As a result of doing track days this year, as opposes to autocross last year, we are going at higher speeds.
The car was nervous at high speeds and has some snap oversteer.
Changes this time:
600 to 500 rear springs.
2.5 to 4.5 degrees castor.
-0.5 to -2.0 camber front plus 1 degree per inch of travel camber gain.
-0.5 to -2.5 camber rear. ( never measured the camber gain in the rear)
Added BEAR bump steer kit.
The included washers with the kit were not enough. I had to add a couple of washers for a total of 0.952 spacers.
I also added a safety washer to the bottom.
We will be testing tomorrow at Grissom AFB.
Bob
Last edited by Bob_n_Cincy; 06-04-2016 at 06:00 PM.
I think those changes should help a lot. Good luck tomorrow and report back!
What is your rear toe set to? That can cause a lot of issues too.
Tamra
Building 818SR #297 picked up 10/25/14 with Andrew (xxguitarist)
First start 12/21/14, First "drive" 1/17/15 First Dyno at EFI Logics 3/7/15- 310whp at 15psi for break in, full spool by ~3500rpm! First autocross 3/29/15
1st Registered 818 in Connecticut 7/24/2015. 9 months - 1 day from kit pickup!
I think those changes should help a lot. Good luck tomorrow and report back!
What is your rear toe set to? That can cause a lot of issues too.
front is 1/8" out and rear is 3/16" in.
I suspect our big problem was bump steer. We were going from 1/8"out to 1.5" in during 2" bump.
So during a left turn, the car would roll right causing the front right to dig in and throw the back end around.
That's my theory and I'm sticking to it.
Bob
Sounds like you are on the right track, Bob! Rear toe in of 3/16" is good. I bet your issue is bump steer like you are thinking, so hopefully that fixes it. We run toe out up front too since it sharpens up the front responsiveness, but too much can make it twitchy like Lance said.
Tamra
Building 818SR #297 picked up 10/25/14 with Andrew (xxguitarist)
First start 12/21/14, First "drive" 1/17/15 First Dyno at EFI Logics 3/7/15- 310whp at 15psi for break in, full spool by ~3500rpm! First autocross 3/29/15
1st Registered 818 in Connecticut 7/24/2015. 9 months - 1 day from kit pickup!
Our big swing at suspension change ended up being a foul ball.
Originally Posted by Bob_n_Cincy
As a result of doing track days this year, as opposes to autocross last year, we are going at higher speeds.
The car was nervous at high speeds and has some snap oversteer.
Changes this time:
600 to 500 rear springs.
2.5 to 4.5 degrees castor.
-0.5 to -2.0 camber front plus 1 degree per inch of travel camber gain.
-0.5 to -2.5 camber rear. ( never measured the camber gain in the rear)
Added BEAR bump steer kit.
The included washers with the kit were not enough. I had to add a couple of washers for a total of 0.952 spacers.
I also added a safety washer to the bottom.
We will be testing tomorrow at Grissom AFB.
Bob
Our big swing at suspension change ended up being a foul ball.
Biggest problem was the large camber changes caused the tire to run on inside edges.
Braking sucked as front tires were only using 2/3rds of tire.
Oversteer was difficult to control. Overall we were not happy with this setup.
Michael and I a both hurting and sore tonight. The car was beating us up.
We tried to use gopro mounts on an galaxy S7. Another fail. The heavier S7 was vibrating all over the place. Also the camera position was bad as the it need to be about 6" lower.
Bob
Our big swing at suspension change ended up being a foul ball.
Biggest problem was the large camber changes caused the tire to run on inside edges.
Braking sucked as front tires were only using 2/3rds of tire.
Oversteer was difficult to control. Overall we were not happy with this setup.
Michael and I a both hurting and sore tonight. The car was beating us up.
We tried to use gopro mounts on an galaxy S7. Another fail. The heavier S7 was vibrating all over the place. Also the camera position was bad as the it need to be about 6" lower.
Bob
Did you happen to mark the tires to see where they are rolling over to (to see how much of the tire you are using in turns)? The camber up front will definitely hurt braking grip. However, in corners, you should be going from using 2/3'ds of a tire to 100% if your camber is correct, which should result in maximum grip. We are running -3.5 in the rear I believe, and found that we were wearing the tires evenly at autocross. A bigger handling difference for us came from adjusting rake - we lowered the rear ride height a touch and the car became much more manageable. When you replaced the springs, could you have changed the rear ride height by any chance?
Did you happen to keep an eye on tire pressures? Some cars are very sensitive to tire pressure changes. I know in a track session you can't check/adjust them as frequently like in autocross, but it may be a good thing to keep an eye on in case you need to adjust your starting pressures/ pressure bias. Sometimes even 1 or 2 psi can make a big difference. Maybe some other track day guys have more feedback.
Tamra
Building 818SR #297 picked up 10/25/14 with Andrew (xxguitarist)
First start 12/21/14, First "drive" 1/17/15 First Dyno at EFI Logics 3/7/15- 310whp at 15psi for break in, full spool by ~3500rpm! First autocross 3/29/15
1st Registered 818 in Connecticut 7/24/2015. 9 months - 1 day from kit pickup!
Did you happen to mark the tires to see where they are rolling over to (to see how much of the tire you are using in turns)? The camber up front will definitely hurt braking grip. However, in corners, you should be going from using 2/3'ds of a tire to 100% if your camber is correct, which should result in maximum grip. We are running -3.5 in the rear I believe, and found that we were wearing the tires evenly at autocross. A bigger handling difference for us came from adjusting rake - we lowered the rear ride height a touch and the car became much more manageable. When you replaced the springs, could you have changed the rear ride height by any chance?
Did you happen to keep an eye on tire pressures? Some cars are very sensitive to tire pressure changes. I know in a track session you can't check/adjust them as frequently like in autocross, but it may be a good thing to keep an eye on in case you need to adjust your starting pressures/ pressure bias. Sometimes even 1 or 2 psi can make a big difference. Maybe some other track day guys have more feedback.
Hi Tamra,
We just went too big on our camber changes. Our tire wear was perfect before on the set up we were running for the last 6 months. Took a set of R888 down to slicks with no cord showing.
We did not have our tires chalked at the beginning of the day. But I did have the tires clean. We were 1" to 1.5" from the arrows.
Our static camber setting will be less than most because we have other changes that increased our camber gain and have less body roll.
After changing springs we did set our ride height back to 4.5 with 600 lbs payload in the car.
Our tire pressures started at 18f/19r. With a 2 person car and a small crowd. There wasn't any time to do much between runs. Feeling our tires between runs, they were maybe 120F. Our tire recommended temperature is 180f.
New plan is to stay with the new Caster and bump steer setting an drop the camber setting to 1.0f and 1.0R and try again next weekend somewhere.
Then a week from today we will do a track night at Putnam.
Hi Tamra,
Our static camber setting will we less than most because we have other changes that increased our camber gain and have less body roll.
If your suspension geometry changes made it so you have increased camber gain, then I think you're right and reducing your camber would be a good idea.
Have you calculated how much more camber gain you have now relative to the stock setup? For example, with us running -3.5 static in the rear with the same spring rate as you, do our car's camber curves cross each other at some point through travel (ie do you end up with more negative camber during max normal compression than we do, despite us starting with more)?
Tamra
Building 818SR #297 picked up 10/25/14 with Andrew (xxguitarist)
First start 12/21/14, First "drive" 1/17/15 First Dyno at EFI Logics 3/7/15- 310whp at 15psi for break in, full spool by ~3500rpm! First autocross 3/29/15
1st Registered 818 in Connecticut 7/24/2015. 9 months - 1 day from kit pickup!
If your suspension geometry changes made it so you have increased camber gain, then I think you're right and reducing your camber would be a good idea.
Have you calculated how much more camber gain you have now relative to the stock setup? For example, with us running -3.5 static in the rear with the same spring rate as you, do our car's camber curves cross each other at some point through travel (ie do you end up with more negative camber during max normal compression than we do, despite us starting with more)?
I haven't looked a the rear in a long time.
The front is now giving us about 1 degree per inch of upward tire travel.
I don't remember what it was before.
Maybe I should do an excel sheet to see what is going on.
Bob
Last edited by Bob_n_Cincy; 06-06-2016 at 05:29 PM.
This is my estimated miles on our 818.
Street/Road miles: 3000 Mostly drives through country and Michaels to/from high school.
Autocross Miles: 300 miles on 500 runs. Very hard miles, Full gas -- full brake-- 1.2 G turns repeat about 25 times per one minute run.
Track Miles: 800 miles, 4 track days with 3 hours on track each day. About 40-80 in turns and 80-120 on straights.
Trailer miles: about 3000 to and from autocross and track events.
Cost: 2.5 years spending a lot of time with my son: PRICELESS
Talking about trailer miles. This was our tow vehicle for the last few years:
That's an awesome tow vehicle Bob. I have no tow vehicle so am going to be very nervous when taking my 818 to the drag strip and road race courses. I could always rent a uhaul pickup and car trailer but that can get expensive.
Bob, How did the car work at Putnam Park with the revised set up?
"Track night in America" is tonight. I let you know tomorrow.
Her is what we are testing:
cold tire Pressure: 18F/19R
front springs: 350
front ride height: 5"
front caster: 4.5 deg
front camber @ RH: -1.0 deg
bump steer : 0"
front toe : 0
rear springs: 500
rear ride height 5"
rear roll steer 0
rear camber @ RH -1.5 deg
rear toe: 3/16 in
Today we went to a SCCA Track night at Putnam park.
Finally we got our handling issues under control.
With no aero, our 818 was very balances, braking was good, tire wear looked even.
Very happy with the results today.
Also, this was our first track event with the temperature around 90. Our fans didn't com on until we were off track for a few minutes. So our nose mounted radiator is working out.
We did have some issue with our data logger and videos. In this video the movie is not synced with the g force, GPS and speed data.
We are in the novice group which is passing with "point by" only in the designated zones.
Michael only gave one point by in over an hour on track. That was only to get to a place on the track with no traffic so he could open it up.
Good job Michael & Bob! Fun track isn't it I've run Putnam several times and would liked to have joined you for Track Night in America but alas the organizers do not approve of the FFR roadster's roll bars...
Good job Michael & Bob! Fun track isn't it I've run Putnam several times and would liked to have joined you for Track Night in America but alas the organizers do not approve of the FFR roadster's roll bars...
Jeff
Hi Jeff,
Yes, it is a fun track.
We are scheduled to do a 2 day Track Day there on June 25-26 with 10/10th Motorsports. So I'm not going to make it to the London Cobra show to see you get your award. Congratulations.
We put a bigger roll bar on our 818S for our own safety. Track Night in America wasn't enforcing roll bar rules as you can tell by the S2000 that was in front of us in grid.
Last edited by Bob_n_Cincy; 06-15-2016 at 10:45 AM.
... Track Night in America wasn't enforcing roll bar rules as you can tell by the S2000 that was in front of us in grid.
Actually Bob TNIA says that is OK---guess they figure that the S2K or Miata windshield frames will keep the cars off your head but my pair of 2" by .120 DOM steel bars won't. Go figure...
I've run Putnam with 10/10ths. They have a great program, some really good instructors and get you loads of track time. Have fun!
Somewhere on the internet [http://www.gcreate.com/#!factory-five-racing/ccwc] is the story on FF purchase of the 3D printer. The article stated that for showing the original car they printed the first set of lights. The article did not identify how big a part their 3DP can form, but I am under the impression it is larger than the Head Light Buckets. and smaller than the fender it attaches to.
I think the headlight bucket prototypes were 3D printed, but the final ones certainly look to be vacuum formed.
I believe, they printed out the mold for the thermal form buckets.
I have fiberglass and thermal formed buckets for the original headlights. They fit each other like a glove.
I concluded that they are using fiberglass or printed parts to create the thermal formed parts.
Bob
I got my headlight buckets a couple months ago and finally took a good close look at them. They don't fit the contour of the fender worth a darn. Does anyone know what type adhesive to use to attach them to the fenders? I'm going to do a little grinding on them to close the gaps but there just isn't enough thickness there to close the worst areas and still have a flange to glue to.
Thanks: 
Likes: 
Originally Posted by Bob_n_Cincy
Reply With Quote
I've run Putnam several times and would liked to have joined you for Track Night in America but alas the organizers do not approve of the FFR roadster's roll bars...
