I have often thought about including a FAQ on my website, and now I think its time I actually did it!
If you have a suggestion for a Question and Answer that should be included in the FAQ then fill in the form below and I will check it and update this page as necessary!
What I am going to try and do is split these up into specific areas to try and make it easier to find what you are looking for. The sections I will use are based on those used on the Locost Builders forum, basically because I think the subjects are ideal! Also you will find that many of the FAQs have links to relevant LB threads for more information.
Chassis
Q: How much tube do I need?
A: Around 31metres of 25x25mm 1.6mm section, aound 9 metres of 19x19mm 1.6mm section and around 8metres of 19mm round.
Q: Has any FEA been carried out on the chassis?
A: Yes, a member on the Locost Builders forum has carried out some quite comprehensive analysis and his results can be found here: http://locostbuilders.co.uk/viewthread.php?tid=1738 and here: http://www.locostbuilders.co.uk/viewthread.php?tid=3802 Look for posts by Cymtriks.
Q: How do I need to modify the top wishbone to get enough self centreing?
A: The offset of the top wishbone should be 22mm if you are using the books dimensions for the mounting points. However you could equally move the top wishbone mounts rearward, but this means changing the position of some of the tubes in the chassis.
http://www.locostbuilders.co.uk/viewthread.php?tid=10446
Q: There is an error (page 64) with the rear trailing arm braket locations, what are the correct dimensions?
A: The dimension between the trailing arm mounting holes should be 4.3" NOT 5.75" as stated on that page!
http://www.locostbuilders.co.uk/viewthread.php?tid=8153
Q: How can I make a jig to hold the wishbone brakets in the correct positions?
A: There are many ways of doing this and each needs a bit of lateral thinking as to whether it will do the job and hold the brakets in the right place, securely while they are welded. The best way to demonstrate is with a link to some pictures I think!
http://www.locostbuilders.co.uk/viewthread.php?tid=21365
Q: Should I use a steel or aluminium floor?
A: There were concerns about using a riveted aluminium floor, as the floor itself is a stressed part of the chassis. However these concerns can be alleviated by using structural rivets (often called closed end rivets) and a PU adhesive to attach the floor. My analysis showed that an aluminium floor could save up to 6kg over a steel floor so it is well worth doing if you want to save some weight!
http://www.locostbuilders.co.uk/viewthread.php?tid=10557&page=1
http://www.locostbuilders.co.uk/viewthread.php?tid=21928&page=1
Q: How can I ensure that I minimise bump steer?
A: Basically bump steer is caused when the track rod is not parallel to the bottom wishbone and is a different length, with the ball joint on the rack out of line with the bottome inboard wishbone joint. Then as the suspension moves the track rod and wishbone move through different arcs, inducing bump steer.
http://www.locostbuilders.co.uk/viewthread.php?tid=6102
Donor Cars
Q: What car should I use as a donor?
A: See my donor cars page, and these threads on LB:
http://www.locostbuilders.co.uk/viewthread.php?tid=20665
http://www.locostbuilders.co.uk/viewthread.php?tid=21894
Q: How do I keep the age related plate form my donor?
A: You need to use 2 or more major components from the donor car. You also need to keep the donor SORN during your build, even if you scrap the shell. Just make sure you keep the registration document and all identifying marks from the shell. If the car is declared scrap insead of SORN, you will probably end up on a Q plate, which is no big deal.
Q: What parts should I keep from my donor car?
A: Basically keep as much as you possibly can, even though you think you probably will not need it. Its much easier to keep extra stuff, than trek to the scrap yard to get another one!
http://www.locostbuilders.co.uk/viewthread.php?tid=5601
http://www.locostbuilders.co.uk/viewthread.php?tid=20304
Running Gear
Q: What rear suspension set up is the best?
A: The 3 main choices are:
Live Axle
De Dion
Independant
I think the best way to deal with this is to take each one in turn.
Live axle: This is the set up that the original Lotus Seven has fitted. The axle can come from an Escort, Capri or Cortina. It is a simple 5 link set up. If you are wanting to race in the Locost series you will need to use a Live Axle. They are getting harder to get hold of now due to the age of the donors. Live axle has the highest unsprung weight of all of the arrangements.
De Dion: The GTS de dion uses the full width Sierra rear end so you dont need to chop up the driveshafts and will still fit into a 'book' chassis. the de dion is also available in +4" format. De dion has a lower unsprung weight than live axle and will also offer slightly better road holding/handling. Fitting a de dion set up also gives you the choice of fitting a LSD if you wish along with rear discs. De Dion Axle plans by Rorty Design can be found here
IRS: MK's car has independant rear suspension, and as far as I know is the only one that does. There are very few plans available for a good IRS system. IRS is complex to design as camber changes during acceleration and braking can limit road holding, along with a few other factors. Though if you read up on the subject then there is no reason why you should not be able to design our own system. IRS offers the lowest unsprung weight of all of the set ups, but as a complete system it is heavier than de dion. IRS plans by Rorty Design can be found here
Q: What front uprights can I use as I cant get hold of Cortina ones!?
A: The most common options are Sierra and Cortina uprights. Cortina ones are in plentiful supply at local banger tracks, just get friendly with some of the drivers. Sierra ones are a good alternative, if a little ugly and heavy. For more suggestions, see:
http://www.locostbuilders.co.uk/viewthread.php?tid=21742
Q: What modifications do I need to carry out to use Sierra uprights?
A: The wishbone design is different, but all of the suppliers can supply Sierra wishbones to suit. However the uprights themselves need to be modified by reaming the bottom taper out.
http://www.locostbuilders.co.uk/viewthread.php?tid=20446
Q: What differential ratio should I use?
A: Use whatever you can get your hands on to start with, then once you have a completed car, start to try and optimise it. There are some tips in this thread about what to chose:
http://www.locostbuilders.co.uk/viewthread.php?tid=9703
Q: How can I identify the ratio of my diff? All I have is a code letter!
A: The code letter tells you what the ratio of the diff is. Here is a reference list:
3.14 M
3.36 A
3.38 U
3.62 V
3.64 3
3.92 D
http://www.locostbuilders.co.uk/viewthread.php?tid=19116
Q: What are the differences between the Escort, Capri and Cortina axles?
A: The Cortina and Capri axles are wider than the Escort axle. For a more detailed explaination see here:
http://www.locostbuilders.co.uk/viewthread.php?tid=23812
Q: What is the track width of the Sierra?
A: 1468mm
http://www.locostbuilders.co.uk/viewthread.php?tid=23755
Q: What are the different rear suspension designs that are available?
A: The main choices are: Live axle with 5 link system, De Dion with 5 link, IRS. Though there are others and more info can be found here:
http://www.locostbuilders.co.uk/viewthread.php?tid=21070
Q: I dont fancy making my own propshaft, where can I buy one from?
A: Most of the kit car suppliers make them to suit their cars. There are also many other independant propshaft suppliers that may offer a cheaper alternative.
http://www.locostbuilders.co.uk/viewthread.php?tid=22477
Q: What are the benefits of fitting an LSD?
A: You get more grip during straight line acceleration, and the ability to do massive powerslides round corners with ease....!
http://www.locostbuilders.co.uk/viewthread.php?tid=18969
Q: What should I set my camber and toe to on the front suspension?
A: For normal road use, a starting point is 3mm toe out and 0.5-0.75deg negative camber. A touch more on both for SVA to assist with self centreing.
Engine/Transmission
Q: How do I set up my cooling system and what header tank should I use?
A: There are many different tanks that you could use, but the best ones are the squareish ones found in Rovers and Astras. For info on how to set up a pressurised cooling system see:
http://locostbuilders.co.uk/viewthread.php?tid=22500
Q: There are lots of types of DHLA carb, which ones should I go for, and which should I avoid?
A: Many of the carbs fitted to Alfas are not adjustable so these should be avoided. Always try and get a pair that have come off a similar engine to which you want to bolt them to. It could save you a fortune on new jets and chokes. The numbers to watch out for are:
DHLA 40
DHLA 40C
DHLA 40E
Its likely that carbs with letters other than those above are 'Emission controlled' carbs which are not easily tunable and not suited to a seven type car.
Q: How much do the different engines weigh?
A: Obviously newer alloy engines such as the Zetec and Duratec are much lighter than engines such as the Pinto. Take a look here for some weight figures for different engines:
http://www.fluke-motorsport.co.uk/weight/engine_trans.html
Q: Which radiator should I use?
A: The Mk1 Polo radiator is probably the best option as it is the largest that will fit in the nose cone. However there are other options such as the Micra radiator. Take a look here:
http://locostbuilders.co.uk/viewthread.php?tid=10911
Q: I have heard the the Pinto sump needs to be modified, how should I do it?
A: You need to chop about 1.5" off the bottom of the sump, and reweld it. A good way of doing this is outlined here:
http://locostbuilders.co.uk/viewthread.php?tid=3374
Q: Can I make a quickshift for my gearbox?
A: Of course you can and here is how: http://hometown.aol.com/dvandrews/quick.htm
Q: My gear lever is too far away and clashes with the dash, how can I overcome this?
A: Take a look at David Jenkins site for plans on how to make an extension
http://www.dwjenkins.plus.com/gear_extend.htm
Q: How can I fit bike throttle bodies onto my car engine?
A: This is quite complex, so dont expect to find all of your answers in this one place, but heres a start:
http://locostbuilders.co.uk/viewthread.php?tid=30857
Electrical
Q: Do my rear lights have to be vertical?
A: No they do not. The only one that has to be vertical is the rear fog lamp.
Q: What is the maxiumum distance my front indicators can be from the edge of the car?
A: They must be within 400mm of the widest part of the car (usually the rear wings on a seven) so you will probably need extensions for them.
Q: How do I wire my hazard lights up so that they work with the ignition on and off?
A: Take a look at the wiring diagram here (I apologise as I cannot remember who originally drew the diagram, but many thanks to them anyway! [If it was you, contact me and I will reference it accordingly!])
Bodywork
Q: How should I fix on my bonnet?
A: The most common solution is to use rubber, over centre catches. Most of the metal ones will not get you though the SVA test. Dzuz fasteners can also be used, but make sure that you use flush mounted ones, of the right length other wise you will fail SVA and your bonnet wont want to stay on...!
Interior
Q: What width seats will fit in a locost?
A: Due to the car being very narrow, there is not much space between the side of the car and the transmission tunnel. In a STANDARD locost the width is 390mm and there are several manufacturers making seats to fit. Personally I quite like the Triton seats...
SVA/Legal
Q: Do I need an MOT before going to the SVA test?
A: No you do not. However it may be advisable as it may pick up on a few things that you would otherwise fail on at the SVA
Q: Should I get an age related plate?
A: I personally see little point. Its a lot more hassle while you are building to make sure you keep the car SORN etc. Besides once registered, if your car is on a Q plate you only get a visible smoke check at the MOT, not the full emissions test...
CAD
Q: Is it worth drawing my car in CAD before I actually start the build?
A: If you have access to CAD software and are relatively skilled in using it then you would probably find drawing the chassis useful. It will allow you to make your own design changes to the chassis, and give you a way of creating plans to make it.
Q: How long did it take to draw the chassis?
A: It took me about 6 weeks of evenings to draw the chassis and bodywork that you can download from this site. Probably a total of a weeks solid work. So if you like what you see and want to use it let me know, as I like to know where my stuff is going to.
Q: Are there any free CAD packages available?
A: Yes there are, but a lot of them are not very good or very limited in their functionality and you would have great difficulty creating something such as the chassis in it. ProDesktop used to be a free piece of software, the version I use is a freeware version.
Q: What CAD package would you recommend?
A: I have used several different CAD packages. The worst of the lot has to be AutoCAD which is very difficult to use and overly complicated. The best packages are SolidWorks, Inventor, Mechanical Desktop and ProDesktop. Unfortunately none of them are free, and are all rather expensive!
