Miata XSB Extreme Street Project

Ok looking for comments and suggestions on my project. This will be for the SCCA EXtreme Street category, particularly extreme street B the category that is designed for Miatas without V-8 swaps. The first couple posts will catch up where were at and there may be a couple of plot twists along the way.

MURDERIATA 

2002 Miata NB 5 speed Satin Black wrap

had some Tien "Master Flex" coilovers, Racing Beat sway bars, 15x8 wheels, Mishimoto rad/fan setup  

Decent Street Touring setup, but no contest for the ST class leaders, and anyways, this is an Extreme Street thread ....

First mod... picked up a torsen dif....dif only...

150$ for the torsen...that felt like a pretty good deal, reused all the old bearings... set backlash by hand, that should be fine right?  But still not exactly Extreme Street yet....

Bought a Megasquirt from DIY Autotune, some 550 injectors from FM, and an old Jackson racing supercharger kit from the local Old Miata Guy.  Lots of different opinions about how to set these up, but with the MegaSquirt(actually MicroSquirt?) i can run the single throttle body in the standard location.  Idle air controller in the original location in the dummy throttle body set in the MS to close under full throttle.  Made a peak of 8 lbs of boost!  It would get a little hot though.... repeated full throttle runs would would get intake air temps up to over 180 degrees.....not great....

this kit was installed with the Track Dog racing pulley kit, and it was a really nice well thought out piece, so I also got the Track Dog intercooler kit.  Intake temps dropped dramatically....couldn't get above 110 no matter what.  But also....

Singular Vents, from FM of course.  Finally this is starting to be a proper Extreme Street Project.  Informal testing showed this setup was faster 0-60 than a mildly modified MazdaSpeed Miata and faster than a rotax supercharged NC PRHT GT !!

Fun!

Do you have a big blowoff valve on the intercooler piping? With a single throttle body in the stock location, you're going to have a big pressure spike in the intercooling plumbing on every shift. You'll want to blow that off before it blows apart.

Also, to help with cooling, get that fan shroud further from the radiator core and seal the gap with some rubber. You want that shroud as far as you can get from the core. If it's a Mishimoto kit, see if you can find some stock fans instead.

Ok plot twist number one MURDERIATA is a great all around driver, decent power, good all around balance, but needs more tire, was only running 205 rivals on the 15x8 wheels, and needs more power...What car doesn't?  Current system is pretty maxed out, already technically overspeeding the little M45 at redline.  I'm really not a fan of turbo cars, the lag and nonlinear throttle response is just a real turn off for me...previously I owned many torquey muscle cars, but more recently a 2004 WRX STi.  That was a fine car with many great characteristics, lightly modded with bigger injectors, full Cobb setup and a custom koni coilover kit, but still with the turbo lag and the extreme nose heavy balance..not the right car for me.  Had a C5Z for many years and my Extreme Street Miata goal is Miata balance and handling with Corvette like power.  So MURDERIATA was a step in the right direction, but clearly not a big enough step....

Another factor...We live in a Golden Age of Performance....similar to the 60s some of the best performance vehicles are coming out from the OEMs, it's not like the 70s and 80s anymore when every car was severely compromised by regulations and emissions controls.  So taking advantage of what's available out there I got......

SNOWFLAKE

2020 ND2 Miata GT soft top 6sp only 5000 miles Snowflake pearl paint and the rare gray top, all stock(I thought). 
Basic plan... STR type build plus power! For Extreme Street action!  So first up suspension wheels and tires....

I love Flying Miata... I live in Hawaii and Flying Miata ships to us free!!! Just like they do to America.  I can only imagine this is still a mistake in there software, because it has got to cost them some money...So please NOBODY POINT THIS OUT TO THEM, so I can still get good deals on parts....

Anyways I probably would have ordered the Fox ND coilovers from FM, but when I got Snowflake, they were out of stock with no ETA on when more were coming in...so I ordered the FM swaybars and the FM  radiator and a few other parts....I got the Xida Coilovers from 949 guys

First install was the FM Delrin Door Bushings.... do they do anything? Probably not... the ND is a modern design with decent rigidity but the door bushings are traditional Miata parts...but the car had them installed already!  Interesting...looking further, the car had the FM sway bars also installed!!
There has been much discussion as to the character of the ND suspension, A common opinion is that the car has too much roll.  I thought snowflake handled decently well for a stock car, but now I saw it had sway bars already.  The factory bilsteins seemed mismatched to the factory spring rates.  The OEM suspension was jiggley as if there was too much stiction, maybe this would wear in as the car was so new, but regardless we are going Extreme Street...

Not having to install the sway bars was a huge benefit... it ts a serious harrasle on the ND.  Installed the coilovers and maxed out front camber to ~2.3 front max caster zero toe ..rear 2.0 camber 1/32 toe in.  
got some konieg Hypergram wheels in gray and 17x9 mostly to match the color scheme of the car

Thats better but basically a STR setup not yet Extreme Street!!!....

Keith Tanner said:

Fun!

Do you have a big blowoff valve on the intercooler piping? With a single throttle body in the stock location, you're going to have a big pressure spike in the intercooling plumbing on every shift. You'll want to blow that off before it blows apart.

Also, to help with cooling, get that fan shroud further from the radiator core and seal the gap with some rubber. You want that shroud as far as you can get from the core. If it's a Mishimoto kit, see if you can find some stock fans instead.

Hey Keith 

Thanks, but I may not have been clear in my description....throttle body at the supercharger inlet which I consider the normal location(for supercharger) dummy straight through at the original  manifold location with the IAC at the dummy .  This worked pretty well but required a high idle because I could never quite get the IAC to respond and track quickly enough.  So a little annoying but no big deal. 
As far as cooling goes, once the Track Dog kit was installed it has good shrouding and MURDERIATA kept cool even under long up canyon runs...sorry no pics though. 
 

I do like superchargers , but this was an ND2 the car I thought I wanted with the upgraded head and more power.  What I didn't know at the time was that Mazda downsized the injectors on the ND2 and seriously revised the engine management, tuning options were much more limited than in the ND1.  Still there were a couple of companies that persevered.  I chose the Edelbrock Eaton TVS 900 based kit from Miataspeed in California 

Not too bad the install took about 15 hours while Miataspeed does it in about 10 at there shop.  It is very similar to the ND1 Edelbrock install, but Miataspeed machines the Edelbrock cooling brick adapter to mactch the ND2s head.  Miataspeed also is responsible for tuning and they claim about 220 whp on their dyno.  This install does include a heat exchanger, coolant pump, piping difficult access from the wheel well, front fascia off, all the good stuff. At the time I also install larger direct injectors that come from a Mazda 2.5 l enigine. 

MURDERIATA and SNOWFLAKE 

Snowflake has been pretty fantastic....a new modern Miata with nice amenities, such a smooth easy driving car performance is pretty stellar, very direct precise handling, really and all around great performer and with the supercharger a decent start at a XSB build.....and yet .....

is the malibu a 64 or a 65?

AngryCorvair (Forum Supporter) said:

is the malibu a 64 or a 65?

65 I think, it's got the larger backup lights in the bumper

Ando said:

I love Flying Miata... I live in Hawaii and Flying Miata ships to us free!!! Just like they do to America.  I can only imagine this is still a mistake in there software, because it has got to cost them some money...So please NOBODY POINT THIS OUT TO THEM, so I can still get good deals on parts....

It's not a mistake, it was a decision :) Thanks for your support!

Ok so the ND.... There's a lot to like about the ND. It handles very well it looks good lowered and with wide wheels.  The handling is very precise...and so on and so on.....but after a while I began to feel the flaws more than the features.  Minor complaints, the seating position is off center, not by much, your average BMW owner probably wouldn't even notice as so many of those cars don't line up.  The GT leather seat is not very comfortable, it has that modern very hard leather feel with stitching right down the center that irritates my spine.  NB cloth seats are much more comfortable to me and centered on the steering wheel.  The brakes are very soft most of the time, as due to odd engine warm up modes the ND uses a vacuum pump to sometimes assist the engine vacuum to the booster, and this makes for inconsistent brake feel.  These are minor complaints and easily accommodated, but there are more serious issues...
The engine management is a bit of a problem.  With the revised ND2 engine ecu no tuning companies seem to have really good access or control over engine parameters.  So as best i am able to tell the tuning strategies involve various tricks to the engine computer, the primary trick being WOT enrichment is accomplished by fooling the computer into a rich catalyst protection strategy.  So full power and 100% throttle plate opening lags throttle application by a half second or so and full enrichment doesn't occur till almost 4500 rpm.  This limits the throttle response to something approaching a turbo car, just what I was trying to avoid.  Now there are two provisos to this that should be mentioned, the tuning company is in California and they are primarily concerned with creating a CARB compliant tune. I know many of you on the board are at least somewhat familiar with the sort of restrictions that are involved in that.  Secondly the ND miata has a reputation for a weak transmission, a well deserved reputation, a number of changes to the transmission were made over the years but it seems like none of them actually made the transmission stronger, the actual improvements to transmission reliability have been the ND's dual mass flywheel and the dampening of the throttle response. I think it was likely a harmonic vibration that developed somewhere along the lines in the high-performance four-cylinder engine that was breaking the transmission and the dual mass fly wheel stopped it.  Slowing the throttle response is a good way to smooth out those harsh transitions and make the transmission live longer.  So I can't really blame the tuning company for the results, but the throttle response is unsatisfactory.  This was also the case with the OEM non supercharged programming 

finally the worst aspect of the ND is the numb chassis. The steering has a distinct lack of feel for whatever reason. Some will blame the EPAS the electric power steering as operating as a damper in the steering column taking away that last little bit of feel telling you what the contact patch is doing.  There are also very large rubber bushings in both the front and the rear that isolate you from communicating with your car, both front and rear. The early Miatas with double a arm front and rear suspension and relatively small rubber bushings and hydraulic steering never had that problem and told you exactly what they were doing at all times.  As I drive cars back and forth at autocross i just get more disappointed in the NDs numb chassis and unresponsive throttle...

Also even with 220 whp it could use more power....

also I never wash anything.....

In reply to Ando :

How do you have an event without numbers on the cars?

Plot twist #2 ....the real thread.....

The Mazda Speed Miata 

Picked  this up from a Miata friend to use as the basis for a SWAP project..yes that's right It's going to be hacked and disfigured, don't worry too much about about this particular MSM it has a million miles on it has been rear ended three times and has a 20 footer paint job.  My general Miata goal is still the same. Miata balance and fun with corvette like power.  
What engine to swap??

Floating Doc (Forum Supporter) said:

In reply to Ando :

How do you have an event without numbers on the cars?

Our events are very small, like 12 cars or so...

Easy to keep everything identified...

So now you have TWO supercharged Miatas and one turbo Miata? I think you should do a world's first and swap the boosted ND engine into one of the NB's. Regardless I am following along with interest as a fellow ND owner.

My old C5Z had about 400 hp for 3020 lbs plus driver 180 so about 8 lbs/hp 

My old C7 had about 460 hp for about 3500 total lbs so about 7.8 lbs/hp 

So a Miata at a total weight of about 2500 with driver should have about 320 engine horsepower to match the power to weight of my previous C7, a car that I felt was sufficiently quick.

Lots of different ways to get to that goal, but retaining the naturally aspirated torquey characteristics of tha American V8 would be ideal, but how to get there without adding too much weight and dramatically changing the car.  V8 swaps obviously are great but can add some pounds and LSs are expensive now.  V8 roadsters has pioneered the LFX swap, the new Chevy 3.6 V6, and that is really appealing, but.... couple small issues like hood clearance is not good, requires a cut hood...not great.  Secondly the LFX 3.6 is a high revving 4 cam engine not quite the torquey American V engine experience I'm looking for...it does make the power though.

LV3 4.3L V6

Enter the LV3 V6, basically an all Aluminum LT V8 with two cylinders chopped off

lightweight 80 ish lbs lighter than an Aluminum LS broad compatibility with LS swap parts, so use the V8 roadster subframe and trans mount kits and a wide variety of front accessory setups are available.

285 HP at 5300 rpm with the small truck cam and aftermarket big cams are available to push the hp over 350.  Transmission, undecided, but maybe use the TKX for slim profile and lighter weight.

so potentially with the LV3 TKX combo you could save over 150 lbs compared to the typical LS/T56 swap while satisfying the power goals

The LV3 was used as the base engine in Chevy trucks from 2014 to 2019 so there are thousands available out there and junkyards unwanted