Offset for compbrake ?

[Big Bob]

Hi

I cant remember what offset is required for 15inch wheels to get over the comp brake kits does anyone know off the top of thier head and what is the standard offest.

Regards

 

[Fletcher]

Et43 speedline 2118s fit over them, if thin balancing weights are used. The palmer spec 2118s ( I can't remember what et they're don't) they fowl the cailpers.

 

[Big Bob]

Et43 speedline 2118s fit over them, if thin balancing weights are used. The palmer spec 2118s ( I can't remember what et they're don't) they fowl the cailpers.

Do you know the standard et ?

 

[Fletcher]

172 cup is ET38 IIRC.

 

[Big Bob]

cheers for that fletch

is the offset still the same when using turini's in 15" (et43) ?

 

[Keith185]

Palmer Spec 2118's are ET 43, normal spec ones are ET 38

 

[Dan]

You can also get cup racer spec with ET 48.5

 

[Big Bob]

You can also get cup racer spec with ET 48.5

Nice 1 this sounds like a plan an extra 5mm spacing sounds good and the slightly wider track will be an additional benifit

 

[MG cup]

Nice 1 this sounds like a plan an extra 5mm spacing sounds good and the slightly wider track will be an additional benifit

ET48.5 will sit further in the arches than ET38. Speedline won't sell you ET48.5 wheels off the shelf as that's a run of wheels they made for the European cup racer championships.

 

[mikekean]

Im not actually sure UK spec cup racers did have ET38 wheels you know. I have one and i swear the ET43 version sits further out than the ones that came with the car. Never measured it but my ET43's rub more.

 

[EVOgone]

UK cup racers used ET 43 and Euro one used ET48. Palmer sport used Euro bits so most likely ET48.

ET38 where not used and cup racers.

 

[Chip-mk1]

Bare in mind that not all wheel profiles are internally the same, so just cause one et43 wheel fits doesnt mean another will just cause they are the same diameter and same ET, the shape of the spokes where they join the main rim of the wheel varies a LOT from different wheels.

 

[mikekean]

Are you sure? Id be more inclined to say UK cars used ET48 as well. If you look at the depth of the spoke on the ET43 wheels they are much deeper (heavier) than the ones fitted on the UK cars and when compared to the wheels on the Euro cars look identical. I dont see why they would have changed the offset for the UK cars.

 

[MG cup]

Im not actually sure UK spec cup racers did have ET38 wheels you know. I have one and i swear the ET43 version sits further out than the ones that came with the car. Never measured it but my ET43's rub more.

I wasn't saying that the UK cars run ET38 I was explaining to the OP the differences that an offset would make. All I know is European wheels are ET48.5 and have speedline embossed into the face where as the original fit UK cars didn't. Pretty sure there lighter too, definitely lighter than 2118's that can be bought off the shelf currently.

 

[MG cup]

Are you sure? Id be more inclined to say UK cars used ET48 as well. If you look at the depth of the spoke on the ET43 wheels they are much deeper (heavier) than the ones fitted on the UK cars and when compared to the wheels on the Euro cars look identical. I dont see why they would have changed the offset for the UK cars.

evo1 and 2 (UK cars, derived from ph1 172's) and evo 3 and 4 which was the last evolution of the car iirc and run in Germany im sure, they barely shared any parts except the base components i.e gearbox, block, shell. Hubs, brakes, axles, engines, etc etc were al, upgraded so its a mixed bag tbh.

Yours has an STSDA fitted right Mike which makes it one of the first cup racers made were ph1's and then face lifted.

 

[mikekean]

Wasn't aimed at you anyway mate. All I was saying is that the wheels that came with my UK spec car appear to sit further In than ET43 wheels which could possibly mean a higher offset. Could just be an illusion though.

 

[Big Bob]

Want the wheel to sit away from the car and run a slightly wider track

So standard ET= ?????

and 2118 ET required to clear compbrake kit = ?????

and turini ET required to clear compbrake kit = ????


please fill in if your sure

thanks

 

[MG cup]

Well ET37 2118's will be the lowest offset you can buy and give you the widest track so go for them. If any of the offsets its these that will clear.

You want cup turinis again as there the lowest offset at ET38 iirc.

Like Chip has said, its not as simple as saying this offset clears. Internal design is wheel specific. Numerous people have compbrake/will wood calipers with both them wheels you want, have a look through some projects.

 

[EVOgone]

Are you sure? Id be more inclined to say UK cars used ET48 as well. If you look at the depth of the spoke on the ET43 wheels they are much deeper (heavier) than the ones fitted on the UK cars and when compared to the wheels on the Euro cars look identical. I dont see why they would have changed the offset for the UK cars.

Yes Euro car run 5mm deeper offset to accomodate the 5mm extra track of the rear hubs and keep the same rear track.

All my Cup racer wheels at ET43 and Euro cars i have seen for sale the wheels are ET48

 

[mikekean]

Yes Euro car run 5mm deeper offset to accomodate the 5mm extra track of the rear hubs and keep the same rear track.

All my Cup racer wheels at ET43 and Euro cars i have seen for sale the wheels are ET48

Fair enough, ive never been able to find any markings to confirm offset on them which is why I wasnt sure. All i know is the new ones i bought weight a tonne compared to the ones that came on the car!

 

[EVOgone]

interesting everyone i have weight was 7.5kg same as a williams speedline

 

[mikekean]

Yep thats what the ones that came with the car are like. But the ones you can get from speedline now are much heavier more like 9kg each, the spokes are much deeper and thicker and the inner edge of the rim is also much thicker. Its as if the ones on the cup racers were specially made for them by speedline to be much lighter. I could do with picking up another 4 proper cup racer ones to complete my set if you know of any.

 

[Dan]

7.2Kg for the ET48.5 cup racer 2118s

 

[Dan]

Yes, both sets of phase one (blue decals) & my set of phase two (embossed) cup series rims all weigh pretty much dead on 7.2kg. As you say they're ET48.5, have a different spoke depth and no ET stampings.

My palmersport/whatever that speedline currently sell with the ET stamping on them weighed around9.4kg yes.


wheelweight.net or whatever it was had them listed as:
2020 : 15x7/Cast Mg/7.39355612kg
2118 Racing 2000 : 15x7/Cast/9.61615888kg

& for reference
2120 Turini : 16x7 /Cast/8.93577028kg
OZ Racing F1 : 15x7/Cast/8.98112952kg
OZ Superlegerra : 15x7/Cast/5.2163126kg
TD Pro race 2 : 15x7/Cast/6.39565284kg


Copied one of pablo's posts, he knows his stuff on wheels!

 

[deer_dodger]

To the best of my knowledge, increasing track, reducing offset will increase torque steer to a degree.

 

[mikekean]

It will yes because it creates more leverage on the steering.