I'm pretty sure that in a road car - everything except the MRT, formula cars and GTR cars - it would cause small engine damage but would not show up in under 500km of doing it as there is a rev limiter to stop you from taking the engine into revs it cannot handle. As someone else said, the rate of change of RPM would, however, cause damage. The question is weather this would show up in the engine in a normal race.

However I'm also pretty sure that it would lead to plenty of gearbox damage. Some 'ricers' power shift their engine (flatshift) and then replace the gearbox frequently. The question that should be asked is weather you will cover enough km's in one race for this to show up.

Quote from axus :

The question that should be asked is weather you will cover enough km's in one race for this to show up.

Yes, exactly what i was trying to ask all the time! Does flatshifting cause damage during a race, and is it to serious, to be expensive for teams..? I know that i surely would not drive my everyday car like that, but this is a race, and race cars that we are talking about, so.. ?

Quote from Boris Lozac :

expensive for teams..?

bend a valve: 8 valves £100
crack a piston: full rebuild £thousands

Miss a gear and one of these is likely to happen, thankfully bending valves is more likely. Those prices are for a CVH (Escort engine) a modern production based competition engine will cost a lot more, you've got 16 valves for a start ,

A basic new or reconditioned Hewland box and clutch (4 speed) is about £2750 but you've got to factor in adapting the car as racing parts are made in batches and it's not economical to remanufacture them (until they become eligable for historic racing). A Formula 3 spec box (which is about the FOX's spec) is £6150.

A sequential full race box and it's be more like £20715 for a GTR type and £28000 for a Le Mans Prototype spec endurance box.

My guess is an F3000 box would be around the £15000 mark.

http://www.hewland-engineering.co.uk/

Quote from Dibblah :

You do realise that the drag car engines are rebuilt after just about every race, don't you?

Top fuel cars are rebuilt after each race. Most drag cars are NOT. Many of my friends drag race their cars on the weekend, then take them to work during the week. The only time their engines get rebuilt is when they break, which isn't very often considering they hit the rev limiter many times per pass, and make many passes per day. Many of these cars are driven HARD and have over 100,000 miles on them.

Wow, thanks a lot guys. Fantastic and very educational feedback.

Bob: the wheel is a Thrustmaster Ferrari F1 Force Feedback -- I think that's what it said on the box. It's quite heavy duty with a big solid aluminium shifter bar across the back of the wheel.

(And nice aluminium pedals, although good old Thrustmaster / Guillemot saw fit to mount those aluminium pedals on a stupid plastic base, necessitating a bit of a rebuild with my carpentry 101 skills.)

Flat shifting isn't faster as proper use of clutch/throttle in a road car, except for a turbo perhabs. (because of pressure)

If you leave throttle while shifting with clutch rev will go up to the limiter. Next gear and then clutch will slip a bit before torque can be used to accelerate the car. Perhabs its faster with a real good racing or dragster clutch, but not in a road going car with usual clutch, because it won't be able to get the torque on the street while bringing rev to the rev of next gear.

It wouldn't be faster, it would heat up the clutch and damage it. An overheated clutch doesn't work that good

It depends on the engine, but with peaky RACE cams flat shifting will make a huge difference, as when lift you go out of the power and, unlike a road car there's almost no torque, same applies for full race Chevy and Ford V8s, despite being 5 litres they have very little torque, but a hell of a lot of power in the powerband.

The revs in each gear are the same no matter if you flat shift or lift shift, so it makes no difference to the power band. Revs and Speed are a FIXED relationship (clutch and wheel slip permitting)

Of course, flat shifting is slightly quicker, so you'll less speed as you'll spend less time off the throttle, but this is only gonna be about 50rpm - not much really.

Quote from Hallen :

Boris, what everybody is trying to say is that it depends on the car IRL. Some race cars have standard H type transmissions with clutch, some have sequential with clutch, and some have sequential with all the gadgets to allow flat shifting with no clutch.
For a standard car like the GTi, flat shifting will cause damage eventually IRL. The clutch, the engine, engine mounts, transmission mounts, drive shaft and differentially will all get hammered over and over again causing damage. You will always lift and blip when shifting in these cars. The point is not necessarily the max RPM's you hit, but the rapid change in RPM's that happen during this manuever.
For some sequential boxes, you can upshift without using the clutch, and some you need to lift and some you don't. Sports cars with sequential systems usually require that you use the clutch for downshifting and that you match revs by blipping the throttle. However, if the rules allow, just about any pure race car can have systems that allow for flat, no clutch shifts using the different methods listed above.

You put that far more lucidly that i ever could of, bang on!

the main thing to consider is that all the cars are different, you should take into account that the UF1000 shouldn't have a speed limiter, so, even if you're just revving it hard you'll star to cause damage (usually it's the valve bounce that naturally limits the rev's i can hear that ning,ning,ning noise like it was yesterday )
whereas the GTI + turbo's would certainly have ecu's onboard and thus almost certainly have some rev protection.
the full on racers would all have programmable ecu's which are all mappable for all sorts of inputs and uses like speedlimiters, rev-limiters,throttle cut,Anti lag and of course that 'orrible traction control.
it's just a case of reflecting what sort of system that car would really have.

Quote from tristancliffe :

The revs in each gear are the same no matter if you flat shift or lift shift, so it makes no difference to the power band. Revs and Speed are a FIXED relationship (clutch and wheel slip permitting)

Of course, flat shifting is slightly quicker, so you'll less speed as you'll spend less time off the throttle, but this is only gonna be about 50rpm - not much really.

Think of the clutch. If you shift up rev in next gear has to be lower, because as you say Revs and Speed have a fixed relationship.

This difference between the revs of the engine and the revs of the wheels (gearbox) has to be equalized before engine torque can be transferred properly to the wheels. Thats exactly the task of the clutch. If you put your foot off the throttle while shifting, rev will decrease naturally because there is no connection and no throttle. Therefore rev difference between engine and wheels is lower when next gear gets in. Therefore clutch hasn't that much slip, because it hasn't that much difference to equalize.

If you stay on the throttle you even increase or stay at full revs. Difference between engine revs and revs in next gear is a big gap. This gap has to be closed by the clutch which slips as it tries to equalize full revs to the revs of the correct speed in next gear.
If the clutch slips it can't transfer full torque because it partly gets lost in the slippling clutch.
Your engine torque energy then is used to heat up clutch and not to accelerate the wheels/car.

I watched a lot of videos about that stuff. Watch Walther Röhrl accelerate a Porsche 911. He has a little start rev. Leaves the throttle like it is when he disengages the clutch. Only then, when foot is fully off the clutch he puts the foot on the throttle to the floor. Before clutch is disengaged it can't handle full throttle power.

Thats why it isn't faster in most cars. I don't know about Dragster gearboxes, but we are talking about street cars or usual race cars. Either they have a sequential gear box which cuts ignition automatically or you have to do that manually.

You guys talk a lot about damage but very little on what happens in LFS during a race.

I normally drive with the aids off, short of the auto clutch as I don't have a 3 pedal system with a stick shift...maybe one day. I don't really try to rev match or anything when driving. It's odd cause I drive a manual in real life and always constantly make an effort to rev match both up and down gears. In real life, my car will lurch or buck, sometimes violently if I neglect my matching. LFS isn't so physical with you. Without the feeling, it's a lot harder to make an effort to do such things. About all I do in LFS is let off for a second between shifts so I don't bury the needle in the red. S1 punished you easily if you didn't. S2 doesn't seem to care so much. Still, I do it. In LFS for down shifts I don't even match the rpms, just gas off. For the road cars, it doesn't matter much unless you're cornering at the limit. You can upset the rear tires easily and start a drift. I drift a lot, so I personally don't care. I've gotten used to it. In the lower powered cars, it doesn't matter too much what you do with the gas pedal.

Now, when you're working with the Formula cars, it's a different story. If you're off with the matching, you're quite likely to whip the car around. When I first started driving the Formula cars, I actually put the blip and cut aids on to keep me from spinning out all the time. With so much power to the ground on such a light vehicle, delicate footwork becomes oh so much more critical. THIS is where things like flat footing becomes a no no. You just can't do it, not safely anyways.

If you're really working the limits of the car, I'd suggest making an effort to match rpms. If you're in a lazy mood, throw the auto blip and cut on. If you're not running the car at the limits all the time, you have some play room for mistakes and you can leave them off. I personally like them off as I have more fine control over what happens. It's quite helpful when drifting when you purposely want to upset the car. In racing, it may or may not be of use, maybe at times. For speed, eh, I guess that depends on if you screw up because of it. One mistake will take out any gain you would have gotten from it. It's up to you.

I somewhat disagree with what you are saying Squirrel. With the formula cars, you don't need to lift on up shift. They shift so quickly, that you can shift flat and not cause any damage. Most real life formula cars use the electronically controlled throttle cut for shifting anyway so this is reasonably realistic.

For downshifts you definitely do need to mach the revs. You have to downshift quickly in the formula cars, so the blips come fast and furious. Automatic blips would be appropriate if you were driving something like an F1 car, but I am unsure about how the RL Formula 3000 or G2 GP cars work.

to be honest you're all right, some of the time, like i said before the cars all need to be treated differently, and modelled differently.

the only reason ANY of those pro's can shift flat is because the car is designed to do that, be it electronic or mechanical design. I don't think we can say that you can flatshift a GTR or cannot do it in a GTI, it's merely down to what you're driving, and i'm driving LFS, so i'll lift 'n' blip for now 'cos it feels good.

BTW i can't remember EVER seeing a drag-racer shift flat (not like we are talking about - with manual gearboxes), 99% of drag racers use a auto-box, those who don't use 'em are almost certainly driving a road car, auto's are perfect for the strip due to a few things - no clutch to burn out or cock up shifting with, very very little actual break in power when you do shift, you've also got a torque converter so they'res not a massive amount of power instantly that would spin the wheels. (well not like a sidestepped clutch anyhow )

Quote from tristancliffe :

Of course, flat shifting is slightly quicker, so you'll less speed as you'll spend less time off the throttle, but this is only gonna be about 50rpm - not much really.

Normally you'd be right, but in a low powered (140 bhp) high downforce single seater the data analysis results are obvious. The FOX has more power (190 bhp) and most people run with very unrealistic low downforce setups. In reality everyone runs with a large amount of downforce and flatshifts, even at the fast tracks like Snett (and some cars spend a lot of time and money testing, and have knowledge from their Formula Renault racing).

Depends how you look at it. The wing angles may be low but that undertray still produces loads of force. At top speed it's enough to increase the effective weight of the vehicle by two thirds. With both wings at maximum you can just about double the effective weight.

So even with the wings removed there's lots of downforce there.

More the mindset when setting a car, IRL it tends to be maximise the downforce at the expense of straight line speed, in LFS the opposite. Not to say other options haven't been tried and failed, don't know why this is the case in LFS, to find the reasons you'd need accurate data for a Formula Renault car and a good understanding of car physics (neither of which I have got )

Quote from Theafro :

BTW i can't remember EVER seeing a drag-racer shift flat (not like we are talking about - with manual gearboxes), 99% of drag racers use a auto-box, those who don't use 'em are almost certainly driving a road car, auto's are perfect for the strip due to a few things - no clutch to burn out or cock up shifting with, very very little actual break in power when you do shift, you've also got a torque converter so they'res not a massive amount of power instantly that would spin the wheels. (well not like a sidestepped clutch anyhow )

Have you ever actually watched or participated in drag racing? It is totally untrue that 99% of drag racers run automatics. Many do, but nowhere NEAR that amount. Many, many, MANY people drag race with a manual transmission. Manuals are lighter and cause less parasitic drag on the car (so more power gets to the wheels). Drag racing clutches rarely "burn out" because they are not designed to slip like a normal road car clutch. You prevent wheelspin by using slicks and proper rear suspension setup, not by using an automatic. Most drag racers who do use an automatic have very stiff shift kits installed and use high-RPM lockup stall converters so the power is transmitted very quickly, just like a manual tranny car. Many bracket racers tend to use an automatic because they're consistent, but a LOT of racers still use a manual tranny either because of it's advantages or because they like to row their own.

Quote from Boris Lozac :

BUT, if real drivers do not drive like that, and they DO lift off the throttle when up(down) shifting, then i would like to see damaged engine for flatshifting.. the more real the better.. For now.. i will continue to flatshif because others also drive like that..

With a real Clio S1600 rallycar for example, you don't need to lift off when up shifthing (only when down). I think all WRC and all competitive S1600 employ that system.

In F1 i think too.

With Clio i'm totally sure i tried 1 last year.

I've raced some and have driven a lot of rally cars (from 70 HP group N to WRC) and race cars (up to supertouring & GT).
You can flatshift without damaging the engine in any (race or road car) trhat has rev-limiter. The damege to clutch/gearbox/engine mounts/joints... with flatshifting if you awoid doing 1-2 (and sometimwes 2-3, depending on power, gear ratios etc ...) is negligent. Not matching revs on downshifting will cause much more damage because shock loading is much greater than with flatshifting ...
Even if you're quite brutal, gearbox and other stuffv will usually take normal race without apparent damage (but will fail eventually if you do not rebuild it after that) ...