JDMac's Autocross

Joined
Apr 3, 2019
Messages
185
Reaction score
154
Analyzing run videos is one of the best ways to get faster. I think part of the issue is the open differential. That will make it harder to put the power down in the sweepers. Also, what rear gears do you have in the car?

The issue the V6 faces is that it's hard to keep the car in the power and hard to dig out of slow elements. That's where rear gears, an aluminum driveshaft and an aluminum flywheel provide big benefits. Without them, it can be hard to keep the revs up. The solution is to feed throttle in early, but that can lead to losing grip with an open differential. It's a delicate balance. But finding that balance will improve your autocross skills. The other solution is to put in a Traction-Lok differential.

Do you think you could've replaced the braking at 0:32-0:34 with a partial lift? It's always hard to judge a course from a video, so I could be wrong. When I drive my V6 I have to remind myself to eliminate braking more than in my GT. Braking, then having to accelerate back up to speed really hurts in a V6. I tend to lift a little and let my 3.55 rear gears slow me down, shifting weight forward ahead of my turn. That allows me to get right back in the gas after the turn.

The shimmy could've been the rear end getting some traction back. It's hard to tell.
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Analyzing run videos is one of the best ways to get faster. I think part of the issue is the open differential. That will make it harder to put the power down in the sweepers. Also, what rear gears do you have in the car?

The issue the V6 faces is that it's hard to keep the car in the power and hard to dig out of slow elements. That's where rear gears, an aluminum driveshaft and an aluminum flywheel provide big benefits. Without them, it can be hard to keep the revs up. The solution is to feed throttle in early, but that can lead to losing grip with an open differential. It's a delicate balance. But finding that balance will improve your autocross skills. The other solution is to put in a Traction-Lok differential.

Do you think you could've replaced the braking at 0:32-0:34 with a partial lift? It's always hard to judge a course from a video, so I could be wrong. When I drive my V6 I have to remind myself to eliminate braking more than in my GT. Braking, then having to accelerate back up to speed really hurts in a V6. I tend to lift a little and let my 3.55 rear gears slow me down, shifting weight forward ahead of my turn. That allows me to get right back in the gas after the turn.

The shimmy could've been the rear end getting some traction back. It's hard to tell.

I have the factory 7.5" axle with 3.27 gears that the car came with. I've been debating on either adding a limited-slip carrier to my existing 7.5" axle or getting an 8.8" axle out of a wrecked GT with limited-slip from the factory. After doing a little math, I think that somewhere between 3.55 and 3.73 would be the ideal gear ratio for my clubs if I were to regear.

The section before that had some serious exit speed leading up to a sharp turn. I would have had to let off the throttle very early in order to lose enough speed and don't think it would have been faster.

As always, thanks for your input!
 
Last edited:
Joined
Apr 3, 2019
Messages
185
Reaction score
154
I hope that the input is helping. And I appreciate you sharing your videos. The car looks great out on course!

Because the V6 doesn't have a lot of low-end torque, rear gears are an important upgrade. The decision between 3.55 and 3.73 rear gears should be made on a case-by-case basis depending on the length/speeds of your local courses. 3.55 is generally a safe choice, given the factory redline for the V6.

I recently looked into having a 7.5" rear end rebuilt with a new limited-slip diff and rear gears, and it ended up being about the same cost as finding an 8.8" rear end and having the diff rebuilt and 3.55 rear gears installed. If you check out MPS Auto Salvage in GA, they usually have 99-04 rear ends listed on Ebay. You can get them at LKQ for less, but I rarely see V8 Mustangs at my local LKQs. The 8.8" rear end can take more power (not really an issue with our V6 cars) and it allows you to use quad-shocks (which I prefer to use on SRA cars).
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
This has been a big week for CAM class in my region...

My buddy with the 1996 Camaro that I typically battle with sold his car and bought his dream car, a C6 Corvette Z06. It is currently stock but he already ordered enough parts to take him out of A-Street and put him into CAM-S. He said that he is going to start in CAM-S so that he could roll the points into the rest of the season. Right after he posted that on Facebook, another guy who is also a good driver posted how he just bought a C5 Z06. Then somebody that I haven't met before posted that he was going to show up to the next event with his 2015 Camaro Z/28!

The bar for our CAM class has been raised! I know that I can still be competitive with my 200hp car, but I (should) have some pretty serious competition!
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
As expected, CAM class definitely stepped up since the last event.

MBR Event 4 Track.jpg

The course was very fast with a lot of big sweepers. I started by working the course inside the loop and saw many people struggling to come off the bank and enter the loop without spinning out. It felt like your run would be determined by how well you could enter the loop and make it around the cone at the bottom of the loop. I'm not saying that the rest of the course was too easy or that you couldn't mess it up, but the consequences of a bad line weren't as severe.

I started off the morning session poorly. The turn to enter the loop really messed with me. I couldn't figure out how to slow down and make it through the gates in a smooth motion. I was giving the car a little brake and steering input to make it through the first gate, but the second would come up on me and I'd have to apply more brake with the wheel turned. This upset the car and caused me to get runs in the low 42s. I knew that there was a better way to do that, but couldn't figure it out.

I worked the afternoon session and started my session by riding with my friend/rival in his C6 Z06 who was running mid-40s in the morning session. He had a little different method for getting around the track, and I liked most of it. I was able to link those two gates together and was much more smooth with that corner. So smooth that I shaved 1.5 seconds off my time! I had a couple of 40.6 runs and then a 40.7 run. I played with a little trail braking on those runs to help the car rotate, but it didn't help my time. On my very last run, I pushed the car hard and ended up getting a 40.280 run.


With my car being in CAM-T, I had a larger handicap when compared to the CAM-S guys. I got whooped by the Z28 guy (who was insanely fast) but wasn't far off from everybody else in CAM when comparing raw times. I ended up getting 3rd in CAM after PAX was considered. It doesn't feel right bragging about PAX time, but I've also been battling with my buddy since I started racing and it feels great to finally beat him.

MBR Event 4 Results.JPG

My plan is to look over the car and ensure everything is good for next weekend where it will be a 2-driver car for a 2-day event. Should be a lot of fun!
 
Joined
Apr 3, 2019
Messages
185
Reaction score
154
Nice driving! Your inputs looked really smooth out on course. Courses like the ones you run on are really challenging for a Mustang with low torque, an open diff and 3.27 rear gears. But you are keeping the car composed while getting back on the throttle early. And, based on your times, you are making good driving/line adjustments on your runs. I always enjoy seeing what a V6 Mustang can do up against V8 cars! I'm looking forward to hearing how both drivers do at the next event!
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Nice driving! Your inputs looked really smooth out on course. Courses like the ones you run on are really challenging for a Mustang with low torque, an open diff and 3.27 rear gears. But you are keeping the car composed while getting back on the throttle early. And, based on your times, you are making good driving/line adjustments on your runs. I always enjoy seeing what a V6 Mustang can do up against V8 cars! I'm looking forward to hearing how both drivers do at the next event!
Thanks! It sounds like my co-driver has been dominating the KC region rallycross events in his stock 2003ish Focus. I'm not sure how quickly he will be able to learn my car, but he is a good driver for sure. It should be a lot of fun!
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Now that was a fun weekend! We beat the snot out of my car but it handled it great. The course was on an old Air Force base and super fast. I was initially worried that I would struggle with slow acceleration with how fast the course was, but I was able to carry a lot more speed through the elements than expected. We ran the course one way on Saturday and ran it backward on Sunday.

Saturday started off slow. We were both learning the course and seeing where we could and couldn't push the car. This was the first time I used my car as a 2-driver. It heated up much quicker than expected. I was surprised we didn't have any issues with the engine temp. The needle never moved farther than usual and (I think) my UltraGauge never showed above 223F. My brakes handled the heat great. Absolutely no issues with power steering fluid. My tires did really well. Because of the huge lateral g-load from the big sweepers and fast elements, I had to raise the pressure a lot more; from 34/31 psi to 39/36 psi. We made it through the morning session without a problem, but we found the temperature limit for the Falken 660s in the afternoon. Luckily I anticipated something getting hot so I brought my water sprayer. A quick spray of water between the last couple of runs and the tires were much more predictable.

The morning session started with a 58 run but we eventually got down to consistent low 54s and 53.9s. The afternoon session seemed to be a curse to us and we were struggling to hit mid 54s, so we were very excited when I was finally able to break it with my 53.862 run. There were a lot of fast cars there, and this put us in the middle of the pack.


Sunday's course was very similar but had a couple of changes to allow for running it backward. We kept the same settings as the day before and we just focused on driving. My main goal was to carry more speed through elements. This can be heard by how much I was on the rev-limiter!

It started sprinkling towards the end of the morning session; luckily I had my best run of 51.777 right after it started. The afternoon session was bad because we were trying to push the car too hard and struggled to get anything better than a 53.


Unfortunately, we had to cut the afternoon session a couple of runs short. My co-driver was pulling out of grid and we heard a loud pop from somewhere in the front end. He said that he felt it in the steering wheel, so I called it a day for the car. It was already making a weird rubbing noise from the rear of the car. I didn't think that it was worth breaking the car worse and possibly crashing and ending on a much worse note. The car felt fine as I put it back on the trailer. I'm planning on doing a bolt check and inspecting the car this week so that it's ready to go for next weekend.
 
Last edited:
Joined
Apr 3, 2019
Messages
185
Reaction score
154
Great job on both days! It's been fun to see how your level of attack has increased this season. Your inputs are really smooth, and you're clearly capitalizing on looking ahead and looking your way through elements. Your aggression is consistent through the runs, and the fact that you improved your times with a passenger in the car is awesome (V6 Mustangs don't like added weight). I hope nothing major is wrong with the car. I'm looking forward to your next post!
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Luckily (or unluckily?) I couldn't find anything wrong with the car other than the exhaust hanger. I put both hangers back on the car and used a cowboy's zip tie (fence wire) to keep them from falling off. I like the way my Flowmaster exhaust sounds, love the way it looks, but can't say I'm impressed by the fitment and quality of parts like exhaust hangers.

IMG_6038.jpg

I looked over the front end and steering components and didn't see anything wrong. The ball joints looked like they had plenty of grease in them, but I added more just in case.

While I had it up in the air I added the Steeda 35mm sway bar that I ordered last week. Just screwing around in a big empty parking lot, the car felt like it wanted to oversteer more than before. I've had my front shocks set a little softer than the rear to fight oversteer, but don't think I'll need as much now. I set my shocks to full soft and it felt much more balanced than before.

IMG_6042.jpg

I'll be using my car as a daily driver this week, or until my F-150 gets back from the dealership. My plan for this car has always been to keep it a very "street-able" car and avoid turning it into a "race" car. I'm glad that I went with adjustable shocks and reclining seats and that I kept the radio, AC, sound deadening, and so on!
 

white95

Apex Junky
Admin
Joined
Dec 30, 2007
Messages
18,313
Reaction score
5,209
Location
Prairieville, LA
I'll be using my car as a daily driver this week, or until my F-150 gets back from the dealership. My plan for this car has always been to keep it a very "street-able" car and avoid turning it into a "race" car. I'm glad that I went with adjustable shocks and reclining seats and that I kept the radio, AC, sound deadening, and so on!

Take it from someone who has no AC, aggressively valved dampers and no sound deadening….

It sucks :p
 
Joined
Apr 3, 2019
Messages
185
Reaction score
154
Adding a larger front sway bar will add understeer to the car (and reduce oversteer as a tendency of the car). If you are running an OEM 24mm rear sway bar, my experience tells me that you will have too much front sway bar. I run a 35mm front sway bar on my SRA Fox Body with an OEM rear sway bar AND a Steeda adjustable rear sway bar. I ran the same setup on my 2000 GT before the IRS swap. Because the Steeda adjustable rear sway bar is discontinued, the advice I give to people is to run a 25mm rear sway bar, THEN determine if you need a larger front sway bar.

A V6 with an OEM GT 24mm rear sway bar should be pretty neutral (especially if your shocks & struts and alignment are set correctly). Your oversteer tendency is probably due to the open diff and when you are getting back on the power (which has to be early in a V6). Essentially, your setup is at odds with how you have to attack the course (but you are doing a really good job of driving around that issue). The question is: Are you moving the overall limit of traction of the car further IN or further OUT by adding the larger front sway bar? My advice would be to come up with a plan for adjustments you'll make based on how the car feels on each run prior to your next event, so you can dial in the car at the event.

Forgive me if I've recommended this video to you already, but proper adjustments make a huge difference in how these cars handle...

 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Forgive me if I've recommended this video to you already, but proper adjustments make a huge difference in how these cars handle...
I don't think that you have recommended this video yet, but it was the first one I went to when I initially installed and set up my adjustable shocks.

I remembered that section of the video where you mentioned that a bigger front bar could add understeer to the car. Like I mentioned earlier, I've only played with it in a big parking lot and a little bit on the street (where safe); I do like the feeling of the car now better than before. I have an event this weekend that I don't NEED to do well at. If I don't like the new sway bar then I can easily swap it back before the next.
 
Joined
Apr 3, 2019
Messages
185
Reaction score
154
I don't think that you have recommended this video yet, but it was the first one I went to when I initially installed and set up my adjustable shocks.

I remembered that section of the video where you mentioned that a bigger front bar could add understeer to the car. Like I mentioned earlier, I've only played with it in a big parking lot and a little bit on the street (where safe); I do like the feeling of the car now better than before. I have an event this weekend that I don't NEED to do well at. If I don't like the new sway bar then I can easily swap it back before the next.
I'm a big proponent of experimenting and testing, so it's worth seeing how your car feels with the larger front sway bar. If you have access to a larger rear sway bar to test, I would try that too (without the larger front bar). When I help people set up their suspension, I always make sure they (safely) test different mods to feel firsthand how they impact the handling of their car. Testing at an event will be ideal.

Moving the limit of traction is a tricky thing. This example doesn't exactly pertain to your situation, but it's one I use to illustrate my point. A Mustang that is super-low, with stiffer springs, stiff shocks & struts and huge sway bars will "feel" great under normal driving conditions (on smooth roads). But the limit of traction of that car will be really far IN. If you push that car on an autocross course, it will have a tendency to understeer and oversteer (a lot).

My autocross cars don't feel as "present" when driving normally on the street. But they feel incredibly responsive out on course. If I adjusted them to feel better on the street, there would be less "attack" in the cars on course and less composure at the limit.

It's also worth considering the diversity of your courses when dialing in your car. If the larger front sway bar requires you to run the front struts at full-soft, there's no room to adjust (up front) for understeer on those tight, sweeper-heavy courses you run on. Looking at your videos, I would run a "short course" setting (softer up front) on the oval courses, and my regular setting at the Air Force base. You always want to have room to adjust to the course.

Dialing in the car can be frustrating, but it's my favorite part of building an autocross car. I'm looking forward to seeing the videos from your next event and hearing how the car responds to your adjustments!
 
OP
OP
JDMac34

JDMac34

New Member
Joined
Apr 11, 2022
Messages
37
Reaction score
31
Location
NE Ohio
Saturday was a good time! There were two other cars in CAM-T; a built 1988 IROC Camaro and a 1996 Camaro SS with basic mods. I've raced with the IROC before and he had me by a second on a longer course. The surface we were running on wasn't the best. There was a lot of loose gravel in spots, a couple of big bumps, and a few transitions between asphalt and concrete. The course was fun.

Because of my new sway bar, I started the day with all of my shocks set evenly. Because my Koni shocks don't have notches or clicks, I just refer to half of a turn from full soft as a click. The fronts have 5 available clicks and the rears have 4.5. This course seemed fast and without many tight elements, but I wanted to have room to adjust both ways so I started with both sets of shocks at 3. My last event really took a toll on the outside edge of my front tires. I swapped the fronts with the backs and decided to run a little extra air than I normally do with 37psi front and 34psi rear. The car felt very unpredictable during the first run. It would have grip then suddenly lose it without warning. I pushed through the big sweeper at the end and had to go on the wrong side of that last cone for a DNF. I blamed most of the mistakes on the gravel, softened the front shocks a click (now 2/3), and went back out there. The next run was much better but still had the tendency to snap loose without warning. I softened all corners another click (now 1/2). This seemed to be the winning setting because it was much easier to ride the line of traction. My 4th run ended up being my fastest with a 45.300. I pushed a little through the last corner, but I'm pretty sure that's because I cranked the wheel under braking. My 2 runs after that were okay, but I was trying too many things that didn't result in a better time.


They haven't posted the detailed results yet, but I won CAM-T! I believe that the other cars were close to each other in the low 46s.

As for the bigger front sway bar, I'm not sure yet. With how much gravel was on that pavement, I don't think that it was a fair assessment. I know that the car felt more planted and responsive in the parking lot and on the street. I wish that I would have tried taking one more click out of the front shocks for testing. I'll do another parking lot test later and decide if I think that it's worth switching back to the 29mm sway bar or not.
 
Joined
Apr 3, 2019
Messages
185
Reaction score
154
Congrats on getting 1st in CAM-T! The run looked very smooth. It's always hard to be 100% sure from a video, but it looks like you could be faster out of some of the elements (0:09 to 0:12 & 0:23 to 0:26). I also think there was more time to be found in the last sweeper with a smoother steering input; maybe entering a little wider to prevent the front from losing grip when exiting. A slightly different line there might have allowed you to get on the throttle earlier. Watch the video while the experience behind the wheel is still fresh and see if there was a way to be faster out of the sweepers. You did a really good job of being early and attacking the open spaces. You were also able to capitalize on adjustments at one event, which isn't easy (it's like driving a different car on each run).

When it comes to adjustments: You changed tire pressure based on the course conditions (which is understandable), but that does impact the handling characteristics of the car. Ideally, to test whether the sway bar is helping or hurting, you would keep every other adjustment the same as your last event.

Thanks again for continuing to update this thread and for showing people what a 3.8L Mustang can do on an autocross course!
 

Latest posts

Forum statistics

Threads
75,930
Messages
1,467,947
Members
13,999
Latest member
Aaronh007

Members online

Top