Downshifting

[Venamm]

Ok here comes the dumb questions:
Why the need to drive in a "toe and heel" format"??
and what the hell is a "Blip"???

[65cobra1]

Originally Posted by Steve Cassani

Pedal arrangement is crucial and the design Superformance uses to replicate the arrangement of the original cars could be improved. .

Steve, I totally agree with your assessment.

I can drive my little Chevy Tracker all day long and never miss a smooth downshift because the pedals are setup correctly.

I once took a racing school (Not Cobra) whose cars all had throttle extenders. They worked good for the three days.

When I took a subsequent school with an FFR car, it was easy to use the H & T technique UNTIL the end of the day when the brake pedal went below the accelerator. End of smooth downshifts.

I was fortunate and spoiled (When racing earlier in my life) that the two road race cars I drove had great pedal setups. Never needed modification.

I think, from seeing some of the very creative solutions, I'm going to try and get some way to raise the brake pedal a couple of inches. Perhaps bolting another brake pedal onto the existing one.

That way, the height should be OK for normal braking and when depressed (The pedal, not me) it should be about even with the loud pedal.

Before trying that, however, I'll see if I can wedge my old bones down under the dash to see if there is some sort of an adjustment that can be made.

Thanks to all for taking the time to contribute your ideas...It was a big help.
Ivan

[65cobra1]

Originally Posted by Naumoff

What type of throttle linkage do you have?

Hi Tony,
I have solid linkage. I was thinking about adjusting that but to get it down to the level of the brake pedal, it seemed that I would lose part of my travel.
Ivan

[65cobra1]

Originally Posted by Venamm

Ok here comes the dumb questions:
Why the need to drive in a "toe and heel" format"??
and what the hell is a "Blip"???

When pushing the car a little around corners, it's smoother and more fun for me and a lot easier to accelerate after going through the corner.

A blip when you increase your rpms to match your downshift.

Regards, Ivan

[CHANMADD]

You know .....Blip..Blip..Blip..Blaaaat!!!!!

[cbreez]

Heel and toe was also originally used for non-syncronized gearboxes (which we don't have today BTW, it's better today). The engine blip was used to get the speed of the gears in the transmission spinning close to the same speed internally to prevend a grinding downshift. In most cases today it's not necessary, but purist's like the sound. (Like in the movie "Winning"). It's difficult to master...

[xracerbob]

To get the most speed out of the car on a road course it is necessary to be able to master. As you brake for a corner, you want to be able to go back to power as you exit the corner (or sooner) which in most cases will require a down shift or two. Since you are already braking on the threshold of locking the brakes, if you abruptly downshift and add engine braking to the rear wheels, you will probably spin the car. The idea with the double clutch downshift is as previously stated is to match the revs of the drivetrain to the wheels. You want to maintain a stable platform for the tires to do their thing; no pitching of the car fore and aft, no yanking of the steering wheel, etc.

The sequence for the down shift is:

Brake and clutch in, shift to neutral, clutch out, roll your foot over while maintaining brake pressure to blip the throttle, clutch back in, shift to lower gear, clutch out. Repeat as necessary.

It takes longer to say it than do it, once you "get it". I drive a manual car as a daily driver and do it every downshift out of habit. I used to teach this at Skip Barber's school, and some people struggled with this even after they did some race series events, but then it just clicked for them and they were suddenly faster and more relaxed. Plus it's just a lot more enjoyable to drive.

[Naumoff]

Originally Posted by 65cobra1

Hi Tony,
I have solid linkage. I was thinking about adjusting that but to get it down to the level of the brake pedal, it seemed that I would lose part of my travel.
Ivan

Mine worked out great but I am running a factory 2x4 set up and it doesn't require much pedal travel from idle to full throttle. The reversed carbs and the ratio of the linkage is very quick. It makes it a little strange to jump in a single four barrel car as I am use to using a lot of finesse on the throttle.

[Jerry Clayton]

This technique came about years ago when the transmissions were scncro in big trucks---It was adapted to race cars so that you could use engine braking to help with decelleration for turns--today with modern brakes and scycro transmissions there is no need for it
set your brakes up balanced for max decel and put the trans in the gear you want to leave the corner in
The risks of unbalanced decelleration far outweigh any consistent improment of lap times most drivers would get.
A good seat with proper orientation to the steering wheel and pedals and a harness at the proper angles will yield better, more consistent laps

Jerry

[Aussie Mike]

I find if I dont blip the throttle on the down change it can upset the balance of the car as I get more engine braking from the rear. There's no problem with getting the car into gear as the T56 has carbon blocker rings and shift very nicely. It's just getting the car settled so it doesent feel like it's going to unhook the rear end on entry to the corner.

I guess it's probably more my poor cornering technique that I need to work on.

Cheers

[Jerry Clayton]

Mike-- your experiencing the unbalance decelleration I was writing about--just put it in the gear you want for exit and let the clutch out when your ready to accelerate
One of the McLeod drag pack for the hydraulic throw out bearing would be nice here--it would release the clutch when you released the brakes

I'd like to know more about what you did to move your shifter as I'm building a car with the Ls. T56 and C4 vette suspension

Jerry

[xracerbob]

set your brakes up balanced for max decel and put the trans in the gear you want to leave the corner in

Jerry-

The key is getting the car into that gear smoothly. If you just jam it in a lower gear and then let the clutch out, you will upset the balance of the car. If you brake early and downshift and then creep throught the first part of the corner, clearly you are losing time.

Also- engine braking is generally a bad idea- the risk of over-revving the engine, wear and tear on gearbox and ring and pinion, etc.

There are also non-synchro transmissions still used in many forms of racing as well as many vintage cars.

[Jerry Clayton]

Bob

I said not to let the clutch out until your ready to accellerate

And I totally agree about the point of over revving the engine on downshifts--this is what kills engines --a rev limiter will not help you

McLeod has a package for a to brg and line lock for dragracing that if used wouldn't release the clutch until a driver released the brake pressure(gizmo would have to be energised by a switch like a stop lite switch)

[65cobra1]

Originally Posted by careermd

Heel and toe was also originally used for non-synchronized gearboxes (which we don't have today BTW, it's better today). The engine blip was used to get the speed of the gears in the transmission spinning close to the same speed internally to prevent a grinding downshift. In most cases today it's not necessary, but purist's like the sound. (Like in the movie "Winning"). It's difficult to master...

I respectfully disagree...I was taught H & T in several schools and it worked very well in competition.
The reason I do it on the street is to keep it natural and automatic for the next time I go to have some fun at another road course school.

I noticed a big difference in practice and qualifying times between braking then downshifting vs braking and downshifting at the same time right right before hitting the gas.

I also noticed that when some of the other cars downshifted too soon they either over-revved the motor, upset the car balance or experienced wheel hop.
Ivan