DatsunS130 wrote: Hope you get that 97 Are you planning any suspension mods? Sway bars or coilovers? Or is it just weight reduction and stiffen with roll cage?
Not really sure where to start suspension wise. If we pull 500 pounds out of it and change the weight distribution it will be completely different from a standard miata. I am pretty sure a rear bar will be detrimental given the lack of weight back there.
Maybe Keith can chime in with some guidance...
I imagine this would be the extent of your suspension mods.
I believe it will be best suited for us to compile all the parts/tools needed for the build well before the event this time. Even if it means we won't qualify for any last minute award. The scramble to put something together in the parking lot is enough fun and winning isn't everything.
I will check with Tommy to see if this will still qualify. We technically are not turning it into a challenge car until the last minute. I guess it depends on the modifications we plan to perform or lack there of other then weight reduction. I am fine with it either way and want to be fair to all of the other teams competing in that category.
If it's a 1997, then it might be an STO package, in which case there is no Torsen.
Not to worry I have a spare Torsen in a broken housing laying around.... Not that we would want to attempt installing it in a best western parking lot.
That sounds like an excellent idea, I will keep that in mind.
Sway bars might be the only suspension mod I would do, and maybe just the front. It has a short wheel base and it will be lighter in the back. So a front bar might keep it from snap oversteer at every turn. I would think the stock springs will be more than enough with all the weight reduction. I am no suspension expert and might be totally wrong.
pimpm3 wrote:DatsunS130 wrote: Hope you get that 97 Are you planning any suspension mods? Sway bars or coilovers? Or is it just weight reduction and stiffen with roll cage?Not really sure where to start suspension wise. If we pull 500 pounds out of it and change the weight distribution it will be completely different from a standard miata. I am pretty sure a rear bar will be detrimental given the lack of weight back there. Maybe Keith can chime in with some guidance...
Yes, the weight difference will make it behave drastically different.
No, stock springs won't be enough.
As a point of reference, the '97 weighed 2359 lbs. and the OEM spring rates were 154/97 lbs. The Mumpkin weighs about 1850 lbs. (332 lbs under stock) and wore 800/500 springs.
But we can certainly come up with options- My suspension setup was done for under $200. Pretty sure I could do something reasonable for the Challenge for under $50. 
JohnRW1621 wrote: Here is a googled photo of the Fiero parkinglot build of two years ago in the early stages. I know it is of the early stages because the sun is still out and the car has not been painted to grey yet.
Another give-away is that the Mumpkin is still parked next to it.
I figured it would be wise to relocate once the spray bombing started.
How much pre work is going to be done ? Or are cutting it up at hotel? I am making a trip out of it and will be there Monday. If you want to get a slightly earlier start.
The plan is to start Thursday morning with a stock miata, a welder and a stack of whatever parts will be thrown at it. Hopefully 14 or so hours later we will have a ghettocet.
Right now I am leaning towards arriving Wednesday night so I can set up and start bright and early.
Come help, the more the merrier.
SVreX wrote:pimpm3 wrote:Yes, the weight difference will make it behave drastically different. No, stock springs won't be enough. As a point of reference, the '97 weighed 2359 lbs. and the OEM spring rates were 154/97 lbs. The Mumpkin weighs about 1850 lbs. (332 lbs under stock) and wore 800/500 springs. But we can certainly come up with options- My suspension setup was done for under $200. Pretty sure I could do something reasonable for the Challenge for under $50.DatsunS130 wrote: Hope you get that 97 Are you planning any suspension mods? Sway bars or coilovers? Or is it just weight reduction and stiffen with roll cage?Not really sure where to start suspension wise. If we pull 500 pounds out of it and change the weight distribution it will be completely different from a standard miata. I am pretty sure a rear bar will be detrimental given the lack of weight back there. Maybe Keith can chime in with some guidance...
What's mumpkins weight distribution look like? What would you recommend shock wise on a budget? You had mumpkin well sorted, we won't have that option.
Datsuns130. You still have keith's book I let you borrow? If so I can grab it when I am in Orlando for the conference in june. I am sure it will have some usefull tips...
pimpm3 wrote: What's mumpkins weight distribution look like? What would you recommend shock wise on a budget? You had mumpkin well sorted, we won't have that option.
Hmmm... I don't remember the exact number, but it's not too far off of 50/50. I can check and let you know in a couple of days.
I'd get a set of motorcycle struts for the rear, and use the stock front struts with Ebay springs (Mumpkin's front springs were made from (1) 12" NASCAR spring cut in half to get an 800# rate. Cost $10 on Ebay). Alternately, I'd pitch in the Mumpkin's previous year's struts (completely mis-matched Tokicko rear struts off a VW Jetta), which earned a 2nd place finish. Sounds pretty ghetto, but it works.
You gonna buy wheels and tires? That matters a lot.
pimpm3 wrote: Datsuns130. You still have keith's book I let you borrow? If so I can grab it when I am in Orlando for the conference in june. I am sure it will have some usefull tips...
Umm. I don't remember borrowing a book from you. If I did, I owe you a book. Also Ted and I can probably be there wednesday as well. Let me know.
I thought I loaned you the miata book. Maybe not, I will look in my office I could be retarded.
SVreX wrote:pimpm3 wrote: What's mumpkins weight distribution look like? What would you recommend shock wise on a budget? You had mumpkin well sorted, we won't have that option.Hmmm... I don't remember the exact number, but it's not too far off of 50/50. I can check and let you know in a couple of days. I'd get a set of motorcycle struts for the rear, and use the stock front struts with Ebay springs (Mumpkin's front springs were made from (1) 12" NASCAR spring cut in half to get an 800# rate. Cost $10 on Ebay). Alternately, I'd pitch in the Mumpkin's previous year's struts (completely mis-matched Tokicko rear struts off a VW Jetta), which earned a 2nd place finish. Sounds pretty ghetto, but it works. You gonna buy wheels and tires? That matters a lot.
I am bidding on a set of bilstein sports on ebay right now.
I have a set of 15 x 7 inch wheels. I am going to buy a new set of hankook c51's to use, since they will work on my track car after the challenge.
I was asked to chime in and give handling suggestions for a car that doesn't exist with unknown weight and distribution.
Umm...
Sticky tires and stiff springs. That's all I got at this point. It'll probably end up pretty close to an Exocet in terms of weight distribution, and we basically set those up like a Miata and soften or delete the rear sway bar. For autox and drag racing, I'm not sure you could go too stiff on the springs.
Why are we limiting ourselves to a miata? Anything could become a cart with a roll bar.
In reply to pimpm3:
You asked me about struts, I answered primarily about springs.
The reason is, honestly, I dont think struts are really that important for Autox or drag racing. Sure, they are nice. But the speed priorities (in order) IMHO are:
Tires (compound and contact patch and weight)
Springs (about 5X stock)
Weight reduction
Alignment
Brakes (everyone always forgets this one- but it is really important- makes the car MUCH faster)
Roll center
Power delivery
Limited slip
Anti- roll bar (which may have already been covered in the springs- Mumpkin ran without rear bar)
Corner weighing
Then somewhere WAAY down the list I will consider struts (sometime after the fuzzy dice)
Keith Tanner wrote: I was asked to chime in and give handling suggestions for a car that doesn't exist with unknown weight and distribution. Umm... Sticky tires and stiff springs. That's all I got at this point. It'll probably end up pretty close to an Exocet in terms of weight distribution, and we basically set those up like a Miata and soften or delete the rear sway bar. For autox and drag racing, I'm not sure you could go too stiff on the springs.
Given a similar weight distribution to an excocet does SVreX's suggestion of 800 / 500 sound about right? I will probably be using a set of bilstein heavy duty shocks and a stock rear bar or no bar if that's a better option. What about alignment specs?
All the camber with a bit more up front. Depends in part on the tires and this may be a handicap in the drags, but I'm not sure you're going to be challenging for the top spot in the drags anyhow.
800/500 is in the ballpark. It'll be a stiff little sucker, you'll want to brace up that chassis well with the roll cage.
Great thanks kieth. I am probably going to run hankook 205/50/15 c51's on a set of 15 x 7 wheels, since that is what I run on my track car. I could get 225/50/15 but those pooch out on a 15x7.
205's?
With no body panels to worry about, I'd be looking for a set of 275's or bigger, on a 9 or 10" wheel.
More contact patch= more traction.
I've never tried the Kooks, but the rules do not require DOT legals. We were running Hoosier 25 compounds.
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