Quote:
Originally Posted by Tygen1
If I could figure out a way to make a WRA (Warm Ram Air) without hacking up my car, I might try it.
|
Hi - Newbie so this may be rubbish.
In my old Mini (circa 1989 so thats Mini not BMW MINI) here in the UK the air intake had just such a device. The pipe just before the air filter had 2 intakes, one from just behind the grill and one from just above the exhaust manifold. The junction between the two had a bimetalic strip which had a piece of air-filter style sponge on it. The idea was that when cold the engine would take air from around the manifold (at the back of the engine, transverse - FWD) and when warm would take air from behind the grill.
The strip was springy enough so that on full throttle, well full throttle for 998cc and 40 Hp (DIN), the junction would open from either side.
A performance "mod" was to remove the strip to increase airflow, mainly as temps didn't really drop below -2 or 3 deg C. Now due to global warming they are usually around -3 or 5 deg C.
It added around 0BHP really but helped the stupidly efficient SU carb a bit more that usual - my MPG went from ~40 to ~45 (Imperial) and the SU was helped by allowing the pressure to drop a lot so more fuel went in so response was much better. Ok I was a boy racer then (even with only 40 BHP).
I've kind of thought about something similar for my current motor (Diesel hatch) but there doesn't seem enough room under the bonnet plus there is a turbo and an intercooler to disrupt matters anyway.
As an aside my friend with a carb-feb (SU) Mini with 1litre and an SU carb can make more MPG than a new Hyundai i30 with 1litre and fuel injection which makes me think of the extra weight of moderns, the extra "carp" they carry (air con and so on), and also how good the 1920's design of the SU really was.
