5 replies to this topic

[kike]

I´d like to know if there´s any system for this purpose in F1 engines and how it works. I mean if only varies intake valve closing (I.C in degrees ABDC), or also intake valve lift, exhaust valve opening,...
anybody knows intake valve close ABDC at max r.p.m.? I made this question before and think it was missunderstood.
Thanks.

[Top Fuel F1]

Kike:

Some of the F1 engines have variable intake trumpets. This has do with tuning the air columns to meet the engines needs at various RPM. So it is variable but may not be what your looking for, as it may not meet your second qualifier: "distribution".

[kike]

Thanks Top,
I know the use of lifting trumpets, but what I want to know is if there´s any item to vary valve timing, to maximize charge at any rpm. (special in max. torque and max. power point), as vvt-i of Toyota i.e.
Thanks

[Top Fuel F1]

Kike:

I have Vtec on my Honda V6 engine. It uses a different cam lobe for better torque at low RPM than it does for higher RPM (for better breathing). Anyway, so far, I don't see anything in the 2000 F1 Tech Rules that would have specifically prohibited variable valves in F1. However when I look at a data matrix for all the F1 engines they simply say 4 pneumatic valves per cylinder. The rules allow 5 valves. I have seen some discussion where people were speculating that some teams may have variable valves. I don't know how they could keep this a secret in that some physical evidence would have to be in the cam area. That is unless the teams can keep the FIA from looking. If they can, I guess F1 is the only form of racing that could do that.

Regards; [p][Edited by Top Fuel F1 on 12-03-2000]

[Frank R. Champs]

Hello,

Regarding variable valve timing...Honda's VTEC system isn't the only way to vary valve timing. BMW, Porsche, Toyota, and others, have all introduced a continuously variable valve timing system that works in a totally different manner to VTEC.
VTEC simply switches between two stages of valve timing, ie. low lift, short duration/high lift, long duration. These other systems use a rotary device on the end of the camshaft to alter the cam's degree of rotation in relation to the crankshaft, thereby "degreeing" the cam to alter duration characteristics. While these systems do not create as much of a dramatic effect as VTEC, the valve timing variability is continuous, meaning that it can be constantly changing throughout the rev range.
More recently, Toyota and Porsche have developed systems that combine their continuously variable valve timing systems with a variable lift system very similar to VTEC, though not identical.

It is my firm belief that most Formula 1 teams are, or were at some point in the last few years using a simple continuously variable valve timing system, but not a variable lift system. Since the rules don't say anything about it, it is not illegal, and it wouldn't add much weight or complexity to devise a rotary device powered by the already existent hydraulic systems on every modern F1 car.
Part of the reason of my belief is that we often see F1 technology trickle down into Ferrari road cars, and Ferrari's most recent road going car, the F360, is the first Ferrari road car to feature a continously variable valve timing, hydraulically powered.

Regards,
Frank

[Top Fuel F1]

Frank:

Thanks for the good insight into VV!

Best Regards;