Ok guys (and gals), I'm at a loss here. Could someone (in layman's terms) explain to me how down shifting works, why it's necessary, and what are the benefits? Also, could someone also explain to me how, why, and when it's necessary to "blip" the throttle?

Thank you.

 

http://www.drivingfast.net/car-contr...e-shifting.htm

 

Thank you for the link, but I'm NO WHERE near that level of driving knowledge and expertise. My question is do I really need to worry about down shifting, blipping the throttle, and matching RPM's at this stage in the game?

 

probably not for street driving but...if you want to be a smooth driver and not upset the car and your passenger when downshifting you should develop the skill...when you are good at it you can go down the gears without jerking the car one bit...this is important in tracking because the car may be near the limit and any jerkiness will upset it...don't get in the habit of compression braking (that means slowing the car by downshifting, letting out the clutch without throttle and having the engine slow the car instead of the brakes...these cars have great brakes and it is not necessary to compression brake...having this habit can lead to a possible money shift (shifting from 5th to 2nd instead of 4th)...sounds like you are having fun with the car and that is the most important thing of all

 

You typically downshift to get into a better power band [for passing or getting on a highway on-ramp]. For example, if you are in 6th gear cruising at 60 MPH, and you want to pass someone, it will take you a while in 6th. So you could shift to 4th and when you hit the gas - you will fly by them.

Well, when you are at 60 MPH in 6th, your engine is at [say] 2500 RPM. Now, if you were already in 4th, you would be at [say] 5000 RPM. But you aren't in 4th, you are in 6th at 2500 RPM (60 MPH). But you want to be in 4th at 5000 RPM (also 60 MPH). [For this example, we're going to use these numbers, but they won't be spot on]

So, you shift from from 6th to 4th by pushing in the clutch and shifting. Now, while you have the clutch in, your engine RPMs drop to idle [if you have the clutch in long enough] or around 1000 RPM. BUT your wheels will still be spinning at 60 MPH. So when you let the clutch out to engage 4th gear, your engine will NEED to be going 5000 RPM! Well, when you let the clutch out, everything connects and your engine revs up really abruptly so that your RPMs in 4th gear match your speed (60 MPH). You might feel jerking or lurching and you will definitely feel the engine dragging the car slower until you put on the gas.

Now, take a step back to when you had the clutch pushed in to change gears. If, right before you let the clutch out, you gave the throttle a blip, the engine would rev up. [This type of blip is just pushing on the gas pedal like you were parked in the garage not moving, just a little faster]. Well, if you could rev up to 5000 RPM and then let the clutch out, your engine speed [RPM] would be just right for going 60 MPH in 4th gear! No lurching, jerking, or other foulness.

You can simply press on the gas and pass the slower traffic in a heartbeat.

This is just a very basic example, but I think you will get the idea. Put simply, you blip the gas so you can match the right RPMs for the gear you will select based on your speed.

Make sense?

-td

 

Seems like overkill just drive it. Have you guys never slammed the car down a gear or two really hard

 

It will become second nature once comfortable. And WAYYYY easier on the car than just, as you put it, "slamming the car down a gear or two really hard".

 

Sorry used to own a supra

 

blipping the throttle during downshifts helps aide in rev matching somewhat

 

Nope.

Have you ever rev matched a 2 gear downshift? It isn't overkill or hard. In fact, it is smooth as silk without any "slamming."

As a different perspective: slamming might mess up your clutch, your $5,000+ transmission, or your $15,000+ engine. Rev matching costs zero.

-td

 

When doing highway pulls in the supra. If say I was in 5th gear at 60mph I would push the clutch in down shift to 3rd and when letting the clutch out floor it.

 

just experiment, i do....if you think it makes sense, do it...the car can handle it. i go from 6th to 3rd sometimes (if im under 60mph). practice on an open road. it all depends on you, what can you handle and experience.

 

Thank you td. This makes sense to me, some what. I'm a slow learner and learn a little differently than others. For me, it really boils down to practice. We can theorize until the cows come home, but until someone shows me and I do it over and over again, I won't get it. So this does make sense. Now I need to read and re-read and apply it when I out driving.

 

Thanks tre. I'm just so afraid of screwing something up. It's worse when I'm under pressure. But if I can just relax and do what feels comfortable and natural (because I have a pretty good idea as to when something doesn't feel right or goes wrong), then I'm doing ok.

 

You realize that is a very similar concept to blipping the throttle right? If you were simultaneously letting the clutch out and 'flooring it' you are bringing the revs higher up (to match where they should be, and then some, at your given speed in another gear) and doing something similar.