Gearbox question - new SB Formula cars

[StuartG]

First off... hope everyone here in U.S. is having a Happy Thanksgiving!

I'm signed up for a couple of racing schools next Spring at Laguna Seca and have a question on gearboxes in the SB Formula cars... I know the new cars now have 5-speed sequential shifters, but is the trans synchro or still non-synchro (dog ring)? Basically, just curious if double-clutch downshifts are needed (or no clutching at all). I'm pretty proficient at heel-toe, single-clutch downshifting my street car, but I can imagine that adding in double clutching certainly takes practice and time to build good "muscle memory."

Thanks!

-Stuart-

[Jim Pace]

Stuart,
Good question. Different shifting techniques are better suited for different types of cars depending on the reason behind the procedure. Depending on the cars you drive you can use different techniques to keep the shifting smooth and efficient.

#1. A Sequential box will shift up & down without the clutch just fine and the "heel toe" portion is "needed" to blend the speed of the engine with the road speed to prevent upsetting the rear tires when the lower gear is selected (think turn 17 Sebring). In this case a simple heel-toe blip of the throttle will do just fine. Some cars (Skippy Formula among them) will respond better using the clutch on the downshift to avoid shocking the driveline and adding a little forgiveness to your technique (again Sebring 17). Most Skippy Formula guys will suggest the clutch on the downshift but not on the upshift. Yes on Heel-Toe. It will of course go into gear no matter how bad your technique and certain guys can Go Fast no matter what they do.

#2. A Non Synchro box (Hewland style being very popular) needs the Heel-Toe to match the actual gear revs before the lower gear can be selected. In that case it is recommended to do a proper Double Clutch Downshift, the essence of which is to Rev the engine in Neutral with the Clutch out. How you arrive at Neutral and what you do after is not so important as long as the Blip occurs in Neutral with the Clutch out. Many variations exist on the double clutch theme but again the essence is Blip in Neutral with Clutch Out. Many Non Synchro drivers only use the clutch to get started and stopped. Once this proper Double Clutch technique is learned you can drive most anything with or without the clutch. Street car, race car, vintage cars, trucks...pretty much anything besides a Sequential. Again with enough force even bad technique can be overcome and many drivers do just that. Problems occur not on every shift but on the occasional bad shift while passing or other traffic issues where poor fundamentals generally jump up and bite you on tail. Many stories of exceptional SKippy guys making the next step into higher level cars only to find they had poor shifting fundamentals and paid a high price to learn in the new cars. Engine over revs and broken trannys cost staggering amounts at that level!

#3 A Synchro box in a street car (typical H pattern) can be Double Clutched to save wear on the synchros but not needed. In this case the Heel Toe is needed to blend the engine speed to the road speed like with the Sequential. These are great for double clutch practice however and with patience you can "FEEL" the synchro working less when done correctly. The gear selector is not forced into gear but rather you feel it when the revs match and then it "falls" into gear. The Mazda MX5s (all the Mazda school cars) are very good for this practice and asking an instructor to show you is a good idea.

Up shift or down, regardless of the box, try to feel what is going on inside the tranny and you will be better intune with the car.
Best of luck in your school! Feel free to ask questions.
Regards,
JP

[WatertownNewbie]

Stuart, you could not have asked for a better answer from a better person. JP, I miss your feedback.

[oldredracer]

Originally Posted by Jim Pace

Stuart,
Good question. Different shifting techniques are better suited for different types of cars depending on the reason behind the procedure. Depending on the cars you drive you can use different techniques to keep the shifting smooth and efficient.

#1. A Sequential box will shift up & down without the clutch just fine and the "heel toe" portion is "needed" to blend the speed of the engine with the road speed to prevent upsetting the rear tires when the lower gear is selected (think turn 17 Sebring). In this case a simple heel-toe blip of the throttle will do just fine. Some cars (Skippy Formula among them) will respond better using the clutch on the downshift to avoid shocking the driveline and adding a little forgiveness to your technique (again Sebring 17). Most Skippy Formula guys will suggest the clutch on the downshift but not on the upshift. Yes on Heel-Toe. It will of course go into gear no matter how bad your technique and certain guys can Go Fast no matter what they do.

#2. A Non Synchro box (Hewland style being very popular) needs the Heel-Toe to match the actual gear revs before the lower gear can be selected. In that case it is recommended to do a proper Double Clutch Downshift, the essence of which is to Rev the engine in Neutral with the Clutch out. How you arrive at Neutral and what you do after is not so important as long as the Blip occurs in Neutral with the Clutch out. Many variations exist on the double clutch theme but again the essence is Blip in Neutral with Clutch Out. Many Non Synchro drivers only use the clutch to get started and stopped. Once this proper Double Clutch technique is learned you can drive most anything with or without the clutch. Street car, race car, vintage cars, trucks...pretty much anything besides a Sequential. Again with enough force even bad technique can be overcome and many drivers do just that. Problems occur not on every shift but on the occasional bad shift while passing or other traffic issues where poor fundamentals generally jump up and bite you on tail. Many stories of exceptional SKippy guys making the next step into higher level cars only to find they had poor shifting fundamentals and paid a high price to learn in the new cars. Engine over revs and broken trannys cost staggering amounts at that level!

#3 A Synchro box in a street car (typical H pattern) can be Double Clutched to save wear on the synchros but not needed. In this case the Heel Toe is needed to blend the engine speed to the road speed like with the Sequential. These are great for double clutch practice however and with patience you can "FEEL" the synchro working less when done correctly. The gear selector is not forced into gear but rather you feel it when the revs match and then it "falls" into gear. The Mazda MX5s (all the Mazda school cars) are very good for this practice and asking an instructor to show you is a good idea.

Up shift or down, regardless of the box, try to feel what is going on inside the tranny and you will be better intune with the car.
Best of luck in your school! Feel free to ask questions.
Regards,
JP

What he said. I could have told you the same thing but it would have taken an hour and a half.

[StuartG]

Thanks much Jim! This helps greatly!

Sounds like the sequential gear box in the new Skippy formula cars do have a synchromesh or synchronizer -- but as with street manuals, a heel-toe blip (with the clutch in) still helps smooth out the downshift.

So with the sequential stick, is there a "neutral" (center?) position with the shifter? I'm assuming it's push forward to downshift, pull back to upshift? (although I'm told this does vary among different gearboxes and is sometimes the other way around).

Cheers,

-Stuart-

[oldredracer]

Originally Posted by StuartG

Thanks much Jim! This helps greatly!

Sounds like the sequential gear box in the new Skippy formula cars do have a synchromesh or synchronizer -- but as with street manuals, a heel-toe blip (with the clutch in) still helps smooth out the downshift.

So with the sequential stick, is there a "neutral" (center?) position with the shifter? I'm assuming it's push forward to downshift, pull back to upshift? (although I'm told this does vary among different gearboxes and is sometimes the other way around).

Cheers,

-Stuart-

Just in case Jim's full of...turkey: No synchros. Push forward all you want but you'll never get lower than 1st gear. Neutral is indeed pushing forward from 1st, but there's a pull-out knob driver's left which you'll need in order to find it. So, from neutral, you just keep pulling back from first to fifth, one gear at at time. Upshifts are easy. Apply a little back pressure on the shift lever, ease back on the throttle slighty and it'll pretty much jump to the next higher gear.
It's also a really good idea to remember which gear you're in, as there's no indicator for anything but neutral...sometimes.

Welcome to the club.