E Production 2nd Gen Racers - Rear Camber Question
01-20-10, 05:56 PM
#26
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J9FD3s and others: The difference between RA1s/R888/HankookSlicks/etc. and CANTILEVER slicks from Hoosier/Goodyear is night and day. MANY seconds per lap! Believe me as I have raced on pretty much everything since I started in 1971. (SCCA, IMSA(old one), TransAM, GrandAM, NASA, Escort Endurance, 25 Hours of Thunderhill, etc. +?) + that is why NASA has such a high PT points add-on for those slicks.
.
btw i worked with corey c after he moved up here to northern CA
01-20-10, 06:08 PM
#27
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Mazdatrix: Thanks for the information. I plan on running 15" wheels but haven't ordered those yet. If the cell sits too low, I can remake the 2 side brackets, not that big of a deal, as everything else is contained. I currently have some cross drilled rotors on the car, but for the 1st season, I'll use those in PDXs and wear them out while I dial the car in.
GTU_FAN: Thanks for that long writeup, that was very good inspiration and information. You are right, as is K2RD, I need to collect data before I redesign something. Am I trying to make a "better" control arm? Well, I don't think I'm that good, but Mazda didnt have a pure race car in mind when they designed that arm, and I do, so we have different objectives. I will use the stock arm now, and use this time to get better at the design and analysis process so when the time comes, I can effectively and efficiently create a new control arm. I'm thinking I may have to pull some negative camber out of the arm, but this is just shooting in the dark until I actually collect data.
I have already sold the diff and will be looking for an NA replacement, if you have any suggestions, speak up! One person suggested oversized shims in a stock diff. Other peoples thoughts?
I'm going to run the turbo trans that I have until I can afford a dog box, which will hopefully be next year.
Again, everyone, thanks so much for the help!
GTU_FAN: Thanks for that long writeup, that was very good inspiration and information. You are right, as is K2RD, I need to collect data before I redesign something. Am I trying to make a "better" control arm? Well, I don't think I'm that good, but Mazda didnt have a pure race car in mind when they designed that arm, and I do, so we have different objectives. I will use the stock arm now, and use this time to get better at the design and analysis process so when the time comes, I can effectively and efficiently create a new control arm. I'm thinking I may have to pull some negative camber out of the arm, but this is just shooting in the dark until I actually collect data.
I have already sold the diff and will be looking for an NA replacement, if you have any suggestions, speak up! One person suggested oversized shims in a stock diff. Other peoples thoughts?
I'm going to run the turbo trans that I have until I can afford a dog box, which will hopefully be next year.
Again, everyone, thanks so much for the help!
01-20-10, 06:13 PM
#28
lmao! appreciate the compliment, although we're not doing anything special.
tires, we also thought one weekend was enough for testing. we switched from the toyo R888 to the hankook slick. we actually had 2 weekends of testing, lap times dropped instantly.
however when we actually RAN the 25, the tires ended up with a funny wear pattern, making us have to change front tires earlier than we'd expected.
we're thinking now you almost need to go thru a set of tires to get the car setup, unless you're good or lucky. going from the Ra1 to the R888, wear was better, but the drop in lap times took suspension tuning, while going from the R888 to the hankook, it was the other way around.
tires, we also thought one weekend was enough for testing. we switched from the toyo R888 to the hankook slick. we actually had 2 weekends of testing, lap times dropped instantly.
however when we actually RAN the 25, the tires ended up with a funny wear pattern, making us have to change front tires earlier than we'd expected.
we're thinking now you almost need to go thru a set of tires to get the car setup, unless you're good or lucky. going from the Ra1 to the R888, wear was better, but the drop in lap times took suspension tuning, while going from the R888 to the hankook, it was the other way around.
Speaking of the rear suspension, what is your opinion of it? Are there any flaws or disadvantages with it that warrant custom parts that don't already exist?
Even if there is... I'm sure custom ones aren't allowed in E-production so SHM might be designing like a GT or unlimited class racer, which is cool, but his competition will be much harder!
I need to refresh myself on the rules... *goes to read SCCA rulebook*
Oh yeah, and I realized I goofed on my little diagram too. Actually to remove rear camber you do this... my bad.
01-20-10, 06:29 PM
#29
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i think you're gonna need less camber too, and possibly toe, but how much is the question
other than that, you have to be really conservative, the 25 is longer than the whole rest of the season put together, so we replace a lot of stuff that in a sprint situation you wouldn't have trouble with. i was thinking about making a post...
01-20-10, 06:48 PM
#30
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Thread Starter
The control arms are unrestricted in EP, so I can redesign the control arms
My thoughts are that the unsprung weight of this system is very high, so I can possibly take some weight out of it to improve chassis and suspension dynamics.
My thoughts are that the unsprung weight of this system is very high, so I can possibly take some weight out of it to improve chassis and suspension dynamics.
01-20-10, 07:56 PM
#31
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shm21284: Strongly suggest you join the Production discussion board.
http://prodracing.com/prodcar/
It is where you should be asking your questions, and there are quite a few Rotary production racers there.
http://prodracing.com/prodcar/
It is where you should be asking your questions, and there are quite a few Rotary production racers there.
You are going to need a 5.12 RP with the stock or Miata gears. Very hard to find as they are custom made by joining a 1st and 2nd gen pinion. If you are willing to spend the money (IIRC the RP is about $1k alone) - good luck finding one used, I was lucky - I know someone who is making them but he's not into wasting your time or his, you need to be prepared to buy and not BS. To say he knows his stuff is putting it lightly. The last time I saw one complete was from ISC at about $2500.
. I thought it would be pretty obvious when I got under there to install them anyway.
01-21-10, 10:52 PM
#33
I got so practiced using these camber adjusters I could probably remove them, service them, and reinstall then in like 15 minutes flat lol.
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