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Hi and welcome to this great site.
Your contact patch will be roughly the same size regardless of the make or size of tyre at it is a function of car weight and pressure.
How old are the tyres, as they can harden over time?
Lowering can, as mentioned above, affects suspension geometry and never in a good way. Out of alignment tracking and hard tyres can make a car very skittish.
What do you mean by “too thin and too big”? 185s are the right size if the rims are the standard 5.5” width.
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Mar 16, 2023 18:37:40 GMT
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Decided to get back to the heat shielding. This is quite important as the car is basically carbon with a dash of fibreglass :-) The exhaust is plasma coated so most of the heat should stay in the pipes but better to be safe than sorry. I have already made the under and over shields for the exhaust - Aluminium patterns used to make carbon versions which were then skinned with Zircotex's Zircoflex III. However there is only a sheet of carbon between these shields and the car's electronics so I decided to add a layer of Zircoflex to this bulkhead, which is in progress. Photos show the first section of Zircoflex added to the bulkhead and the top sections of the shield. The lower sections are still in place. And I fitted the new pushrods. More clearance between pushrod and wishbone.
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Last Edit: Mar 16, 2023 18:49:53 GMT by nalesutol
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Mar 16, 2023 11:56:39 GMT
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Good morning to all, another mini update. Decided many years ago to use TPI's 7075 grade aluminium wheel nuts, resulting in an 820gm reduction in unsprung weight. However, I appear to have either mislaid, or forgotten to buy, a suitable socket. TPI have been no help so far. Ebay has a few that appear to be OK but, before I splash out on one, anyone know where I can get a TPI socket or are they the same as the other nuts/sockets of this type? The nut on the left is the TPI version with a standard steel one to the right. They look similar.
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Last Edit: Mar 16, 2023 11:57:30 GMT by nalesutol
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Mar 15, 2023 18:12:46 GMT
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This one is for the "You're wasting your time, just have a dump before you race" brigade :-) Whilst lifting the rack 6mm so the boot misses a cam support tube, I decided that it was an opportune moment to do a little weight shaving. Well, it would have been rude not to :-) Apologies for the rubbish photo, no idea what happened there but must be driver error. By removing 71gms the clamps with spacers now weigh slightly less than they did without the spacers. One of the clamps fitted.
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Last Edit: Mar 15, 2023 18:21:10 GMT by nalesutol
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Mar 14, 2023 10:35:08 GMT
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Whilst making the pushrods I was using the cross slide (compound) on the lathe and the replacement slide is stiffer to move than the original. Not sure why but there could be a slight mismatch between the sliding parts. So I decided to make life a little easier by adding some mechanical advantage. Turned out to be a simple task for a change and the slide is now much easier to operate. This hack would also work on a properly working slide as the original handles are very close together, making fine adjustments a little tricky. Should have done this years ago.
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Mar 13, 2023 18:42:06 GMT
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New damper pushrods finished. 40 minutes to make functional and another 40 minutes to make pretty :-)
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Last Edit: Mar 13, 2023 18:43:02 GMT by nalesutol
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Mar 13, 2023 18:20:32 GMT
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All rules have exceptions, otherwise they are unworkable :-) Marking when torqued seems to be good compromise.
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When returning to a project after a few years of relative inactivity you keep finding little surprises. For example, this morning I was continuing to fit hose clamps when I discovered that the throttle body was only held on loosely by two bolts. That is now rectified but I am going to have to keep both eyes open for any more unfinished jobs. At least I had the foresight to mark nuts and bolts when they had been properly tightened. I would be having 100 paint dots on some fasteners since the hobby seems to be how many times do I fit and refit any given part? :-) But this is preferable to “I won’t tighten this until I am sure I am not going to take it off again”. Did this around 40 years ago. When fitting twin DCOE Weber’s you have to wrangle the fuel pipes and throttle linkage as they want to occupy the same space. I left the fuel pipe banjo loose so I could adjust it as I fitted the linkage but forgot to tighten it and the obvious happened. Fortunately it went up as I pulled up outside a friend’s house in the middle of a party. People streamed out with beer mugs and washing up bowls full of water (including crockery). By the time the fire brigade turned up we had the fire out, or so we thought. The firemen checked the car over and discovered that it was still alight behind the heater unit. A very lucky escape. They said that they usually arrive at Lotus fires to find only the chassis left so I was very lucky that it happened where it did, otherwise I wouldn’t still be working on the car.
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Recommended rim width for 175/13 tyres is 5 - 6” Anything wider and you start to compromise tyre grip and performance. There is a reason that manufacturers state recommended rim widths :-)
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Last Edit: Mar 13, 2023 7:58:44 GMT by nalesutol
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Last Edit: Mar 13, 2023 7:50:10 GMT by nalesutol
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Old Ford Transit? My M reg motorhome has a pump attached to the alternator.
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Mar 12, 2023 22:00:57 GMT
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Took most of the day, but finally completed the installation of the water and air hose clamps. When I first fitted the intake hose clamps they were slightly too large so the excess was waving about in the breeze and looked tacky (the next size down was too small) so I took them off and shortened them by around 30mm. Did this to all the hoses. Not only does it look tidier it removes the risk of catching myself on them. As an aside it also removed around 40gms but that is bye the bye :-)
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Last Edit: Mar 14, 2023 10:26:25 GMT by nalesutol
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Mar 12, 2023 14:02:18 GMT
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When returning to a project after a few years of relative inactivity you keep finding little surprises. For example, this morning I was continuing to fit hose clamps when I discovered that the throttle body was only held on loosely by two bolts.
That is now rectified but I am going to have to keep both eyes open for any more unfinished jobs. At least I had the foresight to mark nuts and bolts when they had been properly tightened.
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Mar 11, 2023 20:14:30 GMT
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Spent the afternoon in the garage doing little jobs. Started to fit the new hose clamps. Secured some wires. Looked at issue with steering rack. The drivers side boot fouls one of the support tubes for the front clam. I can solve this by raising the rack 6mm by slipping spacers under the rack clamps. Quite a simple fix for a change and it also improves the angle between the rack and wishbones so less adjustment will be required when sorting out bump steer. Don't have any aluminium of this thickness and width so that is ordered. May have to add a little dent into the aluminium rad bottom hose as it is very close to the rack. Also fitted rad cap.
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Last Edit: Mar 11, 2023 20:18:29 GMT by nalesutol
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Mar 11, 2023 13:42:21 GMT
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Finally, decided on size and style of wheels and tyres. Only taken around 10 years 🙂
Nankang AR-1 275/35r15 and 165/50r15 tyres fitted to 9.5 & 6” Image Wheels’ 3 piece billet Ultralites. Form sent to Image for price.
I have gone with 6" fronts so as to avoid any problems with clearance and fouling. There could also be an issue with steering restriction due to the front clam support tubes being hit by the tyres. However, by using 3 piece wheels it is a relatively simple task to increase width by simple replacing the inner rim section.
Need a lie down now :-)
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Last Edit: Mar 11, 2023 20:51:59 GMT by nalesutol
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Update on Push rods. Got a quote for 1m length of 15.88mm OD seamless steel with a 4.06mm wall thickness - £139 including shipping! Ouch, rethink time. Gone back to an earlier design using 6082T6 grade aluminium. This is the strongest of the 6000 grade alloys, which is particularly suitable for structural applications and also for welding & machining. How does the alloy compare price wise to the seemless steel? 😶 £12 :-)
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Update on Push rods. Got a quote for 1m length of 15.88mm OD seamless steel with a 4.06mm wall thickness - £139 including shipping! Ouch, rethink time. Gone back to an earlier design using 6082T6 grade aluminium. This is the strongest of the 6000 grade alloys, which is particularly suitable for structural applications and also for welding & machining.
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The trouble with taking so long on a project is that you re-visit and re-assess previous work, but this can have a positive side. A case in point are my rear inboard damper push rods. Whilst sorting out wheel specs I kept looking at these rods. As mentioned in my previous post I wasn't happy with their close proximity to the top wishbone, even with the mods. The original rods were steel, but this was before I caught the weight reduction disease. I decided that they were too heavy so made carbon ones with aluminium threaded inserts glued in. Although the glue used was designed for such use I have never been 100% happy. Although most of the forces are in compression, if the glued joints fractured disaster could result. So, I have decided to revert to steel push rods. However, as usual, not that simple as the original rods have different threads in them as, at some point, I changed the rod end specs to left and right hand threads so the suspension height could be adjusted in-situ. So, at the moment I am sourcing 14mm OD thick walled tube as opposed to solid bar so I can keep the weight increase to a minimum and increase the gap between rod and wishbone (carbon tubes are 18mm).
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Last Edit: Mar 8, 2023 23:19:43 GMT by nalesutol
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OK, time to man up and sort out the wheels. I have been putting this off for years :-) Fronts: Either 15 x 7 or 14 x 7 Image Wheels 3 piece billet Ultralites. Will depend on final tyre choice. Plenty of clearance. Rears: A little trickier due to clearance issues. However, on checking with the 15" rim I have, there is JUST enough clearance. So these will be 15 x 10s With regard to the amount of wheel outside of the hub, 3 1/2" brings the wheel in line with the arches on front and back. However I think that I will go with 3" giving me some wriggle room with spacers if needed. On looking around I revisited the damper push rod. I made these from carbon tube with left and right hand threaded aluminium inserts. There was no clearance to the top wishbone so this was attacked with the wheel of death and strenghened. It is still very tight and I am not happy with the safety issue. If the insert comes out.......... So I am reverting to the original design of steel tubes. I can use 12.7mm 16swg T45 seamless as this will take a 10mm thread, doing away with the need for an insert and giving me more clearance. A bit heavier but a lot safer IMO.
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Last Edit: Mar 6, 2023 18:55:57 GMT by nalesutol
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Just found this, brill!! I will be impressed if you can keep it below 800kg, as it is surprising how much all the little bits you forget about end up weighing :-) Using thin wall T45 will help. I am struggling to keep my Elan build below a basic Elan's weight (700kg). How much did the complete body end up weighing? Just found this, brill!! I will be impressed if you can keep it below 800kg, as it is surprising how much all the little bits you forget about end up weighing :-) Using thin wall T45 will help. I am struggling to keep my Elan build below a basic Elan's weight (700kg). How much did the complete body end up weighing? I don’t have all the body parts yet however based on weight of doors and center I expect body to be around 60KG Chassis about the same again, I think the Alfa Engine weighs 198kg + box probably around 250 -260kg combined, actually hoping close to 700. Lancia themselves had a Grp5 Stratos Race weight of 790kg that’s with there heavy stamped steel tub + Ferrari V6 is heavier lump, Iron block. Definitely everything adds up, but I’ll try weigh everything as it goes. 700kg will be impressive. I have gone carbon wherever I can (front clam, roof, doors, boot, floor, interior, seats etc), along with Titanium (some centre drilled), aluminium and plastic fastenings where appropriate, bare minimum interior, polycarbonate glass, T45 roll cage etc etc and still struggling to get below 700kg.
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