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-   -   Issues with NASCAR turns? (https://www.miataturbo.net/race-prep-75/issues-nascar-turns-58048/)

ThePass 05-25-2011 03:50 PM

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

FatKao 05-25-2011 07:15 PM

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

Savington 05-25-2011 07:31 PM

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.

hustler 05-25-2011 07:39 PM

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

Savington 05-25-2011 07:41 PM

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.

Full_Tilt_Boogie 05-25-2011 07:47 PM

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.

Gotpsi? 05-25-2011 08:16 PM


Originally Posted by Savington (Post 731255)
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.

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.

Savington 05-25-2011 09:20 PM


Originally Posted by Gotpsi? (Post 731265)
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.

spoolin2bars 05-25-2011 10:47 PM


Originally Posted by hustler (Post 731254)
The turns aren't scary at our speeds, but they present a lot of load.

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

mcarp22 05-26-2011 02:37 AM

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

bellwilliam 05-26-2011 03:00 AM

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 ?

ThePass 05-26-2011 02:15 PM


Originally Posted by bellwilliam (Post 731361)
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

spoolin2bars 05-26-2011 03:15 PM

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.

bellwilliam 05-26-2011 03:15 PM

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 ?

Savington 05-26-2011 03:27 PM


Originally Posted by spoolin2bars (Post 731578)
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.

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.

Savington 05-26-2011 03:28 PM


Originally Posted by mcarp22 (Post 731358)
I was under the impression that the really high banking like daytona and such didn't get along well with wet sump oiling.

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

spoolin2bars 05-26-2011 03:52 PM


Originally Posted by Savington (Post 731583)
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.

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!

ThePass 05-26-2011 04:58 PM


Originally Posted by bellwilliam (Post 731579)
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 ?

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.

bellwilliam 05-28-2011 03:50 AM


Originally Posted by ThePass (Post 731625)
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.

ThePass 05-28-2011 02:58 PM


Originally Posted by bellwilliam (Post 732140)
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 ;)


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