mikymu

1. Brake, clutch, push lever forward, blip throttle, release clutch and repeat if multiple down shift

or

2. Brake, clutch+push lever forward+blip throttle all at the same time then release clutch

Video below looks like the driver do clutch+push lever forward+blip throttle all at the same time. I finally got used to push and release clutch with each gear change. Let's leave auto blipper out of the discussion for now ...

Cheers

Mike

fleadh

#1:


Watch for the shift lights on each gear down.

Auto-blipper is girls. :-)

-mike

mikymu

I tried #2 and the car jerks ... maybe the driver in the video above is doing #1 but super fast?

What was the difference in your video? One with auto bliper and the other your right foot?

fleadh

That's a video of me (left) and JvO (right) in my car (no auto-blipper), we're both shifting as described in #1-- clutch release on each gear downshifted. I just installed a dual chasecam setup in the car with 1 camera pointed at the pedals, I can post a video after I test the car on Sep 1st if it'll help.

-mike

mikymu

That will be great Mike! I am trying to figure out the best way to down shift ... just hate to hear gear grind every time I push the lever forward

Cheers

analogmike

If you blip after you hit the shifter, it won't help, too late. Should blip just before for best results. The auto blipper can't do that, works at the same time and seems ok but not quite as good as a perfect downshift. If you don't hear a grind, you did it just about perfectly. A good downshift will still grind a bit. Hope that helps!

mooty

dam, we got three mikes in this thread.

i am with analogmike. the sequence of movements should be same regardless of sequential or H pattern. brake as needed, clutch, blip and shifthing occur close to each other but NOT same time. the clutch should be on the floor and then blip, if clutch is not down, you can't blip. you are still in gear.

once you blipped, fraction of nanosecond later, you shift.

GT3 Techno

Very well said.

And autoblipper is not girls.

After 50 hours in my car without it, I had the tranny opened for rebuild and it was in perfect condition so I can say I didn't "need" a blipper. Got one installed this year just to do the downshifting sequence quicker (for multiple gears downshifts) and focus on braking at threshold. Couldn't use it much yet because of a recurring issue on the engine (resolved now !) but liked it a lot when I did.

fleadh

Another thing I've recently caught from looking at motec data from my 09 Cup is that timing of the downshifts is supremely important. If you downshift a little to late, you'll see your longitudinal G get closer to zero (car stops slowing down). I've been working on it, but it's really hard to get rite.. below is a screenshot of my personal best lap at TH (1:47.5) where all 3 of my downshifts into T14 are about 200-300rpm to late which causes the rear wheels to want to spin faster than the current speed when I let out the clutch. It also includes clutch pressure and gear force lever volts so you can see the timing of everything.

Mikymu, you should have the exact same motec system in your car so you should be able to compare your data to the screenshot...



ps: had a chance to test a grand-am/continental GS car last week.. if you can get the 997 cup braking rite, you can drive anything! :P

-mike

GT3 Techno

I am not good at reading data but do you mean downshifting too late or blipping too hard for the wheels speed so the car feels like it wants to accelerate while you brake ? If I downshifted late I had to adjust the blip strenght to match the revs. With a blipper I guess you can't do that and timing is even more important ?

fleadh

If I'm in a threshold braking zone like this, I tend to always do the same level of blip.. it all happens so fast I can't really adjust the blip amount very well when I'm banging down through multiple gears. In this case, I simply took to long to go down the first gear which then made all 3 downshifts late by about 200 rpm (ground speed versus rpm when the clutch was released)-- so as you mentioned, it had the effect of slight acceleration of the car for a few feet on each downshift.

I like to downshift as early as possible in the braking zones to stabilize the rear of the car, my goal is to have the shift lights come on for 1-2 seconds on every downshift. On this lap the shift lights came on for all 3 downshifts, but just not long enough and it resulted in the loss of longitudinal G in the braking zone. These cars are very sensitive....

For ultimate lap time I don't think it hurts too much, but for passing under braking, etc.. you obviously want your braking zones as short as possible.

edit: this is just my opinion of course, i'm always open for advice/tips from others that do things differently!

-mike

mikymu

Thanks. I think my problem is that I blip too late or my footwork is just too slow. It wa Ok on a street GT3 but no good in a Cup. Once in a while my downshift do not grind and I have no idea what I did right ....

mooty, change your name to Mike mooty and you will shave 3 seconds at TH ove the top. You should drive one of these 7 Cup and expereince my joy of fraustration

Mike H, these graph are like greek to me! I am going to have TRG coach me and provide track side support at LS 9/9 - 9/11. Hope I can understand these graph better. Grand AM GS ... ABS make it so much easier to drive

mooty

why dont u just clean up and wax your car, then i'll come drive it

mikymu

It's all clean and ready for you Mr. mooty

Spoke with TRG yesterday, they told me to down shift and blip all at the same time since Cup sequential do not have synchro ...

GTgears

Actually it's not really that it doesn't have synchros as much as the fact that it's sequential. If you had an H-pattern dog box there would still be some usefulness to double clutch rev-matching, though if your rpm drops are right, an argument could be made that it isn't required. But given how the internal function of a sequential works and the fact that it never really is in neutral, like an H-pattern box is, there's absolutely no need to double clutch. The blip is strictly to bring the engine up in speed a little bit to get it closer to the speed the gearbox shafts will be spinning to minimize the shockload on the driveline when you release the clutch.