Ah, So its more like aerodynamic resistance in the crackcase? With a vacuum pump it would thin the atmosphere in the crack and reduce resistance.... Altho the vacuum wont effect the mechanicals directly, it clears the working space around them?....
Alot of Diesels dont have throttle plates or exhaust restrictors but still brake like a petrol....
Mechanical drag must make up atleast 40% of engine braking if not more... If not it means that the throttle flap vacuum in the intake is many times stronger than that of the pressure in say a 10:1 compression ratio stroke...
Altho it will help a bit, i think its not almost solely throttle vacuum that creates engine braking. Without fueling, an engine is just a heavy compressor....
Mk2 Astra 1.4
Cavalier Sri 16v
Cav Ls 16v
Carlton Gsi 3L for £150 with 6 months t&t from auction
1.8 Astra Gte which went into
Nova 1.8 Gte
Astra Mk3 Sri
V6 Cavalier into
V6 Mk3 Astra Sport
800 Vitesse 2l Turbo with fishtank valve mod to 270-280bhp.... Lasted 3 weeks.. Another £100 auction car with 3 months t&t
Impreza 1.8 GL
Passat 1.8 20v Turbo
Mk4 Astra 1.8 Sport
Theres several others ive missed, mostly £100 auction cars bought for thrashing til explode or t&t is up....
Plugging the pc into th stereo is probably th best option really....
Even if u fitted an amp, it is still better to use the stereo as a passthru, It will convert 2 channel audio upto 4 channel and you would keep all the sound options n cd/radio features of the stereo working....
If u just wanted to use an amp on its own you would have to rewire all the speakers and basically have the stereo disconnected sitting in the dash taking up space.....
So u want a stereo thats cheaper and better than th one u have altho the one u have does what u need anyway?.... U wont get much more than 4x50W in a headunit so if u want clear and loud u need an amp.....
My Kenwood stereo was £50 from Halfords... It has 3.5mm input, 2 amp outs, 55Wx4 and can play upto 10 hours of mp3s off normal cd's....
Ive got a 900w Aiwa Hifi wired to my Pc.. Gets much better fidelity and bass than any Pc speakers, Especially when playing films/music loud or surround sound games....
Get one off ebay for under £100...
Just dont put the speakers right next to ur monitor....