When do YOU down shift??????

[Clois Harlan]

Cranky (Roger), John M., Rick, Scott, Morris, Dean, and others,

Just thought I would get a few juices flowing for the upcoming season of racing. I wanted to pose a few questions for those formidable racers that are pushing their cars all they way around the track:

Here is the scenario:

Coming out of some twisty turns and into a long straight (say 1500 - 3000 feet long) where speeds should reach 120 - 140 mph or better and into a HARD right (outside this turn is a gravel pit or maybe a cement wall) beyond this turn is a short straight and then an gentle left turn with plenty of run off (also assume there is no banking and all turns are relatively flat).

1. When do you brake: 500 ft., 400 ft,. 300 ft., 200 ft., ??

2. At what RPM do you downshift (if at all)

3. At what point do you get off the binders and power out of the turn?

4. What gear are you in going into the left hand turn, what speed?

Feel free to add any other scenario you would like. Just for kicks here are some tracks to consider:

http://www.roadracetracks.com/CGI/tr...gi?track=CAWSR
http://www.roadracetracks.com/CGI/tr...gi?track=OKHRC
http://www.roadracetracks.com/CGI/tr...gi?track=VAVIR
http://www.roadracetracks.com/CGI/tr...gi?track=WIRDA

http://www.roadracetracks.com/USAMap.shtml

Clois Harlan

[Turk]

"When do you down shift"?

If you have a big block, NEVER. You don't have to.

With a small block, I would guess, OFTEN!

TURK

[Clois Harlan]

Good morning Turk, are you ready to fire up your new race motor?

C

[CSX 4027]

Car control is an art and cannot be learned by typing. I suggest you take a credible racing school 3 day course. You will learn a lot.

But just for the heck of it.

The back straight at "The Glen"

Up through the gears to 4th and 7000 RPM's(154 MPH in 4027)
300ft - Hard Brakes then Downshift to 3rd blipping matching revs.
Turn in to Bus Stop

[Ron61]

Clois,

To me that is a very difficult question to give a definitive answer to. It all depends on the condition of the track on a particular day, how far I can see around the corners, and how many other cars are around me and what kind of drivers are they. Normally using your description I would go pretty close to the corner if I could see the other side, iE a flat track versus one like Thunderhill where you see sky until you are around the apex of some corners. And as for down shifiting, I do that before I enter the corner if I do it. Cranky and his group can give far better answers as they run all the time and on a variety of tracks.

Ron

[GeorgiaSnake]

Originally posted by Turk


"When do you down shift"?

If you have a big block, NEVER. You don't have to.

TURK

You never need to brake either - BB's plow through the corners -limiting exit speed - which limits straight away speed - which eliminates the need to brake

Randy

[Ron61]

Randy,

That is only if they survive the 1500 to 3000 foot straight without blowing up.

Ron

[coyled]

Clois, generally, I downshift just before I turn the wheel. I also tend to be off the brakes at turn in. I don't trail brake, my chassis does not behave well when I do. If the turns are close together, get the car in the best gear for all the corners before the first corner, focus on your line and drive through it. Your big block should have enough torque to drive through it. Scott

[Clois Harlan]

Ron, Steve, and Scott,

Good explaination Steve and Scott. That is pretty much the same way I do it (void of the 7000 RPM's), Also, on my first lap or two (especially on a new track) I will brake between 500 and 600 feet just to make sure how the car handles at that time and get my bias adjusted if necessary.

Steve, maybe you and some of the Crankoids can make it to Road America this year. I won't be making the Glen this year but maybe next (new engine). The BB does have enough torque to drive through some of these corners but you better be comfortable with some drifting and know where the edge is at.

This thread was just to generate some race chatter. Unfortunately, with RA and R&G overlaping I just lost one of my planned weekend events.

Clois

[DAVID GAGNARD]

Clois;

I'm no expert,just a budding beginer,but I like to downshift before turning in also,one less thing for me to do in the turn,my downshifts are governed by my rpms,with my gears I know were my rpms need to be before downshifting,(to soon and I over-rev the motor,rev-limiter will not help with this).....

At the schools I have attended,the instructors all pretty much agree with the 3 second rule of thumb,if you can not stay in a gear for at least three seconds,do not down shift or up shift.........

Case-in-point;at Nashville Superspeedway,about the third turn off the front strait,hard,sharp right hander,exiting into the S's,I would downshift to second going in and upshift to third thru the S's,always a little too loose coming off the turn in second,chasing the rear end,instructor suggested staying in third gear thru the hard turn,tried it and that was the only change I made,lap times improved by a full two seconds,I could "stand on it" in third coming off the hard right hander and stay on it all thru the S's,kinda lugged the motor a little coming off the right hander,but accelarated well thru the S's.........

Of course all this goes out the window when you figure you entered the turn wayyyyyyy to fast and you do not have enough brakes and the wall is looking wayyyyy too close,then anything goes as far as downshifting,braking and whatever it takes to keep the car off the concrete wall.....

That's one of the things I enjoy most about road racing,trying different lines,braking points,shift points to see how it affects my lap times.......nothing like "seat time" to work these things out.............

David

[REDSC400]

"Heel-toeing" is the commonly-used term for matching the speed of the engine to that of the transmission when downshifting.

For example, let's assume that you're in 4th gear at 4,500 RPM and going 100 MPH at the end of a straight, and are approaching a turn. You know you want to take exit the turn at about 60 MPH so you will have to brake, take the turn and begin acceleration. You also know that you want to be in 3rd gear to power out of the curve.

That all said, you know you will need to downshift to 3rd gear. 3rd gear at 60 MPH is probably about 5,500 RPM (these numbers are theoretical). Therefore, in order to make the shift as smooth as possible, you need to simultaneously brake down to 60 MPH and "blip" the throttle to 5,500+ RPM right before you re-engage the clutch in 3rd gear.

Done properly, this minimizes the weight transfer from the front (breaking) to the rear of the vehicle (once in third) since the shift is less abrupt, minimizes driveline strain, maximizes rear wheel grip since the tires don't get a sudden speed change, and minimizes wear on the clutch since the clutch and flywheel are spinning at closer to the same speed.

[Clois Harlan]

David,

Hope to see you in Tulsa, June 9-12. I am planning on running the Vintage Races this year.

Clois

[RACER X #99]

I alway keep the rpms in my power band 3500-7000.
I agree with Turk though, with a BB you don't have to downshift as much, of course while you are lugging along at 3000 rpms the guy with the screaming small block is blowing exhaust fumes in your face. But at least you not wearing out your right arm shifting. Lets face it if your using your right arm to shift, how are you gonna hold that cigarette?

[Turk]

Hey Cranky,
Those small blocks scream alright. Their owners screaming can be heard all over the forums..

[RACER X #99]

Turk,
Nice try. I just saw Bills new moder, now that's a BB to brag about.

[DAVID GAGNARD]

Clois;

Not sure if I'm going back this year yet,I would love to and I like Hallett's challenging track,but they need to re-pave that track reallll baddddd........I spent as much time dodging the pot-hole repairs (bumps) as anything while on-track........

Enjoyed the whole weekend,cook-outs in the parking lot and BBQ's at the track and the people are great,kinda like a "family reunion".......

My buddies have four rooms reserved,so that will not be a problem if I do decide to go at a later date.........

Also depends on my car,how it's running and if it holds together long enough for me to get there.........

Also, they have a good swap meet,waited too long to buy a couple of things I needed and we all got rained out on Sunday........will not do that again.......

David

[klayfish]

OK, I'm still rather new at open tracking, so ths is a very interesting thread.

I'm learning with each session I run. I find I'm confident in my ability to brake, but sometimes I overbrake and enter the corner like I was in a school zone. The next lap, I may not brake hard enough and enter with too much speed. Ruins the corner. I think maybe it's because I'm carrying a different speed into the corner, depending on how I got off the last one???

Since I'm still concentrating on learning my line, I try to do as little downshifting as possible. I'm sure it costs me seconds per lap, but that's OK for now. I've got enough to concentrate on. Heel and toe and true rev matching is a skill I'll work on as I get better.

I generally do well getting back into the gas. By time I'm exiting the corner, I'm into the gas hard and pushing the car through. That's one of my favorite parts.

I got several laps in the Track Turd at Watkins Glen with Cranky last year. Whenever my helmet wasn't trying to rip my head off or face shield trying to give me a nose job, I was trying to watch and listen (to the engine) closely what he was doing. Hopefully I'll get to learn more this year.

Steve

[SCOBRAC]

LMAOROF... Ditto. what turk said.

[SCOBRAC]

Seriously,

Steve, Learn the line the speed will happen. Stop listening and start watching. Light moves at 186,000 feet per second, sound travels at under 600 mph (at sea level) Stop listening to what's going on and start (occasionally) watching what's happening on your dash but more importantly what is about to happen, not what is happening. You'll get it.

[Excaliber]

At the end of the straight at about 140mph turn one is a first gear hair pin (Hawaii Raceway Park).

Assuming your NOT trying to save your brakes:

Would you downshift through the gears or just brake hard and slip from 4th to 1st? I'm 1st (one way or the other) when I enter the turn and depending on entry speed may "drift" it some.


OK OK, I've flat spun out there more than once.