Mx-3 for racing on 1/3 mile oval

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CircleTrack96
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Mx-3 for racing on 1/3 mile oval

Post by CircleTrack96 »

Hi there guys. I'm new to the Mx-3 world and I'm looking for advice for setting up my Mx-3 for circle track. I've (briefly) run a protege, and have owner an Rx-7 for years. I guess the first thing I should do is explain the rules of the class. Please bare with me because they are lengthy.

Peterborough Speedway: Four Fun class.

This class is open to any driver who has not raced a Stock Car in a class with more than 4 cylinders.However the track reserves the right to move any driver and or car up into the Mini Stock Division inthe fairness of competition.This class is open to 1999 and older 2 & 4 door sedans, hatchbacks & wagons. They must be automatic unless listed otherwise and 4 cylinders max., no turbos, superchargers or DOHC.
I have been given an exception to allow me to run my 94 mx-3 w/ 1.6 dohc + 5 speed tranny with a weight penalty

The following cars are permitted and must be completely stock with the exception of the items listed
in these rules. Consider nothing legal if not in these rules.
 Chev: Cavalier, Celebrity, Chevette (standard permitted), Corsica, Geo Metro (Standard permitted), Sprint (standard permitted).
 Chrysler: K-Car
 Dodge: Aries, Colt, Daytona, Omni, Shadow, Spirit.
 Ford: Escort, Festiva (standard permitted), Fiesta (standard permitted), Mustang, Tempo,
Probe.
 Honda: Accord, Civic (no V-Tec, ZC or multi-port)
 Hyundia: Elantra, Excel (standard permitted), Pony (standard permitted).
 Mazda: 323, 626, GLC, Protégé.
 Mercury: Capri, Topaz.
 Nissan: Altima, Micra, Pulsar, Sentra, Stanza.
 Oldsmobile: Cierra, Firenza.
 Plymouth: Acclaim, Colt, Horizon, Reliant, Sundance.
 Pontiac: J2000, 6000. Firefly (standard permitted), Grand Am, Le Mans, Optima, Sunbird,
Tempest.
 Saturn: S1, SL1
 Suzuki: Swift (standard permitted).
 Toyota: Corolla, Tercel.
 VW: Fox, Golf, Jetta, Rabbit.

Any car not listed may be run if first approved in writing by track management.
I have permission for the Mx-3

SPECIFICATIONS
APPEARANCE
Body must be stock appearing and in stock position on frame. All chrome moldings, ornaments, door handles, glass, lights, or plastic components must be removed, except grille and windshield. Appearance of race cars participating in racing event must be presentable in appearance.Cars that are considered unsafe or improperly prepared will be rejected by the tech committee.

No worries here.
BATTERY

Batteries must be securely mounted in a sealed container behind the driver.
E.g. a marine battery container with lid.

No worries here.

BODY
A) BUMPERS
Front and rear bumpers must be stock and in stock position. Both bumpers must have safety chains attached from the bumper to the frame. Each car must have a tow hook or chain front and back.
B) DOORS
All doors must be welded or bolted shut to the satisfactions of the tech inspector.
C) HOOD AND TRUNK LID
Full stock hood and bracing must be retained, with easy access in the event of a fire. No hood openings allowed. Full stock trunk and bracing must be retained. A quick hold-down release must be used. No modified rear spoilers.
D) REAR & SIDE WINDOWS
Absolutely no rear or side windows permitted
E) WHEEL OPENINGS / ROCKER PANELS
Original wheel arches must be retained. Rocker panels must be stock clearance from the ground, no after market skirts.
G) WINDSHIELD
Windshield is a must. Windshields must be safety glass with 4 safety clips or lexan. No Plexiglas screens or half windshields allowed. The top 5” of windshield must be kept clear for Peterborough Speedway division sponsors.
No worries here, everything is prepared properly.

BRAKES
All four wheels must be working. No brake biasing of any kind, including valves, blocked lines etc. No brake lines allowed in the driver compartment. No rear disc brakes.
No worries here, new stock brakes.

CHASSIS AND SUSPENSION
A) ROLL CAGE
Full roll cage is optional. (see mini stock diagram) Cage is not to extend beyond the cockpit area. All cars must install safety bars of ¼” x 3” flat bar or material of equal or greater strength bolted tight to the body on both sides. These bars go on the widest part of the outside of the body and must go across the doors and overlap the front and rear fenders by a minimum of 12” or to the wheel opening. 3/8” carriage bolts and large washers on inside to be used. If there is no roll cage you must install a minimum of 1 roll-over post made of min. 1 3/4” X .095” pipe with a 6” X 6” X 3/16 thick plate welded on each end placed just behind the driver which goes from the floor to the roof in the centre of the car bolted in place. An additional bar must be bolted or welded which runs horizontally from the roll over post to the body to stop the seat back from going
back in a hard impact and to fasten the shoulder belts to.
B) SHOCKS
Stock factory replacement shocks only. No racing shocks allowed.
New stiffer shocks (but they appear stock)

C) SUSPENSIONS AND FRAMES
All suspension and frame components must be stock for the make, model and year of the car, with no modification. Suspension may not be adjusted.

Suspension MAY be adjusted as long as it is within the stock limitations (or appears to be). I have the suspension set up as well as I think it'll get, but I'll continue to work on it through out the season. I'm using the set up given to me by a former champ as a starting point. Front wheels toed out 1/8 of an inch, 2 degrees positive camber on the left front, as much negative as possible on the right front, even toe on the rear, 2 degrees positive camber on the left rear, 2 degrees negative on the right rear, tire pressures adjusted (can't remember the exact specs)

CLAIM RULE
Anyone including the management of Peterborough Speedway can claim any car in this class for$700. Claimer to deposit $50 cash with Tech department before any race. Balance of cash to be paid within 5 minutes of race finish. If claimer changes his/her mind, $50 goes to the claimee. If clamiee refuses, $50 goes back to claimer & claimee car and driver will be suspended for four race nights and they forfeit all money owed and all points to date.


No worries here. No car has ever been claimed.

COOLING SYSTEM
Larger rads permissible only if they fit in stock rad cradle. No antifreeze permitted, A overflow canmust be installed on the firewall, behind the right front tire. Front rad cradle must be retained.

Car has new stock rad, I have an oversized rad ready if I crack this one. .


DRIVELINE
Cars must have a safety driveshaft hoop installed at the front of the driveshaft if using a rear wheeldrive, and driveshaft must be painted white.

ENGINE
Engines must be a max of 4 cylinders , no rotary engines. No turbo or super chargers. Must be theengine made for that year and model of car. Engine must remain stock in every respect. IF IT ISN'T STOCK, IT ISN'T LEGAL...NO EXCEPTIONS***

Here's the tricky bit. Do you guys have any advice for making more horsepower while remaining legal?

EXHAUST SYSTEM
Stock exhaust manifold only. No headers. Some type of muffler is required, but catalytic converter may be removed. Max 2” OD exhaust pipes must exit to the outside of the car to the rear of the driver and within 18" of the rear wheels. Exhaust should be firmly mounted high enough to avoid contact with the track surface during racing conditions. The exhaust cannot have any sharp edges or protrude outside of the body line. All Hondas require a non direct flow muffler, 1 ½ “inlet & outlet.

Exhaust will be more or less open.

FUEL
Pump fuel or Track fuel permitted, the gasoline shall not be blended with alcohols, ether or other oxygenates it shall not be blended with aniline or its derivatives, nitro compounds or other nitrogen containing compounds. No lead additives allowed. No NOS systems.

Track fuel is 110 octane. We ussually just use Sunoco Premium (97 Octane). However, if you guys suggest advancing timing etc. maybe track fuel would be worth trying...

FUEL PUMP
Stock fuel pumps only. Electric fuel pumps allowed provided car was manufactured with it. No high pressure after market electric fuel pumps allowed. When using an electric fuel pump an oil sender safety shut-off must be used.

FUEL SYSTEM
A) FUEL TANK
Fuel Tank may be left in the stock location if stock location is ahead of the rear axle. If not, it must be securely mounted in trunk compartment between frame rails on the top of the trunk floor and not in the spare tire valley. Hatchback cars require a latching, accessible compartment or firewall to be constructed of 22 gauge steel to house the tank if the tank is in the trunk. All others must have a full rear firewall if the tank is in the trunk. No fuel lines inside the car. Maximum “in trunk” fuel capacity is
seven gallons. Fuel tank protection bars recommended. Fuel tanks must be secured with steel straps to the floor of the trunk. Minimum of two straps front and back, one side to side (straps must be steel and a minimum of 2” x 1/16” flat strap). All filler caps must be non-vented. No car will be permitted to run if any sign of fuel leakage is found. The mounting of the fuel tank is at the discretion of the tech inspector. A single safety hoop with two uprights (similar design as rad hoop – see diag.) is permitted.
Tubing may not exceed 1 ¾” x .095”.

No worries here, everything is prepared properly.

B) FUEL SHUT-OFF
There must be a fuel shut off valve in working order and mounted in the rear firewall or window parcel shelf accessible by safety personal. It must be brightly and neatly marked "ON" and "OFF".

IGNITION & CHARGING SYSTEM
Ignition system must remain stock in every respect. Stock replacement parts only. No aftermarket high performance ignition systems. Charging system must be completely working. Kill Switch Mandatory in main battery line or use of Ford solenoid is permitted, either system must be clearly marked and in reach for safety personnel.

INTERIOR
With the exception of the driver's seat, all upholstery materials and trim and padding must be removed. The front and rear firewalls must have all holes and openings filled with sheet metal. NO SHEET METAL SCREWS TO BE USED. Pop rivets or welding brazing only.
All inner metal door and quarter panel bracing must be retained unless full roll cage door bars are used. Any holes in the floor pan must be covered with sheet metal. Original floor pan must be retained. Seat belts must be firmly mounted to the floor or chassis of the car. From front firewall forward must be 100% stock unless listed in these rules.
Stock interior mirror is permitted. No fuel or brake lines or fuel filters permitted in the driver's compartment. All glass except the windshield must be removed.

No worries here, everything is prepared properly.

PAINT AND LETTERING
Only those cars who are entered in the Four Fun division and registered are permitted to pre-number their car (One or two digits) no letters or fractions. Registered drivers numbers must be on the sides of the car in large (minimum 18") letters in a colour that clearly contrasts to the paint job on the car. All cars of non-members must have sides and roof clear so the number assigned by the track official can be placed on the car. Sponsor's name and logo may be placed any other place on the car. 4" number required on right front of car – windshield preferred. VULGAR WORDS AND EXPRESSIONS ARE NOT PERMITTED. Top 5” of windshield must be kept clear for track division
sponsor.
No worries here, everything is prepared properly.

RADIOS
No two-way radios. Race Receivers are mandatory for all regular point nights, these radios can be purchased or rented from the speedway
REAR END
Rear end to be stock, no locked or posi.
SAFETY
A) HELMET & APPAREL
Driver’s fire suit is required. Fireproof gloves, neck collar are HIGHLY recommended. A Snell 2000 SA or newer approved racing safety helmet must be worn in all practice and race events and until car is parked in pit area.
B) BELTS AND HARNESS
All cars must be equipped with a quick release type, 4 point harness with a minimum 3" lap belt and shoulder harness of 3", properly affixed to the floor, roll cage or chassis with aircraft quality bolts, no less than 1/2 inch in diameter. Head restraint strongly recommended. Harness must be dated within the last 3 years.
C) FIRE CONTROL
Cars must have a 2 ½ lbs fire extinguisher with either a steel or aluminum head mounted in an steel mounting bracket and must be bolted down, and within driver’s reach with seat belts fastened. Fire extinguisher must be serviced and inspected each year and dated no later than January 1st of the current year.

No worries here, everything is prepared properly.
D) SEAT
OPTION A) Bucket seat may be used. Back must be welded or secured so it cannot fold down.If seat remains in stock position it must be anchored at the bottom in 4 places and securely attached to the role cage. The seat cannot be adjustable front to back if the seat track is used it must be welded to avoid movement. Head rest mandatory when using stock seat. Driver must have at least 2" top clearance between helmet and roof.
OPTION B) An aluminum racing seat may be used, bolted to roll cage, not bolted to the floor. When mounting seat use minimum 3/8” grade 8 bolts with large washers to hold racing seat to seat framework. Minimum of two bolts on the seat back and two bolts on the seat bottom. Seat must be positioned completely to the left of the centerline of the car. An approved head restraint must be made of some energy absorbing material. Headrest side plates recommended.

No worries here, everything is prepared properly. I went with a cheap aluminum seat for weight savings.

E) WINDOW NET
Drivers side window net mandatory with minimum 3/8 inch rod. Must have top release.


TIRES
60, 65, 70, 75 & 80 series tires only, speed rated S or T. No performance rated, snow, directional or racing tires. Maximum tire size allowed is 205x65x(rim size). Only one tire size difference from side to side or front to rear. All tires are subject to approval of official in charge. All tires must be DOT approved and cannot have a tread wear rating of less than 200, if either the DOT approved or tread wear rating is removed from the tire it will be deemed illegal. A 1/8” tread depth rule will be enforced.

Running the best tires I can get my hands on.

WEIGHT
Cars must weight the following – 3 cyl. 1900 lbs base weight, 4 cyl. 2200 lbs base weight. All ballast weight must be securely fastened and located ahead of the rear axle. All Hondas must have 150 lbs of weight located where the passenger would normally sit. 1994 - 1999 base weight will be set by tech staff in fairness of competition eg – 1999 Sunbird 2550 lbs, 1997 Cavalier 2500 lbs. To equalize the field as much as possible an additional 25lbs of weight will be added to the total weight of the car on any given drivers second feature win and for each subsequent feature win after that, The first 50lbs of penalty weight will be added in the passenger seat location any additional penalty weight after the first 50lbs may be located at the speedways discretion. Penalty weight will
not be removed with the exception of the last night witch is not a points event. These weight penalties only apply to points events only.
Peterborough Speedway reserves the right to add any amount of lead to any location to keep the class competitive and fun.

My car has to weight 2200 w/ driver.

WHEELS
Stock OEM wheels only maximum width of 7" measured from bead to bead seat. All wheels must be either 12, 13, 14 or 15" diameter. No intermixing of wheel size permitted. Aluminum wheels allowed provided they are stock production for the vehicle.

I'm running stock steel rims on the left side, and aluminum on the right side.

Ok, so hopefully that gives you an idea of what I'm working with and what I've done. Any advice for making her faster? Anything you guys can offer is appreciated.

Thanks,

Keith

P.S. Here's some pictures:
Image

Image

Image

Cheers,

Keith
Last edited by CircleTrack96 on June 15th, 2009, 11:23 pm, edited 1 time in total.
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fowljesse
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Re: Mx-3 for racing on 1/3 mile oval

Post by fowljesse »

Excellent.. a new frontier for the MX-3! I know little about the 4cyls, but am going to watch this thread!
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Re: Mx-3 for racing on 1/3 mile oval

Post by onlytrueromeo »

Sounds like alot of fun! Too bad you can't drive the 1.8 6 instead though :(


Gains: Engine management will be your best bet, otherwise 110 octane fuel is stupid. I didn't see if this was allowed in your post.

Miata cams fit, you need to switch them (exhaust for intake and vice versa). They won't be able to see them, and they're technically still 1.6 B6 cams...

A CAI MIGHT get you like 1 extra HP, if you are allowed. Just make sure w/e intake you use there are no air leaks! Also make sure your VRIS is working.

Disconnecting EGR and plugging it up may yield HP AND Gas mileage. (both good for track)

I wouldn't advance the timing more than 14-15* BTDC. Again, management system will help with this.


Can you replace bushings? You should buy new bushings from the group buy we have going :mrgreen: They will be ready in June.

LOL you could also strip a b6 block down and rebuild the valvetrain to handle higher rpms, get new cams, put in high compression pistons, etc, and get a good chunk of hp out of it, but thats not really in the spirit of things.
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BuGS
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Re: Mx-3 for racing on 1/3 mile oval

Post by BuGS »

as far as making more power, you can 1 shave the head a tad, 2 get miata stage 1 or 2 cams (with stage 3 they will now for sure they aren't stock), and 3 look into making a bottle-neck exhaust setup. If you search the board, there is info on small suspension things like removing the front sway bar but that might be auto-x... and also search for the bottle-neck exhaust thread. There were interesting finds.... Also throw in an rx7 fuel pump or something rather than larger injectors :) No one will make you open your fuel tank.

Have fun. don't get caught.
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onlytrueromeo
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Re: Mx-3 for racing on 1/3 mile oval

Post by onlytrueromeo »

Yeah I wouldn't add larger injectors, they aren't necessary!

I forgot to mention the suspension things, my bad! You should add a rear sway bar, no they're not stock on the 4bangers but they ARE stock on the 6's, and you can have them for fairly cheap at a j/y...it WILL look stock because it came from another mx3! This you SHOULD do. You said you have new, slightly stiffer struts - did you get KYBs or ZX2's? (ZX2's fit perfectly and are stiffer than KYBs) I would also look into getting some v6 springs if you can't use lowering springs (H&R's, eibach's, b&g's or intrax). The v6 springs are slightly stiffer up front due to the heavier engine used.

Since you're only driving one direction, how will you have your camber set? OBX camber bolts on ebay are cheap. What rims/wheels are you using? I suggest a lightweight 15x7 or 15x8...949 6UL wheels can be had for $160 each and they're 10lbs, otherwise enkei rpf1's or kosei k1's will be your lightest wheels.

Can you do a tranny swap? You're running an F-series right now, and you would seriously benefit from a g-series tranny. They're built stronger and have ratio's meant for acceleration rather than mileage. Again, this is something they wouldn't see, and it'd take an expert on mx3's to notice from driving.
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Re: Mx-3 for racing on 1/3 mile oval

Post by Nd4SpdSe »

fowljesse wrote:Excellent.. a new frontier for the MX-3! I know little about the 4cyls, but am going to watch this thread!
I've wanted to do dirt track racing for a LONG time, but around here, back then, it was SOHC 8-12valve only, with meant I coudn't even use a B6. A 626/Mx-6/Probe with an F2 would barely make it, just being a few cm under the length limit...but looking at it now it seems they've changed their mini stock requirements.
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Re: Mx-3 for racing on 1/3 mile oval

Post by Ryan »

BP throttle body(bigger inlet, maybe overbore it more too, and hourglass) and P&P will gain some too. More things people won't know about.
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Black '93 BP RS - wrecked, parted, scrapped.
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Re: Mx-3 for racing on 1/3 mile oval

Post by onlytrueromeo »

^Yeah I forgot to mention those. I was a 4cyl guy before I got my ZE :) Didn't end up throwin a BP in, but seriously thought about it and did the research.
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Re: Mx-3 for racing on 1/3 mile oval

Post by Savin »

BP TB won't work on the DOHC B6, just the SOHC.
viewtopic.php?f=24&t=34812" onclick="window.open(this.href);return false;
And please NOTE: This throttle body upgrade only applies to you SOHC guys. The BP throttle body will NOT fit on the DOHC 1.6 in the 94+ MX-3 RS.
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Re: Mx-3 for racing on 1/3 mile oval

Post by Ryan »

Oh, thanks for the correction. I'm a SOHC guy, or used to be :)
Now with Moderator power!

Black '93 BP RS - wrecked, parted, scrapped.
Green GS - Sold.
Black GS - Summer DD/Race car - Fancy KLZE
Red GS - K8-ATX -> MTX-KLDE - Frakencar. Scrapped
White GS - Rusty. Parts. Scrapped
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mzdamx3rsdohc
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Re: Mx-3 for racing on 1/3 mile oval

Post by mzdamx3rsdohc »

hey, good luck man. since i have a doch 1.6 i thought id mention a cple unnoticeable mods:

1miata cams- you already have them and are an easy install(couple hours) because in the miata the motors facing a different way for rwd you have to just put the intake cam from the miata on the exhaust side of the mx and vice versa- this will be the most beneficial to you

2- since you cant have a intake mod your airbox- just drill some holes in the bottom under the filter(unnoticeable)get a k/n filter

3- test pipe in place of cat

4- you mentioned putting a resistor in the iat- this just richens up your air fuel mixture i can't see it being beneficial

5- cut a piece of sheetmetal and cut to fit so you can block your egr

6- my Vics never worked for 3 years i had it and never knew. theres a solenoid at the back of your intake manifold, spray some lube on the rod and manually move it to work it thru- u wont hear it too much unless you mod your airbox- but at 4800 you can hear it engage and you will feel a difference(def. make sure it is functioning)

7-eventually you'll need a clutch- get a lighter flywheel its not like they could tell and its not like their going to pull the motor and tranny(this doesnt make a power increase but allows the engine to rev much free'r)

8- ditch the pre cat just put in a down pipe in its place- or at least gut it(its the log right under the exhaust mannii)

9- since the cars gutted more than likely remove the heat shields on the underbody i did this on mine and theres 20-40 lbs under there over your exhaust

10- ditch the steel rims- their heavy and our cars came with 14" alloys also(much lighter) you will notice a diff. i did. a nd there cheap maybe 100 $ if u look

11- im thinking you have acess to a large amount of tools and a shop in your yard or something- if so pull the head use a thinner headgasket- much cheaper than shaving the head- plus you have a block in the garage from the miata. you could just swap out for the miata pistons(higher CR)

12- GS rear sway bar- definatly bolt this in- unnoticeable(10$) at a wreckers

13- if you already have new suspension i wouldnt worry about zx2 struts etc. you'll handle better than the cavvys etc. neways. but make sure you have solid strut mounts i say this cause i go thru a set of rear strut mounts a year and their cheap neways

14- ditch a/c if you have it.,

15- rev- it to the limiter- the car makes its peak power at 6300 and limits at 6700- so just take it to the limiter in first(if you dont it will drop out of the power band in 2nd) . ive driven my mx3 on and off for 8 years and hit the rev limiter daily everyday- i dont lift the throttle when i switch from 1st to 2nd just bang and go (as it grabs 2nd much harder and in a meatier zone cuz when u let off and shift ull just notice and adapt for yourself )and ive gone from 85000kms when i first got it to 255000 now and still have 170-175 compression across all four cylinders so these motors can take abuse, i have replaced one tranny 3 years ago and have been problem free since- they def arent fast or quick cars but if you drive the s--- out of it it will impress you for what it is. and is way better than others in that class as the non vtec or zc civics will be underpowered- 2.2 slofires and crapaliers are junk for any type of racing- id say you have the best car in the class

although if they allowed those cars with a turbo id go with the sprint...LMFAO... i seriously would tho those little karts can boogey when modded
dohc b6, intake, exhaust, miata cams ready to go in
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Re: Mx-3 for racing on 1/3 mile oval

Post by CircleTrack96 »

Thanks for all the great ideas guys. I'll list the things I've done, and the questions I still have.

Airbox - I removed the tubes going into the airbox, so it has two large holes in the front of it, and it is getting fresh air from the absent headlight.

Test pipe in place of cat - done.

EGR - Where is the egr on this car? Is there a great benifit to eliminating it?

Vics - What is the Vics? Vaccuum Intake Chamber or something like that (is my noob showing?)

Clutch - I'll upgrade when I need it.

Pre Cat - So that's what that is! That's the next thing to go.

Heatsheilds - Gone. Noise deadening stuff may be next.

Rims - I'm happy with the rims. Costly rims get beat up way too quickly to replace them.

Head Gasket - When I need to replace the head gasket I'll have a smaller gasket.

Struts - may replace the right side.

Rev limiter - I was just hitting redline at the ends of the straights in practice. The gearing should be about perfect to hit the rev limiter at the end of the straights once I've got it handling a little better.

Bottle neck exhaust - couldbn't find any useful info on this, can you elaborate?

Rx-7 fuel pump / injectors - Any big gain here?

Timing - is 14-15 degrees BTDC optimal ?

Again thanks for all your imput so far. I'm really looking forward to running the car as soon as the weather coopperates.
Last edited by CircleTrack96 on June 15th, 2009, 11:27 pm, edited 1 time in total.
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mzdamx3rsdohc
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Re: Mx-3 for racing on 1/3 mile oval

Post by mzdamx3rsdohc »

bp throttle body does not work on the DOHC- it was probably someone who has or thought you had a SOHC-bore yours out and fabricate a throttle plate.\

miata cams- ARE A MUST- just put the miata intake cam on the mx3 exhaust side and the miata exhaust cam on the mx3 intake side thats the most difficult part...lol... seriously though theres write ups on here that have step by step procedures on how to do this just click search at the top and type miata cams- and it was my most beneficial mod.

blocking the egr- yes do it, not only does it increase performance nut reduces carbon in your intake manifold,etc. just follow the copper like tube that comes off the drivers side of the exhaust manifold to where it attaches to the intake manifold, its hard to see with the silicone or whatever intake on so just unscrew it and wam you have access to the egr, its on the bottomish part of the intake manifold if you follow that tube you wont miss it
dohc b6, intake, exhaust, miata cams ready to go in
mzdamx3rsdohc
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Joined: September 14th, 2006, 2:34 pm

Re: Mx-3 for racing on 1/3 mile oval

Post by mzdamx3rsdohc »

vics is variable intake chamber resonance or something like that...lol... its a butterfly valve on the back passenger side of your intake manifod that is closed and open at certain rpms, you should be able to move the rod by hand. and you will notice a surge and deeper bog when it opens, this is a must as it is what provides the car with a flatter torque curve and powerband throughout the rpm range,

CEL codes- no mod is worthwile if your engines not operating 100%- i have had codes before like o2 sensor that dont trip the CEL on the dash. just put a paperclip between the ten and gnd pin in the underhood diagnostic box and turn the key to on- not acc or start. the CEL will flash now if theres a code. first digit is represented by slow long flashes and the second by quick short ones eg. slow slow fast fast fast fast- that would be a code 24, 2 slows 4 fasts. if your car loses power also this will be key to helping diagnose it.

pre cat- it bolts right to your exhaust manifold. so you'd need to make a flange or just gut it like i did and get a new gasket. while your doing this pull your exhaust manifold and o2 sensor- clean the sensor. and put the new exhaust manifold gasket up to the exhaust manifold. ull notice the ports on the manifold have shrunk due to carbon build-up, mine had 1/8 to a 1/4" of carbon it which right at the head is very restrictive. i just took a die grinder with the pointy rock like bit and ground all the carbon out to match the gasket and head again. this did make a difference, mind you i did all3 at the same time but by doing so there was a noticeable gain.

dont forget routine thigs that may have been overlooked by the previous owner-plugs, cap, rotor, fuel filter.

fuel pump and injectors- for your mods you will not be near the duty cycle of the injectors so no need. and a fuel pump wont give your engine more fuel, as your computer determines how much fuel by how much air your bringing in so your fuel pressure would remain the same-now my car and others run rich from the factory for 2 reasons-1- long term reliability and to keep your air fuel ratio in the optimal range for your emissions. a fuel pressure regulator would be more beneficail as now you can set your fuel pressure-lean it out a bit=more power
dohc b6, intake, exhaust, miata cams ready to go in
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onlytrueromeo
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Re: Mx-3 for racing on 1/3 mile oval

Post by onlytrueromeo »

I still say engine management, not FPR.
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