MK5 Golf GTI
All Things Mk5 => Modifications & Technical Area => Track Day Technical => Topic started by: fuscobal on August 18, 2010, 07:30:21 am
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Until now I've been on Nurburgring and Hungaroring with 235/35/19 and F1 asymmetric. As I felt there's too little grip for the power this car makes and the sidewall for this tire is too small for the track, I decided to go with 8x18" rims and semislicks. So the sidewall heights are as follows :
- 235/35/19 > 82.042mm > min 8" rim - current wheel
- 225/40/18 > 89.916mm > min 7.5" rim > R888 weight is 10.45kg
- 235/40/18 > 93.98mm > min 8" rim > R888 weight is 11.35kg
So, the question is, would I benefit more from the extra grip and sidewall from 235 or from the lower weight of 225 ?
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The main thing is the tread width and with those two tyres you actually get an extra 20mm of width from the 235 section tyres over the 225 section (244mm v 224mm) and the tread width is actually less than on the 225 section 17" tyre (231mm). I know as it was one of my reasonings for going for 17" alloys over 18" :happy2:
On the 225 x 17's I had all the grip I needed at the 'Ring. I reckon dropping to a 8.5 x 17" alloy you could go balls out and fit 255 (265mm tread width :party:) section tyres. The smaller rim would be lighter and make up for the heavier tyre (12kg). You may struggle with clearance though if you haven't got camber mounts :wink:
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17" would be the cheapest option as I already got the OEM 17" so I'd only need tires. The problem is, with the S3 front brakes, the caliper sits only 2-3mm away from the rim and I'm afraid the brakes won't cool efficiently ! What rim and tire sizes would you put on my car after all Hurdy ?
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17" would be the cheapest option as I already got the OEM 17" so I'd only need tires. The problem is, with the S3 front brakes, the caliper sits only 2-3mm away from the rim and I'm afraid the brakes won't cool efficiently ! What rim and tire sizes would you put on my car after all Hurdy ?
I don't think it would affect the cooling in a major way as the cooling comes from the hub side of the disc, meaning the center of the disc and then flows outwards. :smiley:
Look at F1 cars and other top racing cars they also drive 17" and max size brakes
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17" would be the cheapest option as I already got the OEM 17" so I'd only need tires. The problem is, with the S3 front brakes, the caliper sits only 2-3mm away from the rim and I'm afraid the brakes won't cool efficiently ! What rim and tire sizes would you put on my car after all Hurdy ?
I don't think it would affect the cooling in a major way as the cooling comes from the hub side of the disc, meaning the center of the disc and then flows outwards. :smiley:
Look at F1 cars and other top racing cars they also drive 17" and max size brakes
^^^^This^^^^^ :happy2:
If you have coilovers already, then I'd go for camber mounts and run 8.5 x 17 wheels with 255x35x17 R888's on track.
For normal road use I'd stick with 8x17 or 8x18 and run normal 225 section tyres.
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Isn't 255 too wide for this car ? If I stick with 17" I'd use the OEM rims wich are 7.5x17. This rim doesn't allow more than 235 unfortunately ! I have PSS10. What camber mont would mate with this coilover ?
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Isn't 255 too wide for this car ? If I stick with 17" I'd use the OEM rims wich are 7.5x17. This rim doesn't allow more than 235 unfortunately ! I have PSS10. What camber mont would mate with this coilover ?
I have some camber mounts that I bought that would fit my PSS10's but haven't fitted them. They are KW spec and still fit the Bilsteins. I'll dig them out tomorrow and find out the exact kit number :happy2: There are a couple of GTI's in the USA running 255 section tyres for track use and both say they have no scrub and use a coilover/top mount camber adjustment set-up.
Hmm, if you are wanting to use the OEM wheels then I recommend sticking with the 225 section rubber :smiley:
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Thanks Hurdy. Yes, OEm wheels are 7.5" so they don't take more than 225. Anyway, with the 235 I have now on my 19" the wheel is perfectly aligned with the fender/arch because I only have about -1 negative chamber. If I want to go 245 or 255 I will certainly need more negative chamber. How much camber do you aim at the track ?
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Fuscobal, i have a set of KW camber top mounts that i won't need as i find i have enough negative camber with the T&T mk " lower control arms. Spring inner diameter for these is 61mm and outer diameter is 81mm. Smaller than the stock diameter springs. PM me if you are interested :drinking:
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Danish, will they work with B16/PSS10 ? I will try to measure the springs when I get the chance. I've talked to Toyo and for the weigth of my car they've recommended going with 33 PSI cold pressure and max. 38 PSI while hot. The ideal thread temperature is between 71C and 105C with a recommended maximum difference between inside, middle and outside of the thread of 15C !
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Danish, will they work with B16/PSS10 ? I will try to measure the springs when I get the chance. I've talked to Toyo and for the weigth of my car they've recommended going with 33 PSI cold pressure and max. 38 PSI while hot. The ideal thread temperature is between 71C and 105C with a recommended maximum difference between inside, middle and outside of the thread of 15C !
I have a friend with same coilovers as you, i'm trying to get him to measure his :happy2:
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Ok, thanks Danish. I will measure the damaged front springs I've just replaced. After 3 years with PSS10, one spring was 3cm shorter (1.2") !!!!!! Roads are really bad here. With the new springs installed my PSS10 came to life again. What are the differences between the OEM camber plate and the aftermarket adjustable ones in terms of noise, comfort under normal road driving... ?
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Inside diameter > 82mm
Outside diameter > 105mm
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Inside diameter > 82mm
Outside diameter > 105mm
you will need to make new plates for the springs to rest on i'm afraid :sad1:
Looks like st. spring diameter to me
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Well, if the B16 springs go on the OEM plates it would seem logical to me for them to have the same upper diameter as stock ! From what I see, there are several choices on the market like K-mac, H2sport and K-sport (these are made for their own coils but seem to also work with others). K-mac goes for about 500$ while H2sport are half that (i don't know why this big difference). TT lower arms in my country are about 750 Euro (1000$) including ball joints, bolts, bushings... The 2 options :
1) Camber plates > will pull the upper part of the damper towards the interior of the car, creating more negative camber and more room for the wheel to go well under the fender/arch, especially if the wheel is much wider than stock. From what I've read the ride with those + coilovers is harsher than only coilovers
2) TT arms > will pull the lower part of the damper towards the exterior of the car, creating more negative camber and a wider track between the front wheels but will not help much with the wheel going under the fender/arch. The ride is same as with the OEm arms so these have an advantage on bad roads
Those said above represent my logic and may be innacurate. Can anyone comment on them ?
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Well, if the B16 springs go on the OEM plates it would seem logical to me for them to have the same upper diameter as stock ! From what I see, there are several choices on the market like K-mac, H2sport and K-sport (these are made for their own coils but seem to also work with others). K-mac goes for about 500$ while H2sport are half that (i don't know why this big difference). TT lower arms in my country are about 750 Euro (1000$) including ball joints, bolts, bushings... The 2 options :
1) Camber plates > will pull the upper part of the damper towards the interior of the car, creating more negative camber and more room for the wheel to go well under the fender/arch, especially if the wheel is much wider than stock. From what I've read the ride with those + coilovers is harsher than only coilovers
2) TT arms > will pull the lower part of the damper towards the exterior of the car, creating more negative camber and a wider track between the front wheels but will not help much with the wheel going under the fender/arch. The ride is same as with the OEm arms so these have an advantage on bad roads
Those said above represent my logic and may be innacurate. Can anyone comment on them ?
you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi715.photobucket.com%2Falbums%2Fww160%2Fjakethemoss%2FTT_lower_control_arms.jpg&hash=3365f0211369dbf0c8fa7559728214c372a3cf66)
:smiley:
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Very good articles. Just found on youtube the video of a guy with an STI WR1 with 317HP/432NM and just 1330KG. The car surpassed just about every car at Hungaroring (including me and some M3, GT3 RS...) and made a lap time of 2'07" on Michelin Cup 24/64x18 slicks > . The time is absolutely phenomenal for a street car considering that on the same day (09.08.2010), the fastest lap was made by a Leon WTCC > 2'05" !
24/64x18 is approx. equivalent to 245/40/18 !
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you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi715.photobucket.com%2Falbums%2Fww160%2Fjakethemoss%2FTT_lower_control_arms.jpg&hash=3365f0211369dbf0c8fa7559728214c372a3cf66)
:smiley:
....Do you have a link to that American forum thread, Jake? :happy2:
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you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi715.photobucket.com%2Falbums%2Fww160%2Fjakethemoss%2FTT_lower_control_arms.jpg&hash=3365f0211369dbf0c8fa7559728214c372a3cf66)
:smiley:
....Do you have a link to that American forum thread, Jake? :happy2:
i have looked, but so far without luck, i'll keep searching though RR :smiley:
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that guy in the BMW at first is well and truly shocking behind the wheel.
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I looked again at R888 recommendations > http://www.toyomotorsport.eu/tiredetail.php?tireconcept_id=20&id=3 and I've seen now that a 7.5x17" (OEM rim) would take 235/45/17 at the limit. They say :
- permitted rims : 7.5" - 9"
- measuring rim : 8"
I don't know exactly what they mean by "measuring rim". Is this the recommended rim width ? Is there any risk in running a 235 on my 7.5" wide rim if the car is so heavy ? (1700kg)
If there's no problem, it would be the cheapest option as I only need the tires and don't have to buy rims as well !
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I looked again at R888 recommendations > http://www.toyomotorsport.eu/tiredetail.php?tireconcept_id=20&id=3 and I've seen now that a 7.5x17" (OEM rim) would take 235/45/17 at the limit. They say :
- permitted rims : 7.5" - 9"
- measuring rim : 8"
I don't know exactly what they mean by "measuring rim". Is this the recommended rim width ? Is there any risk in running a 235 on my 7.5" wide rim if the car is so heavy ? (1700kg)
If there's no problem, it would be the cheapest option as I only need the tires and don't have to buy rims as well !
I run my semi slick tyres which are 225 on a 7.5 rim with no problems, that includes a trip to the ring, so i think you would be fine with 235. :happy2:
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That's what I want to know...if going from 225 to 235 would be a problem. I've also run 235 street tires on 7.5" on the street but that can't compare to track use ! If there's any chance of the tire failing or going off the rim, I'd stay with 225 !
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^^^^
Depending on how low slung your suspension is set up, wouldn't you have to possibly make some adjustments to stop 235 tyres rubbing?
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Stick with the 225's on a 7.5 x 17 rim :happy2:
My Team dynamics Pro race 1.2's were 8" wide and on 225's and still looked very chunky on the alloy rim (see pic below). No danger of scrubbing and you can get on with the job at hand on track.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s001.jpg&hash=32005b0d328e730da0d6e78f0af2ffb0d082c40d)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s005.jpg&hash=a7a33e56ab8f8b1c6bc462e13053d3600a305fdf)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s009.jpg&hash=3207fd3f436987cbe98895f8e5ff178d60543b3e)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s.jpg&hash=24b9f8ce4d8b57fb071d3656435220d6c8ce9cf6)
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I will stay with 225 then. My camber is currently lower than -1 wich is not that great. If I'll have the money, I will probably install the TT lower arms. Hurdy, in the pics it looks like you have a lot of negative camber. How did you get that much ?
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That may just be the fact that the car was parked on an angle at the time I took the pics. The car is lowered and running Bilstein PSS10's and that is all that could affect camber.
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I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber and the 225/45/17 Kumho V70a. The improvement was of 11secs/lap wich is huge !!!
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I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber and the 225/45/17 Kumho V70a. The improvement was of 11secs/lap wich is huge !!!
Am i getting confused. I thought that the TT arms only give an extra 0.5 degree of camber. :chicken: 2.3 sounds like the morego jobbies.
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I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber
Am i getting confused. I thought that the TT arms only give an extra 0.5 degree of camber. :chicken: 2.3 sounds like the morego jobbies.
....Perhaps his car starts off with -1.8 degrees and the TT arms add the 0.5 extra to give -2.3 :confused:
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Your car gains more camber the lower it goes, so you're just adding to that variable.
I've got to say I wouldn't go more than 235 on a MKV, strange as it sounds, you don't want too much grip. The more grip you have, the more force you put on components not designed to take it causing failures, wheel bearings, bushes etc etc.
Also, the more grip you have, the faster you are - the faster you are, the quicker a barrier comes at you when you run out of talent! An example of this is pretty much every UK TDO (track day organiser) won't let you run full slicks without a MSA reg'd cage, 1 piece seats and harnesses.
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My camber was about -0.55 with OEM arms for the same lowering so the increse was much motre than 0.5deg (more like 1.2deg). Here's some movies :
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Here's some movies :
....Am I right in spotting that you weren't wearing a helmet? :surprised:
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Nope, wasn't wearing a helmet although I had it with me. Most drivers didn't use it. This track is not as dangerous as Nurburgring. I've seen no serious accident since I'm going there !
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I looked again at R888 recommendations > http://www.toyomotorsport.eu/tiredetail.php?tireconcept_id=20&id=3 and I've seen now that a 7.5x17" (OEM rim) would take 235/45/17 at the limit. They say :
- permitted rims : 7.5" - 9"
- measuring rim : 8"
I don't know exactly what they mean by "measuring rim". Is this the recommended rim width ? Is there any risk in running a 235 on my 7.5" wide rim if the car is so heavy ? (1700kg)
If there's no problem, it would be the cheapest option as I only need the tires and don't have to buy rims as well !
''Measuring'' is the rim they did the measurings on shown in thar table. Some specs may differ on another width rim.
Stick with the 225's on a 7.5 x 17 rim :happy2:
My Team dynamics Pro race 1.2's were 8" wide and on 225's and still looked very chunky on the alloy rim (see pic below). No danger of scrubbing and you can get on with the job at hand on track.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s001.jpg&hash=32005b0d328e730da0d6e78f0af2ffb0d082c40d)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Ft8%2Fhurdy_album%2FNewTeamDynamicsandR888s005.jpg&hash=a7a33e56ab8f8b1c6bc462e13053d3600a305fdf)
Regard the team dynamis is ET35, isn't it?
My camber was about -0.55 with OEM arms for the same lowering so the increse was much motre than 0.5deg (more like 1.2deg). Here's some movies :
Dont't get confused:
- 0.55° is NOT 0°55' !! 60' = 1° in europe. 100' = 1° in US.
You should have 0°55' (55 minutes), so almost - 1° with oem arms an Bilstein B16.
Your car gains more camber the lower it goes, so you're just adding to that variable.
I've got to say I wouldn't go more than 235 on a MKV, strange as it sounds, you don't want too much grip. The more grip you have, the more force you put on components not designed to take it causing failures, wheel bearings, bushes etc etc.
Also, the more grip you have, the faster you are - the faster you are, the quicker a barrier comes at you when you run out of talent! An example of this is pretty much every UK TDO (track day organiser) won't let you run full slicks without a MSA reg'd cage, 1 piece seats and harnesses.
:happy2:
@ all: Remember that all track tyres are wider than road types.
With 235/40 track tyres you'll get problems with the wheel arch fenders cos they in real these tyres are more than 240 mm wide.
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My camber was about -0.55 with OEM arms for the same lowering so the increse was much motre than 0.5deg (more like 1.2deg). Here's some movies :
Dont't get confused:
- 0.55° is NOT 0°55' !! 60' = 1° in europe. 100' = 1° in US.
You should have 0°55' (55 minutes), so almost - 1° with oem arms an Bilstein B16.
Yes, I know, it's a hexagesimal system. By -0.55 I meant 55' out of 60' wich would equal 1deg so I should have written :
- 0deg55' with OEM arms + B16
- 2deg30' with TT arms + B16