn in two at the rear quarter by a Redi-Mix truck. The 427 is $8800 and puts out 480 HP in stock trim. A set of junkyard
L92 heads and manifold cost 600.00. Porting the heads is $600.00. E-rod cam and lifters from GMPP $485.00. Reflash of ECM for new cam and heads $375.00. So, for $4060.00 I should get about 75 Hp more than the 427 and I get to keep $4740.00!

[Fitz]

Once the shell is stripped clean the trans tunnel is cut where it meets the firewall and widened 2 inches on each side. The new tunnel is shaped into a uniform taper for 8 inches then the cut edge of the firewall is folded over the tunnel skin and seam welded to cover the cuts. In addition, the shroud over the frame rails extending to the firewall are cut away and 1/8 inch plate ells are welded to stiffen each side where the frame rails meet the firewall.

This makes room for the bell housing for the T56 clutch which is considerably larger than the Miata clutch. At this point, the body is ready for body work and a coat of primer.

[Indian113]

I thought a 5.3 in my S10 was Fun but your going to have a 4 wheel ROCKET!

[68Timber]

I read an article not too long ago where the writer got to drive someone's Miata that had a Ford V8 swapped in, he said wheel-spin was pretty much instant even in third gear. Looking forward to seeing this...

[Fitz]

Been waiting for the new front subframe which finally arrived. Time to test fit the motor! I had to make new motorplates to move the motor back a half inch but the view was almost the same. The motor is now as far back as it will go.

[Fitz]

Originally Posted by Indian113

I thought a 5.3 in my S10 was Fun but your going to have a 4 wheel ROCKET!

I have to admit that this wasn't my idea. Stacey David did a ford 5 liter swap into the same year Miata on his TV show, Gearz. The ford is a bit smaller so it's easier to fit and it has a lot less power but the video "Banshee Payoff" is still on his website if you want to see what a Miata with 200 HP less than this car will do on a track. It is a Porsche killer.

[68shortwide]

You're finally makin a build thread? def subbed! That vid you sent me was pretty awesome, showed me that not all miatas deserve my hatred

[Fitz]

Originally Posted by 68shortwide

You're finally makin a build thread? def subbed! That vid you sent me was pretty awesome, showed me that not all miatas deserve my hatred

The build thread was your idea. I didn't know this section existed until Liz posted her note the day after I answered your post. The car is actually further along than the thread, but it's still fun. Glad you liked the vid. That car IS fast and the guy behind the wheel can really drive. Check back once in a while. There's a few subtle things about the way I built this car that really make in interesting.

[Fitz]

Rear suspension is fully independent but the stock diff is a Torsen unit rated at 120 ft-lbs of torque and the axles are 0.5 in in diameter. They simply aren't going to stand up to the power tha motor puts out so I swapped in a Ford Cobra R 8.8 in independent with axles made by The Driveshaft Shop in Salisbury NC. They supplied a set with new hubs that match the Mazda bolt circle and the other end matches the ford Diff. The rear suspension is similar to the Jaguar in that it is removable as a complete unit by unbolting the driveshaft yoke and the suspension frame.

[dfrank]

Originally Posted by Fitz

Rear suspension is fully independent but the stock diff is a Torsen unit rated at 120 ft-lbs of torque and the axles are 0.5 in in diameter. They simply aren't going to stand up to the power tha motor puts out so I swapped in a Ford Cobra R 8.8 in independent with axles made by The Driveshaft Shop in Salisbury NC. They supplied a set with new hubs that match the Mazda bolt circle and the other end matches the ford Diff. The rear suspension is similar to the Jaguar in that it is removable as a complete unit by unbolting the driveshaft yoke and the suspension frame.

Your gonna need some bigger brakes!!!!!

[Hart_Rod]

In...

[Fitz]

Last trial fit of all the mechanicals after two coats of epoxy primer and before disassembling yet again for color paint. The GTO serpentine accessory drive is too wide to allow engine removal from the bottom so it was replaced by a Cadillac CTS-V system which is 5 inches narrower. The tiny Mazda rad was replaced with a four row Griffin unit and the GTO oil pan was replaced with a MAST Motorsports unit. Sanderson 1-5/8 in headers were installed and the steering clearance checks made and , finally, after three weeks of cutting and welding I have an AQMD compliant exhaust. That was by far the most difficult part of this build because the system needed to stay in the driveshaft tunnel until it reached the rear suspension and wind it's way through that for a rear exit. Getting 2-1/2 inch stainless through that independent rear without causing so much restriction as to cripple the engine was the hard part. Not to mention keeping it all above the reinforcing members in the floor pan of the car. The pinch welds at the bottom of the pan are only 5.5 inches above the road and hanging 2.5 inches of exhaust below that is not an option. Note where the shift lever comes out in the cabin. Right in the stock location.

[Fitz]

With the final fit done time for paint! I decided on Auto Air Burnt Orange Metallic but before I could spray the color coats the body panels and plastic bumper covers needed a sealer. The Auto Air paints are water based and semi transparent so I tried their "sealer light" and "sealer dark" on two test panels and did not like either one. The dark sealer made the metallic look flat but the white sealer made the test panel look like the inside of a Chinese cathouse on new years eve. A quick call to auto air solved the problem. They suggested a 50-50 cut of sealer light and flame red as an undercoat for the burnt orange so, after wet sanding the epoxy primer with 600 grit I shot the sealer then the first color coats. The nipple pink sealer got more than a few laughs from my girlfriend but the color goes on blotchy until 4 coats are finished. The great thing about shooting water based automotive paint in the desert is it dries dust free in about one minute so you can shoot the stuff outside if there is no wind.

[screamin_c10]

Sub'd... That thing is gonna scream... Your gonna need bigger brakes and more rubber on the ground.

[IIGW]

the old 5.0 swaps were super fun, this Ls should be just as awesoem, and cost 10x as much..

[Fitz]

Originally Posted by IIGW

the old 5.0 swaps were super fun, this Ls should be just as awesoem, and cost 10x as much..

The car was finished two years ago. Total cost; $9000.00 including the purchase of the car. 10 times as much as a 5.0? Don't think so!

[Fitz]

Originally Posted by screamin_c10

Sub'd... That thing is gonna scream... Your gonna need bigger brakes and more rubber on the ground.

Bigger brakes? Bigger than stock but remember, it's a 2000 pound car, not a truck. 11.75 in slotted wildwood rotors front and rear, 4 piston wildwood calipers front, 2 piston Spec Miata calipers rear. Tires are 245-45-ZR15 Toyo R888 's front and rear.

[Fitz]

Clear coat on the car in my Zipwall paint booth and boy-racer stripes. Almost forgot. It does have wheels and tires!

[jjzepplin]

Gotta see this for sure! The car is finished? You tease! Bad azz so far.

[Fitz]

Originally Posted by jjzepplin

Gotta see this for sure! The car is finished? You tease! Bad azz so far.

I wasn't teasing. Someone asked me to put together a build thread so here we go. Building it was fun, driving it is more fun. Just thought I would show everyone what can happen in your garage at home. All of the work is mine. I bought a front subframe from a company that builds racers because that was the only way to be sure the suspension would be safe, but everything else is my work, done in my garage except for the paint I shot in the back yard. The point being if you didn't build it, it isn't yours. It belongs to the guy who did the work.

So with that said: