laxen

Hi,

I am considering buying a new set of 18" Kerscher KRS Speedline look-alike rims for my 964T -91. After having read numerous posts on this forum, I think I'll go for 8" on 235mm tires in front and 10" on 285mm rear. The car has Bilstein HD shocks, H&R springs and will be running 964RS height. However, I am not sure what would be the optimal ET, given that I do not want to install spacers? Anybody who is running a similar setup or otherwise knows what would be a good ET? Thanks.

/Rikard

jim dorociak

Speedlines are 8 ET 52 & 10 ET 61. RH 3 piece Turbo wheels are 8 ET 52 and 10 ET 54. jdorociak@gmail.com jim

laxen

Ok, but how come there is such a big difference in rear ET between original Speedlines and RH? (there is no difference in the front).

jim dorociak

Speedline wheels use different offset that is manufactured into the centers for the front centers vs the rear centers. This means if a wheel was built using the same size inner and outer rim on both a front and rear center the rear center wheel would actually push outward about 1/4" further. The RH wheels use exact same center on the front and rear and because of that RH builds its rear wheels with 2.25" rear lip vs Speedline that uses 1.75" and the RH rear inner rim is 7.75" vs Speedline 8" inner and the Speedline uses a crush ring with a O ring to seal between the halves. When I looked at the Kerscher site because I do not speak or read German I got the feeling these were 3 piece wheels but I have never touched a Kerscher centers to know about their manufactured offset. jdorociak@gmail.com jim

V

Hey Rikard,

Jim is your man when it comes to speedline wheels.

Regarding offset and wheel sizes, I think 8.5 front and 10.5 rears are a safe bet, fits better than 8 + 10 and will give better handling with more stretch on the tires and stiffer sidewalls for better steering response etc.

So in the front you will want 8.5x18 with ET between 48 and 56.

In the rear you will want 10.5x18 with ET between 55 and 60.



Some have even fitted 9+11 but that's pushing it a bit. With 8.5+10.5 you could go 235 front and 285 rear, although 295 will probably also fit.

I sent you a PM on PCS as well. Have a nice weekend.

laxen

Jim and Viggo,
Thanks for your response, I appreciate your feedback!

I think I've changed my mind regarding rim width; I will probably go for 8.5" front (235mm) and 10.5" rear (285mm). I checked Kerschers table over different rim sizes, see last page in http://www.kerscher-tuning.de/raeder/pdf/ga-rs-18.pdf

For 8.5" in front, I assume that flat (flach) wheel centre with 1.75" outer rim and 6.75" inner rim ET 48 would fit nice? However, I'm not sure about 10.5" in the rear; what do you think would be the best fit:
1) Flat wheel centre with 2.25" outer rim and 8.25" inner rim, ET 60.
2) High wheel centre with 2.25" outer rim and 8.25" inner rim, ET 54.
3) Flat wheel centre with 2.75" outer rim and 7.75" inner rim, ET 48.
4) High wheel centre with 2.75" outer rim and 7.75" inner rim, ET 42.

I might consider rolling the fenders if necessary. Yet I'm planning to run rather low (RS-height) and want to feel safe that there will be no rubbing etc.

/Rikard

jim dorociak

I feel reasonable sure you will not get a 2.75" rear lip to fit. I would use 2.25" and what ever size inner rim that you want. If there is a lower ET center I would use that on the rear. On the front I would use a higher ET center and then use a 1.25" - that would give you the size you want, but the look of a Speedline wheel. jdorociak@gmail.com jim