Looking to dive in to racing.

[opelwasp]

I don't know what has gotten into me, but I am seriously looking into racing a Manta A. Here are our track car build rules, what kind of competitive car could I build? Where do I need to see if I can fudge?


Twin Cities Speedway Mini Stock Series
General Rules: Technical and Race Format
Revised 7-30-06
The rules contained herein supersede any previously published safety and conduct rules. Twin Cities Speedway may hereafter be referred to as TCS. The rules set forth herein are designed to provide for the orderly conduct of racing events and establish minimum acceptable requirements for these events. These rules will govern the condition of all events and by participating in these events the participants are deemed to have complied with these rules. No express or implied warranty of safety shall result from the publications of or compliance with these rules and/or regulations. They are intended as a guide for the conduct of the event. They are no way a guarantee against injury or death to participant, spectator or official. The race director or promoter is empowered to impose or permit reasonable deviations from any specification herein or impose further restrictions that, in his or her opinion, do not alter the minimum requirements. No expressed or implied warranty of safety will result from such alterations of the specifications. Any interpretation or deviation of the rules is left to the discretion of the officials. The decision of the officials is final.
UNSAFE CONDITIONS: NO UNSAFE CONDITION WILL EXIST. AN UNSAFE CONDITION, IDENTIFIED BY THE TECHNICAL INSPECTOR, RACE DIRECTOR OR PROMOTER WILL BE FIXED IMMEDIATELY OR THE CAR CANNOT COMPETE.
SEATS: Only an approved racing seat may be used. Head rest or high backed seat mandatory. Seat must be secured to roll cage. Headrest must be secured to roll cage.
HELMET: Snell institute approved SA95 helmets or better only. No exceptions.
NECK BRACE: Required
FIRESUITS: One or two piece approved firesuits required.
GLOVES: Approved fireproof gloves mandatory.
HEADSOCK: Fireproof headsock or skirt headgear mandatory.
SHOES: Approved fireproof shoes recommended.
FIRE EXTINGUISHERS required in each pit with car number boldly placed on unit.
SEAT BELTS/HARNESS : Only approved aircraft type or racing specific belts are allowed. Lap belt must be 3" wide. Shoulder harness must be 1 1/2" wide. Crotch strap mandatory. Belts must be securely mounted with grade five bolts with minimum 3/8" diameter. NO EXCEPTIONS. Eyebolts must be one piece with 3/8" shank minimum and not formed and welded hook. Belts will be replaced every two years. Belts must carry 2001 or newer date. ALL BELTS MUST BE SECURED TO THE ROLL CAGE ONLY.
ROLL-BAR PADDING: Required: Driver cage area and driver’s side door bars. Consult with technical inspector for assistance.
WINDOW NET: Approved window net required on driver’s side window.
PIT SPEED 10 MPH: $25 fine and 5 Championship Point penalty for speeding in the pits.

WEIGHT RULE: 2050 lbs. with driver and all drivers’ equipment. Driver must not exit cockpit prior to weigh in.

TYPE OF CAR: Any American or foreign production economy sedan, coupe, station wagon or pick-up. No 4-wheel drive, rear or mid-engine cars. Maximum wheelbase is 100.5”. Exceptions to the wheel base rule may be made on some stock mini-trucks that may exceed the 100.5” limit.

BODY/CHASSIS/PAINT/NUMBERS: Minimum 22 gauge steel or aluminum body, hood and roof panels. After market bodies OK. Must be firmly attached to secure mounting points. After market nosepiece of plastic, fiberglass or rubberized materials OK. Body panels will be painted and numbered to the satisfaction of race officials. NO JUNK. Large and distinctive numbers easily read from the scoring booth will be required. Number on roof, left and right sides required. One or two digit numbers only. Example: 1 through 99 and 00 through 09, X and XX OK. NO inappropriate lettering on cars. Help us on this one. Our sponsors have noticed (IE. sexual or vulgar comments).
1. Body may be altered in trunk area for fuel tank. Fuel tank must be behind rear axle.
2. Bumper may be replaced by any bumper no wider than the outside of the tire front & rear. NO SHARP EDGES. NO EXCEPTIONS. Wrap around bumpers only.
3. All body panels may be gutted. Doors will be safely welded or bolted shut. No roof openings.
4. Fender wells may be cut may be cut for tire clearance. No sharp edges.
5. Firewall and floorboard will be stock and in the stock location.
6. Glass and flammables will be removed.
7. Rear deck lid spoiler OK. Maximum vertical height of 6.5 inches measured from deck lid

BRAKES: Must have working brakes on at least 3 wheels. No cockpit adjustable proportioning valves. Disc brakes OK. No exotic metals. Calipers and rotors must be O.E.M. After market cockpit adjustable pedal assemblies are NOT allowed. Locking rear end does not constitute one brake. No cockpit adjustable devices. NO TOLERANCE.

DRIVE TRAIN:
1. On rear drive cars; a drive shaft safety hoop will be required 4” behind front u-joint. Hoop must be .25” thick - 1.50” wide steel strap.
2. Flywheels and clutches: After market clutches or fly wheels OK. Must be steel. Clutch must be operable at ALL times.
3. Stock automatic or manual transmissions allowed in stock location. All gears forward and reverse must be in working order.

REAR END: Stock type only. No exotic or quick change rear ends. Locked rear ends OK.

ENGINE/CARBURETOR/IGNITION: Water cooled, stock as delivered in line 4 cylinder of 2600 cc’s or less. Crossbreeding of head block and internal parts is allowed if they can be bolted together without alteration. Engine same manufacturer as chassis. NO EXOTIC METALS.
1. One 2-barrel downdraft 500cfm carburetor, or less, is allowed. No fuel injection. Carburetor will be checked with Go-No-Go Gauge.
2. Carburetor adapter will not exceed 1” in height from stock location. Blending adapter to manifold OK. Blending limited to 1.5” down from stock carburetor base.
3. Ignition will be stock or aftermarket. No magnetos. Distributors may be locked out for advanced system. After market coils allowed. Any type distributor may be used (i.e. crankfire, dual point or stock).
4. CAMS: NO VACCUUM CHECK. Cam timing adjustment devices OK. Any hydraulic or solid camshaft may be used with any type of engine, no matter what make or model.
5. All engines will be allowed to carry 200 lbs of compression.
TEST: Engine will be cranked with all spark plugs removed-5 revolutions. Throttle will be locked open during test. Cranking speed minimum: 200 RPM. Compression is not averaged.
6. Mufflers mandatory. 95 dba at 100 feet.
7. Aluminum intake manifold OK. Exhaust headers OK. Aftermarket or stock headers allowed.
8.Cockpit exhaust OK if shielded (by approved cockpit sheet metal. See tech inspector) from driver and exits behind driver. No exhaust may invade driver’s side of cockpit.
9. Two valves per cylinder and one camshaft per engine. 3 valves on stock Mitsubishi OK.
10. Any stock or after market valve springs and retainers allowed. No exotic metals.
11. NO CYLINDER HEAD PORTING ALLOWED.
12. Firewall and floor pan must be in original stock position to the rear axle. No engine setback allowed.

FUEL SYSTEM:
1. Electric fuel pump OK. May not be glass or cockpit mounted. Kill switch required from outside car. Driver’s side near dash. PAINTED WHITE.
2. Fuel cell optional and recommended. Gasoline only. Racing gasoline OK.
3. Firewall required between fuel tank and driver. NO EXCEPTIONS)
4. Must have a 1/4 turn shut off valve on the fuel line accessible to driver, and painted red. Must be in plain sight to right of driver.

SUSPENSION:
1. One shock or strut per wheel. Stock NON-ADJUSTABLE replacement shocks struts and springs are OK.
2. No weight jacks, adjustable struts or shocks, traction or ladder bars of any kind allowed.
3. Inner panel from strut tower back must remain intact.
4. From strut tower forward may be removed.
5. Quick or speedup steering allowed. (Recommended)

TIRES/WHEELS:
1. Tires not to exceed 8” in tread width.
2. Hoosier “Dirt Boss” is the specified tire at Twin Cities Speedway; or Less. Diamond backs OK.
3. No slicks, racing tires or racing recaps allowed. Tire grooving allowed.
4. Steel wheels only.
5. Maximum width of 8” bead to bead.
6. Any questions on other tire eligibility should be directed to the promoter or technical inspector.

ROLL CAGE/DOOR BARS:
CAGE WILL BE SAFE TO THE SATISFACTION OF THE TECHNICAL INSPECTOR
Roll cage padding required.
1. Full cage roll bars required with full loop from frame over driver. These bars to be connected on top and both sides by another bar. Cage will be within 3” of the roof of the car and within 6” of sides of top. In back loop, running from top right to bottom rear at approx. 45 degrees there must be a bar. All bars will be safely welded together and/or bolted or welded securely to the frame with no less than 7/16” bolts. Must be welded to frame or subframe filler on unibody cars. Gusseting on all bar junctions recommended. Mandatory 1/4” hole to be drilled in driver’s door bar for inspection. You may be asked to drill a .25” hole at any point, at any time, in the cage for inspection purposes. ALL BARS MUST BE OF 1 1/2” x .095 or 1 3/4” x .095 minimum. Existing cars built prior to the 2003 season with 1 1/4” tubing will be allowed through 2004 season only.
2. Three left side and minimum two (three recommended) right side horizontal or door bars (“X” bars OK on right side) are required (same material as cage). These bars must be attached by a minimum of one vertical bar of the same material (2 recommended).
3. Front horizontal cage loops allowed inside body in front of radiator. Mounting radiators to a bar with stock mounts removed OK. Two additional bars angled from top of cage to extend past rear axle to frame rail required.

[jeff denton]

I take it this is a dirt track.
The rules are very liberal! You can build an engine with mixed up parts, so try to gather up some 2.2 stuff. Internals must be stock, perhaps, kind of vague there...I see no rules about oilpan. Any flywheel and clutch may be used.
You can run the big 500 2 barrel. No porting, but nothing about big valves. Nothing about intake modifications! No cam restrictions, no vacuum test. Exotic ignitions okay!
Do the in-cab exhaust.
Rear end may be tricky, they say stock type, not stock. Remember gear choice is 3.18, 3.44, or 3.65 unless you have lots of money. You'll want to weld the spiders. I absolutely suggest a rear end swap, for better gear availability and for fixing crashes...
Build the car as light as possible, the weight given should be do-able, but you'll have to very thoroughly gut the car. Leave absolutely nothing un-needed, every little scrap of metal is excess, especially on the right side. Build the cage to favor the left side, they give you 6" gap between the main hoop and the roof corner, so use all that on the right, none on the left. Aluminum body parts-wow! Do all you can here, especially on the right side.
To be competitive you need some chassis set up experience. To drive the damn thing you just need balls.
Have fun!!!

[namba209 (R.I.P.)]

Hey Chris, is that the old Triple M speedway off Linda Road? If so I used to race my bikes there. IIRC its a 1/4 mile flat track dirt oval.

[opelwasp]

Yes Ron that's the one, 1/4 mile dirt.

Wonder if I can milk a 2.4L out of it using "stock Opel" parts.
Can a 2.4L crank be fit to the 1.9L block, or can the (1.9,2.0, 2.2) be matched to fit 2.4L piston/rods?
What would be the best head to use?1.9, 2.0, 2.2, 2.4 SOHC (no DOHC allowed, damn!)
What is a list of questions I should ask the tech advisor as far as do's and don'ts specific to building a fierce Opel racer.

I assume 73-75 Manta would be best body to use.

[Paul]

Now's the time you'll need RallyBob's advice more than ever. Ask lots of questions and print/catalogue everything!!! Combined with input from Jeff, you should do well!

Yes a 2.4 crank will fit in a 1.9 with some clearancing. If no head porting, then do a search on a post Bob did a while Bob did on Camoflauging (sp?). If they won't allow Chevy valves then get the ones Bob has for sale. You'll need to find Impulse and swap rear ends. That will get you a 3.89 rear gear...

You'll have to do every trick in the book and get the best rear wt %, left% and cross wt.

Sounds like you'll have a blast!

[RallyBob]

Sounds like a lot of leeway. You could probably build a monster that could win it all, but it might set you back $7-8k. Lots of room for creative thinking as far as I see.

[jeff denton]

Notice the Circle Track Racing thread got bumped up again, by the new owner of Joe Bower's famously successful Mantas. They are now owned by Bob S. of Oregon. Joe said Bob got all his goodies with the cars, plenty of good extra stuff. I have his phone numbers and those of the shop that built those engines if you need them. I strongly suggest you hook up with Bob S, calls himself MSM at this site. By all means pay attention to RallyBob's advice, he has been huge help. Another expert nearer you (in Artesia) is Roger, I could give you his phone number, he loves to talk racing and he knows what he's talking about! He also has lots of parts and can spec out and supply some real razoo illegal stuff.
RallyBob recently had some 4.30 gears available. I'd like to have them, but, I'll get by with the 4.22s.
As RallyBob hinted, be ready to invest a lot of money in this endeavor, like three times as much as would be normal with a Ford.
Serious advice: whenever discussing rules and brilliant variances from them or clever interpretation with a track official, be sure to write down their response and ask them to initial this record of it. Because sooner or later someone will cry "foul" and the official may not want to to remember what he told you. Mark my words!

[opelwasp]

Follow RallyBobs advise? HA, I'm driving his advise now, and what a blast it is! I love my 2.4 LS motor (Legere Spec)
Now I just have to solve the traction problem, maybe I should start a new thread whining about it.

It says "stock type" rear end does that mean the 4.22 gears and the Quaif LSD in my dad's GT4 racer would be OK?

Would the brakes from a 75 Manta Bigbrake be OK to put on a 73 or 74?

I'm starting to have too much fun and it isn't even built yet!

[jeff denton]

To me, if the rules say stock rear end, like ours do, it means run the rear end that came in the car. Here the rules also say you can run any gear in the stock rear end and you can lock it. Your rules say stock type rear end, to me that means one that is similar to what came in the car, such as anything that has axle tubes solidly attached to the center housing. Anything but an IRS, perhaps.
I don't know enough about the LSD to guess whether it locks up sufficiently for dirt track use. The gearing is all dependant on how fast you can get around the track and what RPM you're turning. In my case it was purely try-this-and-see, there is a thread about how all this unfolded. I made up a chart to show all the various possibilities with all the ratios available, throw in the ratios of the numerous transmissions in second and third gears, and you see hundreds of options. You just try something and analyze it from there.
Perhaps another racer can tell you what his rear ratio is, and the ratio of the trans gear he's using, I found this to be bull$hit here, advice wasn't even close. 3.44 was no go in second or third gear. My 4.22's are just a bit too fast, 4.30 would be a tad better. I use third gear.
Your 2.4 may be suitable, I don't know, are you willing to run it 7500 rpm for fifteen minutes? I have to use a 1.9, racers like the 2.2 stroke better.
For a flywheel you could run the Unorthodox beauty, were I to do that I'd have them customize it a little to use the Vette clutch.
So what is the problem with traction in the street car?

[RallyBob]

On the Manta, races are going to be won with the suspension. Don't get me wrong, power is great, but a crappy handling car won't win no matter how much power its' got. The Manta has a great chassis to begin with. And it's easily modified compared to a GT. Plus the 50-series chassis absolutely rocks in rallying use, therefore the transition to dirt oval is a pretty smooth one.

So you could probably build a fairly wicked 2.2, gear the car for the track, upgrade all the brakes to the '75 spec, welded rear axle, good shocks and proper spring rates and go stompin'. A properly set up car will not only be fast, but will drive easy.

I notice the rules allow for a steering quickener. If you build this car, just DO IT, don't even question it! I hate driving stock Manta's with their slow steering, all my cars (since the early '90's) have either the Swedish fast rack or the Quaife Manta B fast rack (adapted). But these are hard to get and expensive these days. There's another solution, and if I get a camera soon I'll post pics and a parts list. Basically you just use a stock car steering quickener adapted directly to the front end of the car. It's slick, and you can choose from 1.5:1 quickener (2.6 turns) or a 2:1 quickener (1.95 turns). Stock is 3.9 turns, so the difference is night and day.

Bob

[opelwasp]

So what is the problem with traction in the street car?

I keep spinning the right rear all the time. My dad wound let me have the Quaif for my street car but likely will for the race. I just have to wait and be patient till I can pop in the BMW IRS(and try not to eat up that tyre )

[RallyBob]

I keep spinning the right rear all the time. My dad wound let me have the Quaif for my street car but likely will for the race.

There's talk on another Opel forum about having Gripper diffs in the UK make some Opel limited slips, they're trying to organize a group buy-in. These would be 'plate' style diffs, not torsen, so they woul be better suited for performance applications. I prefer the plate-type diff to the Quaife, FWIW. Just a thought.

Bob

[namba209 (R.I.P.)]

I keep spinning the right rear all the time. My dad wound let me have the Quaif for my street car but likely will for the race. I just have to wait and be patient till I can pop in the BMW IRS(and try not to eat up that tyre )

I had the same problem with the monza and an Auburn posi cured it. Figured to have the same problem with Willit? so I got an NOS ZF posi from Germany via England. Here's a quote I tell folks about the monza. "I used to smoke one tire all the time, now I smoke two, 1/2 the time."

[Mini Stock Manta]

Jeff, Bob no longer owns the Bowers Opel collection. I purchased all of it from Bob S. he has no PC we are MSM. I do have a huge surplus of parts. WSK knows how to build these Opel motors. They pull hard and drive well. From what we are learning cris, you are only $'s away from having a good car. They are more expensive to build but when you have it done it should be very reliable. Glad to help any way I can.

Too bad we got cut off on the phone, I'll talk with you another time. When you get it done you will have to bring it to DCS in Roseburg.

"Circle the Pinto Wagons, the Opels are coming"

MSM

[jeff denton]

Oh, my, how things change in the Oregon Opel Racing commune!
You know, I think I saw somewhere in the GT.com Racing rulebook a directive to keep members informed of changes of ownership.
So now you have some fast little race cars! I hope you have the success that Joe and Clint did!
I like the "circle the Pintos" thing. We have a Pinto here that is suddenly spanking all comers. Unknown how legal it is, the tech man ordered its (and two others) head pulled after the last race, the whining that ensued worked perfectly, track management stepped in, again I'm assured there aren't any real rules. Cool. A Wilson head might be un-noticed too, chances are we'll be testing one soon. Hopefully...
Funny how it gets so out of hand.

[madhatterpdc]

The biggest limitation that I saw in the rules was:

SUSPENSION:
1. One shock or strut per wheel. Stock NON-ADJUSTABLE replacement shocks struts and springs are OK.

Going to have to find some creative workarounds. Maybe cut springs and re-valved stock shocks?

Gripper Diffs: what would the power capacity be for this LSD? That could mitigate the need for all the fab work to get the toyota rear end in if there were adequate power capacity.

[RallyBob]

Going to have to find some creative workarounds. Maybe cut springs and re-valved stock shocks?

Gripper Diffs: what would the power capacity be for this LSD? That could mitigate the need for all the fab work to get the toyota rear end in if there were adequate power capacity.

You can fit other springs, or custom order springs that have the correct wire ID, yet have larger spring coil spacing (making them stiffer). Stock replacement shocks is all it says...in other words, no racing shocks. Simple there, lots of 'stock appearing' shocks with greater damping available.

No need for a Toyota rear axle (not legal anyway). Weld up the stock rear diff, and away you go. Cheap, and will work just fine on dirt.

Bob

[Hiro]

looks pretty liberal!
you might build a big 2500cc CIH with 2.2 or 2.4 head & Chevy big valves & carb,
problem may be to transmit all the hp & torque properly to the track...
good luck & have lots of fun!
Hiro

[Mini Stock Manta]

opelwasp,


You are not too far from us and are welcome to come get some ideas from these cars.

[opelwasp]

Thanks, I will sometime. PM me your phone number and I'll try to set up a day.