Discussion and questions related to the course Practical Harness Construction - Club Level
Has anyone out there successfully tried alternatives to DR-25?
Looking at the specs, there are a couple of key criteria that need to be met to keep to the same standard as DR-25 -
Heat resistance - DR-25 is rated to 175 deg c
The use of Elastomer (instead of fluoropolymer, polyelfin etc) - This keeps it to be flexible and also helps with the heat resistance. Also required for the resistance to fuel, brake fluid, oil etc
Wall thickness - DR-25 is quite thick when recovered which helps with the abrasion resistance (and probably the heat to a certain extent)
Flame retardant - so it doesn't burn . .
Looking at the options out there, I cannot find a lot - there are a lot of commercially available heat shrinks that are in the 120 deg range - which inside the cabin is probably more than acceptable - which meets the other criteria but if you want the same thing end to end is is a bit difficult - 3M has some great products that meet the criteria but it makes DR-25 look cheap.
I have found that RS Components has the RS Pro line of Heatshrink which is directly comparable to DR-25 (ticks all of the criteria above except it doesnt have a yellow "DR-25" on the side), is cheaper but only currently available in 3 sizes - 1", 3/4" and 1/8". Are there any other options out there is or d owe just keep drinking from the TE fountain?
A few I’ve found that seem to meet the requirements;
DSG Deray V25
Have a look here, has a cross reference for autm, scl, dr-25 and others.
I remember seeing a product called 'Raceline' a few years ago, but have never tried sourcing it personally. Something to google though.
Great reference Brett.
I have ordered some of the RS Pro elastomer heat shrink which will turn up next week, will see how it stacks up.
I have to make not only an efi harness but a full chassis harness so am looking at quite a few meters of heat shrink. Full dr25 would run to well over a grand so am looking at ways to save a bit of money without compromising quality. TE seems to be the go to choice here for everything and they know it with prices to match, am willing to give some of the competitors a go.
I also stumbled across this:
Looks like a more cost effective solution
Ben, DR-25 isnt the cheapest stuff around for sure, but that is sounding pretty expensive... Where are you sourcing it from?
Hi Zac, I have looked at various sources - a couple of the local Australian motorsport suppliers, DigiKey, RS Components, the US guys. For the larger sizes, it runs around $20-$30 AUD / m, the smaller sizes $10-15/m. As I am making not only a engine / ECU harness but also a full chassis harness (headlights, indicators, demisters f/r etc) I basically need to wire all four corners of the car as well as everything in between. The list of what I am wiring is as follows:
29 sensors with a combination of engine and chassis, covering all 4 corners of the car and a few in between - this may grow before the job is done
4 injectors with wiring for 4 extras
4 fuel pumps (2 x lift, 2 x pressure)
Headlights - high and low beam
Indicators - all 4 corners
Heated screen front and rear - front requires wiring both sides.
Gearbox oil pump
Diff oil pump
2 x PDM's - 1 front and 1 rear to try and keep the wiring shorter.
And a few things I have probably missed.
Except where needed I will be keeping power loom seperate from the ecu loom.
It all adds up to a lot of DR25, branches, boots, SCL etc. The other issue is that as this is my first go at it, I dont have a good grasp on how much of each size I will need so need to order some extra length to make sure I am covered.
This is the Raceline one that Zacc mentioned earlier. Its apparently the same specs as DR-25 but I haven't looked into futher
Ben try GR Motorsport electronics for your DR25 supplied in AUS
Well, there are many cheap products on market. Founding something in 1/3 price range will be easy.............. but. The cheap Heatshrink tubes are not so flexible once recovered, they dont offer so great heat resistance, and they will also not offer so great mechanical durability...... all depends at price what will customer pay.