thrashing a car

[jks24]

Alot of ppl say it and i take it that it means driving the car really hard. Is this the basic idea when ppl say you are thrashing your car?? I usually shift at about 4000, would this be clasified as thrashing??

[kiwi135]

no.....

[jks24]

would it even hurt the engine one bit shifting at 4000 cause my dad always says, they are only four cylinders so just change around 2000-3000. Hes not young anymore and drives soft. lol

[DreadAngel]

Thrashing you're car isn't just about where you shift, thrashing your car is not giving a **** about it, dumping the clutch, flat shifting, not rev matching on downshifts, shoving the stick... Generally treat the car like crap...

[SHOGUNOVDDRK]

As above.

and

4k shifts are ok.

Aslong as you're not going for >9000 EVERY-SINGLE-SHIFT its fine

[jks24]

Thrashing you're car isn't just about where you shift, thrashing your car is not giving a **** about it, dumping the clutch, flat shifting, not rev matching on downshifts, shoving the stick... Generally treat the car like crap...

im a bit of a noob to this stuff wanna explain shoving the stick, flat shifting and not rev mathcing??
I do care for my civic though

[terrabyte]

Thrashing a car, is going overboard with certain things, often causing damage to mechanical parts of the car. Things I would classify as thrashing, although many people may disagree:

Revving out a cold engine, some people just don't seem to understand that engine oil doesn't lubricate properly until it's warmed up, engines when cold also don't have the correct clearances (metal expands when heated).

Sudden acceleration, I'm talking about jumping on the throttle unnecessarily. Foot to the floor is fine, just take longer than 1/8th of a second to put it there. This is especially the case when standing still, either planting the foot in an auto, or dropping the clutch in a manual. Most of the drive train will be stationary (not spinning/turning) and giving it a sudden huge amount of power, can cause things to twist and/or buckle.

Statics (burnouts). If you've got a car with vast amounts of power and the drivetrain is setup for this, so it requires minimal effort to spin the wheels, I don't see a problem with. It's the people who rev the shit out of the car, and simply drop the clutch to generate enough sudden power to get the wheels spinning. This relates to above, Gearbox @ 0rpm : flywheel @ 6000rpm, suddenly connect the two and bad things can result.

Plus many many more.


As for shifting at 4000rpm, really depends on the car, I wouldn't recommend it in a big V8. But as long as your gentle it should be fine. The problems can result if you're not smooth about it. If you're at 100% throttle straight from the get-go until 4k rpm, then shifting up and straight back to 100% throttle, I don't recommend it (not constantly anyway).

[Red_EG4]

its mainly only car enthusiasts that rev match on the downshift.

I would say thrashing is not letting your car warm up. Redlining ever gear, every time you drive. Riding the clutch. Downshifting in high RPM. Not maintaining the car (servicing, checking fluid levels etc).

[terrabyte]

im a bit of a noob to this stuff wanna explain shoving the stick, flat shifting and not rev mathcing??
I do care for my civic though

Flat shifting, is not using the clutch or just jabbing the clutch and ramming it into the next gear. Might make the shift slightly faster, but is it really worth the risk of destroying your gearbox?

Rev matching, is making the downshifts smooth. When changing down a gear, the revs are obviously going to be higher, so while the clutch is in, you accelerate until the revs match what they would be in that gear, then you realese the clutch. This makes it much smoother and you don't feel the car surge backwards as the gearbox makes the engine rev up.

I'll give you an example, travelling in 4th at 2500rpm (around 55-60km/h), I want to start slowing down for a set of lights, so I would put my foot on the clutch, and move the gearstick up to third, but by this time my revs have already starting dropping and I might be at 1500-2000rpm. But in third gear at 55-60km/h I would be around 3000rpm, but my engines only at 1500rpm. So while the clutch is still depressed, I jab at the accelerator so the revs jump to that 3000rpm and then release the clutch. Once you practice it should get so smooth you can't even feel the downshifts (just hear them).

[Type R Positive]

would it even hurt the engine one bit shifting at 4000 cause my dad always says, they are only four cylinders so just change around 2000-3000. Hes not young anymore and drives soft. lol
Tell your dad, its a Honda and revs to 8k rpm..... Not even VTEC yet, yO ;)

[jks24]

yeh i knew about lettin the car warm up, i have never redlined any gear so i spose im safe there. I get my car serviced by honda every 6 months so im safe there. I check my oil and water everytime i fill up pritty much. I used to ride the clutch when i was on learners lol but no tanymore. By revving out a cold engine you mean revving it up to redline right? Ive noticed when i used to drop back to second, i never go back to second above 40 kms. When i used to do this i would feel the change. Hitting the accelator while my cluth is in and then puttin it in second should solve this from what i have just read above. BTW my ek is non vtec so it sounds shit in high revs anyways, lol

[terrabyte]

yeh i knew about lettin the car warm up, i have never redlined any gear so i spose im safe there. I get my car serviced by honda every 6 months so im safe there. I check my oil and water everytime i fill up pritty much. I used to ride the clutch when i was on learners lol but no tanymore. By revving out a cold engine you mean revving it up to redline right? and just for my information what is flat shifting??

Just any high revving or sudden acceleration while the car's cold. I drive like a granny till operating temperature (just remember oil takes longer to heat up then water).

Things like this are a really bad idea: Saw a guy come out of the same movie that me and some mates were watching. Walks over to his supra that's been sitting there for at least 3-4 hours (long movie), it's like 15C and raining, so it's stone cold by now. What's the first he does after he starts it... Hit the rev limiter. :thumbdwn:

[SHOGUNOVDDRK]

jks i was thinking you were a complete nub.

You have proved yourself worthy...


BTW my ek is non vtec so it sounds shit in high revs anyways, lol

epic lulz had.

[terrabyte]

Even without Vtec Honda engines sound fkn awesome up at the top end. If you ever take your car to a dyno or similar have a listen to how good a honda motor sounds from the outside. They just scream, pure hotness. Unlike some of the mazda's on this dyno day I went to, they sound really clunky and not really that great, lol.

[SHOGUNOVDDRK]

hahahahaha, thats not why i was laughing.

[DreadAngel]

its mainly only car enthusiasts that rev match on the downshift.

I would say thrashing is not letting your car warm up. Redlining ever gear, every time you drive. Riding the clutch. Downshifting in high RPM. Not maintaining the car (servicing, checking fluid levels etc).

Rev matching poor way of saying what I was actually trying to say =| Sorry sorry...

Its more like just dropping the gears really quick without a care in the world what revs they are, let the synchros do the work and the gearbox/clutch etc to take the brunt of the force...

[trism]

saying "its only a 4 cyl, shift at 4k" is the bigest load of shit ive ever heard

what about a 4cylinder diesel whose redline is at 3.5k? what about a race built b16 whose redline is at 8k and can rev saftly to 10k? 4k isnt even half of the avaliable revs


it all depends on teh engine and how many revs you have avaliable to use

[jks24]

jks i was thinking you were a complete nub.

You have proved yourself worthy...



epic lulz had.

lol i will improve

[Type R Positive]

it all depends on teh engine and how many revs you have avaliable to usenah, more like peak torque, which is still pretty high in a Honda. :thumbsup:

[Mugen Civic]

Occasional red lining revving out the engine is good too isn't it? Clears some of the carbon build up in valves and exhaust.

Just don't do anything that puts alot of stress on the car parts like dumping clutch and do service on time etc...
already been covered.

I also like the sound of the non Vtec civic. It does scream.
Of couse Vtec sound better thou.

[SeverAMV]

Riding the clutch..

riding the clutch doesnt really equal thrashing unless you're just riding the clutch for the hell of it.

riding the clutch in between shifts or during launch promotes a more gradual torque transfer which can lessen the stress on the gearbox.

[DreadAngel]

Occasional red lining revving out the engine is good too isn't it? Clears some of the carbon build up in valves and exhaust.

Just don't do anything that puts alot of stress on the car parts like dumping clutch and do service on time etc...
already been covered.

I also like the sound of the non Vtec civic. It does scream.
Of couse Vtec sound better thou.

VTEC engines should get some exercise, otherwise they become fatty and lazy =P

[JasonGilholme]

your dads wrong.

a smaller engine will need to rev a bit higher to get enough momentum/torque to get the car moving. By shifting at 2000 RPM your just wasting petrol.

4000 RPM is only half of the available RPM so its a safe place to shift for daily driving.

but 4000 RPM in a v8 is probably close to 3 quarters of the RPM and will be too excessive for daily driving (cause it has three times the capicity and twice as many cylinders)

[Sherweeeny]

shifting too early will have the engine struggling which is probably just as bad or worse

[Lukey]

tell that to my dad

i shift at 3krpm with him in the car and he yells at me for thrashing it

>.<"

[Sherweeeny]

Options:
1) kick him out of the car
2) supercharge it
3) get rid of milo tin gazillion decibel exhaust
4) strip out the car in order to deny your father access
5) constantly pay for 5 escorts to sit in your car and deny your father access

[uniorj]

Your dad is probably just saying that so you don't drive fast. Parents will be parents.

[Lukey]

i run stock exhaust with no muffler

but this was before that

[Red_EG4]

riding the clutch doesnt really equal thrashing unless you're just riding the clutch for the hell of it.

riding the clutch in between shifts or during launch promotes a more gradual torque transfer which can lessen the stress on the gearbox.

True, I should have added excessively or unnecessarily, perhaps.

[TONTON]

Options:
1) kick him out of the car
2) supercharge it
3) get rid of milo tin gazillion decibel exhaust
4) strip out the car in order to deny your father access
5) constantly pay for 5 escorts to sit in your car and deny your father access

never knew integra's were 6 seaters =O

[Sherweeeny]

never knew integra's were 6 seaters =O

who said anything about the girls legally using the right amount on seats? :wave:

[OMG.JAI xD]

lol 4 cylinders so you rev less -.-"
its actually 4 cylinders so you rev more.

in a v8 or v6 you shouldnt rev more as a 4 cylinder.
theres more moving parts in a revolution.
remember a engine can only make 1 revolution at a time. its just physics.
just cause you have 4 more cylinders doesnt mean it turns twice more than a 4 cylinder.
it just means there are more pistons working in a revolution.

[F20C]

9200 when im in the mood for some redlines =) weeeee lol. on the note of "treating your car like crap" how would i have bent a shift fork? and blew a synchro lol?

[jords]

9200 when im in the mood for some redlines =) weeeee lol. on the note of "treating your car like crap" how would i have bent a shift fork? and blew a synchro lol?

drive it like you stole it, dang 9200rpm is some decent rpm, what mods you got?

I treat my baby with more T & C than that.

[55EXX]

i hit in the red (7200) twice a day at least. my car doesn't have much balls below 4 grand. static speed driving its already sitting and 3k. i have a strict service schedule tho and use a full ester synthetic oil. i do high rev down changes with heel toe action most of the time too. i take my car for hard drives up twisty roads and all that but that was what i have the car for. i don't drive it like a stole it. i drive it like i bought it for that reason.

[F20C]

nothings changed on my car except a poddy from b&n i think it was lol cost abit.. spark plugs.. and a different oil thingy but thats about it lol nothing serious yet.. and yeah 9200 in an f20c though lol..

[tiksie]

I have a habit of only revving it up to 3000RPM when driving normaly and only revving up to 2 when it's cold.. Until it reaches normal operating temperature, then I will use 3000! EG :) Most of the time I just let it warm up anyway, a cigarette break while its warming it gives it enough time to warm up to operating temperature!

[Chernoby1]

Hit the 10k limiter on my cappuccino twice, and boy did that feel good! Non-vtec engine revs higher than vtec...... bhhaahah

I have been told i ride the clutch excessivly on starts but i think that has something to do with my first gear.... 4000 rpm @15km/h. If i try to launch at under 2600, car will stall or generally be not plesant.

I must admit that i do thrash my car lol, but unlike most, i have a reason. I live by the philosophy "if it aint broke, dont fix it". So need something to break for me to 'fix' it :P (Cmonnnn diffy... seize the f*** up already!)

[EK1.6LCIV]

hell no, that's when I do shift, except in first gear as the d16 has pretty av. accel in first, lol

d16 is more of a moving speed, hit corners fast kind of engine, drag racing is not it's place of business, lol

[AutoNoob]

wats the redline of a cxi on stock everything? would it break to redline like every time ur at a traffic light? highest i think i did and it didnt redline was 6000rpm. (it's not broken yet)

[tiksie]

Yes, it will break.

[ndeuro_]

my shift poin is 3-4krpm when im modest. driving range is between 2-3k. but yeah driving at night (15 degree) with a SRI and cold air feed is awesome. drinks alot but the roar you get out of it is fkn sick

[Crapdaz]

my shift poin is 3-4krpm when im modest. driving range is between 2-3k. but yeah driving at night (15 degree) with a SRI and cold air feed is awesome. drinks alot but the roar you get out of it is fkn sick
dude, shift @ 7100RPM man!
do you have headers?

anyhow,

APPLICATION: 2003 ACCORD EURO
COLD - shift before 2k
WARM (normal) - 2-3k
WARM (spirited) - 7100RPM

[ndeuro_]

no headers yet

[F20C]

lol.. 3000-4000 when im driving "nicely" lol.. and about 6-9.2k when i feel like a thrashing :)

[na-118]

ek cxi backs off at 7100-200

[AutoNoob]

far out thats pretty high. stock? or with headers, SRI and all the other mods

[Crapdaz]

ek cxi backs off at 7100-200

you mean cut off point?

the euro is 7200rpm cut off, which sucks.

[na-118]

it bounces back at 7200 completley stock

[hectik_7]

my shift poin is 3-4krpm when im modest. driving range is between 2-3k. but yeah driving at night (15 degree) with a SRI and cold air feed is awesome. drinks alot but the roar you get out of it is fkn sick

oh yeah fukin oaf,

revin til 8k feels quite nice :p,

hatin this humid heat we got in melb atm,...:thumbdwn:

[fitvpower]

tell that to my dad

i shift at 3krpm with him in the car and he yells at me for thrashing it

>.<"
its like this..

my dad is deaf and asked me what is vtec..

after the drive i cleared his hearing lol!

jks jks

[curtis265]

would it even hurt the engine one bit shifting at 4000 cause my dad always says, they are only four cylinders so just change around 2000-3000. Hes not young anymore and drives soft. lol

Yeah wth o.0

the 4cyls ar ethe only one that can rev that high!

[F20C]

4 cylinders are made to rev high as 8's arnt. Otherwise you would see 8's revving to 10k or so lol. But then again i guess that depends on what 4 cylinder we're talking about? In general 4 cylinders are ment to rev higher.

[fitvpower]

is double clutching good for the car and gearbox? i hear a lot of things from it that its bad and good..

[VTECMACHINE]

Take corners and clutch kick, with a 20kg loose sand bag in the car... learn to control the car in a drift - scare the s**t out of your Dad.

[jks24]

haha my noob thread has appeared again :0

[F20C]

Clutch kick and destroy your clutch sounds fun lol. and double clutching was made for the olden day cars with no synchros. we have synchros so use them -.- having said that yes it will hurt your car lol.

[Min988]

you mean cut off point?

the euro is 7200rpm cut off, which sucks.

Mines at 7395rpm.

[redmugenjazz]

is double clutching good for the car and gearbox? i hear a lot of things from it that its bad and good..

good for gear box if done properly, bad for the clutch if its kept in when u do the rev match, i go: current gear ->clutch-> neutral-> clutch out -> rev (with heel) -> clutch in -> gear down -> drop the clutch. do it right, car would slow down smoothly whist in gear, do it incorrectly, car jerks. ps: this is all done with the presence of constant braking with the ball of my foot. hope this helps migs

[fitvpower]

oh yep thanks nam thats what im practicing lol! but with no brake since ma pedals are real tiny atm...stockk

[Crapdaz]

Mines at 7395rpm.
yeh min newer euro's have cut off at 7400.

[aaronng]

Mines at 7395rpm.

Is that read through RSM? 2004 should be 7200rpm

[aaronng]

4 cylinders are made to rev high as 8's arnt. Otherwise you would see 8's revving to 10k or so lol. But then again i guess that depends on what 4 cylinder we're talking about? In general 4 cylinders are ment to rev higher.

I used to have a 4cyl that revved to only 5000rpm............. fail...

Can't generalise that 4-cyl can rev high. It depends on the design. There are many 8-cyls that rev to 7000rpm or 8000rpm. Look at the C63 Merc. 6.2L V8, yet is able to rev higher than many 4-cyls.

[EG52NV]

good for gear box if done properly, bad for the clutch if its kept in when u do the rev match, i go: current gear ->clutch-> neutral-> clutch out -> rev (with heel) -> clutch in -> gear down -> drop the clutch. do it right, car would slow down smoothly whist in gear, do it incorrectly, car jerks. ps: this is all done with the presence of constant braking with the ball of my foot. hope this helps migs

why do you shift to neutral and engage the clutch?

How I normally rev match my down shifts is

approaching a turn -> current gear -> clutch in + down shift + brake with the ball of my foot + blimp accelerator with my heel (all at the same time) -> clutch out -> accelerate in and out of the turn

[aaronng]

why do you shift to neutral and engage the clutch?

How I normally rev match my down shifts is

approaching a turn -> current gear -> clutch in + down shift + brake with the ball of my foot + blimp accelerator with my heel (all at the same time) -> clutch out -> accelerate in and out of the turn
You're doing heel-toe rev matching. Redmugenjazz is actually doing heel-toe double clutching, which saves his synchros at the same time. His technique is more difficult and even I haven't mastered that yet.

[dsp26]

actually is it true for some cars when new you have to drive it the way you want it to drive eventually.

i first heard this with the corolla sportivo's... apparently someone from TRD Pennant Hills advised that if you want the ecu and engine to wear in for performance you have to thrash it heaps before the 1500km service.

[EG52NV]

hmmm can't say I've ever tried heel-toe double clutching.. might try it tonight lol

[SMI-33K]

as long as you dont over rev or crunch any gears its all good
just service the car every 5000k and it will be bulet proof

go hard or go home

[aaronng]

actually is it true for some cars when new you have to drive it the way you want it to drive eventually.

i first heard this with the corolla sportivo's... apparently someone from TRD Pennant Hills advised that if you want the ecu and engine to wear in for performance you have to thrash it heaps before the 1500km service.

It's not the ecu. It's the sealing of the piston rings. You get better sealing if you run the car in hard from new.

http://www.mototuneusa.com/break_in_secrets.htm

[dsp26]

It's not the ecu. It's the sealing of the piston rings. You get better sealing if you run the car in hard from new.

http://www.mototuneusa.com/break_in_secrets.htm

bookmarked as part of my tech collection :D

[redmugenjazz]

You're doing heel-toe rev matching. Redmugenjazz is actually doing heel-toe double clutching, which saves his synchros at the same time. His technique is more difficult and even I haven't mastered that yet.

lol so is that what its called, yea it takes time to get used to it, it works better for drive by cable cars as opposed to drive by wire cars. i tried it in euros and the new civic - epic fail. for the jazz it works best if you time it out correctly - the timing for each step seems to be the same for each gear downshift. OR just drive normally.

[F20C]

yeah thats why i said it depends on what 4 cylinder we are talking about lol. As you know an s2k rev's to 9200 :P but not all 4 cylinders do. But assuming we are speaking of performance 4 cylinders not silly excels they would generally rev higher wouldnt they?

[eg5civic]

b16b

Redline 8500rpm
Rev cut ~9000-9200

ggz:thumbsup:

in saying that stock EG si exhaust sucks and chokes it like wayne brady chokes a bitch

[F20C]

lol eg5

[aaronng]

yeah thats why i said it depends on what 4 cylinder we are talking about lol. As you know an s2k rev's to 9200 :P but not all 4 cylinders do. But assuming we are speaking of performance 4 cylinders not silly excels they would generally rev higher wouldnt they?

Another reason why there aren't 8-cyl road car engines that rev to 9000rpm is because Honda hasn't gotten into 8-cyl. :p

It's more due to the fact that we love our S2ks and Type Rs, which have performance engines and rev so high that a black hole is created. 8000-9000rpm comes more from the fact that they are performance engines, and less from because they have 4 cylinders.

[F20C]

lol. i wanna see an 8 cylinder vtec rev upto 10k would be the sexiest sound ever :| or that v10 nsx Acura have decided to take on lol.

[lil_foy]

Um isnt stroke one of the main factors of the cars limiter?

[aaronng]

Um isnt stroke one of the main factors of the cars limiter?

I've ridden a k24 with 99mm stroke revving up to 8000rpm. :)

[interfooler]

Old V10 F1 engines used to rev up to 19,000 rpm lol

[F20C]

Lol but their f1's!! I wouldnt think the stroke of the car means they can rev higher.. I always thought it just improves the low and mid rpm? Dont think it makes the car rev higher.. otherwise stroked 5litres will be revving a stupid amount? I could be wrong though..

[aaronng]

Lol but their f1's!! I wouldnt think the stroke of the car means they can rev higher.. I always thought it just improves the low and mid rpm? Dont think it makes the car rev higher.. otherwise stroked 5litres will be revving a stupid amount? I could be wrong though..

We are talking about a longer stroke limiting the maximum rpm it can spin reliably at.

[F20C]

ahh i see.

[lil_foy]

Just trying to work a few things out and check if they are correct.

Because the stroke is longer and the piston has to move further the force is why there is more torque? Say under 1000rpm a piston with 87mm stroke is moving at 145cm per second. Compare it to a engine with a 95mm stroke running at 1000rpm 158.33* cm per second. Since they both need the travel the same distance to make the same torque the one with the large stroke can make it at a much lower rpm correct?

[F20C]

sounds like it makes sense if you think about it. but i wouldnt know, not the best with technical things yet :P

[EG52NV]

You're doing heel-toe rev matching. Redmugenjazz is actually doing heel-toe double clutching, which saves his synchros at the same time. His technique is more difficult and even I haven't mastered that yet.

Ok tried it out last ngiht, at first I was like WTF is this technique and was doing all fcuked up shit lol but in the end it's not that hard if you approach it from the correct angle

all you gotta do is break it down and practice it in 2 steps and then combine into one

step one: driving along in gear -> clutch in -> shift to neutral -> clutch out ->

step two: perform heel toe rev match down gear from neutral

when combined perfectly you get the double de-clutch technique, I ended up mastering it in 15 mins :)

but I still like the normal heel toe rev match down gear technique better, maybe its coz I'm lazy..

[aaronng]

^^ yeah, but regular heel-toe rev matching doesn't let you brake down to 40km/h and go into 1st gear on the track.

[lil_foy]

^^ yeah, but regular heel-toe rev matching doesn't let you brake down to 40km/h and go into 1st gear on the track.

Exactly!
And if you just jam it in there enjoy your ****ed syncros.

[EG52NV]

lol so what other benefits don't I know about this technique? Coz I didn't notice much different when I was using it last night, maybe its coz I've never tried shifting back to 1st while car is in motion above 5kms.. It's probably coz I lack knowledge on how the internals of a box function..

[redmugenjazz]

lol so what other benefits don't I know about this technique? Coz I didn't notice much different when I was using it last night, maybe its coz I've never tried shifting back to 1st while car is in motion above 5kms.. It's probably coz I lack knowledge on how the internals of a box function..

well under normal downshift, ur engine's gotta use its power to transfer to the gearbox to pull the rpm up. If this occours around a corner, you will loose power going around. hence if u rev b4 hand, and say going around a corner in gear, ur engine's power is fully directed towards the wheels becuase the rev is already matched. off the track, on local roads it just means smooth downshift and smooth cornering

[aaronng]

lol so what other benefits don't I know about this technique? Coz I didn't notice much different when I was using it last night, maybe its coz I've never tried shifting back to 1st while car is in motion above 5kms.. It's probably coz I lack knowledge on how the internals of a box function..

The input shaft RPM is matched to the road speed when you blip the throttle in neutral with the clutch out. So when the input shaft goes into the lower gear, there is very little wear.

Consequently, you can skip gears when downshifting without wearing synchros. I do this (without the heel toe part of course) when I want to shift from 6th to 2nd for some instant acceleration. :thumsup:

[lil_foy]

well under normal downshift, ur engine's gotta use its power to transfer to the gearbox to pull the rpm up. If this occours around a corner, you will loose power going around. hence if u rev b4 hand, and say going around a corner in gear, ur engine's power is fully directed towards the wheels becuase the rev is already matched. off the track, on local roads it just means smooth downshift and smooth cornering


That is sooo irrelivant.

The syncros in your gearbox have to speed up the gear because it will be at a higher rpm for the lower gear. This causes wear. Rev matching helps ease the wear on them.

[curtis265]

well under normal downshift, ur engine's gotta use its power to transfer to the gearbox to pull the rpm up. If this occours around a corner, you will loose power going around. hence if u rev b4 hand, and say going around a corner in gear, ur engine's power is fully directed towards the wheels becuase the rev is already matched. off the track, on local roads it just means smooth downshift and smooth cornering

lol hahahahahahaha

Yer, where'd you hear that from? How does that even work?

[CB7_OWNER]

would rev matching a downshift from say 5 gear (going says 80km/h) to 2nd gear, mean raising the rpms's to roughly as high as 4-5k , which means your free reving your engine, which means its bad for the car ???

[redmugenjazz]

That is sooo irrelivant.

The syncros in your gearbox have to speed up the gear because it will be at a higher rpm for the lower gear. This causes wear. Rev matching helps ease the wear on them.

performance wise this is how it benefits, i dunno what actions it has on the syncros. thnx for telling.

[redmugenjazz]

lol hahahahahahaha

Yer, where'd you hear that from? How does that even work?

i try things out, not hear about them.. drive a manual and hit the corners then u feel what i mean,

[aaronng]

would rev matching a downshift from say 5 gear (going says 80km/h) to 2nd gear, mean raising the rpms's to roughly as high as 4-5k , which means your free reving your engine, which means its bad for the car ???

It is a very short duration that you rev to revmatch. It involves blipping the throttle for a fraction of a second, and not holding the throttle down for long durations. So your engine will be alright.

[F20C]

aarnog you seem to know abit about boxes.. how would someone bend a shift fork and blow a synchro?

[aaronng]

aarnog you seem to know abit about boxes.. how would someone bend a shift fork and blow a synchro?

Using a short shifter and flatshifting often.

[Mr_will]

The input shaft RPM is matched to the road speed when you blip the throttle in neutral with the clutch out. So when the input shaft goes into the lower gear, there is very little wear.

Consequently, you can skip gears when downshifting without wearing synchros. I do this (without the heel toe part of course) when I want to shift from 6th to 2nd for some instant acceleration. :thumsup:


if youre in 6th doing a speed which allows you to downshift to 2nd without overrevving, then 6th was very likely the wrong gear.

[aaronng]

if youre in 6th doing a speed which allows you to downshift to 2nd without overrevving, then 6th was very likely the wrong gear.

Accord Euros can cruise at 60-70km/h in 6th gear without lugging the engine. At that speed, 2nd gear will go in at 4500-5000rpm, which is the sweet spot for max torque.

[F20C]

a short shifter? how would one blow it in an s2000?

[lil_foy]

a short shifter? how would one blow it in an s2000?

Ok so syncros are what helps speed up the gears so they match in revolutions when changing down gears. If you use a short shifter your shifting time is obviously shortened when shifting hard.

Doing so means the syncro has to slow down and get over speed, this causes alot of wear on the syncro which is why you blew one.

[EG52NV]

no one has actually explained how blimping the throttle in neutral with clutch engaged then shifting is different from blimping the throttle while shifting with the clutch disengaged..

Or maybe they have and I just didn't get it..

[terrabyte]

no one has actually explained how blimping the throttle in neutral with clutch engaged is different from blimping the throttle while shifting with the clutch disengaged..

Or maybe they have and I just didn't get it..

In neutral (foot off the clutch) your actually spinning up the centre shaft (someone correct me please) of the gearbox so everything is completely in synch. Where as with your foot on the clutch, your matching the engine to the wheel speed, but the synchro's on the gearbox are forced to match the rest up.

That's my understanding, I could be completely wrong though.

[lil_foy]

no one has actually explained how blimping the throttle in neutral with clutch engaged then shifting is different from blimping the throttle while shifting with the clutch disengaged..

Or maybe they have and I just didn't get it..

This is my understanding.

Ok so when you rev match with the clutch in all you're increasing the rotations of is the engine since the one thing that spins the clutch isnt touching anymore. So when you revmatch without the double clutching technique the syncros still have to speed up but they don't have the load of speeding up the engine to the correct speed aswell.

You will still get wear from not using the double clutching but it will be significantly less since the load put on the syncro itself is reduced dramaticly.

When you put the car in neutral you're spinning the main shaft but since the selector fork isnt on a gear the wheels won't get turned by this. So say you're going from 3rd (3000rpm) - 2nd (4500) when putting it in neutral the actually speeding up 2nd gear itself so when you put it in second using double clutching it 1. Doesnt have to ramp up engine speed, 2. Doesnt have to syncronise the gears because they are already at the correct speed. This means very minimal wear.

This is just my understanding don't quote me on it.

[EG52NV]

can someone translate that to English? LOL

its like trying to read the help files in Microsoft products..

In the end I still don't get it..

Thanks anyway guys..

[lil_foy]

Put simply when you rev with the clutch in, none of the gears move.
This means you're not matching the gear speeds just the engine speed.

You will still get wear but the engine resistance is one of the main things putting wear on your syncros.

Double clutching means you speed up the engine and gear speeds.
=Less wear, smooth changes.

Once again thats my understanding don't quote me on it.

Also if you're new to double clutching don't go trying it around corners where it will bring your focus off the road. Last thing we want is someone crashing because they were too keen.

[aaronng]

^^ lil foy got that right.

Basically in layman terms,
Revmatching reduces clutch wear. (you're blipping to match the flywheel speed to the clutch speed)
Double clutching reduces synchros and clutch wear. (you're blipping to match the flywheel speed to the clutch speed AND the input shaft speed to the gearbox speed).

[curtis265]

i try things out, not hear about them.. drive a manual and hit the corners then u feel what i mean,

Yeah i drive manual already, thanks for the tip.

What i meant was - your statement about losing power around the corner made no sense to me. Downshiftnig doesn't necessarily mean you lose power - you engage a lower gear, so that you can take a corner at a tractable speed, as well as be in the correct RPM range to accelerate nicely.

You also downshift before the corner rather than in the corner, in order to keep traction - a less-than-perfect shift will result in a bit of a jolt in the transmission and will cause a loss in traction.

[blk05gli]

this is interesting, i was always taught to double clutch by my old man, guess it was normal driving for his era when cars didn't have synchro matched forward gears.

[Mr_will]

Accord Euros can cruise at 60-70km/h in 6th gear without lugging the engine. At that speed, 2nd gear will go in at 4500-5000rpm, which is the sweet spot for max torque.


I doubt it. what rpm are you at at 60km/h in 6th?

6th is for highway speeds - 60km/h is not a highway speed. you're likely using more fuel, and compromising in gear response as opposed to being in 5th or 4th

[aaronng]

I doubt it. what rpm are you at at 60km/h in 6th?

6th is for highway speeds - 60km/h is not a highway speed. you're likely using more fuel, and compromising in gear response as opposed to being in 5th or 4th

Flat road, minimal throttle required. RPM's at about 1500-1700rpm. As I said, it is for cruising, you should not accelerate in 6th gear because of lugging the engine. That's why I use double clutch downshift into 2nd gear. No one said anything about accelerating in 6th, causing it to use more fuel and risk damaging the engine.

[Mr_will]

Flat road, minimal throttle required. RPM's at about 1500-1700rpm. As I said, it is for cruising, you should not accelerate in 6th gear because of lugging the engine. That's why I use double clutch downshift into 2nd gear. No one said anything about accelerating in 6th, causing it to use more fuel and risk damaging the engine.


if you cant accelerate in a gear then its the wrong gear - why would you be in 6th when you could be in 5th using no more (in fact, probably less) fuel, and getting better response if you need to accelerate?

[curtis265]

if you cant accelerate in a gear then its the wrong gear - why would you be in 6th when you could be in 5th using no more (in fact, probably less) fuel, and getting better response if you need to accelerate?

so your saying that crusing at higher RPM's means less fuel consumption?

[Mr_will]

so your saying that crusing at higher RPM's means less fuel consumption?


in some instances yes. because fuel consumption is dependant on load/throttle position not RPM.

the ECU decides how much fuel to let it based on throttle position, etc, so for example if in 6th and trying to accelerate from 1500 rpm, you will use more fuel than say, 3rd from 3000 (dont quote me on the ratios, is just an example) because acceleration from 3rd will require less throttle.

[curtis265]

in some instances yes. because fuel consumption is dependant on load/throttle position not RPM.

the ECU decides how much fuel to let it based on throttle position, etc, so for example if in 6th and trying to accelerate from 1500 rpm, you will use more fuel than say, 3rd from 3000 (dont quote me on the ratios, is just an example) because acceleration from 3rd will require less throttle.

But, Aaronng isn't going to accelerate from 6th gear at 1500-1700 rpm... I use 5th gear when i go at 70, which cruises around 1500 as well... it sounds like hell accelerating from there so i don't bother anyway...

[Mr_will]

But, Aaronng isn't going to accelerate from 6th gear at 1500-1700 rpm... I use 5th gear when i go at 70, which cruises around 1500 as well... it sounds like hell accelerating from there so i don't bother anyway...


youre missing the point - the point is that there is no reason to be in that gear in the first place, 4th will not cause you to use any more fuel, and will give you better response than 5th so perhaps you wont need to downshift at all

[curtis265]

youre missing the point - the point is that there is no reason to be in that gear in the first place, 4th will not cause you to use any more fuel, and will give you better response than 5th so perhaps you wont need to downshift at all

Are you surelysurely-surely sure about that? (in this case)

I don' tknow what rpm's they sit on right now... so i'll get bak to u on that later.

[90LAN]

i rev mine to 2000 rpms and get 700 plus kms out of a tank
so reving your motor is not good for it

[Mr_will]

Are you surelysurely-surely sure about that? (in this case)

I don' tknow what rpm's they sit on right now... so i'll get bak to u on that later.


I am 100% sure that fuel consumption is dependent on throttle position not RPM.

Lower rpm does NOT instantly equal less fuel.

For example in my da9, i could sit at some stupidly low rpm in 5th at 60, or about 2500 in 4th, or a bit over 3000 in 3rd. the fuel consumption difference between these is negligable - and given that in 4th and 3rd i dont need to downshift to accelerate, and dont risk lugging the engine, its much better overall

[blk05gli]

I doubt it. what rpm are you at at 60km/h in 6th?

6th is for highway speeds - 60km/h is not a highway speed. you're likely using more fuel, and compromising in gear response as opposed to being in 5th or 4th

guys, i think we're all missing the point here. just because the Euro can be in 6th at 70km/h, doesn't mean that you should, the word used was can. My driving pattern is 1-3-5 as I can't be arsed changing all the time.

entering freeways, its normally redline 2nd and straight into 6th.

bring on the flame :cool:

[aaronng]

if you cant accelerate in a gear then its the wrong gear - why would you be in 6th when you could be in 5th using no more (in fact, probably less) fuel, and getting better response if you need to accelerate?

I can be in 6th, I can be in 5th like you said. Either way, I will want to downshit from 5th/6th to 2nd without going through 4th and 3rd gear. Double clutching lets me do that without wearing out the synchros. :)