1st Autocross

[BDA]

Congratulations on your first autocross! Having fun is the main thing! 

[Clifton]

Clifton, your car looks incredible in your photo.  Is there a post where you have more photos and a description of what you have done with the car?

It's great you had fun. 11 runs is a lot. We get 5. How was the handling? understeer or oversteer? Are you doing another?

This thread has most of the mods I've done on it.
http://www.lotuseuropa.org/LotusForum/index.php?topic=1035.0

[Richard48Y]

How many cones?
Any spins, stalls, or missed shifts?
Has to be a reason for #68. 

[rjbaren]

The main reason is I guess I am not a very fast driver.  I have only auto crossed once before in like 1990s in a Sunbeam Alpine.  So it was my first auto cross in 30 years and my first time driving the Lotus off road so to speak. 

There were 18 BMW M 2s, M3s and M4s.  18 BMW non M cars,  6 Porsches, a 2021 Toyota Supra, 7 Miatas, 2 Nissan 350Zs, 2 Subaru WRXs, an Audi S4, 2 Honda Civics that finished 8th and 13th, 2 mini Coopers, a Lexus IS 300, 3 Volkswagen GTIs, etc.  It seemed like pretty stiff competition.   I felt like a fish out of water just trying to figure out what's going on.  The only car I beat was a 1987 Saab 900 turbo.

I know my car was sliding but I am not sure which end of the car was unattached.  I was kind of waiting for the tires to reconnect before pressing on the gas again.  I laid too much rubber at the start, but it was fun and felt like I was going fast but I really wasn't.
There were 9 seconds between the 1st and last place cars.  But that is a lot of time on such a short track.  The fastest car was 34.164 seconds and my best time was 43.181 seconds.  my first attempt was 53 seconds so there was some improvement.

My performance upgrades are:  146 HP engine, Mikuni carbs, a header and performance muffler, lightweight alternator pulley, adjustable lower rear links (one stock one was bent), Spax adjustable shocks, 110 pound front springs (the stock springs were way too tall) and electronic ignition.  All new rubber bushings, 5 1/2 wheels and stock sized Barum Brillantis tires.

There is one more auto cross but it is pretty far away and I don't want to drive that far to beat on my car and hope to bring it home in one piece.  In the future I may buy a trailer to haul the car to farther out events.  I would like to try Midwest Council auto crosses which are done on actual race tracks.  This was my first attempt and I liked it, but I need to get a better set up to transport the car and a place to park the trailer.

I would like to buy a different set of tires over the winter.  I have a set of Lotus alloy wheels but maybe it would be beneficial to buy larger rims and tires.  I need to do some research.  I want to keep the car pretty much stock in case I ever want to sell it and it serves as an excuse to finish at the back of the pack.

[jbcollier]

Sounds like you had a great time, congratulations!

[Clifton]

Picking up almost 10 seconds is huge. You will get better and faster the more you get used to the sea of cones, everyone does. The cars that are faster than you have much better (softer) tires though. FWIW, soft tires last a lot longer on light cars. I'm 2600 miles in on some Rival-S 200tw and they have plenty left. They will be too old before too worn. A few guys on here run R888R's and there's the AR-1 too. Tires make a huge difference.

[Richard48Y]

Did my last Auto-X many years ago in a hot-rod '65 Corvair.
Not planned, just happened to drive by and decided to make a run.
Power slid the rear around almost every corner to prevent plowing the front from understeer.
Never touched a cone but was DQ for my 'slightly' loud header exhaust.
My time was actually pretty good, the course workers other comment was, "Did you used to drive British cars"? LOL!
I had about fifteen British and Italian cars at home.
Sounds like you have plenty of power, make more runs!

[rjbaren]

Clifton your car looks absolutely incredible, and the work you have done is beyond belief.  It must be so rewarding and fun to drive.  I think you have a masterpiece.  There are so many talented guys here building really cool cars.  It's amazing.

Thanks for the votes of confidence.  I will do it again next year.  It's just starting to get cold here so not much season left. 

So, for a tire and wheel package question.  Since I have a set of 13x5.5 Lotus alloys that have been blasted and are clean I can put on a set of tires 205 60 13 rear and 185 60 13 fronts.  I have seen Hoosier and Toyo available in these sizes.  Is there an advantage to going with 14" or 15" wheels?  Is the advantage in tire availability and/or is it better to have larger diameter wheels too.?  If so, what are the recommended combinations that will fit without having flares or rubbing? 

[Clifton]

Thanks, it's my final car and I put everything I've learned from other builds into this one.

Hoosier are A7's are the fastest, R7, second but heat cycle out usually before they are worn out. Driving them on the street will kill them quick.  I wouldn't jump straight to these. 15's would give more options on brands and you could run one of the fast autocross 200 tread wear tires but I would just stick with your 13's and run R888R's (100tw). In SCCA it will put you in a non street tire class but you'll be much faster and probably be running by yourself anyway. I don't know if I would run a 205 on a 5.5" wheel. You are stiffer in the front than stock so equal sizes wouldn't be bad. I run 15's because I was building a car that needed big brakes and a wide tire in the rear. It's not just the flares though with 15's, I had to deepen the body by the footwell to clear when turned, this is for a 205 front in 15". If I kept the 4 cylinder, I would have run 13's and no flare. I wouldn't trailer either. It gets old and takes all the fun out of it. I don't even bring tools when I go now. Just check pressure, get gas and go. It's much more fun driving it there and everywhere else. Funny your season is ending due to cold when ours just starts because it finally got cold(Arizona).

[rjbaren]

I looked up the Toyo R888Rs and 5 1/2 is the narrowest rim allowed for the 205 60 13s.  I called Tire Rack to confirm and Isaac agreed, the 205 is OK to use with a 5 1/2 inch wide wheel. 
My figures show the stock rear tires will have a height of 589.2 mms and the 205 60 13 Toyos will have a height of 576.2 mms.  The stock front tires have a height of 575.2 mms and the 185 60 13 Toyos will be 552.2 mms.  The 13 millimeter difference in the rear may mess with the speedometer by about 2%, I think?  I don't believe the front will have an effect on the speedometer but I am not sure of that either.

[jbcollier]

According to this site, less than 1%:

https://tiresize.com/tyre-size-calculator/

You will have a full 1" wider on either side though.

[Clifton]

I would just use my phone to verify speed at 60 and from then on, know I'm off XX at 60, half that at 30 mph. You may be off now and not know.

[rjbaren]

That's a very nice tire calculator.  Tire rack says the Proxes R888Rs aren't expected back in stock till next spring.
I have a set of OEM alloys that have been blasted and are ready for finishing.  I am thinking of rubbing some SharkHide
on them because it's easy and it won't yellow or peel.  When necessary just rub on another coat.
Other wise I think I will have to mask and polish parts of the wheel, not to mention painting. 

[Clifton]

I don't know if you tried Phils tire. They only carry competition tires. Same prices as Tire rack. They carry Nangkang too

https://philstireservice.com/product-category/competition-tires/toyo-tires/

[rjbaren]

I am currently running stock sized touring tires so that shouldn't be a contributor to speedometer error.  But, regarding the speedometer, I can hear my speedo cable, because it's pretty loud.  Could it be that it is not spinning to the proper speed due to too high friction and causing an error?  I think JB has replaced his speedo cable with a GPS type system.