Clarification on variable intakes

[ACRO]

hi!

i searched here a little and found also some topics regarding the variable intake tubes, but can somebody clarifikate that they were commonly used until the ban by the fia?

so was that something experimental or did even engines like lets say the asiatech or the european (ford) had variable intake tubes in the 2001,2002,2003 season?

thanks for any comments!

best regargs!

[Carlos]

The exclusion of variable length intake trumpets arrived with the change from the V10 to V8 engines with the 2004 FIA/F1 regulation changes. Here is an article comparing the BMW V10 3L to the BMW 2.4L V8 commenting on the V10's design which includes variable length intake trumpets/tubes.

http://www.autospectator.com/cars/bmw/0 ... -v8-engine

[ACRO]

a very interesting article you directed to! but the thing that really interests me- did every team had variable trumpets before the ban or was it only a feature for the "rich" teams?

did e.g minardi used this technology?

[midzt]

I never realised how stringent the rules governing engine design were, it seems that there isnt too much for engineers to work with, especially now given the engine freeze

What are the rules now in terms of VVT, variable intakes, variable exhaust etc? Are they still banned? How about variable compression ratios?

Seems ridiculous considering they would have direct benefit onto road vehicle, altho i suppose the big engine manufactures have done a lot of research into them now anyway.

Have the rules of engines changed at all? Such as the dimensions stated?


Sorry about all the question, just intrigued after reading that article.

[Carlos]

midzt - Variable is not a popular word currently, variable length intake and exhaust tracts are inexpensive and efficient, but not allowed in F1, I don't think variable compression has been tried in a racing engine, the only design I have seen is from Mercedes - a chain raised and lowered the crankshaft, changing compression, not quite sure how it's done, I haven't seen any diagrams, not quite sure, what is WT? Many items of the engine freeze seem odd choices to me too.

[joseff]

I think it's "VVT" Variable Valve Timing.

They're all banned.

[jaho101]

Does anyone have that article on how the Honda Rotary V10 engine was banned with the change to the V8? It seemed like an awesome idea, great shame it never came through.

[Reca]

i searched here a little and found also some topics regarding the variable intake tubes, but can somebody clarifikate that they were commonly used until the ban by the fia?

so was that something experimental or did even engines like lets say the asiatech or the european (ford) had variable intake tubes in the 2001,2002,2003 season?

According to my sources (the various Piola’s technical analysis of years 1994->2005)for a number of years around mid 90s Ferrari was the only engine using variable length intakes (Honda, that introduced the solution in early 90s, wasn’t officially in F1 in that period and the “non-official” Mugen-Honda engines didn’t use them), but by end of 90s almost all manufacturers adopted the solution. Actually I was convinced also Renault had them all 90s but apparently that wasn’t the case, and least post 1994.
Cosworth (Ford) AFAIK is the only engine manufacturer that never used variable intake length in F1. I’ve never seen it reported by media but I was told by an usually reliable source that FIA asked Cosworth help for writing the rules on the V8 engine so that could be the reason why it was banned.
If then Cosworth never had them had because of economical reasons or simply as design choice I can’t tell for sure, the system per se isn’t particularly expensive to design/tune (at least, that’s what Theissen said when he expressed his “displeasure” for the ban) but it’s also true that for years Cosworth equipped the small teams so to keep low the cost of the engine was crucial for them.

As for Asiatech, the engine was basically the “old” Peugeot, the French manufacturer adopted variable intakes only in 2000 so you should check which version of the Peugeot engine the Asiatech units were derived from, if the latest, as I believe, then it had the variable length intakes.

Hope this helps.

[scarbs]

Variable inlet tracts were in common use from the mid nineties, pretty much as soon as the teams got their hydraulic gearboxes going the mechanism to go variable on the inlets was possible.
Up until the ban all teams had them except Cosworth, they had planned to develop a system but the impending ban lead to them to continue to optimise the engine without them ahead the ban (in 2006).

Here’s what then Cosworth Tech Director, Alex Hitzinger told me at the time “Moving trumpets have been banned, I’m sure there’s different opinions about that. It reduces complexity in the engine, you need a hydraulic system which is not cheap so we just have fixed trumpets. So may be some manufacturers will change their trumpets all the time, it depends on what everybody wants to do. The other target was reduced performance because everybody had variable trumpets, except us. The reason why we didn’t have them, when I came in we didn’t have them, my plan was introduce variable trumpets for the 2005 engine and we had already started the design and we’d done all the analysis and we were ready to go. Then there was rule change announced which banned variable trumpets, and I thought for one year it was not worth going down that road and we used our limited resources for something else. Actually in 2006 it should be a benefit for us, as we learned our way around variable trumpets”.

[riff_raff]

Mahle (and others) make something called an "air impulse valve". While not explicitly an inlet valve, nor a variable geometry device, it does increase the acoustic effect in the intake by acting as sort of a one way valve. Don't know if they have been ruled illegal by the FIA or not. Or if they've even been tried in racing.

[Carlos]

Did a little research on this interesting Mahle system:
The Mahle electromagneticlly activated air impulse valve lowers fuel consumption and helps to produce higher torque, especially in the low rpm range. it is a fast-switching valve located in the intake pipe ahead of the cylinder head. With a switching time of approximately 3 ms, the valve enables charge exchange control with a high degree of flexibility that corresponds to engines equipped with variable camshaft systems, valve lift controls or switching intake manifolds.

To raise engine torque in the lower speed range, the Mahle valve system enables the generation of pressure oscillations—which can be used for pulse charging—in the intake manifold by means of active control of the flow processes. The air impulse valve can assume the function of a throttle valve, acting as the control system for metering intake air mass flow.

[Conceptual]

Did a little research on this interesting Mahle system:
The Mahle electromagneticlly activated air impulse valve lowers fuel consumption and helps to produce higher torque, especially in the low rpm range. it is a fast-switching valve located in the intake pipe ahead of the cylinder head. With a switching time of approximately 3 ms, the valve enables charge exchange control with a high degree of flexibility that corresponds to engines equipped with variable camshaft systems, valve lift controls or switching intake manifolds.

To raise engine torque in the lower speed range, the Mahle valve system enables the generation of pressure oscillations—which can be used for pulse charging—in the intake manifold by means of active control of the flow processes. The air impulse valve can assume the function of a throttle valve, acting as the control system for metering intake air mass flow.

Got a link to that info Carlos, it sounds very interesting.

Chris

[Carlos]

I had forgotten to leave a link to an article on the Mahle air impulse valve:
http://www.greencarcongress.com/2007/09 ... lse-a.html