Sensory Motorsport

05/26/2026

2 on the floor. Ready for TRAC Series round 1.

05/16/2026

Part 7 - Had the car out this week for a shake down. On Monday, got two short runs at Scotia Speedworld, thanks to Jordan Vienotte for helping us get on track. Weather did not cooperate, but we did get 2 quick runs in to help break in the new rear gear.

We then headed to AMP for a few laps after the PCA club instructors day. Got 2 runs in. Wasn't pushing the car hard, and the tires are quite old, but car felt really good. Got in the 1:12's pretty easy, but more importantly, the rear of the car felt really good. Good power down out of Turn 2, and entries felt stable, with good rotation getting back to power. Braking on the bumps was the weak point, we may try to soften the rear shocks a bit to help this ....but it shouldn't be an issue at Mosport, there are no braking bumps.

So all in all, very happy with the new rear suspension configuration. Next up is VARAC vintage festival June 19-21, CPMT (Mosport). We hope to LIVE Stream the onboard video from this to Twitch, stay tuned!

Here is some on board from the last session. Ran out of fuel after the fast lap, called it a day.

https://youtu.be/MYhnkrmUksY?si=wMzkrAy8aiTtNuet&t=402

05/15/2026

Cool video about one of our fellow racers, customer and student!

Mike with Reese Racing, and the crew head to talk with 2025 TRAC series Rookie of the Year, Adriaan Werson. This dives into his experience Sim racing, and ho...

04/30/2026

Setup day for the Vette. TRAC Series test is cancelled this weekend, but the car will be ready anyway.

04/09/2026

Rebuilding and checking 05 and 06, getting ready for May!

03/02/2026

Part 6 - A little bit of suspension geometry analysis. Just simple 2d front view analysis, that will give us some insight about camber curves and roll center heights. Found this free software from CRD Free Racing Software
Provided by Philanthropy In Motorsports: https://philanthropyim.org/free-racing-software/

I did some quick are dirty measurements of the Vette's rear suspension at full droop, just using a tape measure, ruler and plumb bob. I measured it in the pre 2010 configuration, and I know the the lower inner points get moved down 2.25" and the upper outer go up 1" to get to the post 2010 config.

Measurements taken: Height from floor and width from center of the 2 inner points and 2 outer points, link lengths and angles, height of the center of the wheel hub, and tire diameter and track width (distance between tire centerlines at the contact patch).

Refer to the first 2 images with the mock suspension....The software is an Excel spreadsheet. As the points are entered, the suspension is at full droop (called static in this software), so changing the "Chassis Dive" cell to 2" give the values at out real Ride Height or Setup Height. I also messed around with static camber values to give approx. -2deg at RH/dynamic 2". We can see for the pre 2010 config, the dynamic RC in the green box (dynamic meaning at the dive value, not static) is at 5.5" above the ground. Compared to 0" post 2010 config (as we have been running it). Not really sure why there is lateral offset to the roll center with a symmetrical suspension and no roll....so going back to the favored pre 2010 config, we will be getting a substantially raised rear roll center. This typically frees up the rear and reduces understeer. This should allow us to run more roll stiffness in the front (front bar on stiffer setting). What is more interesting is the camber curves in dive and roll.

Refer to the last 2 images with the matrix of numbers....In the PRE config camber curve for loaded (outside) tire, travelling down the straight would be 2" dive and 0 deg roll, mid corner would be 3" dive 2 deg roll. You can see that the PRE config camber stays very consistent thru this transition, losing around 0.8 deg. But in the POST config, thru the same transition we lose 1.5deg of camber. With the PRE config, there should be a few benefits - the car should be more predictable and have more rear grip, as the camber will not be fluctuating as much. We should also be able to run less static negative camber (car setup), and still achieve the desired mid corner camber (this can be inspected at the track by taking tire temps across the tread post session, or looking at tire wear). Less static camber will also give better contact patch in the brake zones.

So starting with the PRE 2010 config for 2026 season, the bump steer will be improved as discussed in earlier posts, and we can start with less static toe in. The camber curve is improved and we can start with less static negative camber. The rear roll center will be higher, so likely start with the front bar on full stiff (its been on full soft). The cars general characteristic is understeer, so the higher rear roll center should help.

02/25/2026

TECH NOTE:
Simple little tech we use on our cars - everything that has lubrication oil and is not data logged gets one of these temp stickers (or anything else where heat may be an issue). The white (or orange) grid turns black and stays black when the temp is exceeded. I love these little stickers!

They come in different ranges, and Wilwood makes them specific for brake caliper temp range.

The used one is from Vette trans at 3 Rivers - hot day and heavy downshifting track. I like to keep everything under 230oF for engine, trans and diff. Front brake calipers on Vette, also 3 Rivers track - very hot, the EBC labels are not hot enough for racing, Twoth gave us a couple with same range as Wilwood labels for race 2. I don’t run brake temp stuff at AMP, we don’t ever get enough brake temp there to worry. You really don’t want to turn the last block, seals and fluid will start to fail. 3 Rivers is very hard on brakes, I tried to be easy on them, I could have pushed a lot harder, my goal was survival. I will add more caliper cooling next time.

We also use rotor paint - 3 colors, green, orange and pink. Photo is rear rotor on Vette, green has turned (to white), tickling the orange, not into the pink. The front got into the pink. You want to turn the green to have enough temp for pads to work, you would like to avoid turning the pink fully, caliper seals and fluid will start failing. Each paint is rated at certain temps that they turn - 800, 1000, 1200oF, but really doesn’t matter if you go by my rule of thumb above.

We sell these labels, about $25 a 5 pack for the B and C labels (other option available), the Wilwoods are $90 for 10. Rotor paint kits are $165 (3 colors, cleaner and brush)

02/11/2026

Pretty cool that our very own Cole Butcher is running in the Daytona truck race!

01/28/2026

Part 5 - added the bump steer and camber curves into Motec i2 data analysis software. This is a plot of Turn 1 at 3 Rivers. Orange is the LR (loaded) wheel travel. More negative (down) is compression. Bump steer and camber are compensated for static alignment.

This is really just a visualization of what has already been discussed. pre-geo toes in in roll, post-geo toes out. You can also see the post-geo camber goes into positive camber over the bumps, pre-geo goes about flat.

This seems to support running the pre-geo setup.

01/23/2026

Part 4: Interesting day. Conclusions have been draw. Outcome was not expected.

So last night, I dug thru my old notes. I found my measurements and part drawings from last time I measured the rear suspension curves. I had no memory that the last time was 2010! lol, time flies, I thought it was maybe 5 years ago. In 2010 I did some ruff measurements and decided to lower the inner/lower link points about 2”, and raise the outer/upper links ends about an inch. The idea was to improve the bump steer. I did know it was going to reduce camber gain, but thought it would acceptable if the bump steer improved. So the changes were made. I’ll reference these suspension configs as pre 2010 geo and post 2010 geo. Looking at the basic measurement I took in 2010, I plotted them out, and based on everything up to that point, thought it may be interesting to re measure the pre 2010 geo.

So to start today at the shop, I installed the new brackets I made last night, and ran some tests over full travel of rear suspension. I also measured the camber curve at the same time. Bump steer data looked like yesterday. It’s becoming obvious there is no way to change the bump steer curve, but there are ways to change what part of the curve we are on.. The post 2010 geo camber curve has 0.7deg negative camber gain from 2 to 4” of travel, which is very low. If the chassis rolls 2 deg when you travel that far, it would almost be into positive camber (static is -1.5 ish in the rear).

So then I changed the car back to pre 2010 geo. Well well - the bump steer curve is really nice, the camber gain is 1.3 deg for 2 to 4” of travel.

We are also working on CV axles to deal with axle plunge. Post 2010 plunge is 0.35” over full travel, pre 2010 is only 0.012”! So no plunge, good camber gain and better bump steer! Doh!!! Can also removed the extended trailing arm brackets for upper link that hits the chassis fist in bump, and get more suspension travel. It won’t really move farther, as the tire hits the inner fender - but that’s a soft hit vs hard hit..

Soooooo…we have been running bad geo for 15 years! And the fix is to just put it back the way it was when it came to us in 2002. When u look at the curves below, there is a case that the post2010 geo was better bump steer when running higher rear ride heights (so in the lower part of the graph)…but at current setup, and looking at current data, pre 2010 is better.

Not the outcome I expected, but it does mean a lot less work, time and money. Cv axles were not going to be cheap.

01/23/2026

Part 3: Measured bump steer with “as ran” suspension, then mocked up the new toe link. Lots of issues cropped up. Where I mounted the outer bracket interfered with the diff cross member. And I designed the legs on the brackets bass akwards…but I was able to get them clamped on and get some bump steer data. There was a lot of flex in the system due to the fact the brackets were not able to mount securely. But I think the curves measured are in the ballpark.

See curves below. The red is as ran. Note that it toes out in bump (bump/compression is up on the graph) in the area that is most important, between the orange lines. This is the movement we see when rolling into T1 at 3 Rivers or turn 10 at AMP. The other 2 curves are with the new toe link. Blue is first setup, and I could not bump up all the way as the outer bracket hit the cross member. Purple I relocated both brackets lower so I could get more travel. Note the poor readings when the toe changes direction. That should be fixed with new bracket design that’s in the works. Note that with the link, there is not much toe out, with the blue, pretty much none, in the travel zone. This is defiantly worth pursuing. Note that static ride height is about 2”. So the low travel range, in rebound, is not that big of concern, as the tire is normally lightly loaded in this range. The travel range on the graph, and then the high compression stuff (hitting bumps when fully loaded like LR in T10 at amp - that is were we need to focus, and this looks promising.

Another issue that cropped up - the front of the trailing arm is now sliding around - it’s running out of travel, left to right. I was able to test over a decent range by using the toe link to kind of Center things up. I don’t think it will be a big issue, as the spherical bearing in there has spacers build in, they just need to be trimmed.

See pics of today’s mock ups, and tonight’s part design of new brackets for tomorrow.

More bump steer curves tomorrow in Part4 with new brackets.