what if you raised the rear wing higher a couple of inches?

 

I'm not sure that would do much as it's pretty high already and should be getting some clean air. Maybe add a wickerbill (sp?) or go to a steeper angle of attack.

The car getting looser as the day went on could just be from the track heating up?

Oh, and those wheels on the GT3.... nothing like a carbon fiber/magnesium race wheel! Eh, they're only $2k+ each.

 

The wing is above the roof.. but I did consider that it might need to be higher, or.. lower. It might be in a bad spot in the air, without the wind tunnel it may be tough to find out right off.

Getting worse throughout the day could be a track thing, but usually as a track gets greasy it exxagerates whatever the problem is. Early in the day the problem was push in low speed and loose in high speed.. a slicker track would have ment worse low speed push and worse high speed loose, where this just got loose everywhere. (my 2nd spin was in Cotton corners, where the car is doing 40-50mph.

I have a pretty good idea how to fix it, but it's going to take some new parts and some testing. (which is really what we need, more test days to work with some combination of things and see what they do in a controlled environment, and not when you *must* go faster.

 

Jon,
I watched the M-O video where the AMS TA cars was getting lose. It looked like most of your problems occured during right hand turns, was that the case? Do you think one of the rear links has a fubar'd bushing? I'm not sure what all has been done to the suspension, OEM arms versus tubular arms and links. But I would check very closely for cracks and fatigue. Maybe the video made it look worse than it is, but it appeared like there were drastic alignment changes happening dynamically through the turn. Toe for example.

Hope you get it fixed bro before tracking it again. It looks dangerous to drive.

Take care!

 

... and you are the prime example of someone who has beaten works in their class? I believe that all cars in their category would be called pussies for not racing against high budget UNLIMITED time attack cars in that class then ... according to your comment that would be the case.

 

Jon K - Cant wait to see you whoop up on the competition in the Unlimited Class - there is some fierce competition out there...

Any chance you might try to make the Japanese Time Attack Circuit?

 

Not to mention that they ran a faster time than the AMS car so it wouldn't have mattered which class they ran in (unofficial times right now are 1:55.6 for WORKS and 155.8 for AMS).

-- DavidV

 

Baby steps, but if the car, driver and budget were up to the task I dont think we could turn it down.

We are a long way off from that. Remember we are still only 2 seasons into this thing really. One in time attack form

Eric

 

Jon, If it is any consolation you and the AMS Time Attack car made Grassroots Motorsports Dec issue page #137. A nice 1/8th page picture with a mention in the writeup: "Jon K's Mitsu Evo 8 outpaced impressive competition, including several Corvette Z06s, to take the TTU Championship"

Congrats again... I think a setup and sorting day for all the AMS Road Race cars is in order.

 

does anyone know where the final times are posted?

 

Jon/AMS crew -
First off, congrats on getting the car through a tough event and pulling out a respectable time. The car will not doubt continue to improve with more TNT time (TNT is test and tune, not to be confused with TNA )

I am admittedly an aerodynamics novice, but from what I believe or think I know, I have a couple comments for you:Just a couple thoughts. I may be totally off, but just something to think about as you are working toward optimizing your platform. Keep up the good work!

EVOlutionary

 

K.. I go to Oklahoma and I come back to dozens of questions...

Jap Time Attacks.. As Eric said, nothing is out, but getting it right, and very right, is in first order before we ship it overseas. (It's rough enough going 3000 miles nad underperforming)

I have seen the Grassroots, I think the caption got more words than the article did, but I was very happy to see it.


Mayhem: I didn't notice if one way was worse than the other at VIR from looking at it, and Daddio didn't mention it. However... once I looked back at the tape of the Super Street event, it is WAY more pronounced in left handers actually, and it was in a left hander where I had the big spin. Later on, it was a slow left-hander that got me... Yep, I think we need to go over the car nad make sure something isn't broken.

CJ, I agree. Test days.

 

TNA, TNT, it's all good. Wait, are you talking about blowing the car up.. lets try not to do that. Hot girls are always welcome though.

We are novices as well, but the baptism is by fire at this point, so help is always welcome.




True, but it also gets it up in the airstream. (in theory) A wing is going to add to frontal area on any car, but hopefully it lowers lap times through downforce more than the increased drag hurts it. My theory is that if it is in dirty air where it is, we may have to go higher or lower than where we are. (and right off, I would go higher)




I am not sure the exact amount of downforce, the wing is labled as a low drag/high downforce wing and is built by Penon Composites, who builds wings for multiple cars including prototypes, GT cars, and Formula cars. I have seen similar profiles that are listed to produce 600lbs of lift (downforce) at 140mph, at the maximum angle of attack, and in clean air.



Attached to the back of a car isn't optimum however, and because the wing should be being used for ballance running at a maximum angle of attack isn't always a good idea either. You are on the right track with optimizing it with the splitter and undertray, and it is something we are working on. (now i sound like that verizon comercial)




It is possible. But if it does it, it does it quick and not when the tires get overheated. My big spin, which was on my 2nd hot lap of the day (first session brakes were gone so I wasn't pushing) should have had tires close to optimum or maybe a little less than optimum, so the car starts out loose, and gets looser.



One thing that did have me preplexed was that at the start of the day the car was pushing in low-speed corners, and loose in high-speed. The one thing that changed the most was fuel level, and the difference in weight from 12 to 3 gallons of fuel on board. The lighter that car got, the worse it got everywhere. I think it is a set-up issue, maybe a broken part we haven't found, and then a wing that isn't working as well as it can.




In short, no. This is a great point, and probably much of the issue if nothing is broken/suspension isn't changing as weight drops. The splitter is the first generation, really our prototype, and we know it puts a ton of weight down as speed increases. The "old" wing, the APR GT500 had a bunch of downforce but I am sure a lot of drag as well. I think it was always keeping the car ballanced also.



Because of the wing change this explanation is the simple one, and usually the simplest answer is the right one. I would have gone right for this if the fuel level issue hadn't presented itself. (Though, we might be dealing with the weight axaggerating the imballance....)




I don't think you are totally off, not any more than we are. I am fairly new at the aero thing myself, having driven developed downforce cars, and the only R&D with areo i have done is diffusers and wings on my F2000 car.



I do like the open dialog though, It's fun to watch the ideas take shape and the different experiences brainstorming on it. It also shows how hard it is to make a car go this fast, and how hard the Sun Auto, HKS and Works guys have worked to get where they are with their Evos. I feel like we have taken a small step back from where we were at Nationals even, but i think the saying goes something like "you have to take one step back to take two steps forward"

 

was just thinking, in substitution of a windtunnel to check the airflow over the rear wing, you can always do the ghetto tape and string

 

Tape and string works, would even tell us quick what kind of airflow is over it. Not a bad idea at all.

For other downforce testing, we need an airport, then measure shock travel. Wind tunnels are $$$, and without a big rolling ground one, info is skewed anyway.