Sith

I can get perfect changes everytime from 2nd to 3rd under full acceleration. The best way to do it is to feather the throttle during cluch move. You don't loose boost so don't have a drop in power. It just must be feather or the revs fly up and you will fry the clutch.

P.

Edited due to pet Rat running across KB

[Edited by Sith - 12/10/2001 10:22:37 PM]

steve_s

I seem to have a problem getting a smooth change from 2nd to 3rd gear when pushing on. car seems to back off like I've caught it out.This sometimes happens when I change 1st to second too.
The experience is like a jolt when you feed in the throttle. this doesn't occur during normal driving, just when ragging it.
anyone else experience it or am I just a crap driver.
any tips/advice greatfully received

steve

Lust4Life

I get this as well, you can iron it out with very careful balancing of the clutch & throttle but when you are on a mission it is hard.

I think I read somewhere on here that it is related to the diff.

Cheers,

Phil

Dracoro

This one is easy. Just make sure the engine speed matches the gear speed. Practice makes perfect, admittedly it's tricky at first. Let me know if you need more info on this.

steve_s

It's normally when I'm flatout up to 65 in 2nd then try for a quick change to 3rd. am I suppose to double the clutch?? would like to know how I can get round it cos I feel like a right plank who can't drive if anyone else is in the car.

steve

mutant_matt

Dracoro, your tips would be welcome m8 as I've also not found a way round this other than to smooth the change with the clutch and throttle as mentioned above.

Matt

Dracoro

Drive along steady at 65mph in 3rd, check the revs (make a metal note of it). That rev count is what the engine should be doing when you disengage the clutch from 2nd to 3rd.

For example, if at 65 in 3rd the car is at 4500rpm, then when you change from 2nd to 3rd that is what you need the car to be revving at when you let go of the clutch.

Double declutching, wouldn't help very much going up the gears although doing it is better than not doing it, it just takes longer to change gear which defies the point if you are on a charge. It is definitely useful when changing down as the car chould slot into each gear more smoothly.

RichS

Hi

If it's the "KER-THUNK" you get through the tramsimission when
changing up when really pressing on, then yes I get it too (occasionally).

I also enjoyed passenger laps from two other Scoob owners at a recent SIDC track day and can vouch that both of them experience it as well.

It makes you think "this really can't be good for the car!"
Anyway, I guess the only way is through really precise use of clutch and throttle when changing up through the gears.

Rich

chiark

I used to get this, and some people put it down to overboost or strangeness in the turbo. Once the clutch is fully engaged, there's a definite lurch...

It's gone now I've fitted my K&N induction kit. Plus the car's got 20k on it now, too.

Nick.

CM

Well unfortunately got rid of the scoob a couple of months ago, but as it was a lease car, it's fair to say that I experienced the phenomenon quite a bit.

In my opinion, it's definately not down to the driver, but relates to something in the engine management system. Only happens at high revs and v.swift gear changes. The jolt occurs after the transmission is in the new gear, clutch almost fully released (way past the bite point) and the power just literally goes for a fraction of a second, and then returns resulting in a fairly nasty jolt, giving the impression of a v.poor gear change.

Only way around it i found was to just slow down the pace of the gear change, or alternativley absolutely crucify the clutch by holding it just momentarly at the bite point with the accelerator floored - gives a smooth change, but I wouldn't hold out much hope for the lifetime of the clutch!

akshay67

This is problem I'm having, being a fairly new (~3 weeks) scooby driver.

I've found that lifting the clutch slowly helps...

Funnily enough, some of my mates who dont know much about cars thought that it was the turbo boost that was giving the jolt

chiark

akshay, same with me, but I'm worried about slipping the clutch with that much throttle on... Difficult one, innit?

Dracoro

Ultimately in all cars, if you get the engine speed/gear speed etc just right then you will get a smooth and thus faster gear change. Hanging to the clutch longer will make it feel smoother initially but really just slows down the gear change and wears out the clutch quicker.

If you get the engine/gear speed just right and still get a jolt or whatever then there is a fault with the car(either in execution or in design). If your local dealer/'expert' say it's a 'feature'! they are talking complete b#####ks as just about every other car manufacturer makes cars that can change gear smoothly of you get it right. Doesn't matter whether it's normally aspirated/turbo/super charged etc.

As for the 'its coz of the turbo'/ 'its coz the car is so powerful' crap, tell the person they don't know their ar#e from their elbow, I could make a 1.1 fiesta 'jolt' under acceleration.

Anyway, practice and get it right and Happy gearchanging.... ;-)

fast bloke

Probably not the best idea for long life, but clutchless changes will help. Instead of depressing the clutch, pull the car out of gear while letting off the throttle. Hold it against the next gear with a fair amount of pressure, but not extreme force. When the revs are right the car will slot smoothly into gear. When you get the hang of it, a passenger would be unable to tell if you where using the clutch or not. Also works on bikes if you need to maintian wheelies through gear changes

steve_s

Thanks guys for sharing that with me.
At least it's not just happening to me.
I'm not sure if I want to fry my clutch by slipping it as the clutch is running ok at the minute with no judder or slip and it's off for it's 37.5K service on thurs. (Doh - better book it in for a new clutch now I've given it the kiss of death.)
I'll try to maybe restrain myself in the flooring it department - not....

steve

911Boy

If its the case that the higher the revs the worse the problem, would this not mean that on cars that rev very high (e.g. honda typre R) this problem would be even worse?

chiark

Dracoro, I personally buy the "something to do with the turbo" thang, as the boost did dramatically cut according to my boost gauge after everything's fully engaged.

At least it's not just me tho . I'll get the missus a neck brace. And some ear defenders for me.

Dracoro

I certainly agree that 'the turbo thing' doesn't help matters much when changing gear BUT I have been in, and have been driven in, turbo charged cars (incl. scoobies) where I have experienced perfect gear changes under heavy acceleration with no jolt etc. Therefore it is possible if you get it just right. I do sympathise that it is sometimes very difficult to do in a powerful turbocharged car, but this should also not be purely used as an excuse for poor gearchanging, which IMHO many people do.

ScoobyJawa

I used to have this problem too, since fitting a Prodrive quickshift and a full decat exhaust it has become almost non existant............

chiark

Bugger. Must try harder then. Oh well, more excuse to use 2nd at full chat Cheers mate!

JFB

Same problem here and I seem to recall someone on the BBS mentioning the overboost "sensor" kicking in and killing the turbo spool so that you have this "wall" to get through when releasing the clutch on the next gearchange. I am having a discrete (to atmosphere dumpvalve fitted shortly which in theory should help if this is actually the problem. We shall see!

Jerome

Robertio

iTrader: (1)

RichS, I can only assume neither of those passenger laps were with me

I too have been known to suffer from that problem, it is possible to do it smoothly, but you have to be very precise (how anyone can do it while wearing a helmet is beyond me, I rely very heavily on the engine note, and find it impossible while wearing one)
Found out on track that it is far worse between 1st and 2nd, but as I never use first like that on the road it is not a problem for me.
Strangely when I first got the car I had this problem when accelerating hard in every gear, I don't know if I have adjusted to make it smoother, or if I've taught the drivetrain to behave itself a bit better

DaveMcC

I've been having exactly this problem - convinced it wasn't just me when I drove a PPP'd car from the local dealer. Anyhow, convinced it was overboosting I ordered a pressure control valve (as fitted by John Banks prior to his Dawes Devices thing). Dealer fitted it today, and I went out with them when they set it up - initially with me driving. As standard, car ran 13.8psi per Select Monitor. Wound back boost, but I still got this jolt on 2nd to 3rd changes. Technician then wound boost UP to show what overboost was - a completely different effect - felt like car was holding back, and occurred about 3,500 to 4,000 rpm. Then swapped over for technician to drive - he managed to accelerate HARD with no jolt - though he did admit it had taken him ~6mths of practice to perfect it. Believes the problem is that I was changing gear too slowly and thus suffering some sort of turbo lag effect - and that fitting a quickshift might help.

Anyway, fiddled further with pressure valve and ended up with boost which peaks at 16.1 psi with no mid-range overboost. Just need to work on my gearchange now, but car definitely pulls harder, and cos the valve was fitted and set up by the dealer no probs with warranty (still got 2 years to go!)

So, looks like maybe quickshift and more practice!

Dave
MY00