Suspension and camber settings

[STU666V]

Got the car set up today after fitting the new suspension.
I only use the car for racing before you say that the camber is to much. :roll:

D2 suspension
Height 335 MM front
345MM rear with 17” wheels

Camber
-2 ¾ Front

-1 ½ Rear

Toe
Front & Rear 0

Weight 1179 Kg
With ½ tank of fuel, half roll gage, Front and rear braces,
17” wheels with R888 tyres Etc

Weights with driver

868 918

459 523

Weights with out driver

840 857

436 462

 

[STU666V]

Not sure was happened but i posted this 3 times. Doh

 

[stevepudney]

Not sure was happened but i posted this 3 times. Doh

Sorted mate ;-)

Good post :-D

 

[STU666V]

Thanks Steve,
Will let you now how i get on with my first race in may.

Cheers

 

[Fast Guy]

Height? Is that from the wheel arech to the centre of the driveshaft/wheel?

How stripped is the car?

 

[STU666V]

Height? Is that from the wheel arech to the centre of the driveshaft/wheel?

Yes
Fast Guy,
How stripped is the car?

Just run with one seat but not light, (cobra) PVC windows,GF bonnet,no door cards, no AC, and some little bit and bobs, Do you still think thats abit heavy?
Also the total weight, not sure if that was with some one in it? Will need to check with them as i was thinking it was abit heavy?(also when i dropped it of there was a trolley jack in the car so hope they never took that out either :lol: ,If it was out and no driver its still around 80Kgs i have lost. What the standared weight of a pulsar (1260Kg?) is this with fluids in the car?
I was told that you should run the rear heights a bit more than the front?? The car height has went down a bit now and its just about 5 mm more than the front. Its more like 325-330 at front and rear is about 330 to 335MM. I will do a few races then check the heights again. I have not found any posts telling you a good quide as to what to set your car up to for racing so its all quess work!!
As the car does not go on the road i will find out on the first corner what like it is but should be ok as its just tress to hit

about 5 feet from the track, Will take it a bit easy at first as i should get 2 or 3 practice runs then go for it.
It was the first practice race last week but never took the car up, some realy high BHP cars this year and one new bloke never been on this track before bet the track record in his first practice

But with the money they are spending on there cars they should be winning!!The money they have spent on them are about 15 - 20 times the price of my car!!
I will just go out this year and try to beat my last years times.
Might start a new thread some time and put videos up of my races as i go along, Will need a new cam corder first as my other one broke.

 

[campbellju]

Hello Stu,

I'd call myself an enthusiastic amateur, my car is a road/trackday car so has different aims to yours.

just a couple of opinons as I don't know your experience, race series etc and we all have to find out for ourselves what works best.

The cross weights look good.

Even considering you're running the high spring rates of the D2's, I still wouldn't recommend going lower than 325mm, bump stops are found far too easily on our cars.

I'm not a huge fan of the D2 spring balance, its bascialy standard but uprated to reduce roll so low riders don't drive permenantly on the bump stiops. It still gives a balance to understeer. Consider softening the front rate or stiffening the rear, IMO the front but we're all different.

As standard our cars have a forward rake. Increasing the rear ride height 5mm to give a 15mm difference at the back can help shift the bias to oversteer on tight corners and understeer on high speed corners but its down to driver preference.

I notice you don't have the adjustable rear ARB, for the cost it might be worth considering to help fine tune the balance of your car. The front OE ARB is fine and should be left alone IMO.

The front to rear camber difference looks about right. As to the camber on the front, for track use I run -2.2 on road tyres but I've increased my castor to about 5degs that also helps. Looking at action photos this seems to work on my car.

After playing around I found by stiffening my rear ARB I could increase rear camber to give more overall grip but I then had to reduce my ride height to the 10mm OE difference again to tune the balance. Overall it improved things.

I don't know if your toe is truly zero but I like to errr on the negative between 6" to 12", it can help make the car feel more agile. I'd put this down to driver preference though.

I don't know if that's any use to you but its my experience and I'm always interested to hear what other people are doing to make their cars work for them so please do continue to post up.

Cheers,
Jim

 

[STU666V]

Jim,

Thanks for all that info.
I have a whiteline rear adjustable ARB and standard front but with the car not being on the road its hard to tell whats going to work and whats not!! My first race is on 12 & 13 may so should now a bit more then?
Will keep you up dated.

 

[campbellju]

Your ARB's sound good and the rear is easy enough to tweak on the day if not. Good luck with the race Stu, where is it first and what is the series?

 

[STU666V]

Jim,

Its a little hill climb at Fintray (dyce Aberdeenshire)
http://www.prhighlandspeedchampionship.co.uk/
http://www.scottish-sprinting.co.uk/

Cheers

 

[Fast Guy]

Just run with one seat but not light, (cobra) PVC windows,GF bonnet,no door cards, no AC, and some little bit and bobs, Do you still think thats abit heavy?
Also the total weight, not sure if that was with some one in it? Will need to check with them as i was thinking it was abit heavy?(also when i dropped it of there was a trolley jack in the car so hope they never took that out either :lol: ,If it was out and no driver its still around 80Kgs i have lost. What the standared weight of a pulsar (1260Kg?)

Mine with similar to above (but no trolly jack, full glass, door cards fitted) was 1135kg. My car standard (RB) was about 1240kg

 

[R called Jay]

The front to rear camber difference looks about right. As to the camber on the front, for track use I run -2.2 on road tyres but I've increased my castor to about 5degs that also helps. Looking at action photos this seems to work on my car.

Jim, how have you gone about inreasing the castor?

Cheers, Ben.

 

[STU666V]

Free HP
http://www.nerocam.com/SCC_TAP.asp

Fast guy,
Found this picture of your car.

 

[campbellju]

Jim,

Its a little hill climb at Fintray (dyce Aberdeenshire)
http://www.prhighlandspeedchampionship.co.uk/
http://www.scottish-sprinting.co.uk/

Cheers

That looks like fun :-D. Te reason I asked was Phil (bracpan) has a lot of hill climb experience and has also expressed concerns over the high rates of the D2 type springs. Suck it and see I guess, you can always change them.

Good luck with your racing,

 

[campbellju]

Jim, how have you gone about inreasing the castor?

Cheers, Ben.

Hi Ben, my current simple mod to test the theory was to rotate the top mount 45degs by drilling another hole and modding the strut brace accordingly. I then drilled out the bottom strut mount to set camber.

I've been running like this ofr a good year now an it worked well, none of these mods are night and day difference but it is subjectivley better.

BUT, being honest, setting camber from the bottom is a pain so I've been bouncing ideas around with Stu(mo) for a bolt/weld on plate at the top to give up to 10degs of castor whilst retaining adjustable camber.

10 degs castor is probably faaaar to much but I would rather have too much adjustability and back off than wish I had more to play with like at the moment.

I'm trying to get my a**e in gear in time for the GTIROC day that will be the next trackday for me at this rate. I'll keep people informed if the design works so other can have a go too.

Jim

 

[DanDud]

Jim and Stumo have been playing around with castor and camber settings for a while now, and they have both seen good results even just by playing with re-turning - rotating the front struts! Jim especically with the front camber, castor and toe settings! The majority of people for track days seem to be setting their camber between 1 degree and 2.5 degrees negative and in the case of Jim and Stu they seem to be getting a minimum of another 2 or 3 degrees of castor by rotating the front struts by drilling new holes in the turrets! (Bearing in mind these settings are for fast road use and trackdays!) It seems to work really well!
Either way i have not played around with the castor settings on my car but i have found that a minimum of 1.5 degrees negative camber and maybe up to 2 or more degrees gives a good base adjustment setting for the track on the front. I have not played with my rear adjustment up to now but that is my next job!

Generally speaking (of course it is up to the drivers preference) On a Gti-R neutral or very! slightly negative toe on all 4 corners gives good results. It helps to elimiate a bit more of the under-steer associated with the 70:30 weight distribution of Gti-r's! (Slightly!) Although pushing to the limits of the car will undoubtably produce understeer these settings help to minimise the effect!

Take Jims and Stumo-s advice on setting the car up as they know what they are talking about! ( i am only an amature just learning about this kinda stuff) but the info is very helpful!

But if you set the rear ride height 10mm higher than the fronts, and set the rear camber half a degree, and the fronts a degree and a half (both negative) you should see pretty good results! (I did for fast road use and the occasional track day!) You can obviously fine tune the car yourself from there but these measurements are good starting points!

NB: I have had far too many beers at uni tonight and it took me half an hour to type all this out more correctly than it already is but i hope it helps and it did not sound all like bullshit!)

Dan

 

[campbellju]

@Stu, quality post and link

 

[STU666V]

Quote:
Consider softening the front rate or stiffening the rear, IMO the front but we're all different.

How can you softening the front? Just the damper settings? as you can't adjust the spring as its pre-loaded.
I have my MOT tomorrow and had a look at the heights again.
Looks like the fronts are down to 325MM and the rears down to 330MM do you think i should put them back up a 10 MM or so? Or just wait until the first race is over then check and adjust them then? It abit of a pain in the **** to adjust as you have to turn the hole strut.
If i adjust the strut 10MM on the threads do you think this will give me 10MM more height or is that just wishful thinking? It should realy work.
Its just when you jack the car up and down to check the heights its not the true height until it beds in and with the car not on the road its a bugger. :lol:

 

[campbellju]

I should have finished the sentence really

Just doing a few quick calcs on your car, the front cpm is about 129 and your rear is about 144. Both are a too high unless you're running an aero package or the track is especially smooth.


They will work and on a certain track it might work better but if the back skips around then you might want to chnage your springs in the future.

Even if you feel they aren't too high, you might want to soften off the front a little to improve traction and balance.

 

[STU666V]

I should have finished the sentence really

Just doing a few quick calcs on your car, the front cpm is about 129 and your rear is about 144. Both are a too high unless you're running an aero package or the track is especially smooth.


They will work and on a certain track it might work better but if the back skips around then you might want to chnage your springs in the future.

Even if you feel they aren't too high, you might want to soften off the front a little to improve traction and balance.

What is CPM? and aero package?
Sorry for all the qustions, its all a bit new to me.
Pass my MOT today and then i am going to drop of the car next friday to get a new Haltec ecu fitted and get it all set up, Also getting a solenoid fitted for the boost to do away with the manual boost valve.
Then hope thats it for this year, just go and play.

Thanks