Building a 2008 HR based track car
07-20-2016, 10:22 AM
#61
New Member
Thread Starter
Oh, thanks, that's really helpful. I was getting lost with all these tire types, brands, sizez....
Still hard to find the right sizes though. Did I make a mistake going with 9,5" and 10,5"? I'm beginning to think so looking at a poor choice of tires in my country!
595 RSR - no sizes
r888 - pretty hard to get in the right sizes 255 and 275
RA1 - not available here
Pirelli trofeo R - extremely hard to get here
Pilot sport cup 2 - are these really semislicks?
Ventus TD z221 - not available here
So it looks like the only choice I have for semislicks is between r888 and psc2.
Looks like I will actually have a better choice if I go wit hfull slicks but for that I'd need to cage up!
Still hard to find the right sizes though. Did I make a mistake going with 9,5" and 10,5"? I'm beginning to think so looking at a poor choice of tires in my country!
595 RSR - no sizes
r888 - pretty hard to get in the right sizes 255 and 275
RA1 - not available here
Pirelli trofeo R - extremely hard to get here
Pilot sport cup 2 - are these really semislicks?
Ventus TD z221 - not available here
So it looks like the only choice I have for semislicks is between r888 and psc2.
Looks like I will actually have a better choice if I go wit hfull slicks but for that I'd need to cage up!
Last edited by GodISmE; 07-20-2016 at 11:04 AM.
07-21-2016, 11:14 AM
#63
New Member
Thread Starter
One thing I still don't get though - why extactly would 265/35 front and 285/30 rear would be bad if ESP and TC were switched off? What is the reason? Everyone keeps saying no but no one is saying why?
The only thing that comes to my mind is ABS and EBD and how they might be affected if the proportion between front and rear size is outside of tolerance set in those systems. Yes, no?
And then there is a matter of handling of course if the profile in the rear is too low. Is this what you mean?
PS. the tire thread of -7 mm is only reflected in the %
The only thing that comes to my mind is ABS and EBD and how they might be affected if the proportion between front and rear size is outside of tolerance set in those systems. Yes, no?
And then there is a matter of handling of course if the profile in the rear is too low. Is this what you mean?
PS. the tire thread of -7 mm is only reflected in the %
Last edited by GodISmE; 07-21-2016 at 01:33 PM.
07-21-2016, 12:45 PM
#64
You cant really ever truly turn the systems off without pulling the abs fuse or installing a power interrupt switch. The ABS could act up since its always going to think its got some sort of slip which could cause issues.
How much? Not sure, 3/10ths of an inch diameter smaller on the rear might not seem much, but when its expecting to see the rears be roughly an inch bigger, well you get the idea.
How much? Not sure, 3/10ths of an inch diameter smaller on the rear might not seem much, but when its expecting to see the rears be roughly an inch bigger, well you get the idea.
07-22-2016, 09:34 AM
#65
New Member
Thread Starter
Ok, I have a plan: a couple of slightly used 255/35 r888 for front and brand new 265/35 Avon ZZR for rear - they are supposed to be the size of other manufacturers' 275
07-26-2016, 07:27 AM
#66
General & DIY Moderator
MY350Z.COM
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Not a optimum combination IMHO. Anytime you mix two different tire models--from different manufacturers no less--than the coefficient of friction differences make for less than predictable vehicle handling. Not the kind of "wild card" factor that helps when you're trying to understand what a car is doing at the racetrack.
07-26-2016, 08:48 AM
#67
New Member
Thread Starter
Both are medium compound and have a very similar thread, they'll be ok and I will probably not even notice a difference. Anyway, I'll let you know next week 
I'm installing more mods now but not everything yet: enkei wheels and above tires, ss braided lines, new rotors, hotchkis sway bars (medium front, soft rear), differential bushings, esp killswitch, adjustable front upper arms.
Question: will I be able to adjust camber at the the rear on stock suspension?
I'm installing more mods now but not everything yet: enkei wheels and above tires, ss braided lines, new rotors, hotchkis sway bars (medium front, soft rear), differential bushings, esp killswitch, adjustable front upper arms.
Question: will I be able to adjust camber at the the rear on stock suspension?
07-26-2016, 10:20 PM
#69
New Member
Thread Starter
Another track day behind me! Hungaroring this time Pics soon.
How do you guys lower your cars on these Enkei 18" 9,5 / 10,5 with 15ET?! They stick 2cm out on each side!
I had a problem with clutch (stock one) in the last two rounds - the pedal stayed on the floor (loosing pressure) after 10-15mins. of driving. It was back to normal by the time I came back to the pit stops and after one or two cooling laps. I had to finish sessions earlier because of that and drive cooling laps in one gear only. What could it be - fluid boiling, slave cylinder?
Pics soon.How do you guys lower your cars on these Enkei 18" 9,5 / 10,5 with 15ET?! They stick 2cm out on each side!
I had a problem with clutch (stock one) in the last two rounds - the pedal stayed on the floor (loosing pressure) after 10-15mins. of driving. It was back to normal by the time I came back to the pit stops and after one or two cooling laps. I had to finish sessions earlier because of that and drive cooling laps in one gear only. What could it be - fluid boiling, slave cylinder?
Last edited by GodISmE; 08-01-2016 at 03:51 AM.
08-01-2016, 03:49 AM
#70
Another track day behind me! Hungaroring this time Pics soon.
How do you guys lower your cars on these Enkei 18" 9,5 / 10,5 with 15ET?! They stick 2cm out on each side!
I had a problem with clutch (stock one) in the last two rounds - the pedal stayed on the floor (loosing pressure) after 10-15mins. of driving. It was back to normal by the time I came back to the car park and after one or two cooling laps. I had to finish sessions earlier because of that and drive cooling laps in one gear only. What could it be - fluid boiling, slave cylinder?
Pics soon.How do you guys lower your cars on these Enkei 18" 9,5 / 10,5 with 15ET?! They stick 2cm out on each side!
I had a problem with clutch (stock one) in the last two rounds - the pedal stayed on the floor (loosing pressure) after 10-15mins. of driving. It was back to normal by the time I came back to the car park and after one or two cooling laps. I had to finish sessions earlier because of that and drive cooling laps in one gear only. What could it be - fluid boiling, slave cylinder?
Clutch issues; Definitely check your system for leaks as the first step. Are you using the OEM fluid? If so, upgrade to something that will resist the heat a little bit better. You can also swap out the factory clutch line for a stainless steel unit that will help with pedal feel - but that won't solve the overheating issue. Also check to make sure the line isn't close to your exhaust (shouldn't be an issue on a relatively stock car).
Matt
08-02-2016, 09:03 AM
#73
New Member
Thread Starter
Clip from Hungaroring Hotchkis bars were set to the stiffest possible settings (front second stiffest, rear stiffest) - wondering now if that slight snap oversteer at 13:12 was because of the rear being to stiff? Camber -2 / -1.5, toe -0.05 / 0.10.
Next mods will be coilovers, bucket seat + harness... and a new master cylinder!
I should start thinking about adding some more power now becasue even with ESP & TC completely off I didn't lose traction even once ... or is it this stock VLSD - I think it is.
Also, 3.5 in HR is too long for a track. I will do a few more track days this year for sure, including Nordschleife, so hopefully it will be enough for me to decide between 3.9 and 4.08 FD.
Removing cats would be the first choice for HR, right? Should I go with long headers like OBX or with sperate headers and downpipes? Which option will give me more power and tourqe at the lower rpm's?
Hotchkis bars were set to the stiffest possible settings (front second stiffest, rear stiffest) - wondering now if that slight snap oversteer at 13:12 was because of the rear being to stiff? Camber -2 / -1.5, toe -0.05 / 0.10.Next mods will be coilovers, bucket seat + harness... and a new master cylinder!
I should start thinking about adding some more power now becasue even with ESP & TC completely off I didn't lose traction even once ... or is it this stock VLSD - I think it is.Also, 3.5 in HR is too long for a track. I will do a few more track days this year for sure, including Nordschleife, so hopefully it will be enough for me to decide between 3.9 and 4.08 FD.
Removing cats would be the first choice for HR, right? Should I go with long headers like OBX or with sperate headers and downpipes? Which option will give me more power and tourqe at the lower rpm's?
Last edited by GodISmE; 09-06-2016 at 10:35 AM.
09-06-2016, 09:35 AM
#75
New Member
Thread Starter
Another track day last weekend. This time a very short and a rather slow track. My wheel allignment was totally screwed up 
When I went to pick my car up the day before the event, they told me at the shop that they could not set it up because the car was too low. WTF? I only lowered it by 2 cm after installing the coilovers!
Anyway, do I need rear camber arms to get rid of that huge negative camber at the rear?
When I went to pick my car up the day before the event, they told me at the shop that they could not set it up because the car was too low. WTF? I only lowered it by 2 cm after installing the coilovers! Anyway, do I need rear camber arms to get rid of that huge negative camber at the rear?
Last edited by GodISmE; 09-06-2016 at 09:40 AM.
