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Wasn’t expecting for tracks to open so suddenly. Thought we’d at least get 3-4 weeks heads up lol. Car is going to the body shop for a month then finally I get to play with a new set of Trofeo R’s. Past few weeks I’ve just been playing with Dragy and my Mickey Thompson’s in Mexico lol...
I have a problem using my 265/30/20 Hoosier front tires on OZ 9" ET50 wheels and H&R springs... please have a look at the pics bellow.
Weird thing is I have used before Cup2 N1 (272mm wide) on OEM Wheels 9" ET51 so 1mm closer to the springs on both OEM springs and Eibach springs and I haven't seen any problem, as far as I know the Hoosiers aren't wider than Cup2 N1 so maybe the H&R springs are wider than Eibachs?! I dont know yet... but seems like that is the reason.
Now I have 2 options... either switch back to Eibachs (car will sit a bit taller and more like a daily car stance), or I will buy 245/35/20 Hoosiers R7 for the fronts. I guess 245s are the way to go, as I have seen some guys reporting to use 235s or some other combos, in the specs from Hoosiers seems the 265/30 and 245/35 run exactly the same diameter.
Any ideas what I should do? Buy new tfront tires and which ones, swithc to Eibachs or any other options
I'm actually surprised that the rim doesn't rub either. I know that with coil overs an offset of 50mm won't work. In fact you need to bring it down close to 40mm in order not to rub if you plan on using any type of aggressive camber. One simple fix is get a pair of 5mm spacers and run them when using the Hoosiers. BTW while the section width is 0.3 inch wider on the cup 2, the tread width is actually 0.1 inch narrower. Additionally the Hoosiers are 0.1 inch smaller in diameter.
Just for curiosity, other than changing springs, did you change suspension setup? camber, caster, etc.
Randy, you are right i don't think they make spacers for the CL. The other thing i found between my stock wheels vs the aftermarket was the delta between the overall width and the inner width (advertised). Typically there is a 1" variance, but when actually measuring these on the field we found that the stock wheels had a 1.105" delta vs. my aftermarket wheels which had 1.05" delta. May seem minor but that translates to almost 2mm in difference. I still think 50mm seems very tight for the front even when taking into consideration the 20" rim. For example my stock front wheels have a 173mm backspacing. So assuming a 9" wheel, with 1" extra in overall width and 50mm offset, your backspacing would be roughly 4mm inward vs. stock. I think a better offset would be around 40-45 which would allow you to keep your backspacing back to stock and still have no conflicts with your fenders.
Please remember that oem wheels (9" 50ET) worked well with Cup2 265/35/20, but aftermarket with same size and ET seem to rub.
What is different:
1. Switched eibachs for h&r
2. removed the cup2 for hoosier r7,both 265 wide (10.9" wide R7s vs 10.7"Cup2 N2)
So maybe the extra .2" or 5mm might be the problem.. or H&R springs are thicker than Eibach, seems to me lots of guys were running 265/335 Hoosier setup on oem wheels, so maybe the problem is h&r ?
My car is a 2015 TT (non S) with 245/35ZR20 Sport Cup 2’s on the front currently.
non S car here, just put on 265 ps4s’ On the front of my car. Decided to run 5mm spacers to be sure they didn’t rub given the fact the non s rims are 8.5.
1. I don’t think they would have rubbed without the spacer, but I’m actually happy to have a touch more clearance and it makes the appearance of the fronts look better in my opinion.
2. the increased sidewall height in the 265/35 has improved the ride considerably and the front tire doesn’t look so anemic
Please remember that oem wheels (9" 50ET) worked well with Cup2 265/35/20, but aftermarket with same size and ET seem to rub.
What is different:
1. Switched eibachs for h&r
2. removed the cup2 for hoosier r7,both 265 wide (10.9" wide R7s vs 10.7"Cup2 N2)
So maybe the extra .2" or 5mm might be the problem.. or H&R springs are thicker than Eibach, seems to me lots of guys were running 265/335 Hoosier setup on oem wheels, so maybe the problem is h&r ?
Probably a combination of the above mentioned.
Yes the Turbo S uses a 9" wheel vs the Turbo that comes with 8.5" wheel. The reason as to the comparison was trying to show the delta on inward spacing between the wheels. Ultimately the way Porsche design the suspension on the turbos it left very little space inward, i think this is partly due to the fact that the turbo has narrower front wheel base than an RS for example. Could be because of the axles not sure. I was very surprised about this. The wheels and tires are so close to the springs. See pic attached of stock wheel 8.5" wide 173mm backspacing. (keep in mind that i run pretty high camber with axle spacers and lower control arms shims, so its not achieved by pulling the shock in, actually the opposite. Ultimately i ran 45mm offset plus a 5mm spacer and i still didn't rub the outside stock edges (on stock trim).
At the end of the day probably best if you do field measurements before spending a dime. Then at least whichever decision you make you know it will work.
Please remember that oem wheels (9" 50ET) worked well with Cup2 265/35/20, but aftermarket with same size and ET seem to rub.
What is different:
1. Switched eibachs for h&r
2. removed the cup2 for hoosier r7,both 265 wide (10.9" wide R7s vs 10.7"Cup2 N2)
So maybe the extra .2" or 5mm might be the problem.. or H&R springs are thicker than Eibach, seems to me lots of guys were running 265/335 Hoosier setup on oem wheels, so maybe the problem is h&r ?
Just found this on an old thread by A/S. Seems to state tha the H&R are wider thus creating problems with tire sizes.
"H&R are too soft, Eibach are even softer.
KW are a little stiffer than the 991.1 GT3 RS front springs, a little softer than the RS rear springs. They also allow individual corner weight adjustments, something not available in any Porsche 991 except the GT cars. The corner weights in all the 991TT/TTS are compromised from the factory, as these cars were not intended for the track-day users. If you want a more composed and easier car to drive at the limits on a track day, you need the car corner balanced to your fuel load and driver's weight, this accounts for a significant lap time difference.
But I'm not happy with the KW because the springs are bulkier than the stock or H&R, limiting the tire sizes that can be used in the front. Also, despite of the stiffer spring rates, there are still too soft for a 991 TTS. I have a custom made spring package designed after the KW, with the calculated ideal spring rates for a 991 Turbo on Hoosiers or slicks, height adjustable, while re-using the stock shocks + DSC (DSC is needed when changing spring rates), but I haven't installed this system as I've been shopping to replace the 991.1 TTS with a 991.2 TTS (or something from a different brand).
The bushings are too soft in the 991TT, so they need to be replaced, the dynamic toe/camber changes are too big when using sticky tires.
Avoid H&R unless you just street drive the 991TT, in which case you won't get anything by switching from Eibach to H&R."
You might want to reach out to him as he ran several setups using stock shocks with different types of springs.
Thanks for sharing that! I read above that KW are bulkier than H&R, but really hope H&R are bulkier than oem/Eibach too so I can still use my 2 sets of front 265 R7s.
I will send a message to A/S thanks
Just had a great first track-day in the new car. Complete with lots of bugsplat and tire-goo. Can't wait for the next one; so its time to read all 22 pages of this thread! TIA for sharing your know-how.
Pictured - pfbz got both his cars there! - Thx for making me feel part of the CO crew.
05-19-2020, 01:11 AM
