This car has raced in Champcar before. Purchased it from a friend of a friend for Challenge pricing. It came with nothing but the body, suspension, cage, and wheels.
The plan.....
Engine: Honda K24Z3 - acquired
Transmission: NA or NB Miata 5-spd - whatever we can find
Differential: 4.10 w/ LSD - acquired
ECU: Haltech Elite 1500
Swap Kit: Kpower Industris NA Miata K24Z3 swap kit
Brakes: Likely keep what is on the car or the FM Little Big Brake Kit
Suspension: Likely keep what is on the car
Instrument Cluster: AEM CD-7 w/ lap timing capes
Safety: All the required things from seat to belts to fire suppression to nets and arm restraints
Aero: If Points allow a 9LR Big Wang and home made front splitter
190 hp in a miata is gonna be like a 635 pt adder! Don't think you are gonna have room for any aero!
Unless you meant a k24z2 at 177 hp. Then it's only a 264 pts adder!
Their VPI calculator just needs to be deleted and totally redone. The ecotec of choice for a lot of folks is the 170hp 2.4L that alot of folks run in B class. Surely we can fit a K24 into that with some points.
The calculator is the final ruling these days. Good luck!
The calculator specifically ramps up the points at a certain value. In the case of the miata, that value is somewhere in the 160hp range. The ecotech at 170 pts already takes 156pts!
Unless you can find a 170 hp or slightly less k24, it's gonna be a ton of points.
In reply to wvumtnbkr :
I'll cross that bridge with thr board and tech when I get there. I'll leave my comments about the rules and some of the enforcers to myself. We got E36 M3 for purple running lights at Road Atlanta and they weren't going to pass us in tech for that. Plus there's WRL and Lemons
Brakes: are the rule-based advantages to keeping the stock rotor diameter? If not, I'd put on an 11" BBK and of course a proportioning valve that is accessible from the driver's seat.
Suspension: what do you have at the moment?
Keith Tanner said:
Brakes: are the rule-based advantages to keeping the stock rotor diameter? If not, I'd put on an 11" BBK and of course a proportioning valve that is accessible from the driver's seat.
Suspension: what do you have at the moment?
IIRC it can't be more than double what the factory offers on that vehicle and limited to 4 pistons per caliper/corner.
I.e. the Accord is running Coleman 11.75inch rotors with a Wilwood 4 piston caliper.
I need to actually get under the car to see whats on it.
By "double" you mean more than twice as many pistons? Double the diameter? Do you know what your likely wheel package will be (diameter and width, not brand)?
Keith Tanner said:
By "double" you mean more than twice as many pistons? Double the diameter? Do you know what your likely wheel package will be (diameter and width, not brand)?
Looks like they changed the language. It used to be more more than 2x the brakes that came with the car.
"All brake system components, excluding ABS units and brake calipers over 4 pistons per 4.3.2."
"Brake Caliper, 5-piston or more: 5 pts each"
I'd go with a BBK, then. More pad volume, bigger rotor - it'll handle the heat better. The LBBK is aimed more at minimum weight autox/street use.
What's the advantage of a brake kit in this application? Lots of competetive miata running stock brakes..
Better pad choice? Longer pad life?
The tires are most likely going to be a 200tw street tire.
Yes to better choice and longer life, also faster pad changes. And 190 hp running enduros...I'd prefer to have something a little more robust.
In reply to Keith Tanner :
Thanks! It's point free, so why not! I was just curious what the big benefit of spending the money is.
Brakes convert kinetic energy (KE) to heat.
KE = 1/2 * M * V^2 (M = vehicle mass; V = speed)
if more power makes more speed at the braking point, then your brakes have to handle more KE. and it goes up with the square of the speed. Let's use old speed = 100 and new speed = 110. 10% increase in speed results in 21% increase in KE (100^2 = 10000; 110^2 = 12100).
that KE goes into the rotors. The conversion equation is KE = m * Cp * dT (m = rotor mass; Cp = specific heat of rotor material; dT = change in rotor temperature)
so, if you don't increase rotor mass (diameter * thickness * density), then your 21% increase in KE will result in a 21% greater temperature rise, and you run the risk of pad fade, fluid boil, rotor cracking. At a minimum, you're changing pads and rotors more frequently. Worst case, someone gets hurt when you wad up the car.
In reply to AngryCorvair (Forum Supporter) :
Or, increasing your cooling can also reduce that additional 21%.
This car is gonna rip! I'm excited to see how it does.
wvumtnbkr said:
In reply to AngryCorvair (Forum Supporter) :
Or, increasing your cooling can also reduce that additional 21%.
This car is gonna rip! I'm excited to see how it does.
The Co-Owner of the team is now hesitant to use the 190hp variant. We may switch to a K24Ax variant that only has 160ish hp. The K24Z2 came with around 177 but that still puts the car over 500 points. He wants to build a legit B class contender. I acquired a NA 5speed, diff, and prop shaft for $900 this weekend.
This thing is gonna rip!
I drove a 140 hp na and it ripped pretty good in a few races. I can only imagine what this thing will do with 20 more hp AND torque.
I've got most of the parts ordered for this thing; however, it's going to sit on the backburner for a while on my end. Vectoring some labor to one of the other guys on our Champcar team. His pictures are terrible so be prepared. We can at least get this thing moving under it's own power by the end of summer. Do some shakedowns, conform to the new Champcar rules, and go from there.
We are heading back to the drawing board. Champcar technical staff won't budge. So we either go with one of the earlier K24Ax models that only makes 160hp if we want to stay with VTEC. Build a cheaty 1.8 like everyone else (which the car is setup for). Go Ecotec. Or be miserable and stuff a rotary in there.
The alternative is to drop the trans and rear end we have in there. Sell it and pursue this caged S2K that we've been eyeballin instead.
