993fvr

I've been trying to improve my heel toe technique so have been searching these forums as well as books on the subject . One thing that surprises me is that no one seems to agree on the timing of the throttle blip.Speed Secrets, POC handbook and PSDS(according to reviews of PSDS on this forum as I've never been there) say that the blip is done after the gear shift change has already been made and before you release the clutch. Skip Barber, Bob Bondurant and other sources say that the blip is performed as the shifter is going through neutral. Still other sources say that the blip is done as soon as you depress the clutch and before you even begin the gear shift change.Is there a rationale for one technique vs. the others?When I try the Speed Secrets/POC/PSDS method, it seems like I am over-revving and the car lurches forward. Are these distinctions only academic because when you get really fast it's one fluid motion ?If so, when you're still trying to perfect heel and toe, is there one technique that is better? Any advice would be appreciated.

ca993twin

The trick is to match the revs of the gear you are changing to. If your car is lurching forward, you are reving too high. I think the blip should be done while the shift is being made in order to minimize shifting time. The only reason to specify blipping in neutral is if you are going to attempt to double clutch the downshift. While this more advanced technique is probably unnecessary with modern synchros, it has the potential to almost eliminate synchro wear on downshifts. Plus it feels bitchin' to do it right.

Rassel

Hi there,
In modern race cars it should go so fast that it's all in one motion. The main point is that when the lower gear engages, the engine revs should be up so high that your tire rotation speed matches the output of the gearbox. When missed, either the gearbox/clutch takes the punishment or you lose traction and possibly spin.

You can look at your gearing graphs in the instruction manual, you'll see that the gearing needs different amount of input on the throttle. For example down shifting from 5 -> 4 requires less throttle than 2 -> 1. It is usually more throttle the lower the gears you go if you don't have a custom gear set.

If you have problems with it, make sure you have your pedals correctly set up for it. I haven't driven a 993 on the track in years, but IIRC it wasn't really optimum for heel toe. I'm sure someone here can add more input about it?

Edit: I just realized that you probably have a heavy fly-wheel.

The point is that you should have the right revs when you release the clutch pedal. Then depending on how "quickly" your car revs to match you can time it backwards when you should hit the throttle.

993fvr

I've got the Rennline pedal set and have no trouble doing the heel toe maneuver. The problem seems to be more the timing of the blip and getting down the hand/foot coordination so everything is smooth. It sounds like I should be blipping earlier in the cycle. Thanks for the advice.

inverterman

I have stock pedal sets and have no problems. I think that the key is NOT to look at the tach. Just feel the car, listen, get it done. I was forced to heel and toe when I put a new diff with a race lock up. If i did not rev match i would wheel hop. Or it felt like I threw an anchor on a down shift. But there is nothing like going around an entire circuit at 7000 rpm.

IamSMC

Reading a "text book" description and applying the technique takes practice to get right.

Spartan

2nd practice,practice, practice, practice. Took me years to get to the point where I can go down through three gears through the braking zone, while rev matching, *smoothly*. To be honest being able to do that consistently makes me happier than lower lap times sometimes!

dbf73

practice makes perfect but I've never felt the need to go thru the intermediate gears on a multi-gear downshift - just go 5th to 2nd or whatever. lets you devote a little more attention to the braking part of the equation

Basal Skull

+1

Spartan

Its harder to get the rev match on a 5 to 2nd and its easier to make a mistake imo. Although if your driving at a relaxed pace you might be right. Going through the intermediate gears smoothly and consistently is a hell of alot harder though thats for sure. Don't know if it matters but the fastest guys I run with do it, just normal for me but everyone has different styles

Basal Skull

I can brake much later and can stay off the brakes longer by not going through the intermediate gears. Done it both ways found it easier/thought I was quicker by eliminating the frantic shifting. I tend to go through all the gears when I'm taking it easy (opposite of what you describe)! What ever works for you is best in the end, it's all fun.

Spartan

lol its not frantic if your doing it correctly, nice and *smooth* is the way (which is not easy to do). I agree we all have different techniques in the end. After alot of right seat time I also found that those who skip shifts in the braking zone never rev match and let the synchros do the work :/ I hope thats not the case with you guys!

Also 60% of braking zones are two gear down shifts around here with the remaining 30% one and then three. The only place with three gear downshifts would be road america for me. Remember the higher amount of intermediate gears means higher speed which means a longer braking zone so to me there is no increased time or difficulty in one gear downshift in a very small brake zone to a three gear in a long brake zone. Hope that makes some sort of sense

Bob Rouleau

I'd like to answer the original post. Some of the cars used in race schools (Skippy) are non synchromesh "crash boxes". They shift very fast. To downshift without breaking the gear box, you need to double clutch, i.e. get into neutral, blip in neutral and then select the lower gear and let the clutch back out. It sounds tedious but can be done very quickly.

In a Porsche such as the ones used at PSDS, the gear box is synchronized, meaning you do not have to go into neutral before selecting the lower gear. So, in our cars it is clutch in, shift to the lower gear, blip the gas and let the clutch out.

I hope this clears up the confusion.

Best,

inverterman

Really, it is all about practice. I recommend to students in high intermediate and advanced to ask if they could run in a slower run group to practice there H/T techniques. Seems to take some pressure off if you make some mistakes.

Dr911

1985 carrera here. Still working on HT shifting, which was v slow going for the last 9 months with stock pedals. Yesterday, my tech installed a heeltoe pedal and ... Yeah baby!
I do the following: brake, clutch, blip, shift, release clutch, release brake&hit gas simultaneously

I can skip gears eg go from 5 to 3 because the 915 transmission is so clunky its impossible to mistakenly get into 1st. But for the same reason its impossible to go from 5th to second.