05/05/08 Traction Circle Track Day

[Shaun]

Re: 05/05/08 Traction Circle Track Day

MT, please recheck your numbers. At typical lat. accel of around 1G (not looking at spikes) at that driven radius, the apex speeds at T4 are in the 75-80 km/h range. If you are claiming 130km/h apex speeds you're looking at 2.6-2.9 G lateral depending on line and which method of calculation you use. This is not possible for an Evo 9 GSR stock. It is more than twice impossible.

Others may also want to check their numbers. Generally a street car cannot accelerat/decelerate more than 1.2 G long or lat wise and that is being generous.

There's a 700 SGD basic data logger available that will show you the undeniable numbers. Mark Ong the TCC guy sells it. It is very easy to use and is accurate.

==

High downforce lightweight open wheelers can decelerate at peaks of anywhere from 4.5-5.7 G, upper end being F1 so really are in a class of their own. Hard to compare to most other racecars, much less street cars.

 

[centurion]

Re: 05/05/08 Traction Circle Track Day

MT, please recheck your numbers. At typical lat. accel of around 1G (not looking at spikes) at that driven radius, the apex speeds at T4 are in the 75-80 km/h range.

Edited .. yeah I was wondering about the ridiculousness of car vs f1 ... turned out I misread 130m with 130kmh .... lol. My garmin mapsource crashed so I can't access the gps track data for M3 and Evo so I'm taking your 80km/h as law .... LOL ... about the speed of a satria GTi IIRC ...

 

[Shaun]

Re: 05/05/08 Traction Circle Track Day

Yes that's much more realistic.

Incidentally, most cars brake around the 120-130 mark for T4. To brake at the 50m mark from 189 km/h would require average deceleration across the entire brake period of at least 1.4 - 2.0 G . This 1.4 - 2.0 range covers from the most generous to most likely, ignoring the worst half scenario, giving as much benefit of doubt to Wilson. On top of this the assumed corner speed yields 1.5G lateral. If you knock it down to a much more realistic but still optimistic 1.1G, then the braking event gets even wilder... up to 2.25 G average!

1.4 - 2.25 G average during entire brake event is some serious braking more typical of cars like light downforce GT cars on slicks (~1.5 ) up to Formula Renault and Atlantic with more downforce (2+).

For reference, a Lotus on semi slicks might do around 0.8G braking average from 125m. The average is lower than the peak of around 1G because of the time required to transfer load and use maximum braking force. This time is typical of all street cars.. the way they're sprung and have their suspension designed, and is why rolling on the brakes is faster vs slamming them, especially in a car without ABS, or with slow ABS.

There is also the matter of not just making it through the turn, but making the lowest segment times ie. nicely through the turn. On a wide track like SIC you can go late on the brakes and still make a turn, but at a compromise.

==

This isn't far out theory either. It can be very easily backed up with real life measurement. The numbers don't lie. In fact, that was the other reason I was hoping you'd not bail on the 30th May trackday dear MT...wanted to add Cayman to my log database. Your log could teach me how to drive like he-man with all the smooth heel toes and tail hanging out you do Anyone else want their car logged? FOC including analysis!

 

[centurion]

Re: 05/05/08 Traction Circle Track Day

In fact, that was the other reason I was hoping you'd not bail on the 30th May trackday dear MT...wanted to add Cayman to my log database. Your log could teach me how to drive like he-man with all the smooth heel toes and tail hanging out you do Anyone else want their car logged? FOC including analysis!

I think a good driver with the Cayman 2.7 will probably achieve something like 2:40 thereabouts on a good set of tyres. A driver revelling in 5-4-3-2 DD&HT will probably do 3:05 or something crappy like that. I've never driven in SIC in the Cayman before but my time has no reason to be any good. You can't hang out the Cayman's tail as much as you can a Miata, for example, just not built for that being an MR. The only transponder timed I've done was in a satria GTi in the low 3-minutes ... haha ...

if you don't mind you can go up to Sepang on the 29th, there will be a RSR and a few Cup cars there, and lots of GT3 and probably a lot of 993 and 964 also. Mok WS, Darryl O'young and Marchy Lee will be there giving taxi rides in the race cars. I'll probably be tracking the cayman for the first time that day and I'll log the pathetic performance. In fact, I'll log the RSR and the Cup car for you too, provided I can just put it into a waist pouch.

 

[wilman2772]

Re: 05/05/08 Traction Circle Track Day

This thread is to show nice pictures for tcss......dun get too technical leh......

Relack lah......


'The Great White'

 

[centurion]

Re: 05/05/08 Traction Circle Track Day

This thread is to show nice pictures for tcss......dun get too technical leh......

Relack lah......


'The Great White'

sorry bro, sorry.

 

[iScoupe]

Re: 05/05/08 Traction Circle Track Day

This thread is to show nice pictures for tcss......dun get too technical leh......

Relack lah......


'The Great White'

hahahaha...................................

 

[Shaun]

Re: 05/05/08 Traction Circle Track Day

You can't hang out the Cayman's tail as much as you can a Miata, for example, just not built for that being an MR.

I was only going off what you said before.. I don't care if FRs do it better..

No it can't ride in a pouch and needs cig lighter for power. Needs about 2 min setup time too. So all that plus the fact that it is a charity event with official taxi rides will mean they're running way below limit, probably not even on the good fresh tires, and it's not considerate to take others time up with the setup time, low as it may be. Thanks though.

29th is a PCS charity event?

 

[R33Devil]

Re: 05/05/08 Traction Circle Track Day

I
29th is a PCS charity event?

Sunkist REBORN!!!

 

[centurion]

Re: 05/05/08 Traction Circle Track Day

err ... what's sunkist reborn?

 

[R33Devil]

Re: 05/05/08 Traction Circle Track Day

err ... what's sunkist reborn?

Shaun will wear a Sunkist Orange Jumpsuit and run ard in the pits

 

[Shaun]

Re: 05/05/08 Traction Circle Track Day

oh you going on the 29th too? In that case I really don't mind going up a day early. Will she by AIMed by then? Lemme check whether Ivan minds driving up alone on the 30th.. last check had him possibly too busy to take leave even...

 

[SHAMELESS]

Re: 05/05/08 Traction Circle Track Day

technical stuff makes me sick......i just wanna see pictures and drive my mad bmw in sepang.....

more pics wilson..............hee

let the rest argue abt braking...and G forces!!!!

 

[Shaun]

Re: 05/05/08 Traction Circle Track Day

the photos are definitely nice, but what's really sick is a completely wild, outright lie

separately, have you heard about the 9 second discount?

 

[wilman2772]

Re: 05/05/08 Traction Circle Track Day

the photos are definitely nice, but what's really sick is a completely wild, outright lie

separately, have you heard about the 9 second discount?

Wat are you taliking about??

Please elaborate!

'The Great White'

 

[Shaun]

Re: 05/05/08 Traction Circle Track Day

It's just a general question after being reminded by this recent T4 braking issue.

Across a few years, different locals claimed..

- a bone stock 1.4 ton FWD 2.0 NA streetcar on stock tires could do 1:52 at PG (guy will never turn up at SIC somehow because he knows there are transponders. Never been any sort of proof to the claim)
- a SIC lap of 2:45 when in fact the lap was a 2:54 (huge 9 second discount - guy is part of BMWsg, but may have forgotten his previous lie. Sometimes people can convince themselves a lie is right)
- a 46 second go kart track lap when the track record in kart one tier higher was 48 seconds (guy used to be a part of BMWsg till he was called out on this by more than one person)

==

But on this thread I just wanted to mention that 2G really isn't possible, and leave it at that. I don't want to discuss the separate issues here and sidetrack your good photo thread any more than it has already. If anything I'd start a separate thread in a different section. 2008 has been a pretty clean year for me so far and I'd like to keep it like that if possible.

I'm sure many people would be interested in seeing what the GTR can do at SIC in good hands, so if you're interested you could get a logger from Mark Ong and then share the numbers, or if you want I can a box up in your car. I'm curious myself to see the distribution of strengths in a low 30s capable car of unusual parameters. Whatever it is, it's still a fantastic car like I've said in a few other threads.

Peace

 

[R33Devil]

Re: 05/05/08 Traction Circle Track Day

PUBLIC ENEMY NUMBER ONE

It's just a general question after being reminded by this recent T4 braking issue.

Across a few years, different locals claimed..

- a bone stock 1.4 ton FWD 2.0 NA streetcar on stock tires could do 1:52 at PG (guy will never turn up at SIC somehow because he knows there are transponders. Never been any sort of proof to the claim)
- a SIC lap of 2:45 when in fact the lap was a 2:54 (huge 9 second discount - guy is part of BMWsg, but may have forgotten his previous lie. Sometimes people can convince themselves a lie is right)
- a 46 second go kart track lap when the track record in kart one tier higher was 48 seconds (guy used to be a part of BMWsg till he was called out on this by more than one person)

==

But on this thread I just wanted to mention that 2G really isn't possible, and leave it at that. I don't want to discuss the separate issues here and sidetrack your good photo thread any more than it has already. If anything I'd start a separate thread in a different section. 2008 has been a pretty clean year for me so far and I'd like to keep it like that if possible.

I'm sure many people would be interested in seeing what the GTR can do at SIC in good hands, so if you're interested you could get a logger from Mark Ong and then share the numbers, or if you want I can a box up in your car. I'm curious myself to see the distribution of strengths in a low 30s capable car of unusual parameters. Whatever it is, it's still a fantastic car like I've said in a few other threads.

Peace

 

[Rastaman]

Re: 05/05/08 Traction Circle Track Day

Anyone else want their car logged? FOC including analysis!

Me Pls !!!

 

[TripleM]

Re: 05/05/08 Traction Circle Track Day

Tok kok lah you.......

At least I get to test the GTR solid solid.....2nd round of testing will be this 30th Track day.....by then the Mine's ECU will be installed & maybe exhaust & RE070 tires also.....

I'll hunt down alot of cars......slurp........kekekekekeke


'The Great White'

Ah...if I hear complains bout aggressive GTR, that is you then....

 

[wilman2772]

Re: 05/05/08 Traction Circle Track Day

Ah...if I hear complains bout aggressive GTR, that is you then....

Dun worri Dun worri....I wun......relack driving ok......kekekeke

'The Great White'