Dodgey Posted July 18, 2012 Share Posted July 18, 2012 (edited) Hi - Not sure if this should be in the techie section or not. I've got an SEi (narrow) (with bicycle wings) with 15" Wheels on, and I want to buy another set of wheels for the track (I assume - see below) The current setup is "BSA Top Racing" Wheels - 15" with 195/50 R15 82H Yokohama A539s fitted all round - with good tread remaining. I've tried searching for the exact wheels so I can learn their offset, bolt spacing etc, so I know what other wheels I can buy, but I've failed so far. I guess I have to be pretty accurate as i have bicycle wings? I've measured the bolts - which are , as far as I can measure - 75mm apart - center to center, on the square, and 105mm apart on the diagonal. I was told by the previous owner that my running gear is from a Mk3 Escort (discs front, drum on a live axle at the rear) - is there an easy way to confirm this? maybe look for some serial numbers somewhere? (I'm new to this!) - I assume this then makes choosing wheels easier. When I find out what I can get away with installing, I then was wondering why a lot of people seem to be running 13" wheels on the track - any particular reason? Lower gearing? cheaper tyres? As for tyres - well, my A539s are "ok" - I LOVE sliding them on roundabouts ( I assume the tyres are a major factor in how easy it is to drift whilst remaining in control?), but I assume I'll kill them in short order on the track? Edited July 18, 2012 by Dodgey Quote Link to comment Share on other sites More sharing options...
Burlers Posted July 18, 2012 Share Posted July 18, 2012 Hi there. You will find plenty on here if you search, I'm no expert, but here's what I've picked up so far - 13" wheels save weight, some prefer the tyre choices, your PCD is 105 (ford fitment), this will help you with the pitch circle diameter explanation: http://www.nice-whee...dandoffset.html With regards offsets, back space is really important so you don't clash on your linkages and 'guts' behind. Take the wheels off to see if you can find an offset printed on the rear? Measure the width of the rim and then you can work out the offset from mucho advice on the web; this is a nice little toy too for comparing different wheels etc: http://www.willtheyfit.com/ Nice wheels BTW... good luck 1 Quote Link to comment Share on other sites More sharing options...
s2rrr Posted July 18, 2012 Share Posted July 18, 2012 Just a minor picky moment Ford are 108mm pcd and most of us I believe have them. The offsets may be marked on but also they may not be or even worse the wheels may have been machined after marking. The best way is to do the measurements and check numerous times as its really easy to miss something very obvious like, will the rim clash with the uprights, the shocker or even the wheelarch. Theres a sketch somewhere about which dimensions you need and its pretty simple if you intend using the same offets and diameter. Just need a decentish straight edge and a measuring stick aka rule. Have a google for the offset pictorial but someone will stick it on here for you. Good luck Bob Quote Link to comment Share on other sites More sharing options...
Dodgey Posted July 18, 2012 Author Share Posted July 18, 2012 Thanks fellas, been playing with http://www.willtheyfit.com/ since posting the original post. I'll take a wheel off and measure it up ... in fact I'm gonna do that now. Too wet out to drive :-( Burlers - thanks - btw - I said about PM'ing me regarding the August 31st track day but it seems I can't use the PM facility so drop me an email some time at roger.donoghue (at) gmail dot com. Quote Link to comment Share on other sites More sharing options...
s2rrr Posted July 18, 2012 Share Posted July 18, 2012 These might be worth a look at but not the one I was thinking of, it will be in the archives somewhere try a search. http://www.1010tires.com/WheelOffsetCalculator.asp http://kgm.tiwing.com/calcs/offsetcalc.htm Bob Quote Link to comment Share on other sites More sharing options...
greenandmean Posted July 18, 2012 Share Posted July 18, 2012 Minor point but you say its a SEi but then say you have drums at the rear on a live axle, the i denotes independant rear suspension so drive shafts and not a live axle, I only mention it in case you want any parts in the future so you dont order the wrong things. Quote Link to comment Share on other sites More sharing options...
Burlers Posted July 18, 2012 Share Posted July 18, 2012 Doh! 108PCD - thanks Bob, shows I'm no expert! OK Dodgy, I hadn't seen your post there - I'll drop you a line and we'll meet up at Keevil There may be some members from the Wilts & Hants WSCC Forum there too, let's hope it's dry :laugh: Quote Link to comment Share on other sites More sharing options...
SootySport Posted July 18, 2012 Share Posted July 18, 2012 A lot of us have 13" wheels for a choice in tyres, in slicks this is a widely used size but not in road tyres. they also weigh a whole lot less. The boys in the speed series have been converting to them for lightness. If you are planning having a second set for the track then it's worth buying 13" wheels but keep your 15" wheels for the road , their is a wider selection tyres at a better price. As mentioned before measure the ET yourself, you can get it right + or - a couple off mm. PS Join the forum membership, it has a lot of benefits. Quote Link to comment Share on other sites More sharing options...
Dodgey Posted July 18, 2012 Author Share Posted July 18, 2012 (edited) Nice one Burlers - it'll be dry - I am sure of it! As for the Sei - I just assumed that as that's what the insurers have it as. I stand corrected! Just been outside with a meter rule, digital calipers, and a chopstick (it was vital!). Fronts and rears have different offsets due it having drums out back... The wheels are brand new, unmarked, and all the lettering inside is pristine. Oddly, the fronts were missing the ET measurement, and the rears had it cast into the wheel. Strange. Rears ET 15 (as stamped in the casting, and as measured to confirm) PCD 108 - measured with caliper Model - 178 15x6.5 Center hole 60mm as measured by me (irrelevant as the rear is a flat hub) Then there was a marking like ll - ll - no idea Fronts ET 35 as measured by me and verified I was using the same measuring system as the rear (as the tyres are on, so had to get creative!) 15x6.5 Center hole 60mm as measured by me (putting the calipers on the disk hub "nub" measured 63.3mm - one assumes crud and muck for the extra) Weird "PCD" marking with no actual figure Weird "8" marking for no apparent reason Weird " . ' . ' . ' " marking (edit, the PCD was on one spoke, and the 8 on another. I guess they add up to "PCD 8" = 108 :-) - strange how one wheel would have the PCD on it and not the ET, and another have the exact opposite) All in all an education!. Now I know what I need :-) Edited July 18, 2012 by Dodgey Quote Link to comment Share on other sites More sharing options...
Burlers Posted July 18, 2012 Share Posted July 18, 2012 Don't know about your budget Dodgy, but Westfieldrocket has just posted up a nice set of new wheels and tyres on the Parts For Sale section They 'may' fit - - worth a gander? Quote Link to comment Share on other sites More sharing options...
Blatman Posted July 18, 2012 Share Posted July 18, 2012 For an SE live axle, the rear axle will probably be from a Mk2 Escort. There's a *slim* chance it's a Mk1 but only a slim one. For an SEi with independent rear suspension, you will have bespoke Westfield aluminium uprights with either a Ford Escort diff in a bespoke Westfield aluminium casing, or a Ford Sierra 7" diff. Driveshafts will be either modified Ford Escort or Ford Sierra as appropriate. Rear discs will be the FRONTS from a Mk3 Escort, and the calipers will be Ford Sierra. On all models that aren't one of the SDV variants, front brake hardware will be will be Mk3/4/5 Ford Cortina upright with Cortina discs and Cortina calipers. The calipers are known as M16's. Ford wheels have a PCD of 108mm as already mentioned. The wheel spigot (the centre bit) is 63mm give or take, and asuming I remember correctly. My usual advice when buying wheels is to buy the numerically largest offset (usually ET37) and make up the difference on the car with hubcentric spacers. Having the wheels all the same means you can rotate them around the car (asuming the tyres are all the same size... mine are...) when they start to wear. As it is with your wheels, the fronts are the fronts, the rears are the rears and if you have directional tread patterns then you can't really swap them from side to side. 1 Quote Link to comment Share on other sites More sharing options...
Dave Eastwood (Gadgetman) - Club Chairman Posted July 18, 2012 Share Posted July 18, 2012 On all models that aren't one of the SDV variants, front brake hardware will be will be Mk3/4/5 Ford Cortina upright with Cortina discs and Cortina calipers. The calipers are known as M16's. Later (current) non-SDV cars have swapped from Cortina M16 to Landrover Discover rear callipers. (Excepting four pot conversions of course) Quote Link to comment Share on other sites More sharing options...
Dodgey Posted July 18, 2012 Author Share Posted July 18, 2012 Bit pricey Burlers :-) Amazing info Blatman - thanks ! The seller said the running gear was, he "thought", Escort Mk3. So what you are saying is the it is more likely an Escort Mk2 rear axle, front brakes will be Cortina bits with M16's and the rears - well on mine they are drums.... and as the axle is an Escort one assumes the drums are too? Great advice on the spacers - you are dead right - my tyres can't be rotated at all :-( Regarding new alloys - I'm doing a bit of searching. If I go from 15" x 6.5's is the logical step to 13 x 7? I assume "7" because I don't see 15x 6.5 come up a lot in search results Quote Link to comment Share on other sites More sharing options...
Blatman Posted July 18, 2012 Share Posted July 18, 2012 13 x 7's will be fine. I used to run those on my sprint car with 205/60 rears and 185/60 on the front. The road car has 15x7 ET37's all round with 195/50/15 tyres. Quote Link to comment Share on other sites More sharing options...
Pistol Pete Posted July 19, 2012 Share Posted July 19, 2012 I did 80 laps around brands in march on a539 and my tyres show hardly any wear, and much less than the caterhams on avon road tyres I was keeping up with. Quote Link to comment Share on other sites More sharing options...
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