Issues with NASCAR turns?
 

Aside from the obvious distate ;)

I'm all prepped for the Chuckwalla event, so I'm looking forward at the following event which will be at Auto Club Speedway, which of course willl be the infield with one half of the huge oval.

I'm wondering if the huge ass banked turn causes any issues for our cars that might be able to be avoided or combated with some sort of prep? Or is it just a matter of crossing fingers? Can't wait to run here, but I imagine it probably presents some unique abuse to cars...

-Ryan

T3 at VIR is a blast in a Miata. :v

The abuse comes from the 40 seconds of continuous WOT, all of which is in 4th and 5th gear. (Assuming you are WOT through 1 and 2) Run race gas, turn your timing/boost down, and be mindful of overheating.

The turns aren't scary at our speeds, but they present a lot of load.

They're pretty scary at 130+. You need to have a proper line for sure if you want to push past ~115mph or so. I tried going into 1/2 with 320whp and 3.63s a couple of years ago and ended up needing a change of underwear - 161mph on entry, 159mph past the apex of 2, and then the front end washed out and the car wandered up the track about 2 car widths. Scared the shit out of me.

It gives you newfound respect for NASCAR - those guys are doing 180+mph through there all day long.

Running the Vees at Daytona we wouldnt even get on the bank, we would be wide open down on the flat part at the base of the banking. With the added weight of a Miata you would probably want to be on the bank, but at the bottom of it for sure.

But yah, like the others said, being under full boost continuously is brutal on everything.

I think I remember your video of that, didnt you blow a motor due to oil presser issue at that event? or was it a tune? I seem to remember a rather long thread following that event.

Melted a piston, probably due to insufficient charge cooling.

Never been on any, but I imagine coming up to them nearly topped out would be freaky. Who told you they're not?

I was under the impression that the really high banking like daytona and such didn't get along well with wet sump oiling.

Ryan: what kind of gear are you running ? you might run out of gear.

with 200whp, you can probably do it flat. barely though. with 230whp, I had to lift for about a second before I got back on the gas.

It is WOT for a LON..........G time. watch your temp. like Sav says, run race gas.

work up to it. 1st lap, off the throttle for 5 seconds before turn in, then roll back on the gas immediately through T2 and T3. 2nd lap, let off the throttle for 4 seconds. next lap, 3 seconds. next lap 2 seconds, and so on. important part is slow down before entry, but be on the gas through the turn. pretty soon, you will be off gas less and less, and be flat through it, assume your car can take it.

you obviously already got inconel studs ?

4.10's, 225/45's, 5-speed.

On the track I am running on wastegate at 7 psi - 185 whp. I'd like to turn it down even more for this track, and the wastegate is supposed to be 5 psi, but for whatever reason - maybe the really free flowing exhaust? - it isn't allowing less than 7.

I can run race gas without changing my tune at all? I would imagine so, as it just means there's more headroom before detonation but just want to check. Will have to save up some extra $$ for the event, that stuff is like $8 a gallon isn't it?

My turbo uses 8mm studs - so an inconel solution is not readily available. I've talked with Sav about possibilities of getting my manifold and turbo drilled out to 10mm for his kit, but as of right now, the ATP turbo hardware is showing no signs of coming loose yet. The low boost is probably helping with their longevity.

-Ryan

do you know if any of your bolts are exposed inside the manifold/collector area? if not, you probably won't need inconel. my manifold only has 1 bolt exposed and thats the only 1 that has ever broke. the other 3 bolts are literally 10yrs. old with 100k turbocharged miles on them.

185whp, you are flat till T3. you might lose a few mph going into T1, as speed scrubs off.
you don't need to change tune for race gas.
they sell race gas at AAA Speedway.
I am guessing you will be doing ~135mph going into T1
do you have some kind of rear aero ?

Except for the BEGi S4 and custom tubular users who have both experienced stud failure with studs that aren't in the exhaust stream at all.

In Corvettes, sure. Not in Miatas - we only have oiling issues under hard braking.

easy buddy, not trying to take away a sale from ya'
not sure what the except part means, i was just stating my experience. trust me, when my turbo eventually goes out, i'll be ordering a set from you. even though i only need 1! lol... hopefully he'll evetually have stud failure too!

Sounds crazy... Can't wait!

Yes, I'm taking the full point for front aero due to having a splitter, so I've been working on doing everything I can with the front half of the car to reduce drag (streamlining the front, splitter, front fender venting, diverting air away from front tires). Not focusing much on downforce since I don't have a rear wing either, but the rear bumper is also chopped to reduce drag as well. Had to ditch the rear diffuser though due to points.

ok, I am confused. you have front aero. splitter will definitely give you down force (or less lift), but you have no rear aero to balance it out. might get a little tricky down T1.

Well, it seems that it's hard to create enough downforce in the front (or reduce enough lift) to really throw off the balance of the car. It's just not a setup most have tried out because usually once people start playing with aero they go all out. Mostly, from other's accounts, it seems to be the rear wing that throws off the balance, even if you have a splitter, so you have to get quite serious with front splitter size as well as canards, etc. to try to even it out. My splitter isn't enormous. Also, as I have chopped the rear bumper drastically, I'm reducing lift there, which may be just enough to balance out a mild splitter.

Also, the focus of what I've done has been to reduce drag, and I've steered clear of creating too extreme of a front setup in terms of creating downforce that may require a wing to balance it.

Third, my spring rates are the typical 1.5:1 front to rear ratio, such as you get with a 9k/6k spring combo. The difference for me is I currently have a hollow RB front bar and a disconnected rear bar. I'm not sure what everyone else is running for sways, but I imagine there's some sort of rear bar. It sounds like it would understeer, but then a front-aero only car sounds like it would oversteer... I only see a hint of push in the tightest stuff, but I can compensate with trail braking/rotating with the throttle there, everywhere else the car feels very neutral, and as the speeds increase the car feels more and more planted - which I assume has something to do with the front aero... the stiff front and reduced lift and front aero seem to make for a really planted front end, while the front-rear bar ratio being so front-biased keeps the back end in line. The bonus here is no rear bar allows lots of suspension droop in the back, keeping the rear inside wheel down which is key for the Torsen.

Like I said, it's not a setup many have experimented with, but it seems to be working so far. Mostly, I'm trying to keep drag to a minimum - hoping that that plus a solid amount more hp than stock will help make up for the tire difference between me and the 'spec miata on roids' that are doing so well in Mod on NT-01's.

Just finished some spats to divert air from hitting the front tires last night, so will be trying those out at Chuckwalla.

But hey, what do I know?? I'm just effing around with stuff and seeing what works for me ;)

all that about spring rate and sway bar is about mechanical grips.
aero grips is what I was referring to. looking at your picture, it seem you have a pretty good front aero setup. splitter don't have to be big, splitter length is a diminishing return anyway. many would argue rear bump cut out is not a huge thing. I still think your aero grip isn't balanced. just my opinion.

front tire spat also help quite a bit for the front end.

I will see you at Chuckawalla. it is mostly med speed corners, we will see...

I went to Thunder Hill with just a front splitter and had lots of trouble keeping the rear end hooked up, especially on the high speed corners. i wouldn't dare do cal speedway like that.

Didn't mean to be confrontational - just pointing out that having the studs out of the exhaust stream doesn't exempt a setup from the stud issue. :makeout:

Stretching turbo hardware sucks, but at the same time it's definitely a badge of honor. :giggle:

Granted, mechanical grip and aero grip are different and do behave differently, but I dunno, it seems to be working for me so far... naturally it's not the optimal setup - but for the optimal setup the car would be in Unlimited..
Whether the car could be competetive for the class, will remain to be unseen until my own driving skills have developed enough, but I'm in no hurry - I'm having a great time and learning a lot, some day I'll get there.

Just finished up my aero work over the last couple days, most notably added the tire spats, looking forward to seeing how it all works at Chuckwalla!:

Attachment 188586

Do you have any pictures of inside the engine bay behind the driver side headlight? I'm guessing theres an air box there and the hole in the hood is to let the air escape?

Paul walker called, he wants his supra hood back.. That looks freaking badass. What did you do, follow the hood underframe and cut those? Or did you use a template?

+1
Sexiest hood EVER

I love the tire spats. that will help eliminate a ton of front end lift.

The whole car looks badass.
Inspired my car a bit.

How thicks the splitter? 8mm ply?

Dann

Thanks for the kind words guys

I'm still working on the box. Haven't settled on whether I want to mold it with fiberglass or just make a box with aluminum, but yes the intake sits directly behind the hole in the headlight lid. The NACA duct right behind that is to draw out any uninhaled air.
The idea I had is that of course you want cool air for the intake - so boxing the filter off from the rest of the engine bay makes sense. Creating an external source to supply that box with cool air is even better, but that's where many people's setups stop. If you're WOT, all the air entering that box is being used by the motor, but what about partial and off-throttle time? It just makes sense to me that it's going to be much more aerodynamically slick for unused air to have an escape from that box, instead of creating tons of turbulence inside the box, and I think that facilitating airflow through that box will also help keep the box cool even with a heatsoaked engine bay.

The 17 year old me would be so happy ;) I loved the first F&F.
No template, just some time and a dremel, following the shapes in the underside of the hood, which just happen to be positioned perfectly behind the readiator and forward of the valve cover.

It's alumalite - basically two thin aluminum sheets with a composite between them - much like a honeycomb between two layers of carbon fiber. Makes it very rigid yet quite light. Total thickness is ~7mm.

Awesome, not sure where to get alumalite here. Not in that sort of thickness anyway, but Im sure sandwich plate fibreglass will do me.

Dann

For me, finding it just took some time making calls. It can be found in 4x8 sheets at distributors of sign and awning materials. I found a place an hour north of me that sold them in 4x8 for $190, and they would deliver for $5. So I've still got half a sheet of the stuff for future projects.

Like here: http://www.sfsupplies.com/default.sfs?productid=6540

With experience from just Micky Mouse tracks (Not much time in 5th, even with 4.875, so value my remarks accordingly) isn't it just the classical thing that different balance curves intersect at different speeds?

With no aero you get loose at some speed (lets say 80mph sweeper) and tight at hairpins. Classically (on any sports car) you slap a wing on the back and you can balance that out (and potentially even things out over a larger speed span).

If you for whatever reason need to make all the tools that you have at your hands work against each other to get balance (make the springs fight the bars, or the shocks against the aero etc) you will get bigger differences in balance when you get out of your comfort zone (where you have set your balance).
If you feel that you have a high speed balance at 60-80-100 mph, that might be a very different picture when you get to 110-120-130.
Loose is when you hit the wall with the rear end, tight when you hit it with the front...

How smooth are the ovals? I.e. are there spring/shock doodling that could help high speed stability without loosing the low speed control (probably not, an there's a tricky thing in getting an efficient setup, one that probably will feel unsafe).

The thing is, that isn't the case really - most guys who put a rear wing on the miata (a real one) report that the car understeers at high speeds. They then have to get extreme with the front aero to try to balance it. The rear wing doesn't necessarily create balance. From what I've gathered, the biggest benefit guys are reporting at high speeds from the wing is the ability to put the power down much sooner and harder through corners due to the added rear grip from the downforce, as opposed to the same corner without the wing where they might have to be gentler on the throttle to avoid oversteering - but this is power-induced oversteer which is being fought, not to be confused with the handling-induced variety. If you've got a car with a great balance suspension-wise, and want to add a wing but keep the handling the way it was, you'll need a lot of front downforce as well.