4722 replies to this topic

[mbes2]

Hi Nev,

Well done buddy, great read this post.

Get a good vid up, with you screaming while driving your beast!

Thanks Mark, once the slime evorates from the roads here I will try and get out with the video camera. Though, I am on holiday from tomorrow, so it won't be for a while unless I get out quickly tomorrow night.

"get out quickly tomorrow night" is normally a bad, wait till you get back from holiday. ! have a good rest

[cnrandall]

Thats a good video Chris, thanks, lots of slow to fast sections of acceleration. I think my car responds roughly similarily to yours with a similar amount of snaking from the back end. It's just that on the road 'snakeing' is something to be avoided IMO (unless it's wide and no other cars around).

Your off-boost to on-boost transition is really well mapped, I can see why you say you have no lag.

That video is of my messing around, the car is actually very tractable when you don't provoke it. It was on Toyo R1R's that day though and there is certainly more power than grip. One of my next missions is to setup the TC on the Syvecs ECU... I have an accelerometer ready to go on and can map the desired % slip against speed and lat G.

[Nev]

I am slowly coming to the conclusion that: 1/ No matter how wide my rear wheels are, I think it will always be possible to spin them up, thus danger always present. 2/ TC will kill wheelspin dead, thus the danger will be (mostly) gone. Thus it's becoming clear that fitting TC is the way ahead, though of course it is a big effort to install it. Carsten, thanks for all you input, useful and objective information which has helped me make my mind up Anyway, I had a marvelous drive into work today (25 miles). Just pootling along in the traffic at 30 to70 MPH on A and B roads was really nice, not pushing the car hard at all, just enjoying its motion and 'point and squirt' abilities. Makes it all worth while

[steveboyslim]

I am slowly coming to the conclusion that:

1/ No matter how wide my rear wheels are, I think it will always be possible to spin them up, thus danger always present.
2/ TC will kill wheelspin dead, thus the danger will be (mostly) gone.

Thus it's becoming clear that fitting TC is the way ahead, though of course it is a big effort to install it.

Carsten, thanks for all you input, useful and objective information which has helped me make my mind up

Anyway, I had a marvelous drive into work today (25 miles). Just pootling along in the traffic at 30 to70 MPH on A and B roads was really nice, not pushing the car hard at all, just enjoying its motion and 'point and squirt' abilities. Makes it all worth while

The onl way to reduce wheelspin is to improve mechanical grip traction contrl just over rides the driver and reduces engine power, which is something that can be done via your right foot, infact it has been found that a certian amount of wheelspin helps with the stability of a car.
All the traction control will do is automatically reduce the engine power and in some cases such as cornering increase the risk of crashing.
there is not a car on the road or race track which does not suffer from wheelspin or grip problems, F1 teams spend millions of puonds per season and they have not found a solution.
If you do anything install the F88/Syvecs ECU which will enable the engine to be fully mapped improving the power curve/delivery.

Steve

[Nev]

Just got back from a sublime (and rather aggressive!) drive back from work and the car has now completed 1000 miles since first being fired up I gave it quite a bit of welly today and it all stayed under control. I am starting to get quite keen to get onto a track soon, as the car is amazingly problem/bug free. Just need to fiddle with the brakes some more and maybe install an auxillary electric vacuum pump to help with heavy braking.

[LMP1]

Congratulations Mr Nev!

Every day, when i return home, i run to the pc to find a video of your car... Please dont keep us waiting so long...

[cs_]

traction contrl just over rides the driver and reduces engine power

correct, but only for moments that more grip is lost than the driver wants to let go

which is something that can be done via your right foot

wrong for any car, very badly wrong for heavy turbo charged engines

infact it has been found that a certian amount of wheelspin helps with the stability of a car

you know kamm's circle? the more longitudinal acceleration, the less you have left on lateral. TC helps to not letting the longitudinal part getting so high the lateral part gets too small. and physical law is that the moment you just start to lose grip longitudinal you still have plenty of grip lateral. but if you spin the wheels even more, the lateral part gets lost too very fast. THAT means losing stability. TC prevents the wheels to spin too much. the driver sets the limit with the adjuster.

All the traction control will do is automatically reduce the engine power and in some cases such as cornering increase the risk of crashing.

and this is so wrong, my jaw has dropped reading this! the TC reduces power ONLY if one or both of the two driven wheels have a slip ratio larger than what the driver has chosen as a limit with the adjuster on the dash. it does this VERY FAST down to every engine ignition and the moment the slip drops below the chosen limit it stops cutting the ignition at all. so if you chose to operate your car i.e. up to 15% slip ratio which gives some very optimal grip on dry asphalt the TC ONLY cuts ignitions for the time the driven wheels lose grip giving a slip significantly larger than 15%. this keeps the lateral grip preventing(!) the risk of loosing the rear end. and is totally different from anything you could do with the throttle and different from any OEM traction control you find in normal street cars. they have banned TCs from formula 1 some years ago because driving has become too easy making races boring for the audience. the Racelogic TC is purely motorsport breed and you feel that any time it starts to operate.

please don't talk down things you do not know

I am getting myself out of this now because my limited control of the finesses of the english language gives me disadvantage in any hard discussion and offtopic we might get into. I know what I am talking about. and can live very comfrotably with others believing different things. in my native language this discussion would be much easier to do. sorry.

Edited by cs_, 19 August 2011 - 05:16 PM.

[techieboy]

Carsten, you've got more finesse in a langauge foreign to you, than a lot of us do with a language native to us (and certainly more than Nev's right foot has ).

[KurtVerbose]

in my native language this discussion would be much easier to do. sorry.

Grüß Carsten.

Gut gemacht, und danke. Das ist schwierig in eine Muttersprache. In eine Fremdsprache unglaublich!

Respekt!

[Nev]

Carsten, you've got more finesse in a langauge foreign to you, than a lot of us do with a language native to us (and certainly more than Nev's right foot has ).

Nev's right foot must be getting better, cos I got the red shift light to come on today for the first time. I don't know what revs it was at, maybe 7000, or maybe 8000, or somewhere in between. Hard to know. Just went out for another 60 mile balistic trip on the country A-roads north of where I live. And yes, I forgot to take the camera again

I am beginning to think 500 BHP can be tamed !

This evening, I have also had a fiddle with the servo brake pipe that runs the entire length of the car. The servo end of the pipe had a split in it, so I trimmed off approx 1 cm of the end and put it back on (with an extra jubiilee clip). This hasn't made any difference, so I need to address the other end of it (ie the engine end). I started the car up and tested for vacuum and there was certainly some there, but clearly not as much as I need for really serious brakeing.

[moneyhunster]

Nev's right foot must be getting better, cos I got the red shift light to come on today for the first time. I don't know what revs it was at, maybe 7000, or maybe 8000, or somewhere in between. Hard to know. Just went out for another 60 mile balistic trip on the country A-roads north of where I live. And yes, I forgot to take the camera again

I am beginning to think 500 BHP can be tamed !

be careful mate, when you get cocky you get caught!

[steveboyslim]

traction contrl just over rides the driver and reduces engine power

correct, but only for moments that more grip is lost than the driver wants to let go

which is something that can be done via your right foot

wrong for any car, very badly wrong for heavy turbo charged engines

infact it has been found that a certian amount of wheelspin helps with the stability of a car

you know kamm's circle? the more longitudinal acceleration, the less you have left on lateral. TC helps to not letting the longitudinal part getting so high the lateral part gets too small. and physical law is that the moment you just start to lose grip longitudinal you still have plenty of grip lateral. but if you spin the wheels even more, the lateral part gets lost too very fast. THAT means losing stability. TC prevents the wheels to spin too much. the driver sets the limit with the adjuster.

All the traction control will do is automatically reduce the engine power and in some cases such as cornering increase the risk of crashing.

and this is so wrong, my jaw has dropped reading this! the TC reduces power ONLY if one or both of the two driven wheels have a slip ratio larger than what the driver has chosen as a limit with the adjuster on the dash. it does this VERY FAST down to every engine ignition and the moment the slip drops below the chosen limit it stops cutting the ignition at all. so if you chose to operate your car i.e. up to 15% slip ratio which gives some very optimal grip on dry asphalt the TC ONLY cuts ignitions for the time the driven wheels lose grip giving a slip significantly larger than 15%. this keeps the lateral grip preventing(!) the risk of loosing the rear end. and is totally different from anything you could do with the throttle and different from any OEM traction control you find in normal street cars. they have banned TCs from formula 1 some years ago because driving has become too easy making races boring for the audience. the Racelogic TC is purely motorsport breed and you feel that any time it starts to operate.

please don't talk down things you do not know

I am getting myself out of this now because my limited control of the finesses of the english language gives me disadvantage in any hard discussion and offtopic we might get into. I know what I am talking about. and can live very comfrotably with others believing different things. in my native language this discussion would be much easier to do. sorry.

I do know a fair bit about traction control having indirectly dealt with the ex-Benetton F1 software engineer who helped programed and developed a traction control which went on to be used further developed and used by a major car manufacturer.
I understand about kamms circle, but I was refering to actual feedback from testing, both driver and lap times, which were proven to be better with a degree of wheelspin.
When I mentioned possible crashing I was refering to as an example where as car on dry tarmac approaches a bend which may still be wet because it is overshadowed by trees.
High powered turbo or naturally aspirated power delivery can be controlled by the throttle with practice.
I do agree that correctly programmed traction control can help but the first priority must be to improve mechanical grip ensuring that the chassis is working correctly and that the driver learns what the car is capable of.
Looks like we will dis-agree on this subject.

Steve

PS your english is better than my german

[slindborg]

I was researching TC for my uni dissertation and the slip curve vs acceleration was an interesting shape in that a little slip (sub 5%) gave better acceleration than no slip or more than 5%ish. theory is all lovey dovey but tyres and reality are rather different

[cs_]

understanding physics is mandatory!

every acceleration means slip. optimum grip on dry asphalt needs a slip ratio of about 15%. this does not mean spinning wheels. slip and wheelspin are different things.



spinning wheels just mean you got beyond the stable range of the grip curve. this is where the TC helps. you need a certain amount of slip to be fast. that's a fact!

[The Batman]

That graph has pretty colours. That's about as far as all I can tell from it Nev I'm glad you are taming the beast. Do you have the capability of turning up and down boost to control power output?

[slindborg]

Nev I'm glad you are taming the beast. Do you have the capability of turning up and down boost to control power output?

The Throttle Pedal

[jameso]

Lol

[Nev]

I'm not too keen on adjustable boost control to be honest Joe. I'd prefer to avoid fiddling with the power output and characteristics of the engine as this stops you from learning a consistant way that the power is delivered. If the road is wet/damp/greasy, I will just not let the car boost up fully (ie short shift before 4600 revs). Even with this minimal boost, the 300 odd BHP the engine ias already making is plenty for driving about in the wet.

Edited by Nev, 26 August 2011 - 03:39 PM.

[Nev]

I've just been to a weigh-bridge to find out just how much Nipper weights. He was 890 Kg with 1/3 of a tank of fuel. Amazingly light, all this nonsense about 'lardy' Tubbies is just a bit of a blind alley IMO, so long as you have some decent brakes and power, a handful of Kgs here or there makes no difference really. Anyway, this means that on a normal temperature day making around 500 BHP he has around 560 BHP/Ton.

Edited by Nev, 27 August 2011 - 11:46 AM.

[P11 COV]

Sounds fantastic Nev!

I cant imagine how fast it is - i still find 300+lbft mesmerising!!

Blast from the past! Still got it then? Thought you'd sold up?