Monthly Archives: July 2014

Chassis modifications – Planning 2

Chassis

So with a baseline of the existing chassis it was onto modifying it. First off was to model how other manufacturers did it. I won’t mention who.

The results were that my chassis was stiffer. So making it the same was out. Then I took a look at the originals and had an idea…

One model later and I had some more results. Same tests

Single bump

Double bump

And finally side load

Settings are exactly the same as the initial chassis tests and despite being a very unrealistic set of tests the results are clear that the chassis is stiffer with the modifications.

Results

Single Bump Double Bump Side Load
Original 7.447mm 7.127mm 4.347mm
Modified 3.823mm 3.577mm 2mm

Pretty clear improvement. Not that an improvement was the goal, it was more to ensure that by changing things I didn’t make it worse.

Onto the angle-grinder…

 

Chassis modifications – Planning 1

Chassis

So. There I was looking at the lack of clearance between the rear-most downipe and how other manufacturers do it and then I fired up a CAD and FEA package and modelled half of the existing chassis, first off a “bump” one side (force concentrated into the shock absorber pickup):

Then a “double bump”, ie both sides. (force concentrated on shock absorber mounts):

Then a side load (force split into suspension mounting points):

The displacement looks horrific but note that the deformation scale is 25x so you can “see” how it deforms.  The actual maximum displacement in the first test is actually 7.4mm under a large load. I did these a long time ago now but I seem to recall I used 10000N for *each* load, that is equivalent to 1t (1000Kg). Approximately 4x the static load (assuming a car weight of 1000kg, all weight balanced evenly).

 

Engine Update

Engine, Uncategorized

So, last post I had an engine and a gearbox and an adapter plate but no pictures of it in the car.

I did paint the original inlet manifold, piss about trying to get it to fit with the original distributors, ECU etc then gave up.

Plan now is ITB and COP (Coil On Plug) using Lexus IS200 / Landcruiser COP part number 90919-02230 along with proper plugs (part number 90980-11885)

Wiring to the COP is via 20AWG MIL-W-22759 spec wire which is insulated with extruded Tefzel (ethylene/tetrafluorbethylene) and unlike standard thinwall which is only rated for 105°C it has a maximum temperature rating of 150°C.

The ITB setup was originally planned to be two sets of GSX-R1000K1/2 throttle bodies  on custom manifolds but I changed my mind and bought a set of OBX ITB’s. They still need a load of work but far less than making my own manifolds.

They use the original injectors but the injector rails don’t fit. I’ll need to modify or get new ones made up.

ECU is now going to be a Megasquirt MS3 + MSX. Fully sequential injection and ignition. Sensors will be the original crank sensor plus one of the cam sensors.

I have decided to run the thermostat at the front of the car. So the thermostat “bottle” has been lost (partly as it impacted on the bulkhead) which means an adapter needs making up.

The original front water bridge impacts on the bulkhead and had a massive hold in it where the bypass originally fitted. So I need adapters into the head and to run a T piece.

So then I looked at the clearance to where the rear exhaust downpipe would run….

and then I looked at the chassis…. and I looked at the angle grinder….