Minitwins regs - airbox rule
 

I asked this question by way of a email to the Minitwins organisers via the link on the Minitwins website

How come with a 72bhp limit there is a rule that prevents you from modifying the airbox lid which is common practice on Ducati 2-valve air cooled twins even for road use.
Surely if such a modification was carried out and the bike still remained bellow the 72bhp limit it should not be a issue.

As a previous regular SoT racer I changed to the Ducati Desmo Due series for 2005 but did one NG meeting at Pembrey on my 51bhp 583cc Ducati, to comply with the rules I swapped the drilled airbox lid I normally use for the standard one.

I have since purchased a Ducati 750SS with a view to racing it in some Minitwin races, it should be capable of producing a maximum of 64bhp with race cans, K&N filter and a Dynojet kit, as with the smaller Ducati the filter and jet kit work well with mods to the airbox lid although only a small improvement in bhp is to be gained the bike will still remain 6 to 7 bhp below the class limit.

As such could the ruling on modifying the airbox lid be dropped or modified to allow it permissable for 2 vale air-cooled Ducatis to do this mod providing they stay with in the 72bhp limit
I'm sure this rule will also be of interest to the 620 class riders in Desmo Due who may also be considering entering some Minitwin races in 2006.

Regards

Kevin Ellis

And the Answer came back

Interesting point and as much as we are trying to keep all the bikes competitive it is much easier to enforce one set of rules across the board than have lots of exceptions for specific models.

For the 2006 rules we are allowing the use of Power Commanders and similar devices to encourage non-SV650 machines but I think the existing rules cover all eventualities with the 750SS.

Sorry I can't be of more help.

Mike

So from what I can make out is if I had a more powerful later model I could spend a couple of Hundred pounds on improving its power output / response but I can't drill or cut holes in the lid of my airbox to try and improve things while remaining under the 72bhp limit.

And I always thought the idea behind Minitwins was cheaper racing ??

I think Desmo Due Class B is the real form of cheaper racing

Helpful huh ?

I think when TP raced last year at Cadwell they made an exception for him re the airbox rule.

I can see where they're coming from though... they write the rules in consideration of the regulars who'll buy a bike appropriate for the series rather than just the occassional guest ride.

Get a fuel injection manifold on your 583 and PC it up!!

...and if your uncle was a woman, he'd be your aunty!

We got enough rules to complain about over here, why the hell start on Minitwins?!?!?

:lol:

Yes they did make an exception for TP for the MRO round, but that means most DD racers who may want to ride at a Minitwins round would have to get the same approval. This could happen at several rounds and also for several entries at any given round, so why not just amend the rule to suit.

As for appropriate bikes that basically means fuel injected SV650s and not the odd 2-valve air-cooled Ducati and how would they know how many rounds I would enter, I have done several complete seasons with North Glos including two in Sound of Thunder and also two in Streetstocks where the rules took a little time to evolve and I often use to approcah the club officials with concerns from other riders with regard to rule changes.

So Dom was the bike you raced in one of the rounds a legal Minitwin with unaltered Airbox

Didn't say I disagreed wiv you kev... just sounds like their rules are established and they have enough of a grid not to need to encourage more entries.
Get Nino drunk and ask him to fight your corner!

Nick at North Glos Pembrey rounds they could fit another 10 on the grid, I doubt if that would apply to Thruxton, Brands, Silverstone and Donny, it may apply at Darley Moor.
May have to see if NG want to make an exception as they only adopt the Minitwin regs they could easily enough add there own ammendment, especially if it will help encourage others to enter.

Legal???

Pah!!

Legal is for losers :lol:

What airbox? ;)

Yes I rang ahead before I entered Minitwins at MRO to explain the airbox thing because it was the only issue I was illegal on. Unfortunately for you Kev I was granted my exception by the MRO organiser and not the Minitwins organiser. Dave was fine because he realised with my meagre 62hp I wouldn't be threatening the leaders.

I must admit I'm very disappointed with the response from the MT organiser on a few issues lately - it seems it should be the SV cup!

If you haven't already seen my post at NG then you might be interested to read this:

"One of the problems I can see is that the rules were designed around SV650's so, where certain mods that give a performance boost to an SV are not specifically excluded, this automatically discriminates against other bikes because either they don't work on those other bikes are they can't physically be done on those other bikes.

See below for such an example."


"Ironically, with an SV you can jack up the tank to allow more fresh air in and effectively increase the airbox volume as the tank forms part of the seal to the air filter. This is a well-known mod that gives serious power increases in the mid-range and a few more at the top end. This is permissible under the existing rules.

Yet you are not being allowed a DP airbox lid or a few extra holes in your airbox.

That doesn't seem right to me. "

Clearly here the application of the rules favours the Suzuki.

Wait a cotton-picking minute - doesnt that constitute modifying the airbox - its called lifting the airbox lid in my book !
That kind of thing could be tried - lift the tank an inch and then lift the airbox lid to butt up against it.
Given that the airbox lid has such a puny hole as std, an inch gap all across the front alone would be about 4 times the area.

Approx. 4.17362 x more ;)

It's one of the inconsistencies in the rules. If doesn't actually affect the air box or its lid but, the results are pretty much the same. Really, it's case of pedantry - it amounts to the same thing. If that is permitted then Skids 750ss should be allowed a modded airbox lid.

Ooops! Someone didn't like having some pertinent questions being asked about the even-handedness and consistency of the minitwin regs. The thread has been removed from NG's website. :lol:

I asked for the thread to be pulled,
I had the answers to my questions and any outstanding points I will discuss with the relevant people at NG club.
I wanted to know what I was allowed and not allowed to do to my 750SS, not what was going on with SV650s with regards to the rules.
The initial questions I asked and the answers I received were getting lost in what was turning into a lengthy thread.
I Have copied the relevent posts so I can refer to them when discussing things with the appropriate people at NG.

Having already answered your air box questions twice, once in email and than once on the NG forum, I am surprised you felt the need to bring it up yet again. If the bike isn't suitable or you really need that very final 0.5 hp (or whatever negligible amount the modified air box gives you) then maybe you should concentrate a bit more on your riding rather than worrying about the bike.

As for the risers to lift the front of the tank on the SV650s, as I've already pointed out in email and on the NG forum that they are illegal according to both the 2005 and 2006 rules. Why spoil things by continuing to ignore the fact that we police the series based on those rules and people have previously been pulled up for contravening them on that very point?

The rules are there for all bikes and are not focused on the SV650 in any way. As the MRO series for 2006 will have a factory backed Kawasaki ER-6 on the grid isn't it rather sad that we don't have more support from the Ducati contingent?

The various MiniTwins series are more than happy to see lots of Ducati machines during 2006 and we will do our best to accommodate you (see certain rule changes for 2006) but, please, let's all stick to the same set of rules to make it fair for everyone across the country. Trying to encourage different rules at different clubs will only see the series shrink and create confusion as to what is a legitimate MiniTwins bike and what isn't.

Scuse me, this thread was running in parallel to my thread on the NG forum and up until your post today has sat with out any futher input for 2 weeks, which suggests to me you came looking for it.
As a fully paid up member of both the DSC and NG I feel I have every right to post either questions or my views on either of the forums and make fellow club members/friends aware of any of the answers and debates that have gone on.
As this club has somewhere in the region of 65 members going racing in 2006 we can safely say there is a healthy Ducati contingent out there on the track.
As I mentioned I have no interest in what the SV owners are doing to there bikes only what I am allowed to do to my Ducati which will comply with the 2006 Minitwin rules and will be well below the 72bhp class limit.

Good on yu fella I been sitting here waiting for that response.

:mad:

I don't post this to be antagonistic but I think you've only gone half way in your rule changes. I know you've allowed a power commander to be fitted to get around the fact that you can't change the internally stored maps on the 800SS ECU. But, why did you stop at allowing replacement ECU's to get around the clock, ECU and red key anti-theft measure that Ducati has built in? A simple option is to replace the ECU with the FIM version but you don't allow it, this will enable the bike to be run without the original clocks etc.

Do you think that this gives a measurable advantage over just adding a power commander?

I really don't understand this one Mike.

The reason we didn't allow the replacement of the ECU was that after discussion with a number of people, including Ducati experts such as Geoff Baines, the feeling was that it would make policing the series very difficult.

Most ECU replacements, including just changing the EPROM on some of the earlier bikes, allow the ignition advance to be altered. At least if we restrict everyone to standard ECUs then we can keep track of what people are doing and create a fair series for more people.

The rules for the series continue to evolve and had we had such feedback at some point during the last year when we changed the rules to specifically allow larger air cooled motors, done with Ducati in mind, we could have had more time to investigate the pros and cons of such a suggestion.

Surely the majority of riders have no trouble keeping their red keys to hand so don't have any problems with using the stock ECU. I appreciate that Nigel is a special case but in most circumstances I don't see it as being a problem.

Rather than comments such as that maybe you have something useful to contribute?

And that sort of attitude sums up exactly why the thread *was* removed!

Christ! Is it winter by chance?

Why does everybody want to change the rules? The rules are there, if you like them get a bike that fits the rules. Sorry, this may be irritating some of you, but rules are there to be exploited not changed. Just my view...:cool:

Felix I asked the question on NG as it is there series I want to run in. On there site they have the 2004 rule book posted as such I was enquiring if they would be adopting the 2005 rulebook (No 2006 rules published at that time) and if they were could they possibly allow for the use of modified airbox lids on air cooled Ducatis. Not a unreasonable request at the time of year.
But here is a bit more of what went on and when you get to the end you may see why it would be in NGs interests to attract more bikes to their MT grid.


WHAT WENT ON

The Thread on NG website was removed at MY REQUEST as mentioned in my post above.

And why did I start the thread in the first place. Because I thought NG were running there own series independent of other Minitwin series and the regs they had posted on their website was the 2004 rules, where as on the Bemsee and Minitwins websites they had differnt rules called the 2005 Minitwin rules.
So I asked if the rules would be updated for 2006 and if so would modified airboxes be allowed.
A response on the NG website suggest I use the email link on the Minitwin website to ask the questions, which I did. I posted my questions and the answer and then left my feedback both on here and the NG site.

Now as A SoT regular with NG for a few years I saw the grid dwindle to the point where every race was for half points. With half a grid to fill NG decided to fill it by starting a Minitwins class originally sponsored by my mate Paul from the Suzuki shop just down the road from where I work. The intention to be offer a cheaper form of racing a twin compared to SoT and hence attract racers to the grid.

Now in its current format I would not say it has been that successful

NG 2005 Minitwin entries first 2/3 of the year
rd 1 5 X MT Pembrey
rd 2 4 X MT Pembrey
rd 3 4 X MT Darley Moor
rd 4 4 X MT Darley Moor
rd 5 10 X MT Silverstone
rd 6 5 X MT Cadwell
rd 7 5 X MT Cadwell
rd 8 11 X MT Brands
rd 9 11 X MT Brands
rd10 4 X MT Pembrey
rd11 4 X MT Pembrey
rd12 6 X MT Donington

So only when at Silverstone and Brands where the MRO riders used it for a bit more practice you can see it hasn't exactly filled the other half of the grid, not even at Donington where my mates son Craig Polden turned up to take the win.

CONCLUSION
To me it made sense to ask for a simple rule modification to a out of date rule book (2004) that may encourage a few entrants on ducatis and also to clarrify what spec I should build my 750SS to.
Now if anybody sees anything wrong in that they really should take a long hard look at themselves.

Kev

Just checked still 2004 rule book http://www.ngroadracing.org/Pdf/minitwins.pdf

And while on the subject as someone else decided to start it off again.

As for the airbox mod on a Ducati if you study the text and graphs here http://moto-one.com.au/performance/750ssie.html it can be seen that not only does it improve throttle response but it also adds approximately 5% more power from the middle of the rev range up to the redline which when combined with open pipes and the correct fueling curve gives a good 5bhp over the standard bike.

It is a cheap mod that has benifits something that most racers try to find and if it costs next to nothing, Yet it narrows the bhp gap on the competition its not suprising that racers would want it.

I would expect my 750SS when finished and set up with the airbox lid fitted to put out around 62bhp with the airbox lid standard and With a modified lid I could be looking at 65bhp.

Now with a class limit of 72bhp that some bikes will no doubt be very close to it doesn't take a Genius to work out that 72bhp - 65bhp = 7bhp difference which is better than 72bhp - 62bhp = 10bhp difference.

I don't disagree with what you're saying, Kev, and completely see your point. My comments weren't directed specifically at you, Kev. This is certainly not an isolated case and it just struck a nerve.

As far as I can see the link to the Regulations section of the NG web site is broken. Perhaps when they fix it they will post an up to date set of regulations.

Not the end of the world as everyone was policed tot he 2005 rules anyway.

But when I did enter at the last Pembrey of the season it was linked and thats the rules I played to and the link was still there when I decided to prep a 750SS for next season which is why I asked the question on their website and suggested a update.


I can understand that, but I'm not whinging

If you had been with NG for as long as I have (bearing in mind i was mechanicing for my mates before I started racing myself) you would have known they value riders input.

At one time halfway through the season they would hold a riders forum at one of the meetings, where issues and ideas could be voiced with the committee taking note of what the racers had to say especially if the experienced racers raised concerns.
Following one such forum they introduced a warm-up lap before the races, prior to this there was no warm-up lap. You formed up on the grid which was about 10 riders per row and 3 to 4 rows (Wide Airfield circuits). Then when the flag dropped the race started. What changed things was the introduction of the Dunlop D207GP, it was pointed out that unlike the Pirelli Dragons (previous top choice for the racers) the Dunlops need to get some heat in them. Now none of the circuits wwe ran at had power and 1.5kw Gennys and Tyre warmers were a rare sight. So after this was pointed out by the racers it was decided to introduce a warm-up lap and it has been like that ever since.
Also when Streetstocks were introduced at NG a few rules were modified after feedback from the racers with a lot of the riders input going thru me.

Now I don't expect rule changes to be made once the season is underway unless on safety grounds but I do expect organisers to consider sensible suggestions during the closed season especially when made nearer to the end of the previous season rather than close to the beging of the new season.

It's not just about keeping the red keys to hand though, it's about not being able to remove the standard clocks to run another dash if you like. And if you didn't - it's about the cost of replacing the entire suite of key, clocks and ecu which is dramatically more expensive than adding the FIM ECU for example.

I know we both know that Nigel is a perfect case in point here - I'm not suggesting you make a rule specifically for him. I came across the same rule which prevented me from buying a crash damaged bike I could have bought cheaply to enter minitwins. Maybe you'll see this as a valid reason or not but ... if that rule had of allowed replacement ECU's I would have bought an 800SS a few months or so ago and would have been prepping a bike for minitwins right now. I know I'm not reason enough to change rules but I am a definite example of someone who is racing in a different class to minitwins because of this one rule.

I'm not whinging, I'm making a valid point.

Sorry Felix if you feel that it's me who is whinging a bit here ...

TP

Tony understands the issue I have with the 800ss perfectly well but, Mike still doesn't seem to understand it. I'm not really a special case nor am I asking to be made one. As it happens I have two 800ss Dukes. One with a red key and all the instruments (it is new) and one without (a cat C recovered bike). However, I will not use the new bike because I cannot afford to risk trashing the instrument panel on it. This problem would not exist if I could use the FIM ECU because it bypasses the ECU/immobiliser and instrument panel integration.

The problems I and any other Ducati rider face are this (even with the bike with the red key):

1. I cannot replace the instrument panel with something else (like a race tacho) because the bike won't run without the original coded panel.

2. If I break the instrument panel in a crash I cannot ride the bike until a new oem unit is fitted and then re-programmed at a cost of ~£600. This cost is significantly more than an FIM ECU.

Before anyone asks - it is not clear whether or not a used panel could be substituted either. I asked the question of Ducati and they weren't able to confirm one way or another. I've spoken to John Hackett at length on several occasions about this issue and he wasn't sure because at some point in 2003/2004 Ducati changed the way the the immobiliser worked. Earlier bikes did not depend upon the panel to be run but, later bikes do.

It's all academic really - for these two reasons alone I will not be racing an 800ss in Minitwins now. Lest I be accused of attempting blackmail - I want to make it clear that I made this decision purely on the basis of financial common sense.

[Edited on 22-12-2005 by twpd]

[Edited on 22-12-2005 by twpd]

Mike I thought we had agreed to disagree. So far I have kept my peace so, don't kick it off again.

[Edited on 22-12-2005 by twpd]

No nothing, other than suggest you apologize to Kevin for your earlier personally insulting post.

Happy Christmas


:saint:

On what basis was it insulting?

[Edited on 23-12-2005 by Mike Edwards]

I am not going to answer this as i saw your unedited post first and think it may influence my reply



:D