1/4 mile advice required
Discussion
Last night whilst England were playing I was taking advantage of the quiet roads tried a couple of standing starts.
I first tried gradual but rapid dump of the clutch at 3000 revs and had a fun but smoky pull away. Obviously no good for 1/4 mile times (but perhaps good for the show!).
I then tried no initial revs and a gradual squeeze of the throttle. It gave a smooth and very rapid pull away with next to zero wheel spin. (It felt bloody quick too
!).
Its obvious that the 2nd example is the one thats gonna get the best times but does anyone have any other tips?
I was thinking it would be best to change up between 5500 and 6000 (somewhere in that range always works best for me) and not to change up from 4th.
I first tried gradual but rapid dump of the clutch at 3000 revs and had a fun but smoky pull away. Obviously no good for 1/4 mile times (but perhaps good for the show!).
I then tried no initial revs and a gradual squeeze of the throttle. It gave a smooth and very rapid pull away with next to zero wheel spin. (It felt bloody quick too
!). Its obvious that the 2nd example is the one thats gonna get the best times but does anyone have any other tips?
I was thinking it would be best to change up between 5500 and 6000 (somewhere in that range always works best for me) and not to change up from 4th.
Advice, errrrrr... don't drive angry. Always remember; 'mirror, signal, manouvre'. 
For a quick start, be gentle, and (from your other thread) don't pump the tyres up too much.
FWIW, at the Loton Park sprint, they normally give a time for the first 64ft. Often, even quick (over the total course) drivers only manage 2.7 seconds, but the last two years, (I think) beacuse my car was on standard, i.e. softer springs than most others, I was frequently under 2.5 secs. I always use what Martin Brundle would describe as 'granny starts' - alwyas been the fastest way for me.
For a quick start, be gentle, and (from your other thread) don't pump the tyres up too much.
FWIW, at the Loton Park sprint, they normally give a time for the first 64ft. Often, even quick (over the total course) drivers only manage 2.7 seconds, but the last two years, (I think) beacuse my car was on standard, i.e. softer springs than most others, I was frequently under 2.5 secs. I always use what Martin Brundle would describe as 'granny starts' - alwyas been the fastest way for me.
I managed to beat all the other Tivs at a recent even on a start-stop test. The instructors said this was due to my non tyre smoking starts and stops compared with all the tuned Cerbies!
The only person I couldnt beat (although we challenged each other for a while) was Joust in his Noble.
He ended up with 9.46 and I with 9.51
Pretty good considering Im all standard and Noble brakes are huge!
Distance was enough to just change into thrid before hitting the brakes.
The only person I couldnt beat (although we challenged each other for a while) was Joust in his Noble.
He ended up with 9.46 and I with 9.51
Pretty good considering Im all standard and Noble brakes are huge!
Distance was enough to just change into thrid before hitting the brakes.
at the risk of giving my secret away .....
select 1st, and gently build revs and against the clutch, while you're holding the car stationary on the handbrake ( left hand , thumb holding release button in ) until the car just doesn't quite move off against the handbrake
this gets the engine making torque sooner than if you don't do this (MOST effective for turbo engines ), and perhaps more importantly, moves the suspension into the 'set' it's going to take when you launch, so you've already done half the weight transfer without moving anywhere and get better initial traction ...
lights go green, let the handbrake off and increase throttle and clutch almost to the point of wheelspin, then when you're feeling safe, nail it and scare yourself silly
for the two-wheel fanatics, adapting this to right foot/back brake works even better on a bike than for a car, 10.91@132 on a Thunderace proves my point
anyone else use this technique, or am I alone ?
( got another trick if anyone's interested )
select 1st, and gently build revs and against the clutch, while you're holding the car stationary on the handbrake ( left hand , thumb holding release button in ) until the car just doesn't quite move off against the handbrake
this gets the engine making torque sooner than if you don't do this (MOST effective for turbo engines ), and perhaps more importantly, moves the suspension into the 'set' it's going to take when you launch, so you've already done half the weight transfer without moving anywhere and get better initial traction ...
lights go green, let the handbrake off and increase throttle and clutch almost to the point of wheelspin, then when you're feeling safe, nail it and scare yourself silly
for the two-wheel fanatics, adapting this to right foot/back brake works even better on a bike than for a car, 10.91@132 on a Thunderace proves my point
anyone else use this technique, or am I alone ?
( got another trick if anyone's interested )
. 
. never having driven a TVR of any flavour, these are only suggestions ....
the handbrake thing should work a treat in your golf though, have you thought about taking that down a 1/4 ?
at the risk of further destroying TVR clutches, the other idea is to hold the throttle part way down while you shift, so you slide the clutch back in against too many revs ( not redline though, that's just silly ). This works best on turbos and diesels too, esp VAG turbo engines with flywheels off a cargo tanker diesel.
got another tip about when to change gear, but it's going to take a while to type, even though it's good advice ... want that one too ?
the handbrake thing should work a treat in your golf though, have you thought about taking that down a 1/4 ?
at the risk of further destroying TVR clutches, the other idea is to hold the throttle part way down while you shift, so you slide the clutch back in against too many revs ( not redline though, that's just silly ). This works best on turbos and diesels too, esp VAG turbo engines with flywheels off a cargo tanker diesel.
got another tip about when to change gear, but it's going to take a while to type, even though it's good advice ... want that one too ?
HarryW. I remember those postings. I think it was me that started the thread after I had seen some impressive V8S launches on a runway.
(launches/runway; funny that!).
But dont the V8S's have some kinda special launch technique anyway?
Might have to give it a go in the Griff just to see if the same applies.
Im not expecting to beat anyone but if Im gonna enter I wanna at least do it properly. Could be an interesting sport to get into.
(launches/runway; funny that!).
But dont the V8S's have some kinda special launch technique anyway?
Might have to give it a go in the Griff just to see if the same applies.
Im not expecting to beat anyone but if Im gonna enter I wanna at least do it properly. Could be an interesting sport to get into.
timbrown said:
never having driven a TVR of any flavour, these are only suggestions ....
the handbrake thing should work a treat in your golf though, have you thought about taking that down a 1/4 ?
at the risk of further destroying TVR clutches, the other idea is to hold the throttle part way down while you shift, so you slide the clutch back in against too many revs ( not redline though, that's just silly ). This works best on turbos and diesels too, esp VAG turbo engines with flywheels off a cargo tanker diesel.
got another tip about when to change gear, but it's going to take a while to type, even though it's good advice ... want that one too ?
Works in the Golf but I dont think I'll be racing that there, I'll be blown off the track with laughter!
As for the TVR thing, you really have to have a go to understand the torque.
This is my first one so still getting used to it.
Overtaking in 5th is a doddle. (Whatever a doddle is!).
Come down to Thorney Island and meet us all and I'll take you out for a spin.
Before you ask...NO!
I was referring more to the fact that I think PeterH in any Tiv would get a good start, rather than the V8S being brilliant 
.
Serioulsy though I think the griff500 can be hampered by having almost too much torque low down for the best start, once rolling though there's not a lot that can beat it, this side of a more modern Tiv.
Harry
. Serioulsy though I think the griff500 can be hampered by having almost too much torque low down for the best start, once rolling though there's not a lot that can beat it, this side of a more modern Tiv.
Harry
timbrown said:
at the risk of further destroying TVR clutches, the other idea is to hold the throttle part way down while you shift, so you slide the clutch back in against too many revs ( not redline though, that's just silly ). This works best on turbos and diesels too, esp VAG turbo engines with flywheels off a cargo tanker diesel.
Don't! Ever. Not in big RV8 TVR, unless you want to impress (read, usually scare the 5hit out of) you/your passenger/spectators by how well you can light-up the rear tyres at each and every gearchange.
(Imagine an engine with the sort of torque that (until the latest, big BHP trucks arrived on the scene) more normally used to haul artic traillers about, which generates about 75% of that below 2000rpm. Then imagine that in a car which weighs about the same as a mini....)
>> Edited by Digga on Friday 25th June 12:29
Dusty ... before I ask what ?
*wink*
it's probably one of those things on my list of things to do when I have the money ... a list that grows faster than the money
I almost talked my better half into getting a griff last summer ( she has choice of car, I don't ) oh well
seriously though, the other tip involves torque curves, gear ratios, road thrust vs speed curves and changing up where curves on the graph cross to maximise the accelerating force on the car ... too technical ?
or in it's simplest form, change up at peak power, NOT after it. Use the engine between peak torque and peak power, it's more effective than under- or over-revving it
*wink*
it's probably one of those things on my list of things to do when I have the money ... a list that grows faster than the money
I almost talked my better half into getting a griff last summer ( she has choice of car, I don't ) oh well
seriously though, the other tip involves torque curves, gear ratios, road thrust vs speed curves and changing up where curves on the graph cross to maximise the accelerating force on the car ... too technical ?
or in it's simplest form, change up at peak power, NOT after it. Use the engine between peak torque and peak power, it's more effective than under- or over-revving it
timbrown said:
at the risk of giving my secret away .....
select 1st, and gently build revs and against the clutch, while you're holding the car stationary on the handbrake ( left hand , thumb holding release button in ) until the car just doesn't quite move off against the handbrake
this gets the engine making torque sooner than if you don't do this (MOST effective for turbo engines ), and perhaps more importantly, moves the suspension into the 'set' it's going to take when you launch, so you've already done half the weight transfer without moving anywhere and get better initial traction ...
lights go green, let the handbrake off and increase throttle and clutch almost to the point of wheelspin, then when you're feeling safe, nail it and scare yourself silly
for the two-wheel fanatics, adapting this to right foot/back brake works even better on a bike than for a car, 10.91@132 on a Thunderace proves my point
anyone else use this technique, or am I alone ?
( got another trick if anyone's interested )
Hi Tim,
Yup. Sit at 4K, clutch just biting, handbrake holding. Then let brake go, feed in clutch while increasing revs with just the slightest hint of squeek from the tyres.
Absolutely catapults you away.
Only problem is the road surface. It really doesn't work on some and you either end up with axel tramp or skipping the arse out with a lot of noise.
Not sure what the various problems are with handbrakes. Mine works on one notch and can be used to assist turning in the road without using forward and reverse gears.
ok guys, I'm sounding like a teenager in a nova with his cap on backwards, even though I'm old enough to have fathered those teenagers ...
you can only imagine the size of the grin I have reading the replies to my posts, thankyou all so much for brightening my day.
maybe next time I join in, I'll remind myself I'm dealing with people used to 300+bhp/ft.lb instead of the 200+ that I'm used to.
*doffs cap*
you can only imagine the size of the grin I have reading the replies to my posts, thankyou all so much for brightening my day.
maybe next time I join in, I'll remind myself I'm dealing with people used to 300+bhp/ft.lb instead of the 200+ that I'm used to.
*doffs cap*
The curves on the graph should ALWAYS cross at the same point for every car (forget that point, its something like 5250).
Peak power on the Griff 500 is at 5500RPM.
Limiter is at 6400 (or 6200 or similar, whatever. I have done 140 in 4th with out hitting it (on an autobahn and in 4th by accident).
I have found changing up just after 5500 seems about right.
Changing up a lot after does make progress slower.
Due to gear change times though its gotta be better to stay in 4th when getting near to the end.
Peak power on the Griff 500 is at 5500RPM.
Limiter is at 6400 (or 6200 or similar, whatever. I have done 140 in 4th with out hitting it (on an autobahn and in 4th by accident).
I have found changing up just after 5500 seems about right.
Changing up a lot after does make progress slower.
Due to gear change times though its gotta be better to stay in 4th when getting near to the end.
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