G Force Graph Of My 205 Race Car

[parry 23 1 Cars]

Guys, here is the Gforce graph of a couple of laps at my local track. I was surprised I was getting 1.3Gs on right handers. The track is predomantly right handers.

 

I will soon be changing the front springs from 275lbs to 375lbs and will be intresting to see the diference.

 

I am using this graph as a benchmark to measure improvements.

 

Has anybody else got g force figures to compare. I am using a DL1 data logger.

 

The car is on slicks, gaz coil overs, 24mm rear. Weighs 804kgs

[Cameron 16]

Now that is very interesting!

 

Are you able to find what lateral g you were getting through individual corners? Would be very interesting to see what your max g was for corner 1, 2, 3 etc etc so you could see how it relates to the corner radius.

[Batfink 201]

so how do I make sense of that graph so it does not look like a childs scribble. I take it thats multiple laps over the top of each other?

[parry 23 1 Cars]

so how do I make sense of that graph so it does not look like a childs scribble. I take it thats multiple laps over the top of each other?

 

What I like about the "ink blot" is that is shows me the car has consistant g force on right handers at various speeds (right hand side of graph), as this is lateral G against speed. Now what is intresting is that the left handers is not very consistant especially turn 3. I know definately that I am not comfortable with that corner, so I can go faster through that turn, I just need to grow some balls.

 

I will soon show you a graph agaist time and you can see corner by corner.

Edited January 12, 2011 by parry

[parry 23 1 Cars]

Now that is very interesting!

 

Are you able to find what lateral g you were getting through individual corners? Would be very interesting to see what your max g was for corner 1, 2, 3 etc etc so you could see how it relates to the corner radius.

 

Here you go cam. Turn 3 is my nemises, I love 4,5 and 6, I stick to the back side of v8 supercars through there.

Edited January 12, 2011 by parry

[Cameron 16]

Cool.

 

Are those results filtered? If not, you can filter them get rid of all the little peaks and get a curve that better represents what's really going on. Some of those peaks don't really represent what's happening as they're way too short in duration, probably vibrations or something. It's been a while since I did data analysis at uni so I don't know what filter frequency, but around 100Hz seems familiar.

[parry 23 1 Cars]

Here you go cameron, that does look much better. Turn 6 there seems to be understeer occuring. Turn 3 I am not reaching max lateral force and there is improvement on most other corners if I push harder. That is assuming I can do the same Gs in every corner. Would every corner be different? or rougly the same limit.

[Cameron 16]

As far as I know it's different for different corners, I'll have to check though. I'm pretty sure low speed tight corners pull less g than higher speed open corners, but then very slight high speed corners will create less. The force created is down to the corner radius and the speed you go round it, so yes i think the g you create will depend on the type of corner.

 

Ultimately it's down to your tyres and suspension though, so I'd be looking for increases in g with your upgraded suspension to confirm it's made an improvement. Higher recorded g will mean you're going round the same radius corner faster.

Edited January 12, 2011 by Cameron

[Rippthrough 98]

Turn 3 looks like it's setting you up for turn 4 so sometimes you might be sacrificing the peak g at the apex to get a better line on turn 4? Depends on the camber on the track too.

Edited January 12, 2011 by Rippthrough

[Cameron 16]

Just been thinking about this, do you have a graph for longitudinal g too? Would be interesting to see what braking g a 205 can be capable of.

[Henry 1.9GTi 36]

echo the above, can u produce a G-G diagram for the session. Plotting points with no lines, very interested to see it.

 

Looks like your car is very capable to pull consistent 1.3G. I hope my 205 can get close to this! Sorry if I didn't read in the OP but what tyres is this using?

[parry 23 1 Cars]

echo the above, can u produce a G-G diagram for the session. Plotting points with no lines, very interested to see it.

 

Looks like your car is very capable to pull consistent 1.3G. I hope my 205 can get close to this! Sorry if I didn't read in the OP but what tyres is this using?

 

I am running Khumo S700 slicks.

 

Long G is dissapointing and getting 0.75 Gs under braking. the theory books say the braking effort should be 85% of your max lateral for the tire. so either my 307HDi Calipers are not good enough or I have to grow some balls and count to 2 before I brake. I have not locked up once with slicks, so I suspects I am driving them llike my R Spec.

[parry 23 1 Cars]

Is this the GG graph your were after?

 

This is from Sundays race in 37 degrees heat!

[Cameron 16]

Yeah 0.7g decel is a bit surprising, I was expecting around 1g.

 

There's 2 reasons why you haven't locked up, either you're s*it-hot at modulating the pressure, or you haven't been pressing the pedal quite hard enough.

Edited February 1, 2011 by Cameron

[parry 23 1 Cars]

Yeah 0.7g decel is a bit surprising, I was expecting around 1g.

 

There's 2 reasons why you haven't locked up, either you're s*it-hot at modulating the pressure, or you haven't been pressing the pedal quite hard enough.

 

The later is more appropriate. I dont have confidence in my braking. The pedal travel is too long and on Sunday I had to keep bleeding the brakes to get some feel back. I have a pedal box sitting on the workbench that I should install, hopefully that will help give me more feel. Also I have a small vibration under braking that comes once everthing warms up, new disk did not solve the problem, could be pads or caliper or evensome suspension movement. Anyway, thats what I love about this telemetry, helps you understand what the car is doing and any changes can be monitored on paper not just in your head.

[parry 23 1 Cars]

The good news is I won the under 2 liter class on the weekend and finished 14th out of 26 cars. Not bad considering its only a stock 8v with TBs.

 

We had a Enduro Mosler racing with us! It was a tad quicker than me, just 13sec a lap!

Edited February 1, 2011 by parry

[Cameron 16]

Quick question - do you know what your front & rear track widths are?

[parry 23 1 Cars]

no i dont, where should i measure from, outer wheel?

[Cameron 16]

Yeah if you measure from the outer edge of the tread on one tyre to the inner edge of the tread on the other it will give you the track width (as track is measured tyre centre to tyre centre).

[parry 23 1 Cars]

1470 Front

1410 Rear

 

So what is the the standard? and what story does it tell, so I can learn

[Cameron 16]

Standard track is:

Front 1382mm

Rear 1339mm

 

So yours is:

Front +88mm

Rear +71mm

 

My question doesn't have any significance to your thread, I just wanted to see what track you were using to fill those arches. I'd proposed 1500mm front and rear for my new build but it's pretty hard to imagine how wide that is without seeing it on a car, it should be pretty similar to yours though which is reassuring.

Edited February 2, 2011 by Cameron

[parry 23 1 Cars]

Standard track is:

Front 1382mm

Rear 1339mm

 

So yours is:

Front +88mm

Rear +71mm

 

My question doesn't have any significance to your thread, I just wanted to see what track you were using to fill those arches. I'd proposed 1500mm front and rear for my new build but it's pretty hard to imagine how wide that is without seeing it on a car, it should be pretty similar to yours though which is reassuring.

 

 

Who cares about performance it looks fantastic!!!!

[Cameron 16]

Sure does.

 

But there is a good preformance benefit to be had by increasing track width too. Win win.

[parry 23 1 Cars]

Your right, the side benifit are the looks, I won the under 2 liter class on the weekend and 14th from 26 overall. Was a great feeling, especially wining the race on the last lap of the last race! I love my pug, have been thinking about going japanese but there is something unique about a 205. Especially in Australia, my pug is the only one racing in circuit competition outside of track days.

 

On a side note, my new motor is almost ready, just received the missing components, 16 Kawasaki buckets to resolve the solid lifter issue we had. So hopefully new motor will be in with more than twice the power. Mi16 and dry sumped.

 

So what are you building, enough about me!

Edited February 2, 2011 by parry

[Cameron 16]

Have a look in the project starters forum, it's going to be a space-frame RWD monster.