Questions for those that track - McLaren Life
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post #1 of 61 Old 08-31-2015, 01:45 PM Thread Starter
 
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Questions for those that track

Hi all,

Took the car out to the track for the 1st time this weekend. Ran stock everything just to see what the car felt like (Pzeros, stock pads - iron rotors, stock alignment). This was at COTA.

I knew I'd be slower than my prepped R8V10 since I am just learning the car but was surprised at being over 10 seconds slower. When I did the track comparison between the R8 and 12C, I noted that I was WAY slower in the corners (for those that know COTA, esses and 13/14)

I am going to chalk that up to needing more grip via better tires since the throttle and brake application points seems to be about the same.

Where I was truly surprised was that in the back straight (160-165mph) the car felt extremely floaty in the front. In the R8 I'd get little nose-light as I am accelerating up to speed but it settles into a solid track to the braking zone. However the 12C felt very front light the entire run up to braking zone. Is this normal behavior at higher speeds? I kept wanting more aero up front to plant the nose some. Maybe better tires would help with stability? not sure.

Overall, there is so much capability in this car that once I learn the car some more it will easily pace my old R8 and then some but wanted to get some insight from those with more experience tracking the car on what to expect. Should I get Trofeo Rs and some carbotech brakes and call it a day?

Also, the car went into ESC fault limp home mode on Sunday as well. I was pretty much done due to some other reasons but it was frustrating getting this fault (and it kept coming on even on drive home). I am trying to figure out what caused me to throw this warning. A thought I had was that maybe my front tire was off balance (I threw off the balancing lead weights of the front left tire Saturday PM sessions. there was pretty severe shimmy in the tire at lower speed). Is this enough to cause the fault to show up? or am I looking at a more serious issue?

thanks!
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post #2 of 61 Old 08-31-2015, 02:08 PM
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As someone who's tracked both cars a LOT:

1) Change the tyres, P Zeros are just awful IMHO, even so I'm surprised at that time delta, were the PZ's worn? Pressures correct? (which as posted before could count the "floaty" feel up front at speed, uneven wear?... Trofeo R's transform the car on track. My 1st time on track in the 12C I was 15s a lap faster than my TT R8 at Spa in similar conditions and improved on that as the day went on.

2) Sounds like a boost leak... have had this issue too sadly, easy fix at the shop.
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post #3 of 61 Old 08-31-2015, 02:25 PM Thread Starter
 
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Thanks for the info! Had the tires running 33/36 hot front and rear. (Started 24/26 cold)

Should've noted the r8 ran Hoosiers w full harness setup so not a very apt comparison but was still surprised :-p

Boost leak? Ugh.
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post #4 of 61 Old 08-31-2015, 03:24 PM
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Thanks for the info! Had the tires running 33/36 hot front and rear. (Started 24/26 cold)

Should've noted the r8 ran Hoosiers w full harness setup so not a very apt comparison but was still surprised :-p

Boost leak? Ugh.
I'm not sure about the error, boost leak is known issue/problem so worth checking out.

This is the 2nd time I'm hearing of a floaty feeling on the forum. I've never had this. I've hit a touch over a 190 and haven't felt this.

I've been running PSS for a while, but even when I had the Pzero's, I just don't ever remember the front being floaty. You were in track/track mode right?
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post #5 of 61 Old 08-31-2015, 04:01 PM Thread Starter
 
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I was in sport/track mode. was in the process of trying out the sport/track few sessions before going track/track but the ESC fault curtailed my sessions before I could get to track/track mode.

do you think track/track mode would make that much difference? would be great if I could fix it with just a twist of the knob...

can't wait to go try again once I get the car fixed.

Lessons learned:
1 PZeros are garbage on the track
2 brakes are great as stock but would like a bit more bite so will change to carbotechs.
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post #6 of 61 Old 08-31-2015, 04:53 PM
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Originally Posted by jkrmit View Post
I was in sport/track mode. was in the process of trying out the sport/track few sessions before going track/track but the ESC fault curtailed my sessions before I could get to track/track mode.

do you think track/track mode would make that much difference? would be great if I could fix it with just a twist of the knob...

can't wait to go try again once I get the car fixed.

Lessons learned:
1 PZeros are garbage on the track
2 brakes are great as stock but would like a bit more bite so will change to carbotechs.
Sport/track is the right mode to be in when you're starting to feel out the car at the track. No, don't think it would have made a difference to be in track/track. Something is off. The car just doesnt ever feel float. That includes, for me, being in Normal/Track/Manual at around 185 on a crap uneven road..

Zeros are garbage, but they shouldn't induce the float. I'm not an expert, so hopefully others will chime in here, but I just don't see why the zeros would cause the float. Sure, they are plastic like in the turns and will give up grip, but I think you're talking just balls out straight, right?

What dealer did you buy from? I would have them check out the car. Car should not float.

Now that I think of this, there have been 3 mentions of this. One in another thread, then I think Lukey mentioned when he was going north of 140 in a B road he felt a bit of float, and now this. Definitely rare, but with 3 instances, I wonder if there is something in common going on here.

Bone stock the 12C generates downforce on the nose, so at the higher speeds, you should feel the car snugging down on the road. That's how it feels to me at least. Now when you lift, or if you hold a 'floaty' throttle where you're lightly maintaining the speed and maybe lifting up a touch, yea, the car could sit up on slow down, that makes sense (and why the active aero will kick up on lift). Were you lifting a bit, or was it floaty going balls out on the throttle?
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post #7 of 61 Old 08-31-2015, 04:56 PM
 
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Ugh. I'm at COTA this weekend. A little concerned about your boost leak. Did you do a pre-track inspection before going? I'd like to avoid that if possible.

Any Idea what your lap times were?
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post #8 of 61 Old 08-31-2015, 05:25 PM
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Given that the car is not damaged, the floaty feeling comes certainly from too high tire pressure. I run not more than 2,0 bar (28 psi) warm.
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post #9 of 61 Old 08-31-2015, 05:26 PM Thread Starter
 
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Hey ZP,

I will have the car looked at for sure. Was going WOT (this is in the back and front straights of COTA) so basically pedal was on the floor when I started feeling the float. Had a passenger with me and he also commented "thats a lot of movement" as we were approaching ~140-150mph. Definitely something weird going on I think.

Scott,
had the car track inspected prior to the run, no issues at all. I was running mid 2:30s this weekend before the car went into limp mode. I think the car is a mid/high 2:20 car at COTA with better tires,brakes,etc with my skill level - I'm sure others can push it faster. In the old R8 I was running 2:29-2:30s but with Hoosiers and harness. have fun this weekend! Edge guys yes?
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post #10 of 61 Old 08-31-2015, 05:30 PM
 
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Quote:
Originally Posted by jkrmit View Post
I was in sport/track mode. was in the process of trying out the sport/track few sessions before going track/track but the ESC fault curtailed my sessions before I could get to track/track mode.

do you think track/track mode would make that much difference? would be great if I could fix it with just a twist of the knob...

can't wait to go try again once I get the car fixed.

Lessons learned:
1 PZeros are garbage on the track
2 brakes are great as stock but would like a bit more bite so will change to carbotechs.
Bro, you're a track guy. Track/track is a HUGE difference, huge. Would be like me running my motons in gt2 in a street setup rather than track.

Mclaren after driving in normal mode, sport, then going to track becomes as stiff as my full track setup in gt2, bobs just like a track setup!

You need the extra effective corner support/increased spring rate under those G's and braking especially with shitty soft shouldered street tires! This is also the issue under heavy braking, McLaren stopping force far exceeds street Pirelli tire capability

You also had Hoosiers on your r8, when I went from toyo r888 r compounds to Hoosier r6's on gt2 at VIR, I shaved over 8 seconds, and we are talking r compound to almost slick (even tho r6 is still r compound) not street tire to Hoosier

You need some good tires, new alignment, more camber, fresh balance and track/track mode and you won't even believe the difference!

Sport mode is not bad, but very soft when you are use to driving 10/10's in a track setup car.
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Last edited by iLLGT2; 08-31-2015 at 05:34 PM.
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post #11 of 61 Old 08-31-2015, 05:43 PM
 
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Originally Posted by jkrmit View Post
Hey ZP,

I will have the car looked at for sure. Was going WOT (this is in the back and front straights of COTA) so basically pedal was on the floor when I started feeling the float. Had a passenger with me and he also commented "thats a lot of movement" as we were approaching ~140-150mph. Definitely something weird going on I think.

Scott,
had the car track inspected prior to the run, no issues at all. I was running mid 2:30s this weekend before the car went into limp mode. I think the car is a mid/high 2:20 car at COTA with better tires,brakes,etc with my skill level - I'm sure others can push it faster. In the old R8 I was running 2:29-2:30s but with Hoosiers and harness. have fun this weekend! Edge guys yes?
Thanks. I'm having mine inspected this week. I talked to them about the turbo pipes so hopefully that will be checked. I run 2:28's in my M3 track car and 2:33 in my M3 Daily at COTA, so it would be disappointing to not run 2:25's or better in a 12C with NT01's and track pads. Especially considering I only hit 158-59 in the E92 and some are hitting 171 in their 12C.

I've only putted around COTA in a 12C spider, but never full tilt.

The car felt ok, but COTA will always be an aero track. It makes a huge difference @ T2, T16-18.

This one coming up is a two day, so maybe I'll reconsider taking the 12C there and take it for the single day in November.

Yep, Edge! I instruct for thm so I try not to miss. I would have been to Chin Sunday but had other obligations.

How was the oil temps?
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post #12 of 61 Old 08-31-2015, 05:51 PM
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One word of advice, as at least one member here got caught up in it... The reported issue with the leaking turbo is due to a faulty clamp. If your car is diagnosed with this issue, make sure they replace the clamps on both turbos, not just the one that's leaking... If you're going to track the car a lot, odds are in your favor that if one went, the other might as well. Better to get them both fixed at once.

-Jamie.
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post #13 of 61 Old 08-31-2015, 06:39 PM
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Originally Posted by iLLGT2 View Post
Bro, you're a track guy. Track/track is a HUGE difference, huge. Would be like me running my motons in gt2 in a street setup rather than track.
After reading iLLGT2's erudite explanation, maybe the float you feel is from not being in track mode.

I guess it depends on what you mean by float. I feel the suspension working a good bit in sport mode, really compliant evening out the rough, at those speeds, but I don't feel that the nose is getting light, it's planted.

There's no doubt the car is a GOOD bit tighter in track mode, so it may come down to just that and subjective preference on how the suspension feels at those speeds; that and maybe some tire pressure adjustment. Would definitely give that a go as easiest potential solution.
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post #14 of 61 Old 09-01-2015, 01:01 AM Thread Starter
 
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Scott. Temps were high but not bad. I did short shift through some corners (4-6) (13-14) but nothing dramatic. Hope you can make nov w chin. Would be great to get some pointers.


Jamie. Thanks for the advice. Will make sure the dealer address both clamps if that is the issue.


ZP, I intend to move to more track capable tires next go around but will see if track/track and slightly lower pressure help w the float. The front did not feel planted at all at WOT so I definitely need to change things around.

Anyone want some heavily used crap PZeros? :-D
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post #15 of 61 Old 09-01-2015, 02:35 AM
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Sport/track has lots of nanies on, that could be one of the reasons you get faults. Also you will fry your rear breaks. You know costa really well, you should always go on track/track even in warmup lap.
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