Any tips on where to obtain intake air filters? Is there a K&N available, or is UFI satisfactory. Thanks in advance. EHT
Last time I looked, K&N does not make a filter for the 400. They do make a similar size that you can cut down to fit. I think its for a Jag. As for air flow, the filter is the least of the problem. The Bosch K-Jet system is ten times more restrictive than any filter. Eurospares has the OEM filter for around $15 each. If you change them once a year, that probably good enough.
"The Bosch K-Jet system is ten times more restrictive than any filter." I do not belive the Bosch K-jet is much more restrictive then the Weber carburators. The extra horse power that is made in the Weber equiped 400's is becouse of the cam overlap that they can run that K-jet does not tolerate. If you were to change K-jet car to Webers with out changing the cams there would be no HP. increase.
K&N #33-2570 fits volkswagen k-70, verify dimensions http://www.dragtimes.com/Volkswagen-K-70-KN-Air-Filter-Part-59212.html Also, K&N's website is also good as it has dimensions of all its filters.
Fritz, I disagree. The meter plate in the K-Jet pushes against the air flow being forced by the control pressure. The air pushes back and therefor controls the fuel flow. I believe this action creates far more restriction to air flow than carbs or filters. As for HP, at a static RPM the HP rating has little to do with air restriction. Any restriction simply acts as an offset in the throttle position. The real gain in lowering restriction comes in during rapid changes in throttle levels. When you mash down on the accelerator and the butter flies open, the only thing between the outside air and the inside of the cylinder is the filter, the meter plate (K-Jet), and any fluid drag in the intake system. Any metering system that does not have metering plates is going to give less restriction to air flow. When I decided to ditch my K-Jet I was on the fence whether to go with webers or EFI. I chose EFI simply because I'm more of an electronics guy and I liked the idea of running a closed loop system for more control. IMO Mark
Paul, The 'Metering plates' were are talking about meter the amount of fuel to the amount of air going into the engine, has to be there with this systom. Mark, air flow equals horse power. The more flow the more power, weather a pump(turbo) or an effecent engine with 4 large valve and a low restrictive intake and exhoust that can be spun fast to flow alot of air. The nature of a carburator is to have a venturie or as the British say "choke" becouse that is what they do, restrict the flow of air to speed it up and create a low presure zone to suck the gas out of the bowels. Not very "clean flow". Multiple carbed engines have good throttle response becouse they squirt gas right on to the intake valve as soon as the throttle plate gives more air with the next intake cycle of the engine. On a Bosch 'K-Jet' or a CIS to not use a brand name, the operator wants more power and moves the throttle plate opeon, the engine has to revolve some to get more air past the metering plate before the fuel systom gives more fuel. The "warm up regualtors" help by sensing a low manifold vacum and alow more fuel but there is still a delay. A good EFI will be better than Webers or CIS for metering fuel and for more HP. EFI will allow you to run cams from a Weber engine for more top end power. I think we all look forward to your progress, Fritz
I hate to be a bother, but this system is very restrictive. A pair of butterflies ( as in all injected autos ) and two metering plates that open about a 1\2 an inch. This is like a racing horse breathing through a drinking straw. Am I wrong in thinking that it serves no real purpose?
I wonder sort of HP a 400 engine would make using individual efi throttle bodies per cylinder with an appropriate cam?
