DIY Air Intake Mod
 

I have been fiddleing with DIY intake mods for some time and before starting the Mk 2 mod I first fitted a thermocouple in the airbox with a read out of intake temp inside the car.
I'm not doing it for 'show' :D and wanted to be able to remove easily at a later stage

https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png

Basically the aim was to exclude the hot air from the engine bay/radiator and increase the flow of cool air to the airbox.

I first added insulation under the airbox intake and over the radiator.
This is foam pipe insulation covered with Duck tape.

https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png

Next I added an airguide to the underside of the bonnet.

This fits close to the top and sides of the airbox intake when the bonnet is lowered.
I used a lot of trial and error and it is made of layered self adhesive pipe insulation foam from Do It All and black Duck tape.
In it's final version it is now tight to the airbox intake and the insulation over the radiator.
It extends over the crossmember to the front of the rad and cool air.
Total cost about a fiver! :cool:

https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png

I took readings at various points in the development and plotted them on a graph.
The readings are:
1. The cold or ambient temperature
2. The temperature just before getting home from a long run, taken at about 40mph.
3. After the car had idled while stationary for 5 minutes.
4. Turned engine off, reading after further 5 minutes.

https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png
Sorry about the quality of the graph, however I upload it it comes out the same :mad:

The top and bottom line are before any mods other than the rad insulation, at different ambient temperatures.

The other lines show various stages of developement. The latest is the yellow one after I had tightened up the gaps and I took off the centre section of the plastic airguide by the bonnet catch, held by three screws.

The graph is quite interesting. It shows a much smaller increase from ambient to normal running temp with the mod in place.
The next section shows a much smaller increase in temp. when the car is ticking over, as if it was in traffic. Before fitting the airguide the increase when the fan came on was very rapid!
If the lines are projected forward the differences are much more pronounced over time.

Ian

Anyone got a Blue Peter badge? :D

Interesting :)

A little unclear on what each colour of line is for though.

One of these days I will get around to measuring the intake manifold temperatures with and without the use of a vented bonnet.

I am all for the heath robinson approach.. :D

but as stevenM mentions, intake manifold temp is the final point to measure, the airbox temp may have to be very different to make a significant and also measured difference at the manifold.

Sorry, I guess I overcomplicated the graph.

Basically, if you compare the top blue line with the yellow line it illustrates before and after.

It shows a 5.2 degC improvement when on the move and a 10 degC improvement after ticking over for 5 minutes.

The other lines just show the improvements I made as I went along with small changes to the shape and sealing of the air guide.

This was not just about outright performance, although it has got to help, but also about heat soak kangarooing due to the engine inhaling the hot air from the radiator and engine.

Would be interesting to compare with before and after figures for a Spoon type intake. :) (Thermometer was

Nice work again.

I had the Roo's on my old 02 S,I insulated the box and removed the
same 3 screwed plastic cover and it helped a lot.

Russ.

Im no process / chemical engineer, but surely lowering the intake temp will lower the manifold temp to the same degree? To me, there is only the amount of ambient / underbonnet heating to influence the temp after the intake? There is very little generated from friction / bends etc so I would reckon the difference to be linear.

Looks good!

MB

Depends on how you do it.

By directing more air into the airbox you deflect some air from cooling the underneat of the bonnet and as a result the manifold heat may increase.

https://cimg3.ibsrv.net/gimg/www.s2k...1bd993846f.png

I have started the blue and yellow lines (before & after) from the same point to make the graph clearer and added a trend line to project them forward.

This would seem to point to a difference of more than 15 deg C after 10 minutes ticking over while stationary.

It all depends on the ambient temperature too.

I've got something similar, I'm measuring temps in front of the rad, in the snorkle, at the filter and in the engine bay. (4 thermo couples)