DIY dune buggy/go cart 1.4 nissan sunny engine

[JamieH]

ok so where do i start.. I started this build back in january 2010 (i think) i decided after i got a new field car to replace my 1989 nissan sunny that it would be a shame not to do something with the engine which was pretty good and 86hp stock so plenty of power for a cart which will hopefully come in at under 500kg..
So after getting my father on board (metal fabricator ftw ) as i was just gone 16 at the time and this was going to be my first build of any kind, we stripped the engine out of the car. Unfortunately dad had already cut the wishbones, track rods and one drive shaft as he wanted the hubs for a trailer leading to difficulties down the line...

Ok so the first step was to obviously make the frame, we searched the internet looking for a design that we liked and then we used ratio's etc to get rough demensions, then it was time to start fabricating
our state of the art CAD system

might be hard to see but we used chalk on the floor and used a centre line to get our bends/measurements right
then we started bending
floor (changed at a later stage):

the ''sidewall'':

Unfortunately at times the pictures skip a few steps as i hadn't thought as far as a build thread at the time but we then made two hoops for make and front of the ''cab'', and more tubes to join top and floor together
im just going to add all of the frame is made with 42mm mild steel tube and the main bracing done with 33mm mild steel tube.

so we got as far as this:

Progress slowed down considerably after this as i was back to school dad was busy at work and the search for suspension/steeering set-up began.




Thats all i have time for at the moment, ill update asap once i refresh my memory and sort out picture, this build is probably 90% finished and is driving at last
comments/opinions/suggestions are welcome and il do my best to answer questions..

 

[Nodroz]

That looks pretty cool! Do you have any picture of the engine?

 

[JamieH]

That looks pretty cool! Do you have any picture of the engine?

Thanks Nodroz! Yes have over 200 pictures of it altogether just want to sort out whats what first, ill try put up picture of engine/ update next stages in the next 2 or 3 days

 

[exenos]

Wow, that's not a lot of power coming from a 1.4L. Would have thought it would come in at just over 100hp.

Asides from that, the kart looks good, am I safe to assume that your going to brace the side frame?

 

[JamieH]

Wow, that's not a lot of power coming from a 1.4L. Would have thought it would come in at just over 100hp.

Asides from that, the kart looks good, am I safe to assume that your going to brace the side frame?

Its plenty to be getting on with for a sunny, especially if its as light as i hope il be looking at 160hp/tonne which is plenty for the space i have over here.
Thanks yes thats all done just need to sort out pictures and what order things came in from there on, a safe frame was one of the main priorities

 

[Bluethunder3320]

i wanted to do this with a Isuzu G200 engine (about 90 HP) but the engine was too far gone i ended up scrapping it

 

[KieranM]

Looking well Man

 

[JamieH]

i wanted to do this with a Isuzu G200 engine (about 90 HP) but the engine was too far gone i ended up scrapping it

nothing better than using old parts to make something better unfortunate im sure something else will turn up

Looking well Man

thanks man may get the rest up soon

 

[JamieH]

Ok so time to continue..

After getting the basic frame done we decided the front suspension was next up, i picked up a 1988 nissan micra for small money and we used the wishbones,shocks,hubs and steering rack out of this with a custom spring setup. We decided to use dimensions as close to the micra as possible to try and keep the geometry right (unfortunately the wheel base is too long for micra geometry causing understeering problems down the line ) to get the right width we had to make the bottom part of the frame narrower,
anyway time for some pictures

Wishbones mounted and some bracing can be seen in main frame:

made shock mounts:

you might be able to see how its heigth adjustable mount:

next we added the steering rack + arms:

picture of wishbone mounted:

then came steering column, wheel + pedals:

then it got front grille/bull bar and we threw on wheels to see how spring rates were:

as you can see the wishbones are at a severe angle which left very little travel in the shocks and would have givin a very bouncy ride, this meant we had to make a custom spring setup based on formula 3 cars, i dont have any good pics of this but will take one when i get a chance for now though:

you should be able to see the bar sticking up with all the holes, this is welded to both the wishbones, when the wishbones move up these bars swing inwards pushing a 33mm tube into a 42mm tube on which the spring is mounted. the multiple holes are to give the wishbones more or less mechanical advantage over the spring and the compression on the spring can also be adjusted, more pics of this to follow.

A back axle was next up which was sourced from a renault 19 we used this as it had a torsion bar eliminating the need for springs leaving more space and because it was heading for scrap anyway. i cut off the back hubs from the 19 and then bolted on the front hubs (rotated forward 90 degrees) then worked out tracking and welded them on the only pictures i have are in with the engine mock up \/

Next up was to mount the engine we first did a mock mount to get positions right and to know what we had to work with for the engine bay:

more to follow as usual comments/questions etc welcome

 

[brandongeiger2]

Is that horizontal spring up front part of the suspension system? haha

 

[JamieH]

Is that horizontal spring up front part of the suspension system? haha

Yep the two springs on the coilovers were too strong for the light front so we copied the formula 1 etc style where the arc made by the wishbones push the spring in and out

 

[dpaxson]

wait so is that just one shock/coilover shared between both sides of the front suspension? or do you have one coming from both sides and I just can't see the other one in the pictures

 

[JamieH]

wait so is that just one shock/coilover shared between both sides of the front suspension? or do you have one coming from both sides and I just can't see the other one in the pictures

there is two shocks mounted in normal position and then a shared spring between both