825 replies to this topic

[38bfast]

Not very timely advice sorry. When I am taking out a engine for rebuild I will spray some water in the intake track while it's running. Generaly about 3000 RPMs. That cleans lots of the carbon out of the combustion chambers. Saves later work cleaning parts up.

[speedengineer]

Not very timely advice sorry. When I am taking out a engine for rebuild I will spray some water in the intake track while it's running. Generaly about 3000 RPMs. That cleans lots of the carbon out of the combustion chambers. Saves later work cleaning parts up.

 

Noted for next time, thanks!

[speedengineer]

I've mentioned already my lap simulation program that I wrote, and figured I'd do a little explanation of what it is and how it works. 

 

Basically, it takes all of the important macro level vehicle characteristics, such as a power curve, mass, aero drag and lift coefficients, transmission ratios, driver shift times, lateral and longitudinal grip capability, etc, and then models that vehicle driving around a track.  This is not a driving line optimization software though, one of the inputs is the driving path, derived from real GPS data. 

 

The lap simulator is very accurate at simulating the following variables effect on lap time:

-Engine power and power curve shapes

-Transmission and final drive ratios

-What gear to use where on the track for optimum pull off the corner and minimum lap time

-Vehicle mass and how it affects acceleration

-Comparing various vehicle configurations to determine where on track each has an advantage, to determine which will be easier to race

 

It's good at the following assuming that you have valid input data:

-Effect of aero - drag, downforce etc (if you have good aero coefficient data)

-Effect of mass on cornering and lap time (if you have reasonable tire load sensitivity data)

 

It doesn't do the following:

-Driving line optimization

-Setup changes - this is not 4-tire model and does not incorporate suspension kinematics

 

 

 

Here's an example.  I downloaded data of an FRS driven at VIR by Mike Skeen.  I then looked up FRS data on the internet, such as trans ratios, a dyno plot, final drive ratio and tire size, and factory specified drag coefficient, etc.  The red trace is the actual GPS speed trace of Mike's lap, the blue trace is the simulated lap.  As you can see, it's very accurate!  I did not spend time 'tuning' the model to match perfect, just a slight power scaler to match the top speed (dyno data isn't always real wheel power, especially dynojet data) and scaled the lat and long acceleration so that corner speeds matched.  Bam, that's it. 

 

Anyway, enjoy.  If you have some basic physics knowledge and can learn simple coding, I'm sure you could make your own simulator.  Both the knowledge gained by taking the time to build the simulator and the insight the simulation results provide are very worthwhile.  Granted, this isn't something you'll be able to create in a weekend.  This is a project that was added to slowly over several years.  Actually, it started with just a straight line acceleration model, which is much easier.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[speedengineer]

Question - has anyone ever seen this orange stuff on the brake master cylinder and prop valve fittings?  It's pretty thick.  I haven't seen this on any of my other miatas that I have owned. 

 

 

Sorry, bad photo.

 

[dstevens]

It looks like old red RTV.  Does it peel off like RTV?

[speedengineer]

It looks like old red RTV.  Does it peel off like RTV?

 

I apologize for the crappy photo.  It's much more brittle than RTV, crumbles and breaks up very easily between your fingers when you break a chunk off.

 

I thought maybe the booster/master had been replaced, but careful inspection of the line fittings suggests that no line wrench has ever been used on them - no witness marks. 

 

Better pic coming shortly

[speedengineer]

Also, that piece that is located between the front and rear output lines of the proportioning valve (left of the "F" and right of the arrow) used to be bigger.  It was similar to a rubber band that was wrapped all the way around the prop valve.  It broke off though when I touched it, back when I first bought the car. 

 

[speedengineer]

Removing wiring harnesses is fun!!!  ...said no one ever. 

 

 

 

 

 

 

 

 

 

 

Picked up the cage metal last week.  80 feet of 1 1/2" x 0.095" DOM mild steel was $257.  1/8" flat stock in 3" and 5" widths was $37, and 3'x4' of some polished aluminum tread plate for use later to make the floor pans look nice was $33

 

 

 

[dstevens]

A guy that knows what he's doing with a flare nut wrench can get the fittings off and not leave any marks.  Most of the nut rounding is from people gorilla gripping them instead of using the right tool.

 

That sealant that's on your brake system didn't come from the factory like that even if no one has cracked the nuts.  Maybe the last guy thought he had a leak.  I replace the entire brake system (except for the main hard lines, those get cleaned) when I've built production based race cars.  It's good, cheap insurance.

[ChrisA]

 

That sealant that's on your brake system didn't come from the factory like that even if no one has cracked the nuts.  Maybe the last guy thought he had a leak.  I replace the entire brake system (except for the main hard lines, those get cleaned) when I've built production based race cars.  It's good, cheap insurance.

 

My car has the orange paint around the master cyl. & proportioning valve fittings, though less heavy than pictured here. I bought my car new in the fall of '98, it came that way. 

[speedengineer]

My car has the orange paint around the master cyl. & proportioning valve fittings, though less heavy than pictured here. I bought my car new in the fall of '98, it came that way. 

 

Interesting!  Thanks for sharing.  Makes me less concerned that the system has been messed with knowing that it likely came from the factory like that.  Wish we knew why Mazda put the orange paint on there...

[Bench Racer]

What is that chunk of orange between the top outlet portions of proportioning valve?

[NPiekarski]

Every 99 and up I've built had that thick orange zip tie looking piece by or near the proportion valve that Bench referred to. I also wondered many time what it was but just figured it was something used on the production line. I have not seen the rtv looking stuff near the lines before.

[Jamz14]

Every 99 and up I've built had that thick orange zip tie looking piece by or near the proportion valve that Bench referred to. I also wondered many time what it was but just figured it was something used on the production line. I have not seen the rtv looking stuff near the lines before.

You guys didn't remove that thing did you?????!!!!!!! If it doesn't say you can.

[Caveman-kwebb99]

have seen the orange stuff on quite a few but not every car, no idea why but its not out of the norm.

[speedengineer]

Rules clarification regarding door panel gutting?

 

So, the rules allow you to gut the door panel when the cage has door bars that protrude into the door.  It lists things you can remove, but doesn't list near all of the components that are inside the door.  It looks like a lot of people gut everything, as many doors I see at the track are completely cleaned out.

 

I wanted to confirm that this does also include the door wiring harness?  It doesn't specifically say you can.  Doors I see on various builds don't have any harness in them still.  I suppose it's possible that people are pulling this harness back and zip tying it up under the dash?  What's legal?

 

 

edit:  here is the rules snippet:

20.2.18. 
The door window glass, window operating mechanism, and inside door latch/lock operating
mechanism may be removed and the inner door structural panel may be modified, but not
removed. The stock side impact beam and the outside door latch/lock operating mechanism
shall not be removed or modified. This gutting of the door shall only be made if roll cage
incorporates NASCAR-style side protection extending into the door.

[Bench Racer]

 

Rules clarification regarding door panel gutting?

 

So, the rules allow you to gut the door panel when the cage has door bars that protrude into the door.  It lists things you can remove, but doesn't list near all of the components that are inside the door.  It looks like a lot of people gut everything, as many doors I see at the track are completely cleaned out.

 

I wanted to confirm that this does also include the door wiring harness?  It doesn't specifically say you can.  Doors I see on various builds don't have any harness in them still.  I suppose it's possible that people are pulling this harness back and zip tying it up under the dash?  What's legal?

 

 

edit:  here is the rules snippet:

20.2.18. 
The door window glass, window operating mechanism, and inside door latch/lock operating
mechanism may be removed and the inner door structural panel may be modified, but not
removed. The stock side impact beam and the outside door latch/lock operating mechanism
shall not be removed or modified. This gutting of the door shall only be made if roll cage
incorporates NASCAR-style side protection extending into the door.

My rule understanding comment to another similar thread post.

 

"Lets focus on the airbag. By rule, "Airbag system shall be disarmed and may be removed".

 

Let it be suggested that the airbag/bags and sensors may be removed. Airbags and sensors would consist of exactly what one would purchase by Mazda part number for an airbag or the airbag sensor................ You'll find when one removes the airbag/airbag sensors each has some amount of wire and connectors included. < That's what you would receive when ordering an airbag/airbag sensors and that's where you stop removing wire. If you ordered a wiring harness by Mazda part number, the airbag/airbag sensors would not be included. Same with the radio and cruise control."

 

Another example per another rule would be the radio system (radio/speakers/antenna) may be removed. Same deal here, there will be some length of wire and wire connectors attached to the radio, speakers and antenna when one orders by Mazda part number. When one orders any of these radio/speaker/antenna parts the wiring harness will not be included by part number.

 

 

[Steve Scheifler]

Agreed!

Now read the part about the inner structural panel ;not the beam/brace) and tell me exactly how much of that can be removed under what conditions.

[speedengineer]

My rule understanding comment to another similar thread post.

 

"Lets focus on the airbag. By rule, "Airbag system shall be disarmed and may be removed".

 

Let it be suggested that the airbag/bags and sensors may be removed. Airbags and sensors would consist of exactly what one would purchase by Mazda part number for an airbag or the airbag sensor................ You'll find when one removes the airbag/airbag sensors each has some amount of wire and connectors included. < That's what you would receive when ordering an airbag/airbag sensors and that's where you stop removing wire. If you ordered a wiring harness by Mazda part number, the airbag/airbag sensors would not be included. Same with the radio and cruise control."

 

Another example per another rule would be the radio system (radio/speakers/antenna) may be removed. Same deal here, there will be some length of wire and wire connectors attached to the radio, speakers and antenna when one orders by Mazda part number. When one orders any of these radio/speaker/antenna parts the wiring harness will not be included by part number.

 

I already read your response in that other thread    I don't disagree here. 

 

Apparently a majority of the field already violates the door rules.  Examples:

1)  "the inner door structural panel may be modified, but not
removed"  So peoples cage bars pass through the plane of the inner door structural panel.  Everybody has cut out and removed the inner door panel, yet per the rules it can only be "modified"  aka bent or pushed inward, etc.

2)  Wiring harness is not mentioned.  Yet I haven't seen it present in cars with gutted doors

3)  There are other pieces/parts inside the door panel that aren't window, window mechanism, speaker, or latch.  Apparently it's illegal to remove those bits and pieces and yet everybody does.

 

Perhaps this rule needs an update?  If not, pretty sure 50% of the cars out there are already illegal....

[Jamz14]

Jason, Bench happens to be wrong in his comment to the other post. He is suggesting with his interpretation that the defining characteristic is based upon what comes with it when you buy it from Mazda. But nowhere in the rules does it say that his suggestion is the way it is. I define system as every integral piece to make something work. The connecting wires are critical to make the airbag work so therefore are open to be removed. Until someone defines to a gnats ass what "system" means OFFICIALLY in the rule book, he is wrong.