L.M.P. track/race debut

[John Ross]

I'm trying to get my head around how the LMP spend most of its time in 2nd gear AND was likely being short shifted. How short is the Mid Ohio track that you couldn't get into 4th gear let alone spend a reasonable amount of time in 3rd gear? What speeds did you guys hit at the top of 2nd gear?

What tracks would be better suited to the ratios you guys ran with over the weekend?

KV

From the sound of it, Bonneville...

JR

 

[Ryan Ellis]

From the sound of it, Bonneville...

JR

Yeah pretty much! Stock gearing is made for econ mode, meaning to save gas, so the gears run very long. I could use 1st gear up to about 80mph or more. And the reason I was generally short-shifting is because the car is extremely quiet right now, and there is a lot of wind noise, + the dash/shift lights/RPM gauge wasn't working yet, so I was shifting based off of feel. We could probably hit 140+ miles an hour in 3rd gear.

As Fran or Will said (can't remember who), we had a bit of porpoising at high speed due to the front splitter bending, so I had to lift off the throttle around the start/finish line, which probably would be around 140 (+/-10/15mph)

 

[Will Campbell]

Hello to Will
Seems you got from Fran a nice new toy !!
Some questions
Are Continental tyres Radial ones ?
Is there on the car any black box to download info when coming to pits ?
Did you set up the car (aéro speaking) as the Cadillac ?

Wish you to keep the good work to improve all details you writed on the JOB list and then play again with the toy !!
( Have played with similar ones during 15 years in Sarthe! and can imagine how big is your fun LOL)

Hi Michel,

The toy is Fran's, not mine unfortunately. Though I do admit to casting covetous eyes at it.

The new tires are actually tires that were made for the Daytona Prototype cars for running at the high banks of Daytona. They are a little stiffer in the sidewall compared to the tires made for the other, less demanding tracks, but we think they are good for the speeds- and downforce- we are generating. Yes, they are radial construction as far as I know.

We have an EVO4 data logger - and dash display - from AIM that are supposed to connect seamlessly to the GM ECU. However, though we could talk to and configure the dash display and the data logger, neither one could log or display anything from the ECU. So we were essentially blind except for battery voltage and lap timing (done by the onboard GPS on the data logger). We were hoping to gather more data and begin a more formal data logging and analysis program on the LMP, but we need to get the ECU recognized first.

As to the aero setup, we are using the same body, the same splitter, and the same suspension geometry. But naturally, there are small changes. For example, we took off the small tail extensions we came with because they were fouling the wing. We'll put them back on when we re-position the wing. We aren't running the small front canards that some of the original cars had yet as we aren't sure if we need them.

We are having a lot of fun, and LMP customer cars will benefit from everything we learn.

 

[Justin]

When's the next race?

Even though you guys ran 15 laps, it sounds like you got a lot of valuable information. A big thanks to Ryan Ellis for answering our questions.

And like someone else said, we'd like to see some on board footage next time around!

 

[KevinV]

Yeah pretty much! Stock gearing is made for econ mode, meaning to save gas, so the gears run very long. I could use 1st gear up to about 80mph or more. We could probably hit 140+ miles an hour in 3rd gear

Hmmm... that is extremely odd (to me anyway)... these are my thoughts:

* Factory Z06 first gear is designed for redline 0-60 times without having to shift into 2nd gear as far as I understand it (you guys are hitting 80MPH).
* As I said before I have the same ratios (stock C6 Z06) and the same tire height and hit +/-100MPH at redline in 3rd gear (you guys are hitting 140MPH). I am pretty deep into 4th gear when I hit 140MPH
* 6th gear is definetly WAY long in a C6 Z06 for mileage purposes.

I would be somewhat suspect of the actual ratios they put in your T-case.

While I got ya... dont ya pretty much want to limit shifting to 4 gears for the most part anyway? Not sure how much there is to gain by having 6 gears and a fairly flat torque curve motor on a 140MPH track. Thats alot of downshifting in what would be a very short braking distance for the LMP.

Sorry for the thread drift... but probably not worth starting a dedicated thread and I am very curious about this.


KV

 

[Ted - LS MAN]

Hmmm... that is extremely odd (to me anyway)... these are my thoughts:

* Factory Z06 first gear is designed for redline 0-60 times without having to shift into 2nd gear as far as I understand it (you guys are hitting 80MPH).
* As I said before I have the same ratios (stock C6 Z06) and the same tire height and hit +/-100MPH at redline in 3rd gear (you guys are hitting 140MPH). I am pretty deep into 4th gear when I hit 140MPH
* 6th gear is definetly WAY long in a C6 Z06 for mileage purposes.

I would be somewhat suspect of the actual ratios they put in your T-case.

While I got ya... dont ya pretty much want to limit shifting to 4 gears for the most part anyway? Not sure how much there is to gain by having 6 gears and a fairly flat torque curve motor on a 140MPH track. Thats alot of downshifting in what would be a very short braking distance for the LMP.

Sorry for the thread drift... but probably not worth starting a dedicated thread and I am very curious about this.


KV

I would imagine they possibly had the auto trans diff, with the 2:73 gears, would explain the difference in rpm. I'm sure they will have something in the
3:40 - 3:70 range when they test again. Nice thing about this package is you can change out the complete diff by just unbolting it from the rear of trans. Not quite a quick change rear, but pretty close.

 

[Michel]

Thanks for your reply

yes it's really difficult to go forward on the setup if you do not have more info about movment of springs , movement of longitudinal postion of the car
etc etc
Your data logger for chassis info cannot be only started with an RPM signal ?
Hope you will find quickly solutions and start nice track set up sessions !!

Remember ( we experienced that with Michelin) radial tyre are very sensitive with air pressure ( start set up increase a lot in small circuits and modify track car comportment after 10 laps )

 

[ArnieSmith]

RCR LMP - YouTube

 

[ArnieSmith]

RCR LMP - YouTube

 

[Pat]

Thanks for posting the video. Do you have any more footage?

 

[john b]

I've also tried to sort out a race car without a working tach. One is constantly worried about keeping the revs way, way below redline. And if its a race car you have never driven on a track, its very difficult to trust the sound. Not much can be accomplished. With a whole new engine at risk, this no small task.

Hah! I'm not sure how Fran survived with the idea of Ryan using 1st gear coming out of different corners with no working tach!!

 

[Fran Hall RCR]

Trust and a rev limiter...wink

 

[marc]

Katech announced the LMP in their newsletter stating they are the engine supplier of the SLC LMP. They went on to say that the HP and torque were secrets, but their motors are typically front runners. I doubt it was just putting around in 1st gear. Good Luck Fran! Hope you win the rest of the year!

 

[Fran Hall RCR]

More pics

 

[Jack]

Very,very nice. Thanks Fran!

 

[Jon]

Impressive car . I look forward to seeing more from the next race.

I see some common DNA :thumbsup:

 

[Fran Hall RCR]

http://www.gt40s.com/forum/rcr-forum-rcr40-slc-p4-mkiv/37821-all-about-rcr-lmp1.html

 

[Ryan Ellis]

Hey guys, I'll be throwing some onboard video of the LMP debut up today or tomorrow. Sorry for the wait, I'm mid-exam period, and swamped with work! So stay tuned here and I'll post it when I get home!

 

[Jack]

Looking forward to the vid. Thanks Ryan.
Good luck with the exams...I know you'll do well!

 

[Ryan Ellis]

As promised!

Here is the debut of the beautiful Superlite LMP.

http://www.youtube.com/edit?ns=1&video_id=5oiFnej-vN8