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nocones
nocones GRM+ Memberand PowerDork
9/1/23 11:21 a.m.

In reply to AngryCorvair (Forum Supporter) :

That is one aspect of this that I am not sure about.  It has a full to spec 4130 cage designed to meet requirements for a 2800lb car.   I wear a Hans and it has a fire system/FIA fuel cell.

Assuming my fabrication is up to quality then "yes" it does.  I 100% know my willingness to push the pedal all the way will be course dependent.  Realistically the most dangerous part is the OTHER 3500+lb cars on the track.  Hitting barriers/etc it is probably as safe if not safer then any steel tube frame Open wheel car.  

I consider that every time I drag it or the MG on track.  Ultimately these are things I built that are hurtling around course with things to hit and things that can hit me at high rates of speed.  There is a difference between hitting something at 110 vs 135, but it's not dramatically different.   I may decide after 1 or two events with the STI motor that "That's enough of that" and remove it to return it to lower performance or park it entirely.  It is something that at least so far has prevented me from considering putting a more skilled driver in the car at a Track Event.  

This is an unsafe sport with risks.  I have taken as much action as I can so far to mitigate those risks but they cannot be eliminated in any car.  I suspect I will probably this winter or before more substantial track time is spent in this thing at a higher performance tear it appart and have Gumby help me ensure the cage is really good and probably add the taco gussets and tubes required to take it to FIA Pikes Peak/Rally spec with double downtubes and the more elaborate roof structure they include.  

gumby
gumby GRM+ Memberand Dork
9/1/23 11:27 a.m.

Bring it on!
 

If you find the speed potential is above your level of risk tolerance, you don't have to remove the STI engine; just dial the boost back.

maschinenbau
maschinenbau GRM+ Memberand UberDork
9/1/23 11:41 a.m.

I trust your cage and fabrication and that it meets all the design requirements, but after riding in it the only thing I would want is more foam and cushioning. I couldn't help but think what a small bump would do to my knees against all that bare metal.

singleslammer
singleslammer PowerDork
9/1/23 11:51 a.m.
nocones said:
...FIA Pikes Peak/Rally spec...

Pikes peak you say?

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
9/1/23 1:07 p.m.
maschinenbau said:

I trust your cage and fabrication and that it meets all the design requirements, but after riding in it the only thing I would want is more foam and cushioning. I couldn't help but think what a small bump would do to my knees against all that bare metal.

This wasn't a problem that jumped out at me, but looking at it, some padding on the bars below the beltline under and ahead of the A-pillar would be a good idea. Maybe on the "knee bar" too, just in case your legs hit it in a rollover.

nocones
nocones GRM+ Memberand PowerDork
9/25/23 4:45 p.m.

This has been a busy month.  But also not busy.  

I'll post more about it but I'm kinda disappointed right now.  

After some great help and momentum right after LRP to take the car all apart and get the EJ257 to fit the chassis my family went and got COVID.   It took about 2.5 weeks to work through the house and during that time I just got nothing done on the car.  It was all the effort I had to make the removable braces and subframe reinforcement required to restore the chassis to functional after cutting what conflicted with the EJ257, and then throw the EJ251 back in for Heartland Park this weekend.  

The car ran flawlessly this weekend and my times relative to the rest of the Gridlife field are improving.  

But..  now the disappointment.  With only 15 days until the car needs to be on a trailer to Kentucky, and 0 wires terminated on the Haltech, and a unproven engine with no opportunity to test it the EJ257 just isn't going to happen for UTCC.   

I'm trying to stay positive and reflect on what the car has accomplished but I was really hoping to bring the best version of the car I can make to UTCC.   

I know the event will be fun, and the car will still perform well, but I will definitely be bringing a 125 WHP knife to a Mortar fight.  

 

I'm going to take the two weeks I have to do what I can to just clean up some edges on the car and work on drag reduction and aero optimization.   

I reduced the AOA on the rear second element this weekend and noticed a big pickup on top speed acceleration.   

The car had incredible grip.  I think I was more comfortable and able to push the car harder but I really could only do 2-3 hard laps before I became very fatigued and ready for a break.  The car just corners so hard it's not that the laptimes are that incredible, but the cornering loads are very high.  

I apologize I haven't been updating much.  I've sensed that the EJ257 was unlikely to be complete for a while and that has really made me a bit sad about the whole thing.   Again I know I need to focus on the positives but I feel a bit like I failed at a goal I set.  

The benefit is the car will run at UTCC basically identical to how it was when it won the 2022 challenge.  

The modifications I've done sense the challenge have all been safety and reliability.  Yes they have added costs, but the dynamic performance has not changed.   The car at UTCC will be ~$6300 all in, inclusive of the Fuel cell, fire system, Enkei wheels, RT660 tires, IAG oil system and Willwood pedals.   So in that way it will be interesting to see how it does.  It's clearly no longer challenge legal but it's no faster then it was at the challenge.   

I will try to keep everything updated as we approach UTCC.  Unless some of you are super excellent with Haltechs and want to create me a harness this week, and tune the car it's just going to be what it is.  

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
9/25/23 5:24 p.m.
nocones said:

The car had incredible grip.  I think I was more comfortable and able to push the car harder but I really could only do 2-3 hard laps before I became very fatigued and ready for a break.  The car just corners so hard it's not that the laptimes are that incredible, but the cornering loads are very high.  

Tabata Laps
1 Lap As Fast As Possible, followed by 1 Lap of Rest;  repeat for 20minutes

pretty sure that's a selectable option in a workout website somewhere, right?

maschinenbau
maschinenbau GRM+ Memberand UberDork
9/26/23 8:50 a.m.

In reply to nocones :

Good decision. As cool as the last-minute engine swap thrash session would be to follow, you are not a full-time youtuber and may gain nothing from that experience except a less reliable, and likely non-running track car. Take care of yourself and your family and look forward to the bright side. You have a solid, well-sorted track car and a chance to drive it alongside the best cars in the country. That is pretty darn cool and will be an awesome experience!

From my road racing experience with high-G cars.  The neck goes first.    You have two weeks.  You an make improvement to those neck muscles.   A loop around the head with bungee cord attached to a door frame... do reps trying to move left ear towards left shoulder, and right ear towards right shoulder.  Don't over do it, but you can make improvements even in two weeks.

Also, check your seating position.  Your ribs under your armpits should be padded tight to the seat.  You shouldn't be trying to fight G forces by pulling with your arms on the wheel.  I always pour a custom seat with foam that is tight from armpits down to hips.

Have a blast in Kentucky!

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
9/26/23 11:52 a.m.

+1 for Purple Frog's tips. Also IIRC the closest thing the car now has to a headrest is the floral pad on the firewall, some kind of head support could help, it could even be a stiff piece of foam that wraps around to the sides of your helmet.

Sucks about the engine, but getting a DRS setup working would give you a good return on lap times for time & effort spent right now. If you can get that massive downforce in corners and braking zones and then low drag on the straights, that's the best of both worlds. Getting DRS on the front winglets would help too.

Maybe there could be time for a quick & dirty nitrous setup to boost you on the straights as well?

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
9/26/23 12:00 p.m.
nocones
nocones GRM+ Memberand PowerDork
9/26/23 12:16 p.m.

Good ideas on the seats.  That's the kind of stuff I'll be able to do now since I won't be doing the engine.  

I have to look at DRS.  It may only be allowed in UTCC I don't think the SCCA lets Aero move unless it's OEM.

With an astric of this is cell phone GPS/Accelerometer data this is what I'm dealing with..

Is it really 2G?  I dunno probably not. I did confirm the corner navigated at 85 mph would of had a ~240' radius and math says if you navigate that radius at that speed it's 2.0G.  obviously there is some variability due to the cell phone GPS accuracy being what set that 85 mph speed.  So I'm not running around saying the LMP360 corners at 2.0Gs.   It's WAY more then I've ever felt in a FSAE car with aero or in the MG on hoosiers.   Looking at onboards from a dude in a  Radical SR3 that was ~3 seconds a lap faster then me (different event but same track configuration) my corner apex speeds are within a MPH and in some slower corners higher.  I'm spotting a radical Slicks and about 15mph down the straights but the car is becoming quick.  

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
9/26/23 12:37 p.m.

If you have video that's showing the tach (or better yet a speedo as well) you can use that to confirm your speed. 2G sustained on this car wouldn't surprise me in the slightest.

I assume the SCCA events you're running in are autocross, for that you could disable DRS in a fixed position (probably max downforce for most courses), this is where the manual winding knobs on popup light motors will come in really handy.

maschinenbau
maschinenbau GRM+ Memberand UberDork
9/26/23 12:39 p.m.

DRS done the GRM way would be PRETTY SWEET

nocones
nocones GRM+ Memberand PowerDork
9/26/23 12:48 p.m.

In reply to maschinenbau :

My big concern with DRS even if legal is the same thing I'm sure it's banned for.   For a car relying heavily on Aero you are committed to the corner at speeds well beyond what you can do without full aero.   If you are at turn in and find your DRS didn't go back to "full stick" you are heading to the grass or worse.   OE systems have testing and redundancy built in and if we are honest don't actually make that kind of difference.  

SCCA is who is governing UTCC.  I am also running TT nationals as well.  I believe their rules limit UTCC but I could be wrong. 

bobzilla
bobzilla MegaDork
9/26/23 12:56 p.m.
nocones said:

Good ideas on the seats.  That's the kind of stuff I'll be able to do now since I won't be doing the engine.  

I have to look at DRS.  It may only be allowed in UTCC I don't think the SCCA lets Aero move unless it's OEM.

With an astric of this is cell phone GPS/Accelerometer data this is what I'm dealing with..

Is it really 2G?  I dunno probably not. I did confirm the corner navigated at 85 mph would of had a ~240' radius and math says if you navigate that radius at that speed it's 2.0G.  obviously there is some variability due to the cell phone GPS accuracy being what set that 85 mph speed.  So I'm not running around saying the LMP360 corners at 2.0Gs.   It's WAY more then I've ever felt in a FSAE car with aero or in the MG on hoosiers.   Looking at onboards from a dude in a  Radical SR3 that was ~3 seconds a lap faster then me (different event but same track configuration) my corner apex speeds are within a MPH and in some slower corners higher.  I'm spotting a radical Slicks and about 15mph down the straights but the car is becoming quick.  

That same Corner Rio was at 1.04G and the following left at 1.09. Sadly that wasn't my fastest lap. Fastest going into the right at .93 and the left at 1.09 (seemed to be pretty consistent there)

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
9/26/23 1:02 p.m.

Good point about reliability. You'd want contact/reed switches triggered at the max-downforce position to toggle indicator lights in the cockpit to confirm what position the wings are actually in. If you hit the button/press brakes and the light doesn't change, then you know to brake extra and take it easy back to pits. I think you would hear and feel the difference as well.

I think the only serious-business DRS setups in production cars are in the McLaren P1 and the new Mustang GTD.

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
9/26/23 4:31 p.m.

I'm not sure DRS is really necessary...

This is a *guesstimate of what the rear foil was doing before Heartland:

lets keep in mind, that JavaFoil overpredicts CL in these situations (especially since these are '2D' wings in freestream).  So, don't get too hyped.  Drag, though, of 0.148 is "reasonable", although it's also "not all the drag"... but it's enough to start on.  This second element in the above is ~6" and the same foil shaped the same as the original foil, and cranked up to 40deg from horizontal.  These are guesses based on seeing the car at Autobahn.

Let's say we crank the second element into the "DRS" deflection that nocones had at Heartland... which I'm guessing is at about 10deg w.r.t. horizontal.

So, CL went to 2.831 from 3.475 (or 2.831/3.475 = 20% reduction in downforce).  While drag went to 0.05448 from 0.14810 (or 60% reduction in drag)

But, can we have the same downforce and less drag....

well, I guess maybe not "out of the box"... we're getting about the same drag, despite going to a 2nd element that's 4inches instead of 6inches, and it's mounted at 15deg from horizontal.  I'll guess the gap is still a tad too big, and squeezing it down and dropping some angle on the second element could get the same downforce and lower the drag.

preach
preach GRM+ Memberand UltraDork
9/26/23 4:38 p.m.
nocones said:

I don't think the SCCA lets Aero move unless it's OEM.

I'd like to see them tell you what is OEM on a LMP360...

Apply for homolagation certificate.  Show them a picture of 100 LMP360s in a parking lot.

OBTW the third aero picture is very close to the upper elements we run on formula cars.    

At Kentucky are the straights all that long to gain that much advantage to all the work to make it safely move.  Seems a good wing in the corners gains you more than even no wing on the straights.

nocones
nocones GRM+ Memberand PowerDork
9/26/23 8:24 p.m.

In reply to Purple Frog (Forum Supporter) :

I'm not sure I will defer to the experts.  When I ran NCM in the MG it ran a 2:24.44 with a VMax of 107.  The 360 has demonstrated greatly superior cornering and similar VMax to the MG.  There are a LOT of 60-85 mph corners at NCM a place where the 360 seems to thrive.   I think keeping the aero downforce available while reducing drag will pay off quite well to the favor of the 360. 

 

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
9/26/23 8:41 p.m.

not that I'm "the expert", although I reckon taking most of the reins on that role...

the tl;dr of the post I made in the aero thread:

I think: considering the timeframe, it's currently working correctly, and the ability (hopefully) to crank angle back in if i/nocones manage to get the front end making gains;  it's best to leave the rear the way it is for UTCC.

I think the main goal is to try and gin up a way to have the front element make ~the same downforce, with less drag.

In DM's I've outline a few places where I think drag could be trimmed.  The big ones being yanking out the fog lights and closing the lower fender in their place, and hopefully coming up with a top over the cabin... although, if that's a bridge too far, there's probably some things that can be done to encourage the air over the windshield to "hop" the open top.

gumby
gumby GRM+ Memberand Dork
9/26/23 9:45 p.m.

In reply to sleepyhead the buffalo :

Oh no, not the fog lights! I haz a sad.

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
9/26/23 10:06 p.m.
gumby said:

In reply to sleepyhead the buffalo :

Oh no, not the fog lights! I haz a sad.

yeah, I understand.  I'm suggesting it "just for now", and simply because "I reckon" it'd be easiest to pull them and wrap the opening... rather than try and wrap the bottom and integrate the foglight.  I could be wrong.  I realize it's an important aesthetic for nocones, among others.

I just make the suggestion...  and I do take some pains to try to make said suggetions "vague"-ish;  take the chalk and mark where I think things could be improved.  nocones is the one who has the car in his hands, the tools/materials/skill/motivation available to effect a change.  he'll decide what/how can be done in the time allotted.  and we've got 65 pages of nocones taking an idea, even if it isn't his own, and integrating it into the whole in his own unique way.

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
9/26/23 11:43 p.m.

Aero Thread updated.

tl;dr
I think there's an opportunity to reduce the front downforce drag by 60% by changing the 2nd element shape and cranking it down from ~40deg of deflection from horizontal (that's a guess).

Also, I suspect that the main element shape mightcould use some change, biased towards moving the maximum "thickiness" of the foil forward... probably/possibly in conjuction with pulling out the plywood that's under there and replacing with a "sheet of metal of nocones preference"... assuming that yoinking the plywood from there is even possible without a full rebuild of the front aero.

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