Arena Zytek 07S

[SebringMG]

Knighty, there is rumoured to be a new 4.5 litre version of the Zytek V8 about to break cover. What sort of increase in torque would you expect ? And would the vibration be less or not (as a result of having to use less revs) ?

[dj choc ice]

Originally Posted by SebringMG

Knighty, there is rumoured to be a new 4.5 litre version of the Zytek V8 about to break cover. What sort of increase in torque would you expect ? And would the vibration be less or not (as a result of having to use less revs) ?

the 4.5 version of a zytek V8 would give a pretty good gain in torque and a hike in power as well, say 40 lb ft of torque atleast gained probably more than that and an extra 10bhp or so probably more.

[knighty]

Originally Posted by SebringMG

Knighty, there is rumoured to be a new 4.5 litre version of the Zytek V8 about to break cover. What sort of increase in torque would you expect ? And would the vibration be less or not (as a result of having to use less revs) ?

I agree with the above......Looking at the Judd V10 engine data on Mikes website, when they went from 4.0 to 5.0 engine capacity, (a 20% capacity increase) the torque went from 350Lb/ft to 445Lb/ft.....which is a 21.3% torque increase......so as a guide, torque increase correlates quite well to the capacity increase.....so whatever torque figure the Zytec 4.0 was producing, add on another 11.1% and theres your torque gain for the 4.5 Zytec motor.

Using the Judd 4.0 V10 torque of 350Lb/ft.....that would be around 39Lb/ft gain.....which puts it around 390Lb/ft (523Nm) which is stil nothing to get excited about, as the 6.0 units will be pushing 800Nm......

but increased torque and power are not the only good reasons for increqasing capacity, it will be a great benefit to fuel economy, engine durability and oil consumption, as the 4.5 unit will be revving lower........it may also move the rev range out of a nasty torsional vibration / resonant frequency.

Mugen have done this 4.0 to 4.5 conversion already in the Courage chassis last year, and essentially it was still a sprint engine.......but best of luck to Zytec on this conversion, it will be interesting to see how it gos

[class4v]

The Mugen M-Tec MSF 4.5 V8 was not really a good choice. Yes it had more power and torque, but far from the Judd GV5.5 and the fuel consumption was bad for Le Mans. There was also too much vibration destroying the car and also the engine itself. Even with a lot of work on the internals, M-Tec went again for the 4.0L version for the JLMC and had to admit that the 4.5 was a bad choice and wouldn't hold 24 Hours with the car. Knowing the Zytek engine engineers and their approach they will encounter the same problem. They will have the make a serious engine design change in order to make it work for the Le Mans race.

[knighty]

interesting!......I have heard similar problems with the old F5000 engines that run flat plane cranks......once you go above 4.0 Litres, the reasoning for balance shafts becomes even stronger, I dont have time to do the maths, but I know its a known problem.......

back in the 70's and the days of the Mirage Gulf cars, Cosworth had a 4.0 Le-Mans version of the DFV on the drawingboard, and without the aid of powerful computerised analytical technology (like Adams etc) they knew back then that they needed twin balance shafts, to help damp out the destructive side-to-side shaking forces of the flat plane crank....... for 24hr racing this cant simply be cured by pendulum or quill dampers in the cam-drive geartrain (like in F1), it needs something more serious than that......and that is twin balance shafts.

for Mugen, it sounds like the 4.0 was operating its rev range just above some nasty torsional/resonant engine frequencies.......they lowered the rev range via the capacity increase, and I dare say piston mass increased too.......and they landed slap bang in the middle of a vibration nightmare.......

a similar thing happened a few years ago in IRL, but the other way round, when the 3.5 IRL motors went to 3.0 capacity, and they changed the rev limit (I think).......something along those lines, their engine reliability was all of a sudden only 20% of what it was......a real nightmare.

[The Real DMN]

Reading between the lines from Murphys latest blog; could the Arena Zytek be the alternative fuel prototype there has been rumors about?

[joeb]

I had that same thought, especially since there wasn't a definate answer to what the engine in the car would be earlier.......

[dj choc ice]

Originally Posted by The Real DMN

Reading between the lines from Murphys latest blog; could the Arena Zytek be the alternative fuel prototype there has been rumors about?

there were talks of a hybrid zytek engine in the back of the 07S but it was quashed because of weight problems, not unless zytek are pushing ahead with this venture,.

[brielga]

Originally Posted by The Real DMN

Reading between the lines from Murphys latest blog; could the Arena Zytek be the alternative fuel prototype there has been rumors about?

100% no

[ThePenguin]

Originally Posted by dj choc ice

there were talks of a hybrid zytek engine in the back of the 07S but it was quashed because of weight problems, not unless zytek are pushing ahead with this venture,.

There were also talks of an Audi V8, like the one that Swiss Spirit had last year.

[Justin Moran]

Originally Posted by ThePenguin

There were also talks of an Audi V8, like the one that Swiss Spirit had last year.

But Audi have removed the customer engine from Lola and I presume from anyone else too?

[ThePenguin]

Originally Posted by C9/89

But Audi have removed the customer engine from Lola and I presume from anyone else too?

They may want to try again, or they may just get rid of it all.

[KA]

Originally Posted by ThePenguin

They may want to try again, or they may just get rid of it all.

I hope I'm wrong, but after the Swiss Spirit programme spent about as much time in the courtroom as it did on the track, I wouldn't be surprised if Audi are pretty wary of getting involved another customer engine programme....

[TWK]

Reading between the lines from Murphys latest blog; could the Arena Zytek be the alternative fuel prototype there has been rumors about?

Originally Posted by brielga

100% no

It depends on what your definition of "the" is.

Now, use "an" instead, perhaps without a specific team reference...

It's got nothing to do with salad oil and Sebring, for sure.