2000 restricters ?

[scorchio]

Will the Mono Club be restricting the 2000 class who run on throttle bodies?
Were we told that if the gap on power between the throttle bodies and carbs
were too wide the throttle body would be restricted.

Throttle bodies = 205bhp +
Carbs = 175 - 178bhp.

Is this power gap wide enough, I think so - try racing one.

?????????

Will be at the dinner but can't make the afternoon meeting.

Can someone raise this issue?

[tristancliffe]

Vauxhall on Carbs = 175-178hp.
Toyota on Carbs = 185-190hp.
Toyota on TBs = 190-195hp.
Vauxhall on TBs = presumably around 180-183hp?

If anyone tells you that there standard engine is producing more than 200hp then they are lying. Or cheating. Or the dyno is wrong (the most likely).

Bent valves, 48mm carbs on a 45mm inlet manifold with no 'bite' out of the port to match the head port, and an exhaust cam timing pulley that had jumped a tooth would all decrease performance, especially at the top end.

In fact, I think you proved that power, engine condition and careful jetting of carbs is entirely unimportant if you have a good enough driver.

[samier]

I was told no Mono engine is pushing more than 180.. that includes Toyota engines on TB's, your figures blows that comment out!

I think the only way is to have an independent rolling road conduct a power run and have people turn up and get the results of how much power and torque their engines are making.

I am all for it.

[samier]

Will the Mono Club be restricting the 2000 class who run on throttle bodies?
Were we told that if the gap on power between the throttle bodies and carbs
were too wide the throttle body would be restricted.

Throttle bodies = 205bhp +
Carbs = 175 - 178bhp.

Is this power gap wide enough, I think so - try racing one.

?????????

Will be at the dinner but can't make the afternoon meeting.

Can someone raise this issue?

You cant try racing one, they will fly past you 10-15 mph quicker.. you could try making an F1 type wing that reduces drag!!

[tristancliffe]

Who told you that?

Who is going to pay for the tyres on a rolling road (as they usually knacker a set)?

Rolling roads are not very accurate.

Would we be allowed to fit bent valves for the session?

Dallara wings flex, and most cars don't run a slot gap support, so drag (from the rear wing) does actually decrease with higher speeds (well, the coefficient of drag will go down, obviously the actual drag will still increase with the speed²).

Scorchio has been rather successfully racing injection cars in 2010 already. Scorchio is the best driver in Mono2000.

The 10-15mph difference is down to your cornering.

[samier]

Maybe just take the wings off... I remember visiting the first mono race in 2008 (Thanks Tristan for talking me through the race day format) seeing a yellow formula ford with F3 tyres.. in a straight line it looked very fast.. anyone know what happened to it?

[tristancliffe]

Richard Bastow's Mygale SJ00 I think.

Restrictor plates are horrible awful things, but could be used to reduce the 40mm throttle limit to something less. Jenvey throttle bodies don't, as far as I can see, come smaller than 40mm. Because a restrictor plate is an 'orifice plate' they effects are much bigger than the number would indicate, as the flow forms a vena contracta - this is when the flow continues to converge AFTER the plate, making the 'effective' hole quite a lot smaller.

Some experimentation would be required - someone would have to put forward a healthy engine to test on a dyno - to see how small a hole drops the performance sufficiently. 0.5mm (i.e. orifice of 39.5mm) might make a 40mm jenvey comparible to 48mm carbs, but it might be 0.7mm. Or 1mm. Who knows.

What engine do you test with? If we're trying to match a Vauxhall on carbs to a Vauxhall on injection, then that's easy and we can get an orifice plate size. But if we're comparing a Toyota on injection to Vauxhall on carbs a different orifice plate size will be established. So do we end up with different orifice plates for different engines.

How do the club establish mapping differences? Or dual injectors per cylinder? Or sequential injection? Two identical engines mapped by different people (even on the same dyno) might give different outputs.

It's a tricky one, and trying to simplify a problem down to a single number (all air for a cylinder must pass through a hole no larger than x millimeters) is fraught with difficulty. What about airboxes versus box filters?

[samier]

Your right, it does get complex with multiple engines, maps, injectors, ecus...

Just have an open engine forumula where anything goes..would be fun seeing a dallara with a turbo! Drop in a C20LET from the Calibra Turbo.

[tristancliffe]

A friend of ours at the Autosport Show offered us a V8 engine for the Dallara, but I don't think it would have fitted, and John Atkinson would have spotted it immediately!!!

Formula Libre and some hillclimbing classes allow pretty much anything. Hence Judd V10s doing crazy times up the hills in the back of amazing cars.

I'm not against a restrictor (although I'd prefer it if it wasn't an orifice plate, which is a horrible way of doing it that should remain in NASCAR) if it means more cars are racing each other, but somehow the differences in engines, mapping, engine condition have to be thought out. Are we equalising max power, max torque, area under one of the curves?

I'm glad I don't make the rules!

[tristancliffe]

I know of two "Mono 205+ hp" engines. Both are Toyotas.

One isn't really 205+
The other isn't Mono legal or standard.

[samier]

Yours being one of the the legal ones, less than 205 and more than 200! Nice!!

[tristancliffe]

Yours being one of the the legal ones, less than 205 and more than 200! Nice!!

I wish! When we first talked about injection with various suppliers, mappers etc they thought 215hp might be achievable with their products/services, and that 200hp would be easy. Sadly it turned out they were talking up their products/services up (marketing - who can blame them? Nobody would sell anything if they were 100% honest), because we didn't get that close to tge magic 200. We did use some bigger 42mm throttle bodies on tge dyno to see what would happen (they would have been outside the regs) and got 202hp, but the torque curve was more hole than torque.

So no, we don't have 200hp, but we do have more than a carburetted XE. Then again, so did the Toyota on carbs... Lenny is pretty quick in a straight line (until the Reynard's 1988 drag levels kick in).

[Russ]

Vauxhall on Carbs = 175-178hp.
Toyota on Carbs = 185-190hp.
Toyota on TBs = 190-195hp.
Vauxhall on TBs = presumably around 180-183hp?

If anyone tells you that there standard engine is producing more than 200hp then they are lying. Or cheating. Or the dyno is wrong (the most likely).

Bent valves, 48mm carbs on a 45mm inlet manifold with no 'bite' out of the port to match the head port, and an exhaust cam timing pulley that had jumped a tooth would all decrease performance, especially at the top end.

In fact, I think you proved that power, engine condition and careful jetting of carbs is entirely unimportant if you have a good enough driver.

Any forum where power outputs are quoted is up for abuse or ridicule depending on your viewpoint.

The work that was recently done with the FR restrictor sizing showed how flaky some peoples dyno figures are, and how some peoples power quotes are bigger than their egos
The only numbers I agree with above are the difference between an injected engine and a carb one, i.e. about 2%, on a good day
The rest, well, lets just say I don't understand the basis of the scaling or the test conditions used.

The size of the aperture that any Mono 2000 engine draws its air is pretty much fixed, on carbs it physics say that 40mm is as good as it gets, on TB's its the rules.
Carbs can actually run bigger, but the driveability goes down the pan. The main reason a TB setup make slightly more power is due to better atomisation of the fuel.
Tony Cotton’s bike carb setup is very clever, giving some of the benefits of both.

If you think you are significantly down on power, there are a raft of things that can cause this effect, the condition of the engine, its ancillaries, the gearbox, wheelbearings, wing settings, brakes, the list is almost endless. Interestingly the car that Younus says was really quick, Richard’s Mygale, has one of the lowest power outputs of all the engines used in Mono, the Ford Zetec. The slightly lower power also didn’t stop Malcolm Scott beating the Dallaras with a Zetec powered VD last year.

As Tristan quite rightly says, driver aptitude has a far far bigger effect on performance than any tweaking of horsepower.

[andrewcliffe]

Malcolm got a great start and then his Van Diemen became ultra-wide!

[Nat Filmore]

As Tristan quite rightly says, driver aptitude has a far far bigger effect on performance than any tweaking of horsepower.

Ah the truth.... Always so uncompromising and often so unacceptable, especially in motor racing.