FV and heel-toe/rev matching

[Capital Knockers]

I'm a FV sim racer who is looking to get into a real car one day in the future. I race on iRacing, and one of the negatives is that there is really no good way to simulate transmission damage. This allows for drivers to downshift freely without using the clutch (which I believe is possible in real life, if your revs match, but seems risky). Additionally, most people do not lift the throttle on upshift and you can force a car into gear at any RPMs without much penalty.

I was curious in real life how important blipping the throttle and rev matching on downshift is, and if there were any other quirks that the simulator might be missing out on.

Thanks!

[Adriancnh]

I'm a FV sim racer who is looking to get into a real car one day in the future. I race on iRacing, and one of the negatives is that there is really no good way to simulate transmission damage. This allows for drivers to downshift freely without using the clutch (which I believe is possible in real life, if your revs match, but seems risky). Additionally, most people do not lift the throttle on upshift and you can force a car into gear at any RPMs without much penalty.

I was curious in real life how important blipping the throttle and rev matching on downshift is, and if there were any other quirks that the simulator might be missing out on.

Thanks!

They will change gear on downshift with no blip but you lose stability on braking and will wear the dogs faster. The gearbox wont shift up on throttle without really forcing it. Bottom line, when you get in the real car just lift/blip... it's really not difficult to do and becomes second nature pretty quick.

[Ed Womer]

A FV tranny has syncro's so no need to blip the throttle for up shifts or down shifts. Also once moving a FV only uses 3rd and 4th gears so as long as you are a competent manual transmission user you should be fine. NOTICE I said competent!

Ed

[Adriancnh]

Here I am thinking I responded in the FF forum, I've never driven a FV so ignore me and listen to him^

[FVRacer21]

I'm a FV sim racer who is looking to get into a real car one day in the future. I race on iRacing, and one of the negatives is that there is really no good way to simulate transmission damage. This allows for drivers to downshift freely without using the clutch (which I believe is possible in real life, if your revs match, but seems risky). Additionally, most people do not lift the throttle on upshift and you can force a car into gear at any RPMs without much penalty.

I was curious in real life how important blipping the throttle and rev matching on downshift is, and if there were any other quirks that the simulator might be missing out on.

Thanks!

Interesting topic - for people moving from iRacing to a real car. BTW Crash damage is ALWAYS on.

I started in FF but have spent the last many years racing FV. I also race in iRacing, but use the Auto Clutch and the problem I have is NOT being able to match the gears properly on a downshift resulting in a spin - especially with the current FV model. (Note, There is an Auto Blip and I am working on the idiosyncrasies of each...)

As far as double clutching, with a non-syncro box like the old Hewland Mk 9, you had to match the revs on the shifts in order to minimize wear on the dog ears. When upshifting, most of the time the pause and slight lift is enough and it goes right in.
When downshifting you had to pause in neutral, blip the throttle for two reasons. One is to match the revs so when you let out the clutch the engine is the correct rpm. This keeps the balance in the rear when braking or cornering. (an induced Trailing Throttle Oversteer). The second is to manually synchronize the shaft and gear speed so the dog ring ears will slip directly into the gear ears without excess grinding.

Note you are not moving gears in this box, (except for reverse) just unlocking and locking floating gears already in mesh. So your "damage" mode is very hard to program as excessive dog wear usually results in the transmission popping out of gear.

In iRacing - since I don't have a shifter, maybe someone can chime in if you try to force a gear, say in the Lotus 49, do you get a grinding or crunching sound?

With a real FV, Ed is right, the gears use synchronizers, not dog rings, (again, gears are always engaged) so as long as the clutch is disengaged, as you shift, first the blocker ring and synchro cone match the speed of the shafts with the gear, then the shift sleave locks them together.
https://www.gboxweb.com/synchroassy2.png

Now if you don't lift on an upshift or slow the car down before downshifting, you make the blocker ring and synchro cone do the work you were doing before with the throttle. In a street car the #2 or #3 synchros are the first to go as they see the most action. But it usually takes thousands of miles If you want the most out of your real FV tranny, not power shifting or forcing downshifts will make it last longer - but I cannot quantify that. Only the tranny rebuilders can....

So to minimize damage in all non-sequential gearboxes - if you use a clutch and shifter in iRacing, practice double clutching.

If someone could chime in about modern sequential gearboxes, I would be interested if the less expensive ones make you use a clutch or do thy all use a ignition cutout when shifting.

For more info:
https://www.facebook.com/racecrafthq...6453407736679/

PS - At the Skip Barber Driving School - way back when - we were taught how to shift without a clutch in case of a clutch failure. I used it many times on my Corvair when the clutch cable broke or on English sports cars when the hydraulics failed on the clutch.

ChrisZ

[Steve Davis]

If your query is about how REAL FV cars work .. using WAY WAY OLD transmissions... You CAN upshift and downshift without the clutch (if you are experienced and PRACTICE at it)... HOWEVER, you will WASTE TONS OF TIME doing it. Vee transmissions can ONLY be shifted 'at speed' using the clutch (this is between 3rd and 4th only. If you have to use 1st or 2nd and want a 'speedy shift', then you'll have to Both USE the clutch *AND* match the revs during downshifts. I 'test drive' in my driveway on occasion (about 1/4 mi) and have a very tight 180 at each end, where I basically HAVE to drop down to at least 2nd on one end and all the way to 1st on the other end. Getting those downshifts absolutely REQUIRES a knowlegeable and skilled clutch/blip to get it done - more so on the 1st gear end. The gear simply WON'T ENGAGE (assuming your synchros exist (there is a 'non-synchro' 1st gear that could be used which would just CRASH the gears), If I miss either of those shifts at the ends, I just have to slow down MUCH more to avoid running off a cliff (through a fence) on the tight end, or into the road on the other.

There is NO WAY you can experience that in any sim that I've seen. In a vee, you have a very positive connection between the shift handle and the internal gears in the trans.... if you want to KEEP the gears in the trans functioning, then you'll have to learn the shifting techniques required .

'Normal' on track shifting between 3rd and 4th doesn't take a lot of skill .. assuming you use the clutch both ways. It downshifts 'easier' into 3rd by also matching revs with a blip and is a LOT less wear and tear on the synchros. Upshift (with clutch) is no problem at all. Upshift without the clutch will add some 'seconds' to each upshift shift unless you try really hard (force wise) to get it into 4th.. which it MIGHT still not get there any faster, no matter how hard you push (guessing 3 to 4 seconds for the engine revs to come down enough).. and most (I would say NONE) vee shifter mechanisms won't last very long doing that.

Steve, FV80

[Ed Womer]

Something I did forget to mention, on downshifting it will benfit you that under braking do the downshift but don't just let the clutch out as soon as the shift is completed but as you are coming off the brake to go back to the gas so you won't be over revving the engine.

I have raced with a lot of people over the years and you can tell when someone doesn't do this as you can hear their motor screaming since they will jam it into 3rd as they go for the brake. Your engine builder will love the constant repeat business.

Ed

[helipilot04]

As far as double clutching, with a non-syncro box like the old Hewland Mk 9, you had to match the revs on the shifts in order to minimize wear on the dog ears. When upshifting, most of the time the pause and slight lift is enough and it goes right in.
When downshifting you had to pause in neutral, blip the throttle for two reasons. One is to match the revs so when you let out the clutch the engine is the correct rpm. This keeps the balance in the rear when braking or cornering. (an induced Trailing Throttle Oversteer). The second is to manually synchronize the shaft and gear speed so the dog ring ears will slip directly into the gear ears without excess grinding.

Note you are not moving gears in this box, (except for reverse) just unlocking and locking floating gears already in mesh. So your "damage" mode is very hard to program as excessive dog wear usually results in the transmission popping out of gear.

For those that want to shift it properly, Please do not double clutch The Hewland MK9,

The following is directly from www.Hewland.com/faq

[Capital Knockers]

Interesting, thanks for all the discussion!

[FVRacer21]

“Firstly, it is impossible for a driver to co-ordinate the complicated sequence of all five physical movements accurately.”

Gee, I don’t know whether to be corrected or insulted.

I guess the F1 drivers who are steering, shifting, braking, all while adjusting the dozens of things on their steering wheel must really be superheroes……

You don’t normally double clutch on an upshift. The natural slowing down of the gearset works.

Concerning a downshift, I can also see that a very small drop in ratio could mitigate the need for a clutch out blip in neutral, but still require a matching of the throttle to the speed of the car and new gear ratio to avoid excessive engine braking. In FV there are big drops between gears from the spec ratios.

We are getting off the original topic, but the weight of oil also can affect this as the higher the weight oil, the more drag on the gears, which might influence whether to double clutch on a downshift.

Since most schools since 2010 have used boxes with sequential gearboxes, I assume the double clutch is no longer taught. Thinking on how I shift my motorcycle, I rev match but of course do not put the gearbox in neutral while downshifting.

Ross Bentley does not push double clutching (from 2021):
https://speedsecrets.com/q-do-i-need...tch-downshift/
https://www.youtube.com/watch?v=lIgEyyjVJVs

When done right, double clutching (dog ring, H Pattern) makes a very smooth gear shift, albeit at some extra wear on the pressure plate and throw out bearing. If you can downshift without grinding, go for it.

ChrisZ

PS - Totally agree that you don’t usually shift immediately when braking. Until you slow the car down enough, you just run the risk of over revving the engine. Stand in Big Bend at Lime Rock for examples.

[helipilot04]

Gee, I don’t know whether to be corrected or insulted.

Please do not take what I posted as an insult. It was not intended as such.

I wanted to make sure anyone reading this post understood that the MK9 is a different animal than the FV vw (syncro) box.

The MK9, like the LD200 can and should be shifted as the hewland manual states. Quickly and without the clutch. After running both of these gearboxes, I use the clutch for two things, one is to leave the pits, second is to fix a bad/missed shift or during a spin. Normal race shifting is done with rythm and speed, no clutch. Blip on down and lift on up.. easy peasy.

I hope this helps those that are new to the MK9 or LD200..

regards
Bob

[FVRacer21]

Please do not take what I posted as an insult. It was not intended as such.

........

regards
Bob

Bob,

Nothing taken from you, I was referring that Hewland does not think their customers capable of handling this.

I spoke to Bruce MacInnes from SBRS and while they still teach heel and toe (Mustangs); double clutching is gone as the Mustangs have syncros and the new Formula cars have auto-blip on the sequential gearboxes....(they do teach left foot braking)..Sigh, another skill lost to technology....

ChrisZ

[fv9]

I'm a FV sim racer who is looking to get into a real car one day in the future. I race on iRacing, and one of the negatives is that there is really no good way to simulate transmission damage. This allows for drivers to downshift freely without using the clutch (which I believe is possible in real life, if your revs match, but seems risky). Additionally, most people do not lift the throttle on upshift and you can force a car into gear at any RPMs without much penalty.

I was curious in real life how important blipping the throttle and rev matching on downshift is, and if there were any other quirks that the simulator might be missing out on.

Thanks!

Out of curiosity, where in WA are you located? Im in Camas and my dad is in Bellevue. We both race FV on the west coast.

[Capital Knockers]

Out of curiosity, where in WA are you located? Im in Camas and my dad is in Bellevue. We both race FV on the west coast.

Awesome! I'm out near Redmond. If you have any good online resources for local formula vee stuff, please send it my way!

[fv9]

Awesome! I'm out near Redmond. If you have any good online resources for local formula vee stuff, please send it my way!

Ill PM you.