Jump to content
SAU Community

Recommended Posts

hi there i was just wondering if any 1 could help me and tell me if it even does any thing...if this method has a name what is it called ?

ok in 2nd gear get my rev's to 4500 then i put the clutch in halfway keep the throtal around halfway to biuld up the rev's then push the clutching in fast and put it into 3rd gear then let go of the clutch.

Thanks...

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/
Share on other sites

was told it gives that extra power in changing gears but i may of got it mixed around or some thing......

im just trying to learn about cars/n stuff. i had a friend that was teaching me about them but he's just passed away resently. :'(

if any 1 could give me a few tips would be handy :)

-Thanks

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1130748
Share on other sites

double clutching is when you r in gear, lets say 1st, put the clutch in, put it into neutral, let the clutch out, put the clutch back in, put into 2nd, let clutch out.

I have no idea why that line of "not double clutching when you're supposed to" line was in fast and the furious. cause u wouldnt do it in a drag race...it was done on really old cars like moris minors where the box wouldnt handle it..

maybe there is a more modern thing that they call double clutching, but that is what i have always known it as. It also helps on dodgy boxs like my dad's subaru :)

Maybe you are talking about flat shifting...where u just leave the throttle pinned instead of backing off...but that's not really the impression i got from your post.

Either way, it sounds like a good way to wreck ya box and clutch for the sake of a few milliseconds?

Correct me if I'm wrong

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1130761
Share on other sites

*have to lift my chin off the floor*

Okay, when you shift up a gear, the next gear has LOWER revs than the last!

Why people think reving the car before a shift is going to do anything is beyong me. Notice how when you engage the next gear the revs DROP!

Double clutching is nothing like that, can't be stuffed explaining it, but the only time you double clutch up is in a old school car which can't shift fast enough, so when you try to shift, the revs drop to idle before you engage the next gear, then is when you rev to make it engage, as some old cars wouldn't engage. Or in a modern car when you stuff up, and the revs drop to idle, you can give it a little blip to make it smooth, but it's not necessary in modern cars.

Now, if you have to do that, you must be shifting incredibly slowing.

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1130809
Share on other sites

The first post in this thread is a terrific way to spend $800 on a new clutch every 3 months.

Double clutching is generally done if your syncros are stuffed, or if your like me and you ocassionally do it when putting around town just to be gentle and kind to your cars gear box. Its a nice clean way to change gears and learn about rev matching.

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1131234
Share on other sites

Double clutching is generally used on downchanges, but it can be used on upchanges on very old cars where the gearbox synchros are pretty knackered. The basic principle is to match the speed of the gearbox input shaft to the speed of the output shaft, and reduce the load on the synchros.

Most common on downshifts, there are 2 variants - heel/toe and double clutch.

In a heel/toe, most common on modern cars to prevent the rear wheels trying to drive the engine when you engage a lower gear, the idea is to blip the throttle in the middle of the gear change, while the clutch is depressed and the gear lever is in the neutral position between gears. This brings the engine speed up to the match road speed of the lower gear. It is usually done by applying brake with the toe of your right foot, and pivoting the heel of your foot around to blip the throttle, hence its name - heel / toe.

With double clutch, instead of having the clutch depressed, you release the clutch while blipping the throttle, then depress it again to engage the gear. This is to match the engine speed to the road speed when the synchros are crook and don't actually do the job they are supposed to.

Hope that all makes sense.

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1131386
Share on other sites

Double clutching is nothing like that, can't be stuffed explaining it, but the only time you double clutch up is in a old school car which can't shift fast enough, so when you try to shift, the revs drop to idle before you engage the next gear, then is when you rev to make it engage, as some old cars wouldn't engage. Or in a modern car when you stuff up, and the revs drop to idle, you can give it a little blip to make it smooth, but it's not necessary in modern cars.

Now, if you have to do that, you must be shifting incredibly slowing.

Can't say I've heard that before. How old are you talking here? Even my friend's 1940s Vauxhall shifts fast enough. Anyway, the usual time you double declutch is on a downshift, not an upshift.

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1131510
Share on other sites

Double DE-clutching.

Different to double clutching.

Double De-clutching is down, double clutching is up.

Some old cars need it, say morris', haha, and trucks things like that.

Cars whose gearbox is sloppy, synchros worn, things like that. Not necessarily all "old" cars, just a characteristic of a few of them.

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1131533
Share on other sites

just dont do it.

if you want an interesting gearchange (and plenty of interesting things happening to your clutch/gearbox/engine) just try changing gears very fast without lifting off at all (flat shifting like some others have explained)

its best if you try it in someone elses car, such as a hire car :)

Link to comment
https://www.sau.com.au/forums/topic/59217-gear-change/#findComment-1133219
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Let's hope that's not a copy pump either. There were so many copies of them back in the day.
    • Damn it, I was at work last night, and stayed in a room there during the storm with the car outside, but undercover, I just went downstairs and well....there was a large steel locker that has come from some place last night, it wasn't anywhere I could see yesterday, and yeap, it landed on the fraking car....of course it did..... LOL So, I'll need to take it back for paint and panel, luckily it was only the boot that took the hit, so it could have been worse Serves me right for staying at work and getting on the cans with some of the boys
    • Yeah, really happy with how it all turned out As for aftermarket lip, nah, I'm not really a fan for practically reasons on a street car that gets driven everywhere  I did have the full lower kit on my 2015 STI, but found the front lip scrapped alot, even at stock 4x4ish ride height As the NC sits now, with the lowest point of the car at 110mm, so just legal, some steep driveways and steep speed humps will still "just" scrap those little plastic OEM air dam thingies on the undertray just before the front wheels
    • Here's one I help build and tuned a decade ago, Garrett  GTX3071R Gen 1, T3 twin scroll 0.83 rear housing. Went from larger 272 cams down to smaller Tomei Poncams to help with the low end. S13 non VCT motor. Car was purpose built for the track, hence low down was the focus. Note the actual dyno chart shows lower boost, however the EBC and boost gauge showed 1.9Bar (Ignore the torque, I was young and didn't know how to set derived torque)  
    • I’m doing some side developments on SR20det S13 engines, its one my hobby cars used it to compare flow capacity of some smaller size wheels. SR20det is one of another JDM legendary engines I'm sure there are plenty of SR enthusiasts on this forum, I will share results some common turbo configurations here. a quick run down of what the car is: Wide body 180sx Type X with black top engine (blue). It has: Stock bottom end Haltech 1500 ECU 5-0 motorsports trigger kit Kelford SR20DET Beehive Spring with Titanium Retainers Kelford Cams SR20DET S13 188-B 268/272 Cams G25-660 Turbocharger in T2 .64 rear housing internally gated ARP Head studs MLS head gasket 1000CC ID injectors Walbro 450L Fuel pump Front mount cooler kit JJR’s 3 inches turbo back exhaust (its too short for the 180sx it had to be extended) Pump 98 fuel Hub Dyno tune So far made 270rwkws at 22psi full boost by 4500RPM. Engine is very knock limited hence a pretty bad looking top end. From previous experiences it seems like SR20dets are happier with bigger size turbine, some thing like a GT30 would make way better top end, but on same time response is lost. It won't be a problem with S15 VCT engines. I'll be testing alternative turbine housing, turbine wheel and possibly dump pipe options for extra flow to resolve the problem and of course E85 would resolve all the issues.            
×
×
  • Create New...