Hey Guys, first off I wanted to thank you all for this section as it is a wealth of knowledge. MX6.0 has a setup to be envied and it will be very tough act to follow. I have never done a swap and we are currently pretty deep into it im almost a bit skeptical it will all go back together . (We tore it all apart 1/1/14 and work on it about 1 day a week as the shop is rather busy and so am I! You dont make any $$ working on your own stuff!) I have tuned about a dozen swapped LSX Miatas and all of them had some sort of compromise (1bigcam was an exception)....Terrible IATs, choking induction, or constipating exhaust, etc. The nature of what I do day in and day out is make things better and optimize them component by component. So I am hoping to learn from all these that I have seen and make mine better.....in a perfect world. Only time will tell.

About 5 months ago I sold the mistress, 07 Z06 585RWHP 535RWTQ (3350lbs Full race weight) daily driver. Other than God, My wife and kids, That was the next love of my life. She was prepped for HPDE and was a dominatrix as well as very quick in a straight line (roughly 10.3s@137.5mph-ish). The goal for this build was to better the power to weight of the Z06 so somewhere around 500RWHP and 2500lbs race weight. Its not going to be easy to get to 5:1 lbs per HP but we are going to make a noble effort!

I never had as much respect for Miatas till I was on the road course and saw what guys were doing with such little power. The cars are also the most economic racing mass produced vehicle that I know of. If they only had more power....I decided on the Miata because of the support, also V8roadsters.com was selling a car with some suspension mods and other parts for a decent price a '99 NB. Also It will be built for resale and the idea of competing with flyinmiata.com at a 35K turnkey price was interesting. In my mind I had been building a car for quite some time before I had it and I changed my mind again and again.

The combination is currently:
-Forged 6.2L LS3 bottom end (12.4:1 raised Wiseco pistons) balanced by Engine lab of Tampa
-Fully Ported LS3 heads, intake manifold, and TB by Fasterproms.net
-ZR1 injectors, Walbro 485pump capable of e85 and pump gas
-Custom Cam 235/246 112+4 by BrianTooleyracing.com and their platinum spring kit
-UD pulley Powerbond
-T56 fully built for 750RWHP by Fat body performance, Pro5.0 shifter
-Competition clutch V8roadsters spec, also alum driveshaft, and their oil pan
-8.8 rear with 3.08 gear ratio
-All mounting hardware is from V8roadsters.com as well as much tech support!
-Harness is from currentperformance.com PCM is an 08 corvette
Much more to list.....

Getting a little tired here and should be porting blower cases......but I wanted to sum this up. I chose the 3.08 8.8 rear and T56 for the reason of matching in MPH the C6 Z06 gearing. Roughly 60mph at the end of first gear 95er so in 2nd 130 in 3rd and 160 at the top of 4th gear. The Z06 can somewhat put the power down to the ground and with the 3.08 and the T56 it is extremely close to the mph per gear of the C6 Z06. The more TQ you have the less gearing you need, I am also limited by tire size so I am running 949racing 15X10 6UL wheels with 275 Hoosier R6 Slicks all the way around, with autokinexion.com fender flares.
The car will be a mazdaspeed clone (headlights, front bumper, lower lip) plus some more aero. Before when it was still the 4 cyl I bought a super-light fiberglass hardtop and put a Lotus Elise diffuser on the rear and did a center exhaust. I have decided to paint the car the electron blue of an 02 z06 and hopefully in a week or two we can get it to the painter. Its a few shades from the original color and it needs paint bad.

Thanks for reading I will get some photos up in the next day or so....need sleep.
Jeremy Formato

 

Something I am thinking about in reading what you have posted, why not go with 3.27 gears in the 8.8? I see you are wanting to very closely match the 'vette, but isn't your goal to BEAT the vette? Because you are using a better powered and more efficient, and I assume higher revving, powerplant, you should be able to outpower and out accelerate the vette with the smaller and lighter chassis. That should give you an advantage to be able to row the gears a tad bit sooner and keep the engine in the power band. It is a 6% gain in gearing going from 3.08 to 3.27, so that by itself should not affect the speeds possible for each gear by that much. Instead of 60 in 1st, it would be 56.4, and so on through the gears.

Best of luck with this venture and I hope it all works well..

 

Well, this is going to be fun... My stock LS2 - Miata is not finished as of yet (getting close!), so I cannot imagine how that staggering amount of HP and TQ is going to feel in this Mazda project of yours when you go to WOT coming out of a turn on the road course!

I went with a 3.31 in my 8.8 diff,but mine will be 95% street car, I think. Your car should achieve lift-off in that final overdrive gear...

Good luck & post up more pics and details when you can. V8R simply rocks, don't you agree?

 

In for pics

 

Thanks for the kind words, Jeremy.

500rwhp is just about right for a 2500lb car....That is until you get used to it. And you WILL get used to it

I've been pretty happy with the 3.23 I'm running. With the GTO gearset, 24" tires and a 7K rpm limit I get:
1st= 51mph
2nd= 74mph
3rd= 107mph
4th= 153mph

I might also add that with 225/50/15's, traction in anything but 1st gear isn't a problem at all.

 

Here are some pics of the before......
The first was taken new years day. The second was with the lotus diffuser homemade joke of a spoiler and side-skirts. The hardtop weighs about 15lbs or something silly....The last pic was late new years night.
Jeremy

 

Here are a few of the motor and tear down with the V8 Roadsters mounting kit going in slowly but surely.
The early plasma cuts..... Motor 6.2L forged on the stand.

 

Big Ed- The idea is to be able to put the power to the ground, I do want to drag/street race the car a bit as well as road course it. I have been in many vehicles that just cant put the power down and I thought given what I am trying to make this would be the best choice. Had a few guys with big TQ go the opposite way to make it usable, not spinning all over the place. The car will be on full slicks rain or shine.
In regards to your idea of going thru the gear and getting into the next..... well there are 2 schools of thought here. In my mind its avg TQ over time makes a car go fast ( think TQ converter). Thats also acting like essentially 6% more tq and I think I may have enough if all goes well. The Tq to weight ratio is really where its at and its more favorable with this build than the vette. I have another 8.8 waiting in the wings with a 3.27 ratio if I can get all the Aero downforce I am looking for and traction is solid. Also I didnt mention I am going with the 28 spline axles because I cannot find the 31s ANYWHERE. I hope they will suffice.

Toysnake- If you have it apart I would at least mill the heads and do a valve job.... And then add a cam and a FAST manifold and port it and headers and port the heads add an UD pulley.....man I have a problem.
V8R rocks-Yes Shandelle has been patient.....I was friends with him years and years ago so he busts my ***** incessantly.

MX6.0- I have header envy.....want WANT!!!! Unfortunately That is the cornerstone of which I think the combo is going to hang if it makes the power or not. The power is definitely something that you get accustomed to, the vette I was wanting to add a 150 shot to go kill some Hyabusas. Roadcourse it was almost too much but straight line not enough.


a few more of the motor.....

 

which style 8.8 are you using, and what has the 31 spline stubs you need?

 

03 cobra I believe, Also I think the Tbird came with it?.... Aluminum case, IRS.

 

t bird and lincoln mark came with 8.8, but its different housin than cobra.

02+ exploder also came 8.8 irs.

not sure if stubs are interchangeable? ill keep an eye out though, spending a lot of time at junk yards lately

 

quick google says explorer irs is still 31 spline like the explorer solid axle was.

lkq pick and pull tampa shows 2 in the lot on their website.

 

This will be a fun car...... but those 3.08 gears will not work out as you planned.

A Nitto NT01 275/35/18 if you can fit it can put down pretty much all the power once heated up. I'm not sure on max tire height a Miata can swallow.

I run 3.73's with 2.66 1st gear style T56 Magnum and it absolutely rips. My rear tire is 25.9" tall though. 150mph in 4th.

 

Only problem w/ LS Miatas these days is that everyone & their brother has one. Anyway, forget the 3.08. If concerned w/ fuel mileage, just lean out the A/F ratio under normal driving conditions. I run 3.90 rear w/ Viper spec T56 & a 16.5:1 A/F ratio on highway (11.5 SCR) & can get up to 33 MPG. @ 12.5:1 SCR, don't know if you will be able to lean it out that much. Have run that lean for years without issue; 12.9:1 @ WOT. Regardless, 1st gear will always spin. So, just get used to hitting second before the pedal reaches the floor. Hell, if you wanted to could spin the tires through 4th independent of rear end gear ratio & 275 slicks. I also run 275 or 265 slicks depending on tire costs @ the time.

Don't forget the Mazdaspeed steering rack while you're adding Mazdaspeed parts. You will want the 1.5 lock to lock ratio on the road course. Have 12 yrs LSX Miata experience from build through road course driving.

 

Aww come on, They may be getting more popular but I wouldn't go that far. I've only ever seen one other LS Miata and I know the guy who owns it. I also take mine to quite a few shows and only a handful of people have mentioned seeing any V8 Miata, let alone an LS swapped one.


The problem with running wider street tires on a Miata is the diameter. For me, anything over 24" (225/50-15)and I have to raise the car to prevent rubbing. No worries though, the RA-1's easily put the power down in 2nd gear as long as its at least 60* outside.

The OP is running 275/35-15 Hoosiers anyway

 

I know , it was stated kinda tongue in cheek. Having put in a lot of effort building mine, before there were kits, it kinda bugs me that they are now so easy to build.

Kinda chuckle every time I read a post claiming how a Miata can't put 500 HP to pavement; more specifically 400 Ft-#.

 

92-97 lincoln limos (factory spec'd to be stretched) and 05.5+ crown vics, grand marquis and town cars have 31 spline axles in addition to the explorers, but then you have to consider pumpkin offset with the explorer and maybe width with the cars, but if you wanted a solid axle it would be a cheap way to go, and trac-lok would be easy enough to get at the same time.

 

Have MX6.0 build you his headers. You two are using the same kit so they should swap. His headers are a work of art!

 

hes using irs 8.8, not solid axle.

factory offset of the explorer pumpkin wouldnt matter in this car both sides would be sticking out its so small lol

 

hold off a second there
I remember all NB got the same steering ratio, the reason behind the 1.5 lock to lock is because mazda doesn't want the 17" stock rims to rub
please research before u buy

as far as the ford 8.8 rear diff go
03-04 cobra's are 31 spline IRS diff
02-05 explorer are 31 spline IRS diff
06-10 explorer are 31 spline IRS diff
99-01 cobra are 28 spline IRS
90's Thunderbird, Mercury Cougars and Lincoln Mark 8 are 28 spline IRS

all got different style housing,

there are pre-made diff mount kit for Cobra / t-bird / mark 8, all of these for 2 front ear mount
i dont remember seeing anyone use the explorer diff in a miata, not sure why
i think the strongest is the 03+ cobra
you can buy 31 spline axle that fits the miata from factory five racing (call them, they don't list it)


edit:
i love that rear louts diffuser
can you post more rear under-body shots plsssss
i would love to see how you route that exhaust