2016 SM (Street Mod) Autocross Discussion
Apr 22, 2016, 02:33 PM
#46
Evolving Member
Join Date: Aug 2006
Location: Charlestown, RI
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Ran my first event in novice SM on the 17th. Finished 9th out of 40 novices. 2nd fastest raw time but with the PAX modifier it dropped me considerably. I have a lot to work on. But id rather blame the fact that I'm on stock struts with just lowering springs and 235 super sports.
The guy who won smoked the competition by 2+ seconds in both raw & PAX in a BS evo X. Noticed he had 275s 200 tread wear tires. Guess you can get nice tire width on a 8.5 wheel.
And remember always blame the car!!! Rule #1
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codylop (Apr 25, 2016)
Apr 25, 2016, 07:15 PM
#49
Installing the Weir 12 plate rear diff this weekend and sending off the A.C.D ecu to English racing to get reflash.Rotation sucked once I went with r-comp tires.Losing what I can for wieght.
Last edited by codylop; Apr 25, 2016 at 07:57 PM.
Apr 26, 2016, 09:26 AM
#53
EvoM Guru
iTrader: (1)
Oooooo....shiny...
New hubs too. Nice.
New hubs too. Nice.
Apr 27, 2016, 08:27 PM
#58
Heh sorry, been a mad dash to finish everything and overcome a few obstacles to leave for crows in the morning. I just got the right side finished today around 2 and now its installed, aligned, and ready for testing this weekend.
Its such a drastic change from stock hubs that I definitely need to be there for testing friday. Will take more pictures when I swap tires in Crows friday morning.
Its such a drastic change from stock hubs that I definitely need to be there for testing friday. Will take more pictures when I swap tires in Crows friday morning.
Apr 29, 2016, 04:18 PM
#59
Quick update. In my massive rush to just finish these hubs I completely overlooked steering forces on the arms and just looked at steering forces on the bolts connecting the arm. Long story short, I bent the arm on my 3rd practice run here at crows and in my exhausted rush to get out the door yesterday completely missed grabbing the OEM hubs to swap back on.
I have a relatively quick fix to continue testing these by machining the arms 2x as thick (plenty of room to do so) which BH^3, they'll be 8x as strong. Since these lasted 3 runs and just bent a bit, I think that'll be plenty for me to continue testing for any other failures.
In my rush, I ended up with a 1.4" block instead of a 1.5" block (I assumed I had 1.5" and didn't double check cause why would I
). The result of that is the arm that bent is 18mm thick instead of 20mm which is almost 40% weaker. Actually kind of a good thing to find out I was at that threshold so I know it's a critical thing.
I cant seem to rationalize steering forces beyond looking at cornering forces, steering angle, and scrub radii. If someone has a good grasp on realistic forces I can design around that. If not, I'll probably look at what force gets me to plastic deformation on these arms and add margin plus FS to the design
I have a relatively quick fix to continue testing these by machining the arms 2x as thick (plenty of room to do so) which BH^3, they'll be 8x as strong. Since these lasted 3 runs and just bent a bit, I think that'll be plenty for me to continue testing for any other failures.
In my rush, I ended up with a 1.4" block instead of a 1.5" block (I assumed I had 1.5" and didn't double check cause why would I
). The result of that is the arm that bent is 18mm thick instead of 20mm which is almost 40% weaker. Actually kind of a good thing to find out I was at that threshold so I know it's a critical thing. I cant seem to rationalize steering forces beyond looking at cornering forces, steering angle, and scrub radii. If someone has a good grasp on realistic forces I can design around that. If not, I'll probably look at what force gets me to plastic deformation on these arms and add margin plus FS to the design
May 3, 2016, 10:45 AM
#60
I cant seem to rationalize steering forces beyond looking at cornering forces, steering angle, and scrub radii. If someone has a good grasp on realistic forces I can design around that. If not, I'll probably look at what force gets me to plastic deformation on these arms and add margin plus FS to the design
as far as forces go are you trying to find the force exhibited by the wheel?
A few quick assumptions (im sure you've got these):
car pulls 1.5g in corner
front outside tire carries 60-70% of load
now how much of that is on the steering ill have to mull that over