Maligator

What is the maximum speed you guys are downshifting at? Ive yet to downshift like an auto where it screams to redline instantly; two reasons, one I dont want to be on youtube with my z wrapped around a pole, and secondly, the car scares me (first manual 500+hp car). So you are cruising, 30,40,50 or 60 miles per hour, where is the threshold for downshift to first or second? Obviously 3rd is ***** footing it, aka my speed.........I got a little crazy downshifting from 4th to 1st the other day at about 40mph and the azz end kicked out pretty good even though my wheels were pointed straight ahead..........

phipp85

If you look in the owners manual it will tell you the max mph for each gear. The tires are breaking loose on you because there is such a big difference between the engine speed (rpm) and the current driveline speed. To prevent that you need to "blip" the throttle right before you engage the clutch in your target gear. In my head I remember roughly the max mph for each gear. 65, 85, and 120 for 1st, 2nd, and 3rd. If you're going 60 mph and want to go to 3rd gear then before you let the clutch pedal out you need to be right around 3500rpms and the transition will be pretty smooth.

Rupert pupkin

I downshift all the way down to 2nd only @ 40-55mph. I can hear the engine noise and gauge how hard I need to press on the gas pedal to rev match. No way in hell ill downshift from from 4th to 2nd... 4-3-2-1. Need to go in sequence.

darr3239

Why?

rabrooks

Downshifting to 1st is never a good idea unless your going really show. When your rear end kicked out, that wasn't power, that was engine braking. Not good with that kind of rpm variation.

Mark2009

Downshift to any gear you want as long as you rev-match and know what you're doing (have a plan) once you get there. The car doesn't care as long as those two conditions are met. Sounds like the OP lacked the plan

However, I can't see the need to be skipping gears on the street unless coming to a stop.

Maligator

Im working on the rev match, I know about it, but it does take some practice. In regards to that, are you giving the gas a quick stab and timing it where you let the clutch out at that desired RPM? Or can you hold the gas at that desired RPM while letting the clutch out? Im doing the later because my timing blows...........

Rupert pupkin

What I meant to say is that... Get accustomed to the gearing first 654321... Where those rpms fall into, or the range and go from there. Hell I can go from 5-3, 6-4 etc. Depends on speed too of course.

erichg1000

There are times on a track that you will go from 4 to 2 or 4 to 1 when coming off a longer straight and braking into a slow tight turn.

It's no big deal, just don't force it, let the shifter make out with the gate until the synchro's get er ready to go in.

I myself blip the throttle and when the rpm is right then let the clutch out. First practice just blipping and then once you have the rev matching practice down you move into the heel toe action. Takes practice.

Rupert pupkin

I find myself having difficulty doing the heel toe in the Z..

erichg1000

I have a giant aftermarket gas pedal it makes it easier. I do more of a roll over so the side of my foot is blipping the gas.

duhveed

OP is gonna bring the car to the dealer and wonder why his tranny and clutch is effed up lol

Rev match.....please

Maligator

how does not rev matching destroy a clutch and trans? Keep in mind, I dont drive the car anywhere near its abilities or track it. Its to and from the store, or a cruise, thats it...............

erichg1000

Well in mild cases it will not destroy anything, but it will add some wear to the clutch. Minuscule wear if you ask me. The smoother driveline engagement is, the less wear.

It's the difference between a grocery getter getting 180,000 miles on the stock clutch instead of 200,000 for instance.

Now if you were doing this near redline, and often, then it would destroy stuff. (IMO)

Mark2009

1. Clutch in.

2. Blip the throttle while downshifting. May take a bigger blip than you think.

3. Clutch out.

With the correct amount of blip while moving the gear lever, the declining RPM will be pretty close when you let the clutch out. Probably better to be a little high on RPM when the clutch re-engages than a little low. Takes practice. Don't hold the gas pedal.

Example (3rd to 2nd):

1. 2000 RPM in 3rd.
2. Clutch in.
3. Blip throttle to 4000 RPM while downshifting to 2nd.
4. RPM drops from 4000 RPM to 3000 RPM while you are shifting.
5. In 2nd gear.
6. Clutch out (3000 RPM).

Now if you're shifting from 4th at 2000 RPM to 2nd, you may have to blip to 5000 RPM to rev-match (say, RPM drops to 3800 by the time you get it in gear and let the clutch out).

These numbers are guesstimates, I don't have the gear ratio tables in front of me at the moment.

Mark2009

1. More friction (wear) for the clutch to absorb as the difference in RPM between the flywheel and the transmission.

2. More friction (wear) on the synchronizer rings in spinning up/slowing down the two gears that have to mesh. This is how you can tell a car has spent a lot of time being drag raced... the 2nd gear synchros will be shot (will grind on the 1-2 shift) due to be slammed into gear before the RPM has had time to match.

With a perfect rev match, there is no friction on the clutch or the syncros at all. But for typical putt-putting around on the street you don't need to worry about it, unless you're speed shifting just for the fun of it

darr3239

Heel and toeing definitely takes a bit of practice. Even then it's rarely perfect. Depending on the size of your feet, using the pedals can vary from a true heel on gas and toe on brake, to using opposite sides of the foot on each pedal. Practicing different methods would help find the right technique for each person.

Expensive race cars, including the C6Rs and C7Rs, have sequential gearboxes, which makes skipping gears impossible. I think the paddle shifters work the same. Our transmissions don't work that way, and we can skip gears up or down.

Using the brakes is what stops or slows a car, with little to no help from downshifts. So, I guess with a street type, non-sequential transmission, one could come off a long straight on the track, while applying the brakes as long as needed. Then downshifting for the corner once you are there, and doing it once into the proper gear.

I would think, in a true race situation, with someone behind trying to out-brake you, a lot of time would be wasted downshifting through several gears to make a slow turn off a straight. In this situation you would be looking for maximum braking, and it's hard to blip the throttle while maintaining maximum pressure, without lockup, on the brake pedal. It's easy for the sequential guys.

Street or race, it seems there are times where skipping gears going down would be fine.

P.S. - For the OP. If you truly want to continue improving your performance related driving, definitely get some track time. If a beginner, you will have an instructor with you before you are allowed to go on your own. You will learn much, in a short period of time, which you can practice afterwards during normal street driving.

AzDave47

This weekend I'll probably downshift from 5th to 4th at about 140 MPH (~162 is max in 4th gear with stock size tires).

On the Z06, you can "heel/toe" by having the left part of your right foot on the brake and rocking your foot so the right side blips the gas. My feet take a 10-11 medium width shoe. This is easier on the track as you would usually be braking harder than on the street and then the brake pedal is lower and closer to the level of the gas pedal. I seldom find a need to heel/toe on the street and automatically do it on the road circuits.

Maligator

Thanks Mark! Curious, what steps you just outlined, what is the difference between already having it in the next lower gear when you hit the throttle? Example: clutch in, downshift from 3rd to 2nd, blip throttle and let the clutch out;why do you have to downshift while bliping (simultaneously)?

Definitely something im going to look into

duhveed

when you say "azz end kicked out pretty good" just from downshifting that sounds pretty harsh to me just saying