Heres a one lap around PBIR under the lights from last night. Car did great just have to get the brakes cooled as I was babying them the entire night as to not overheat the pads. Easy to do on a 4k LBS car even with full race endurance pads.

 

Looks great....top speed 141 MPH...that's moving.

From my racing point of view....you can go deeper into the turns....looks like your braking way to early.

Otherwise....great telemetry. Nice data. This should provide a good source for improving the driving skills and techniques.

Thanks for posting.

 

The deeper he goes into the turns, the more he will be working those brakes he is trying to keep cool.

A full ceramic set-up on this car would be something else...

 

Hello MaximA great! Video, thanks. I am considering PBIR or Daytona, overall how much track time do you actually get for your money. And how many are allowed on the track at one time. I would be starting at the beginner level. Thanks for any input, love to try this!!!

 

Unfortunately that is part of tracking a car, eating up brake pads. If he were to dig a little deeper going into the turns he will undoubtedly increase track times. And using the power to weight ratios of the car entering and going thru the apex'es will also increase track times. It just takes lots of practice.

 

Open track days are a blast. They do however have a tendency to really eat up tires and brakes, so be prepared.

 

It's not just eating the pads. It's overheating them, and getting fade as a result. The former is merely annoying. The latter can be dangerous.

 

You should display the Tachometer values. What gear shifting mode were you using? From the sounds of the engine pickup it sounds like you could do more shifting to stay closer to the top RPM range where most of the engine power is. Feels like too much RPM drop exiting out of the corners. But, can not tell for sure unless seeing the RPMs.

 

I totally agree with you and appreciate the critique. Feel free to give me more Its been 10 years since I've been racing and before it was mostly autocross and a few track days and schools at some of the major tracks.

I was much more conservative on the brakes this time at PBIR last time I completely fried the stock brakes. So I've been careful the last two track days on brakes until I'm sure I'm not going to totally fry my rotors in one session. I also want to find the right pad compound and may need to go to a hotter front and rear pad. I noticed some overheating with the rear pads but the fronts looked good, but then again I can get much more aggressive with the braking

The Pagid RS29s are great pads but at Homestead they overheated a bit and left material on the rotors, so I had some vibration after the second session. I may have gone in to aggressive at the start and not let them come up to temperature properly but excess material eventually wore off after a few days of street driving. I have to say the Alcons are incredible brakes, I don't know why Jag stopped offering them, they should be standard on all XKR/S.

So back to Homestead next Sunday and I think I'll go up to a higher temp compound in the front, but unfortunately nothing other than the EBC yellows are available for the rear. Trust me those don't hold up to track use on a 4000 LBS car.

As far as the telemetry I went with the Racelogic System that the Jaguar R Advanced Academy uses. It does a great job recording your session but also comes with a "Circuit Tools" which is great for reviewing your sessions and even comparing laps side by side. I also purchased the Vbox OLED which gives you real time lap deltas in the car. Which is great as you try different lines, braking points etc while on the track. So far I've been very happy with it and review the data after each session then make adjustments, it makes it really easy to see where you need to improve. Its amazing how you think you did one thing and the video shows another.

Heres a snapshot of the tool, which I'm sure is similar to a few other products on the market.

 

Man what I wouldnt do for some ceramic rotors on this car.. Thats what this car really needs. Unfortunately they run around 20K for the factory ceramic brakes.

 

For that data I need the CAN attachment for the VBOX which I have not ordered yet. On this track I was in third most of the time, and could have dropped into second exiting a few corners. My goal this time was to get the line down, and be as smooth as possible. Next time I'll get a bit more aggressive and keep the car higher in the rev band.

Next week at Homestead I'll be much more aggressive and push the car as I know that track fairly well.

I'm taking it slowly as unlike a P car there isnt a group of guys with Jags at the track to talk to so I'm figuring the car out as I go.

So feel free to give me feedback, its welcome and appreciated.

 

My suggestion to you after attending different tracks and with different clubs in the area is to attend either hooked on driving to get started. They will set you up with an instructor for the first day to teach you the track and the fundamentals. I know a few of the instructors and they are great guys, I have a blast running with them. You will get 4 on track sessions of 30 minutes each which is plenty to start with. HOD has a A, B, C, and D group with A being novice and D being dedicated race cars. I typically run in C and I have plenty of time on the track and its usually a hour between your sessions.

Once you get a little more experience start attending Chin Motorsports events. They have track days all over the country and are awesome! Lots of great drivers and cars but definitely a more advanced group, although they have a novice class as well. They run three groups and you get a bit more track time and more of a variety of tracks i.e. Sebring, Road Atlanta, VIR.

PBOC Florida is another great club to run with although I have not yet had the opportunity to track with them, I've met a few of the guys who do and can definitely see myself attending their events.

As far as tracks, PBIR is ok but nothing special its just to a small and gets to be a bit boring. If I were you Daytona or Homestead would be the way to go but you have to find the club that is running on a date you are available.

Let me know if you have any other questions or plan on attending any of the events, it be nice to see another jag out there!

 

Sounds good. By staying at the higher RPM ranges you not only getting more power down to the ground but you get much tighter handling. While I have not tracked my XKR I would guess that ideally you would never want to drop below 4500 RPM on the track. So, keep shifting it to stay between 4500-6500. Depending on the tranny ratios, perhaps it is more like 5000-6500. Most close ratio race car transmissions would have less than 1000 RPM drop between gears to you are operating within a 1000 PRM range.

 

Thank you Albert, I will give that a try at Homestead next week.

 

Whatever happened to the tune? I am anxious to come down there and get it done but have been waiting for your updates.

 

Max:

One other point. I would go back and review your dyno results/chart. On the dyno results chart, it will provide what your top HP was at a certain RPM level.

I would try to enter and exit the turns using that data from the dyno chart.

In other words you may be reaching maxium horsepower at say 6500-7000 RPM. If you can keep the RPM in that dyno range especially when exiting the turns, it will create a "launch" type effect to the car entering either the next straight or turn. You will be at maxium power, and not having to push the peddle hard for exceleration. Thus, in order to achieve the maxium HP at top RPM level you will have to use a lower gear ratio to achieve this.

When I ran/raced my Formula F1000, my maxium efficiency of the engine was at around 10,000 to 11,000 RPM's. After that level the power of the engine began to fall off. My F1000 engine had the ability to go as high as 13,000 to 13,500 RPMs.

I am sure the dyno chart will provide a peak performance level in conjuction with a RPM level. We will find that most engines have an upward chart, then peaks in HP, then drops off even at higher RPM's.

Hope this helps and you understand what I am saying.

 

Max,

I found I had to be pretty careful when applying power to the rears in corners to avoid loss of grip, and the resulting intervening of traction control. When that was turned off TC didn't engage but you still had to be careful with your right foot. I also found the E-Throttle's response too exaggerated in Sport mode, making smooth throttle application at the limits of grip quite touchy. Easy solution to improve grip was to apex corners at the lower rpm of a higher gear, and let torque build with rpm as you're unwinding the wheel and the tires can handle it. The engine has so much torque you just can't use it all...or if you can it means you're going waaay to slow in the corners

Bruce

 

Max:

I went back and pulled my Dyno sheet on my Formula F1000 when I had the engine pulled and refreshed. The chart shows max HP @ 177 @ about 12,250 RPM's. This is what you would be looking for on your dyno chart.

Although my engine would handle 13,000 to 13,500 RPMs, I set my rev limiter to 12,500 as that was all I needed to maximize the full value of the engine.

Even though the engine pulled 177HP, I was able to acheive top speeds in the 140 to 147 MPH range. It was a thrilling ride in an open wheel Formula car at that speed.

I would bet your dyno shows max HP in the 6500-7000 range or near that mark. I am not sure what your red line is at on your 5.0L XKR, especially after your tune.

 

I'm waiting for dyno day and will report back on where I am with the tune. Soon as I have a date I'll let you guys know ASAP

 

My dyno results are below but this was right after the tune so I'm not sure where I am right now, but looking at the stock tune its pretty close as far as RPMs. So looking at that I need to be in the 5200-6300 range. For some reason that sounds brutal for that car.. One thing that cause me to shift so early and stay out of the high revs is the massive amount of torque it has starting from 3300 RPM. I'm going to practice keeping it higher in the rev band this weekend.

I'm about 3 seconds off the really fast guys, and I'm losing it in braking and corners. Homestead is the track I know best as of late, so if there is anywhere I can change my technique this is the place.

Brake cooling is still the major issue, they work great when they get up to temp(2-3 laps) but then you can feel the pads over heat and leave material on the rotors. Then I get a shutter which goes away after 50 miles of street driving.. I never get any fade as I'm using Pagid race fluid thats good to ~630 degrees(yes it compatible with street systems). Once I get the shutter you can feel the brake characteristics change and braking distances increase. The thing that surprises me is I'm not even in the ABS at all, so I'm wondering if some of the cars electronics are kicking in although I have them all turned off. If I could just brake later I'd make up a lot of that time.