Hasbro's Build Journal

[Hasbro]

I like how infromative your built is
COntinue in that way Hasbro

I'm sur you'll come to a pretty descent fast setup !

I never comment on your built but i always read

Thanks, I figure it's too wordy to keep anyone's attention. I try to list minutiae so I can use it as a reference and hopefully to benefit anyone else trying to do a build. I've tried to dispel some absolute crap that prevails on the interweb and educate at the same time, albeit with my limited knowledge. Here's some trivia for instance; track tires are way grippier than the best street performance tire but the require at least 160 degrees to be at their maximum. Another problem is they heat cycle, meaning they harden up faster and lose their prime quicker. However, the RA1's composition heat cycle is minimum similar to street tires and as the tires wear, traction actually improves as it wears. It's not to do with composition, actually; after 2 mm of tread wear the tread turns into a slick, lol. And, although they also excel at above 160 degrees, they still perform well at lower temps.

I read somewhere that Nitto NT01s are also good on the street. Turns out they are a subsidiary of Toyo so maybe they use similar compositions? Some nuts even use Toyo R888s but the heat cycle a little more and wear very quickly.

Edit; I left out Yokohama Advan A048 as a streetable track tire, they have a 225/50/16 that has a 9" tread and weighs 21 lbs!

[Hasbro]

aaaaaauuuuggghhhh!!!!!!!

Lol, I used painter's tape to get a feel for body work. I actually drove around like this yesterday. One lady said, "Oh, you bought a new car." Cracks me up so it's my desk top photo for a while.

The two strips on the front and rear bumpers and hatch show where the bumpers get cut off. The patch behind the front wheel is the Gurney Flap. Stripes in front of rear wheel are sort of where an aero flare will be. The two long strips running front to back are just to enhance the dominant design line. These mods are track oriented but hopefully will be muted enough to be discrete on the road without screaming, "Track Car!" But it definitely won't look like a Stance Hardparker.

[Powers]

I like the gurney flap idea. After you do it I may make it one of my aero projects.

[Hasbro]

I like the gurney flap idea. After you do it I may make it one of my aero projects.

You like it 'cause your a sick man.










V This design must be 4 or 5 years old. I haven't changed much since then.





note to self; more stealthish than darth vadorish



Edit; Pulled 15 lbs. last night. When started, garage was 102 degrees. Front carpet/under layer were only at 12 lbs., not 20 as told. The Slings And Arrows of Outrageous Fortune!

Carpet, an aluminum plate from rear floor, center plastic piece under hand brake, plastic foot rest (don't need it, tall ), added up to 15 lbs. Could've been better but a start. Hey, that equals 1 free whp! I feel better for the effort and will list car weight at 2,385 lbs.. That's -400 lbs by the 2786 lb. claim. 17.5 whp/lb., That's a 15.6% hp improvement equaling 157 whp on a stock weight EP. That's 177 whp @ 2250 lbs.. 41 "free" hp. Loves me some statistics!

Still fussing with seat pads, was getting frustrated. Put the seat pad back to stock arrangement and will pull pad out to race. Feels great. Pic shows pad removed and with seat cover on. The cover was $49.00 and is the texture of nylon canvas. Very tough. Always been a seat cover kind of guy. They really extend the life of the seat, can be washed, and can be removed for the occasional arrival at big movie previews and/or hot tete a tetes with rising starlets.




Added Yokohama A048 track tires to the list on post #151.

[Hasbro]

This is a good read;

Keith is right about lighter cars having more grip relative to the normal force. Performance tires generate grip through different mechanisms as load increases. The most efficient method is adhesion through the Van der Waals force. To generate that grip, you just need to press the contact patch into the ground (in the micro sense). Once your little pits and valleys are keyed in, you're not going to get much more adhesion. Grip after that comes from mechanical keying to the road surface and another thing called bulk deformation hysteresis, which have limits and are less efficient for the normal loading. I have driven a 398 lb car capable of a sustained 1.8g with no aero (actually some lift), while 3000 lb racecars with the best slicks can be expected to pull about 1.3-1.4 without aero. I have seen Michelin racing's tyre dyno data, it really is shocking how much grip you have when the weight goes down. In high-school-physics terms, the friction coefficent goes up as the weight goes down. (Please realize that "friction coefficients" are a criminally simplified term in the world of non-linear tire dynamics).

While it may seem contradictory to my argument above, the Miata also has better weight transfer characteristics and static balance than a Mustang. It's going to put more of it's weight on the driven tires. Without drivers, the GT500 is 57.5% front, while a turbo or LSx Miata is around 52.5-54% (stock Miatas are around 52.5%). Since the wheelbase is shorter on the Miata compared to the CG height, the Miata will put a larger proportion of its weight on the rear tires. Any weight still on the front tires can't help you accelerate, and Mustangs leave a lot. Static weight balance is very important, since it increases your ability to induce weight transfer and overall grip. You want something between ~51 to ~45% front weight to maximize your weight transfer characteristics without compromising handling. Obviously this changes with CG height, wheelbase, diff characteristics, and the ability to accelerate harder, which is why you see some high power nose-heavy cars lift the fronts at the strip. On a road course, more rear bias will give you more accelerative traction (up to a point). The downside is fundamental instability and other characteristics that need to be dialed out. If you design the suspension for it, you can run 60% rear weight and still maintain forgiving handling characteristics. Once you get past that, you end up in P-Car Widowmaker territory, which can be faster for very experienced drivers at the expense of predictable-to-the-layman handling.

Another thing that hasn't been discussed is suspension kinematics and geometry. Dampers can make a huge difference. Also, anti-squat is something that affects traction on imperfect surfaces and with transient loads. Basically, it means that the force of acceleration is transmitted through the suspension links themselves rather than the coilover. Most cars have a small bit of anti-squat, since it can be annoying to have the nose pitch up when you get on the gas. The downside is in compliance. When you transmit force through the suspension links, the effective spring rate is dictated by your suspension bushings. Medium-frequency vibrations are not absorbed as well as if they were routed through the shock. The contact patch of the tire is less "cusioned" when you have a lot of anti-squat, but the rear end won't sit down as much with the same springrate.

Mustangs have a lot of anti-squat (~60%). Miatas were never designed for power, so they have very little. Again, this means the Miata resolves a lot of the vertical acceleration load through the coilover rather than the suspension arms and bushings. In general, on road course tires and street tires, traction is maintained when you are relatively gentle with the contact patch. Think of the tire as a big spring dragging across the ground; when you change accelerations, you want to keep it from vibrating as much as possible. (That said, the forefront of tire tech today actually involves controlling and inducing vibration, but we'll ignore that). Another big factor is unsprung mass. Mustangs have a ton in the rear, including the diff. Miatas have less, so the suspension can do a better job at keeping the tires happy. Ignoring the entire IRS vs live axle kinematic comparison, you won't be able to compare accelerative traction between a V8 Miata and V8 Mustang just due to the anti-squat differences.

Why do cars come with anti-squat? To reduce the amount of squat during acceleration, and in the case of racecars, keep the aero trimmed level. It's not for overall grip, except when used to keep the rears off the bumpstops. While the grip is less, a lot of anti-squat can make a car "feel" like it has more traction. You'll see this in autojournals, the testers will champion anti-squat and anti-dive as "feeling" planted and fast. While a proper amount of antis is important in real racecars, that's mainly for aerodymanic performance. For mechanical grip, you want a bit more movement. Go flog around an Elise and tell me it handles poorly despite its body motion. :) Antis, along with tons of rebound damping, are the bodybuilding-Synthol of street car handling.

Some drag racers will contest because 100%-120% anti-squat is fastest on the dragstrip. Drag tires are different and work to cushion the contact patch themselves, so applying a great shock to the tires (compared to radial road course tires) during launch is ideal. It loads up the tires faster, since they act as a radial spring. This is one of the big reasons why drag racers prefer solid axles, it's easy to get 100%+ anti-squat with a four-link setup. While loading up a drag radial is important at launch, it is worth mentioning that a lot of anti-dive can cause traction issues down the strip. It's only useful for launching on very compliant drag tires.

TLDR: light cars can pull harder than heavier cars, especially if they have forgiving suspension geometry. This is why Atom 500s can do 0-60 in the low 2 second range with 245 rears. (Now you might understand my annoyance when we have customers wanting to put 335s on Exocets, which have the same rear weight loading under acceleration as an Atom 500.)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Wow -- thank you for taking the time to share such an informative and engaging post. So it is not solely about the tires . . .

---------------------------------------------------------------------------

Rest assured, it's all about the tires. The important thing is making sure that the car can take advantage of them.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

From this thread;

http://grassrootsmotorsports.com/for...o/66285/page1/

The same guy is building this;

http://grassrootsmotorsports.com/for...a/57663/page1/

[Hasbro]

Forgot I had this. This article is 18 years old but, describes to me, the best street set up. Softer springs, lots of travel, but low and sticky at the same time.

http://homepage.virgin.net/shalco.com/subaru_setup.htm

-------------------------------------------------------------------------------------------------

Edit, 7/03;: This weekend's autox is 2 hours and 40 minutes away, uggh. I really need to go to use Kumhos for last time before RA1s get mounted. And I can spin intentionally with the Kumhos as part of the learning curve. Better the Kumhos than the new $217.00 Toyos!!! Running there would sate my desire to autox hopefully due to knowing what tweaks are needed. That would be perfect as the summer would be over by the time the improvements are done. By summer I hopefully mean sometime in mid October, which can can still be in the high 90s. Then, run all winter with the cooler loving RA1s, seasonally the opposite of you northerners.

I'm going to miss the Kumhos. Outdated by 4 years but held up great, although they will still be on the rear. Hopefully, in the rear they can match the traction of the front RA1s so I can continue to "ignore" the rear end somewhat.


Anticipating things that will be obvious after autox;

- caster. period. alignment in general

- soft springs at full anger...?

- will crave Hondata reflash, if only for the rpm

- will encourage me to install shifter and cable bushings that have been sitting in garage for 2 years

- will be able to get seat where it needs to be

-

-------------------------------------------------------------------------------------------------

Edit, Edit; well, dookey. Need to work this weekend so the fun stuff is out. That'll do it for the summer, then. Takes some weight of my shoulders, anyway. I'll do the tires, camber plates, flares and some weight removal for the summer and relax a bit.

------------------------------------------------------------------------------------------------

Edit, Edit, Edit; Mugen Type R Civic vs. Audi R8 V10 Really "well put" by the narrator/driver.

Pull 600 lbs. off our EP, nice suspension work and a K24 na Frank with 230 whp. and it will stomp the Type R and still be "streetable". And wipe The R8 away in the corners. 9.8 whp/lb. At 2250 lbs., our Ep only needs an extra 30 whp to have the same whp/weight ratio as the Mugen, 13.5/1.


http://www.youtube.com/watch?v=WpA0EHSdjm0

----------------------------------------------------------------------------------------

Edit, Edit, Edit,, Edit; I must be bored. Did a fresh hertz calculation using a guess of 65% weight removal from rear, 35% front. Haven't been able to weigh EP for several years but figure that's the current front/rear %. The next -150 lbs. will be 70-75% front weight. I also left out the unsprung weight. That puts the Lil' Ripper' at 2.0 hz. front/ 2.3 rear. A touch high in the rear. But with all that negative camber that's cool. Then I do a little guessing with the track change and multiply front spring weight by .9 and rear by .95. I know, pure conjecture but there it is. Springs up front are now 302 instead of 336. Rears are 490 instead of 515. This gives me 1.9 hz. front/2.25 rear. Not so bad but we are in transition. Say the next 150 is 75% front weight, 112 lbs.. That put's my convoluted hertz at 2.0f/2.35. It's no longer spring hertz but it gives me a feel for figuring things out. Getting there. Type R bars front and rear cancel each other out in this, uhm, equation.

Now let's add a bigger front spring of 392 lbs. by Swift. Puts the future "hz." at 2.15f/2.35r. Street Perfection. According to my mind.

When the weight is 2250, the RA1s are on, caster plates are on, alignment is figured out, then it is time to do g testing. The ultimate test! Hopefully all done before track school in December .

Next topic ; camber. When Toyos go on next week, I will start all 4 corners at -2.5 camber, with some tiny changes depending on which corner. Similar adjustments as before with regard to weight adjustments.

Think I'll buy a pair of highway tires for long trips. Take the Toyos off, a little less camber, and Bob's your uncle.


------------------------------------------------------------------------------

What RA1s become with a little wear. Better;

[Hasbro]

Been very busy. RA1s arrived at my local Discount Tire, just have to find the time to have them mounted. The waiting is keeeeeeeeling meeeee!

By the time the year is over I will have spent a solid $500.00 for alignments and corner balancing. Might as well get some cool equipment instead. I'll order this from Flyin'Miata this week;

http://www.flyinmiata.com/index.php?...umber=35-70050

By the way, the stands were designed by Keith Tanner. That is his Miata with the Martini Racing colors.

Along with that some vinyl floor tiles for garage leveling, liquid tube level thingy , etc. Then I can change alignments whenever I feel like it. Cool beans, Pauncho.

Then, the next step when I can afford it;

http://www.ebay.com/itm/NEW-RACE-CAR...995db0&vxp=mtr

This Super 20 Miata video is great if you're into tires and cornering. It's using RA1 245/45/16s, same size I ordered. They don't look overly big, I don't think. Just right!

http://www.youtube.com/watch?v=2955gzlg17s



I want these. They are perfect. Very retro. Anyone know anything about them? Look like plastic. Look cheap and cuttable. Want.

[Blue03Si]

http://www.flyinmiata.com/index.php?...umber=35-70050

Those look awesome. If I was sure my garage was a level surface I'd want some for sure. I'd love to be able to tweak my alignment myself without paying a shop for a small tweak.

[Hasbro]

http://www.flyinmiata.com/index.php?...umber=35-70050

Those look awesome. If I was sure my garage was a level surface I'd want some for sure. I'd love to be able to tweak my alignment myself without paying a shop for a small tweak.

Just ordered it along with the level. http://www.flyinmiata.com/index.php?...umber=35-57000

Leveling the garage is really easy. Tape a square around each tire. Get a bunch of 12" vinyl floor squares and a liquid level at Home Depot. With level, find highest and lowest of the four taped squares and equalize them with the tiles. Pull car onto leveled vinyl. Drink a beer to celebrate.

You need two sets of the hub stands ($$$) to corner weigh. My second set will have to wait a while. Kinda blew my budget, timeline, and to-do list but it's all good. It was about $475.00 with shipping and the tires were $515.00 - ouch. Can't wait to play with the new toys!


Picked up the RA1s today. Discount Tire's policy is to mount tires in the rear if the customer is only buying two tires. F%$king lawyers. Fine. So, I haven't moved them up front but they fit fine in the rear. They won't be any problem fitting to the front. In some ways they fit better than the old 225s. They bulge less and have rounder edges. Get this, they are actually softer riding and quieter than the Kumhos!!!!! Couldn't believe it! I won't need any flares to add so that's a relief.

I don't get what the big deal has been about fitting bigger tires on the EP. 245s were such a big deal a few years ago. Hell, I'm ready for some 10" treads, now! Although, the next size could prove very difficult.

[Powers]

Clear your pms.

[Hasbro]

Clear your pms.

Done, thanks.



The RA1's sidewalls have no bulge where they sit. Total width is only 1mm wider than the tread width on each side. The old Kumho's total width protrudes from the wheels exactly the same as the RA1s. The RA1's tread protrudes 15mm wider than the Kumhos. That's 30 mm more gooey sticky tread. Woohoo!


For the next alignment I'm thinking (remember, this is following Andy Hollis' autox Civic so the numbers are contrary to normal EP set ups. I will throw the new numbers his way to be double sure) ;

Front camber left -2.6, right -2.5, 1/16 toe out. Springs 1/8" higher left

Rear camber left -2.6, right -2.5, 1/16 toe in. Springs 1/8" higher left.

Then testing. Maybe a July or August autox (there are four of them). Ugghh, hot, hot, hot. I'll know very quickly (in about 60 seconds!) whether the springs are enough to handle the set up. I'm sure at least the right front should be the next size of 392 lb.s, more likely both sides. That's as high as I'm willing to go so it better work. I know it will kick ass for the street but won't be enough for autox, but still a shit load of fun. Not going any higher with the current Koni set up. Need to schedule installing new springs and caster plate at same time. $$$

Thought ; I'm willing to wager that front camber won't change when caster plates are installed. Minimum recommended camber for RA1s are -2.5 and I can't see adding more camber with the extra caster on the street. That's just nucking futs.

Just realized, with the hub stands, it will now be very easy to access the springs while they are at their correct static level. This will allow a correct measurement of spring travel at static height. It will also allow me to see if more travel can be squeezed out of somewhere, namely the caster plate construction? Thicker spacers to raise plate? Would be nice to gain some travel and have room for assist springs (not helper springs). And maybe another -1/4" drop. Wow, so cool. A fun suspension summer is at hand. I'm loving the learning curve. Hope someone else can benefit from these meanderings, too.

Here's an explanation and specs of assist/helper springs; http://www.swiftsprings.net/products...r-springs.html

Any feedback on increasing travel this way, or shorter damper bodies, or whatever, would be appreciated, even if just to chew on this a bit.


Pretty soon all of the lateral sipes (grooves) with be gone and just the four main grooves will be visible, then just two, then none. RA1s have the unusual advantage of improved handling as it wears and likes to be worn down to the chords. How cool is that !? Ra1s are ancient by tire development, they were even discontinued but racers screamed bloody murder so Toyo brought them back. They really are a quite brilliant tire; at least by my limited knowledge.


Edit ; Note to self; the next -150lbs. should give me -100 from the front. That's 1/8" at least of more travel. I think I'm going for another 1/4" drop of the springs. Premature, yes, with some negatives such as no rcas yet or a chance of blowing a damper. I'm thinking it just needs to be done in order to deal with maximum desired numbers. Anything over 1/4" drop and the track springs would have to come out, not to mention some more advanced dampers. May have to anyway if a shorter body is essential for travel. Especially if caster plate idea doesn't work.

Add rcas to plate/spring install. Start thinking about rear suspension problems; custom upper arm spacer, binding, etc. Crap. At least another grand down the tubes. Guess I'll be single a little while longer.

[Powers]

Thanks for the heads up on the latest purchase man! And every time I read through your post it gets me thinking. Ughhhhh

Ian

[Hasbro]

Thanks for the heads up on the latest purchase man! And every time I read through your post it gets me thinking. Ughhhhh

Ian

Glad that worked out!



Blew my budget out of the water this week. Today I scored an ECU for $100.0. I'm not ready for it but it was too good a deal to pass up. Initially I'll just go with a Reflash, more for the 60+ mph in second gear than the extra 10 or so hp. Actually though, at 2380 lbs. it would bring the hp/weight from 17.6 down to around 16.3/1 so that would be pretty nice. A 7% increase.





Also on ClubEP3 I bought 4 custom new in box 10 mm Adaptec wheel spacers and 20 Blackworks extended wheel studs. Killer buy as seller was willing to deal. By the way,a lot of people mistakenly avoid spacers due to the incorrect assumption that they are not a safe choice. Next time you go to a track look and see how many serious cars have spacers. Some are huge!





Played around with the flaring yesterday. Bent it up at the crease so that the fender will flow down to the edge without a crease. With pulling and the bending it's about 2" wider with a lot more room to go if needed. Why hasn't anyone done this, it's so easy? And it could look perfectly original if one so desired. Will pull wheel off and use a body hammer from the inside to work the shape some more. Then sanding, filler, primer, and paint. Real quick just to get a decent appearance from 10 feet away until I know how it needs to be finished. I have never done body work so this should be interesting.




Edit; Flares - A small but very important change. After looking at the body tonight in the silhouette of small well positioned lamps I decided to go initially with small, fairly delicate eyelash flares. Basically, to me, they are flares that guys have mostly been screwing up since the 1950s, 60s, 70s, and 80s. But a well done job can be beautiful. They also have a curvy roundness that would really fit the body and soften it more.

The fender flows much better, I think, with the flat edge of the fender (near the well edge) unbent. It visually needs an inch or more of exaggerated outward flare but the tires couldn't fill it. Hence, the eyelash flare ; they can stick out a little bit more up top there without the big mass of a full round flare. They are minimalist and show a lot of tire to the front and rear. Good rearward airflow and the fronts can be filled in with a canard-ish aluminum piece. Hope this makes sense. Well, it does to me anywho.

Peace out

[Hasbro]

This belongs to Vik DC5 over on CRSX.com. Nitto NT01, 255/40/17, wheels 17x9, 35 offset. NT01s are very similar to RA1s. Nitto is owned by Toyo.




Thought; You can't just build these EPs to handle well. You have to force them.

[Powers]

My thoughts on that reflash idea is don't even waste your time if you feel that you will eventually need kpro. I picked up over 20whp with a dyno tune.