curly

iTrader: (25)

A few friends and I are seriously considering entering this car in our local chump enduro.



https://www.miataturbo.net/build-thr...nothing-75005/

Or more in depth if you can tolerate CR:

Lazarus: Making Something Out Of Nothing - ClubRoadster.net

We're shooting for the October 24-26 weekend at PIR. They do a 6 hour enduro, a 12 hour enduro, and another 6 hour. We're planning on doing just the 12 hour I believe.

We're also not doing this for points, as we'd rather not hide a bunch of stuff like the megasquirt, and only one of our 6 drivers has chump experience, so we realized we probably wouldn't be sitting on any podiums.

That being said, what fails on a '92 in 12 hours?

Our current drivetrain:

junk yard (60,000?) 1.6 with MS
235k '92 transmission
235k '92 VLSD
FM happy meal clutch/flywheel
235k hubs/bearings
235k 1.6 brakes

We're planning on finding either a 4.1 or 4.3 torsen, and buying MazdaComp hubs and bearings. We'd keep our old bearings and repack them ask back ups, we have my old 120k 5 speed transmission that shifts great and whines as back up, and we have a stock 1.8 flywheel and clutch setup as back up. We're planning on refreshing the timing belt, water pump, seals, and fluids closer to do the race.

You may notice in the CR thread I'm building a VVT motor for it, that's not going in. We currently have no backup engine, should it fail.

Brakes will be generic part store blanks, and cobalt pads. We've proven the pads down to the rivets, although they eat rotors. With the $20 rotor price, we're not too worried. We have SS lines in the front, we'd probably get a rear set.

I've suggested 1.8 brackets, since after the initial $50-80 price of used brackets, pads and rotors are the same price, with more braking and thermal capacity. I've been shot down due to that $50-80 price. Opinions?

Those of you with chump experience: Any car related failures we're missing?

shuiend

iTrader: (24)

The first thing that I want to say is that I would highly suggest getting in contact with the Chump judges now and talk to them about the EC class which is where you will fall into.

I would swap out to the 1.8 rear end just for the reliability factor. I would also highly suggest upgrading brakes to the 1.8 and getting endurance pads for them. I know on the 94 we ran for 24 hours at VIR Hustler wanted longer lasting pads. Proper ducting of the radiator is also a very good thing. Assuming that you have a decent tune on the engine, and temps stay in check a spare motor is probably over kill. I would also go with your plan of new hubs to also be on the safe side.

curly

iTrader: (25)

Yes, if I didn't make that clear, the 1.8 rear will be in the car before any real racing happens. We've done a rallycross, an autocross, and a dozen track days on the 1.6. We're already on thin ice.

What tires and what pads were you using?

shuiend

iTrader: (24)

I would suggest shooting rharris a pm and asking him about pads, tires and other chump questions, he has been a major help to me with random questions. I was crewing for his team.

Honestly tire wise I would run whatever new tires you can afford that fit into the tire rules. If it is your first race as a team, just finishing should be the goal. After a few successful races with no major problems, then you start looking to actually be competitive.

greddygalant

iTrader: (3)

The brakes will be fine, we have run other chump miatas that weigh more on 1.6 brakes with cobalt pads and they last the whole race. We plan on doing EC. Not trying to win, just trying to have fun. Motor is strongl tune is safe, we might work on the light load areas of the map so that we can save fuel if there is a caution period of any sort etc. I see no reason to change the brakes based on current experience.

shuiend

iTrader: (24)

If you guys have had no problems with the brakes then go ahead and leave them. I just know brakes are one of the few things that you are allowed to spend money on in Chump and have it not count against you. So I would always go with the best that you can there.

Seefo

iTrader: (5)

brake swaps are done to get thicker pads, ie no/less need to change brakes (not to mention faster brake pad swaps & even wear). Also larger rotors will require less pad for the same stopping...12 hours might not be bad for stocks, but there is a reason the 949 cars run/ran wilwoods in the enduros. You guys are probably right though, may not be a big deal if you just want to finish.

I would look at motor mount if those haven't been changed. I am noticing my mazdaspeed mounts need replacing here after 2-ish years of track time.

greddygalant

iTrader: (3)

We have poly mounts already

lightw8

you noted the porter field r4 endurance pads that i have for my car, this is a decent pad that is easy on rotors. also: brake bias valve.

we'll see how it all works out soon enough!

curly

iTrader: (25)

Martin is in love with the cobalts, I'm sure he'd hit the brakes once with the porter fields and say "these things suck".

But they are $95 a set vs $300.

Leafy

iTrader: (1)

Whats the problem with the 1.6 rear? For chump with a tiredish 1.6 engine and where fuel economy matters I'd be more interested in running the 1.6 rear with studs on the main bearing caps like some of the spec miata guys supposedly run. Even thats probably unnecessary.

curly

iTrader: (25)

It's been dyno'd at 125hp with the ms. And it's done a dozen or so track days, some of those with multiple drivers. It's on borrowed time.

shuiend

iTrader: (24)

I agree with it being on borrowed time. Ultimately it may not go in the next 12 endurance races, or it may go 30 min into the first race and you are then wasting valuable track time swapping a diff instead of driving. Since you guys want to run EC getting it swapped before hand is just a good idea purely so you get the most out of your seat time.

ThePass

iTrader: (3)

Is a 12hr race on one set of pads possible? Assuming using a dedicated endurance racing pad of course.. you see talk of teams switching to aluminum calipers to speed up pad changes, but if you're only changing pads if you have a failure, it doesn't seem like that makes much of a difference. I wonder how many sets the 949 guys were going through in the T25s...

-Ryan

lightw8

make sure you try preparation H.

hornetball

iTrader: (4)

Sub'd. I'm digging it.

Seefo

iTrader: (5)

well, at 2250 lbs, 1.8 XP8 pads (obviously not an enduro pad) with sticky street tires, my (front) pads last about 6-7 weekends:

6*2*~1h = 12 hours
7*2*~1h = 14 hours
6*2*~1.25h = 15 hours
7*2*~1.25h = 17.5 hours

This is generally shorter periods, so the brakes aren't going to cook as much :/. also, depends on the track. I would expect pads in near continuous 12 hours will die quicker. how much is the question?

curly

iTrader: (25)

I think the pads would be fine.

Our initial plan was a little under $5k into the car, including cobalts, Mazdaspeed hubs, engine refresh, cage, and other bits.

Unfortunately its looking like few of us have the extra $833 (split 6 ways) to spend on the car on top of the $1500 in entry fees and safety gear, which we're struggling to come up with in the first place. Chump is not cheap by any means.

Our other plan is to trust the 1.5 year old water pump and timing belt job, repack the current hubs, trust the diff, clutch, and transmission, and cross our fingers.

This would still leave each driver with:
$500 driver entry fee
$250 shared team fee
and any money required to buy your own gloves, helmet, boots, suit, underwear, etc. Hans if you're not dumb.

Grrrr chump.

Sparetire

I have done three Lemons races. All at HPR, all were something like 10 hours one day and 6-8 the next day.

And its always something you don't expect.

The last two were in a 1978 AMC Pacer. Biggest pile of trash you can imagine. Lightest Pacer still running because half its weight and chassis rigidity rusted out in a Carolina swamp. I swear it looses 15 lbs a year to rust. The first year with that thing I was all freaked out and did this huge write up for the owner on what was wrong with it. I was technically an arrive-and-driver on that, but it was living in my backyard and I was doing some work on it. Anyway, I thought we needed a new 904 trans, a spare rear end, blah blah blah etc.

That pile of garbage ran flawlessly. We won IOE. I was so happy to be wrong. I even spun it in the last hour and went backwards while in drive. We have run another race on that trans since, its fine.

Point being, repack the hubs, trust the pump, coach smooth shifting and it will be fine. Except for all the other crap that can go wrong. Like coils or an alternator or sticking caliper.

Leafy

iTrader: (1)

Same story, the Coronet that I'm in $250 for completed its first race. Welded a brake pad backer plate to the piston and finally called it a day because the valve cover gasket was puking too much oil and no one felt like fixing it. Once we get the brakes figured out this thing is going to be so cheap to run. It hardly wore the Rivals on it. But its still a rusty turd that you can see the ground through the floor, A LOT, and it has no truck and doesnt have enough rear window frame that hasnt rusted away to hold a window any more.