Rallycross Downshifting

[ELVA164]

That's fine, but heel-toe will help regardless of surface. You'll use up the synchros much faster by downshifting without it, whether it's on tarmac, dirt, or snow. It also reduces fatigue on the clutch, differential, and engine internals.

[ForcedFirebird]

That's fine, but heel-toe will help regardless of surface. You'll use up the synchros much faster by downshifting without it, whether it's on tarmac, dirt, or snow. It also reduces fatigue on the clutch, differential, and engine internals.

....and most importantly, the car will not get upset during the shift. I couldn't imagine not heel-toe in mid corner.

[nando]

What i'm doing is taking my right foot off the gas and pushing the clutch down to the floor with my left foot. Then taking my right foot and pushing down the brake pedal. Almost at the same time I'm grabbing the shifter and looking for second gear.

that sounds like a really slow, clumsy way to shift.

[ELVA164]

....and most importantly, the car will not get upset during the shift. I couldn't imagine not heel-toe in mid corner.

Also this, for sure. I would think trail braking would be pretty useful on dirt as well, yeah? So mid-corner downshifts would come into play even more often that way.

[itsonlygeorge]

Here's a good video on heel-toe shifting from Ayrton Senna.

https://www.youtube.com/watch?v=kzLjZWrpzmQ

[Northern]

There's a few other techniques, but the video should give you an idea. I use the ball of my foot to brake, then roll my foot over and tap the gas with the other side of my foot.

This is the way I "heel-toe" in E30s, and now other cars as well. It ends up being much more comfortable than trying to rotate your foot under the steering column.

A small part of OP's problem may also be shifter slop.

[markseven]

A small part of OP's problem may also be shifter slop.

Along with the aforementioned r3v matching and shifter slop:

If you you have enough steering input while you are trying to get into 2nd, bad motor mounts will allow the leaning motor to move the trans far enough out of alignment with the selector rod that you will have a tough time getting it into gear.

[TobyB]

I've driven standard cars for years and I know that this type of shifting does not require any sort of rev matching double clutching or anything like that.

If the 2nd gear synchro is balking you, yes, double- clutching it may very well help.
Early 2002's had to be shifted that way after about 15k miles because the synchros
simply gave out.

The essence of the whole thing is getting the gear lever into neutral, getting
your foot off the clutch, and goosing the engine to 4+k, and getting back onto
the clutch while the engine's spinning that fast. You're trying to get the input shaft
going roughly as fast as it will be AFTER you make the downshift.

It's not trivial, if you're braking.

It works.

Unless your car's fucked up, in which case, fix the car...

t

does it still, sometimes, as it's easier on the synchros.

[ForcedFirebird]

It's not trivial, if you're braking.

Exactly. Or mid-corner even, there's times requiring a down shift and no one wants to upset the car when it's any where near the limit.

[Smrtpunk]

Update: I went to the Rallycross this weekend on the condor solid mounts Engine/Trans.

I did'nt miss a shift. I modded my driving a bit as well.

Firstly, I only upshifted to 3 in one spot on the track. The other spots where I used to (2 others), I just wound the engine out, maybe touching the rev limiter a little in certain spots, but never for very long.

Secondly, in the area where I needed to go back to 2nd I made sure not to do it until the very last moment before I needed to accelerate. I would come up to the corner in 3rd, push the clutch/brake, perform the turn and then when it was time to power out I would go for second and and accelerate again.

All in all I'm very satisfied on how the event went. I put down some of the fastest times I've ever put down and I won Rear Wheel Drive for the event.

Ian

[nando]

you want to downshift before the turn, not after it. that's the whole point of doing rev match downshifts etc. this means you're also using the engine to assist in braking, and you can begin accelerating again before you exit the turn. you can't downshift in the middle of a turn (at least, you won't want to, unless you like spinning), and shifting at the exit is slower.

[Zreberlcoe]

I honestly believe rev matching and double clutching and what not really can save your clutch and synchros. My dad has owned his ix for 12 years with a uuc ssk and every single downshift he has made in that car was a double clutch rev match (exaggeration, but damn near everyone) and he hasn't had any transmission issues in the ownership of the car. It all is in the practice, he taught me when I still had my learners permit by grabbing my right foot and putting the ball of my big toe on the the brake and applying force, then blipping the other half of my foot onto the throttle. Now I am 18 and I have been doing it since I was 15 and no matter what car I am in I have to do it because it's the only thing I know. Just my $.02 about it all.

[ForcedFirebird]

this means you're also using the engine to assist in braking

I was always taught to never use the engine for braking. My old timer coaches would say "engine is for going, brakes are for stopping".

When entering a corner, I apply brakes, while simultaneously blipping the throttle and down shifting (matching revs and maintaining throttle, so when clutch is released, the car has no jerking motion in either direction). I am then in a lower gear still under acceleration (or at least maintenance throttle), once the apex is near, it's back to hard acceleration.

Using the engine to brake causes the rear tires to drag and can cause a spin.

Many times a downshift does happen mid-turn such as turn 17 Sebring where you are entering at the top of 4th (some are in bottom of 5th) and need to be in 3rd for the exit. While yes, T17 should be treated with a double apex and can brake in a straight line between apex 1&2, that always cannot happen when you are in racing traffic.

[irish44j]

No point in me re-hashing all the talk about heel-toe and rev-matching (both of which I'm very good at thanks to road racing). That stuff is the obvious answer for any kind of racing. That said, specific to rallycross:

What engine/rear end are you running? I run entire 60mph courses in 2nd (M42 with 3.91). In general, downshifting on a rallycross course isn't going to save you any time unless you guys have some super-slow turnarounds or something. Most rallycross courses I've been on you're just losing time with a lot of shifts (up or down), regardless of powerband.. When exiting a slow turn, you're usually limited more by traction than by torque anyhow, unless you guys run super-grippy courses. Even with an M42 I find it faster to just lay on the power on exit even below the powerband. The slight time lost there will be made up for by not having to upshift again.

Get a diff that will keep you more in the powerband, that would be my suggestion. Preferably something with a high ratio that allows you to stay in 2nd for the whole course (even if you hit the limiter here and there). Unless you're an ETA, in which case, that's not gonna happen ;)

Also in a slow turn you should be rotating the car with the throttle anyhow, and since you'll be spinning wheels you should be able to keep the engine in the powerband with the right amount of throttle application if you set it up right.

[Chris916]

Using the engine to brake causes the rear tires to drag and can cause a spin.

Only if you don't rev match properly. Ideally you want to be on the brakes as hard as possible while heel-toe downshifting so that when you are ready to get back on the gas, you are in the correct gear at the proper rpm to maximize acceleration. It's not rocket science, just takes practice to perfect. But it is something that can make a good driver into a really good driver, and can save valuable time getting through the corner.