Ride Heights

[titan]

Righto, I've done the tried and tested approach...18x9 TD with 265/35 tyres all round, 20mm spacer at the rear. In terms of meeting the width of the arches, works extremely well.

I noticed UB has a lower rideheight than myself, my height was set at simpsons as a starting point to clear speedbumps etc and allow for drop. Although perhaps a daft point to add, I think the car would look better if dropped further and since the intrax allows for this easily, why not ?

http://www.projectevo.co.uk/gallery2/d/1131-2/IMG_0909.JPG

http://www.projectevo.co.uk/gallery2/d/1128-2/IMG_0908.JPG

Anyone got any opinions on this? I've no rubbing issues currently and the suspension is set very soft indeed. Does look like there is scope for going a bit lower, but wondered if anyone found it a driving benefit?

[shimmy]

Sort of an open question really as depends again what you want out the car.

I would guess that running lower would help on most UK circuits ESP airfield ones but for the road and the Ring it will need you to run stiffer damping and maybe stiffer springs and I think this will slow you down and make the ride worse

[jibm]

Mine is on the same wheel set up but with KWV3 and looks a fare bit lower than yours. Well from the pictures away. It was dropped buy 20mm and it does rub at the front, but only very slightly on full lock and also when the dampers are full compressed right in the middle of rear part of the wheel arch. but it really is minimal. Currently at -2 neg at the front i am go to fit top mounts to go out to -3 for the track and i'm hoping this will stop all the rubbing.

[shimmy]

FYI Titan, I've settled on 643 front and 640 rear ride heights. I think that's measured from top of arch by Simpsons and I am on Intrax as well. Thats not ultra low but no rubbing road or track.

[shane@mbtech]

What are your offsets Lee?

I ran TD 18x9 in both 20 and 30 offset

On same ride heights the 20 caught on the rear outer arch on fast track use.

I did not specify a set ride height, I just used my man Chris @ centre gravity (who is the best geo guy I think about), he corner weighted and dialled in my settings, it was a tad lower than yours iirc.

I also noted that other set-ups where lower rear to front, my car had more rake the other way, which is open to personal preference.

My advice try it yourself, change heights- one mans perfect set-up is shit for another. :thumbs:

[AlexGTT]

FYI Titan, I've settled on 643 front and 640 rear ride heights. I think that's measured from top of arch by Simpsons and I am on Intrax as well. Thats not ultra low but no rubbing road or track.

I'm running same stuff and similar set up as Shim. Set up again by Simpsons.

Titan, yours looks a little on the high side. If settings are very soft that won't be ideal for most UK tracks. Try stiffer settings and ring Ant for recommendations. They'll be happy to help.

[s.mac]

mine looks about the same and im going to drop it as its more track than road. would leave it be for road

[glendog74]

mine looks about the same and im going to drop it as its more track than road. would leave it be for road

You could place your booster cushion on your front tyres the gap is that big lol! :hahaha:

[AlexGTT]

You could place your booster cushion on your front tyres the gap is that big lol! :hahaha:

:hahaha: Like a monster truck isn't it?;)

[s.mac]

:hahaha::gayfight:
I always have my booster cushion to hand, its not just my size but those foOKIN piles.....;)

[glendog74]

:hahaha: :hahaha: :hahaha:

[NZ_M3]

Run the fronts too low and all you'll get is understeer ;)

[titan]

FYI Titan, I've settled on 643 front and 640 rear ride heights. I think that's measured from top of arch by Simpsons and I am on Intrax as well. Thats not ultra low but no rubbing road or track.

Cheers, thats useful. So I'm comparing apples with apples - from top of arch to wheel centre ?

[titan]

What are your offsets Lee?

I ran TD 18x9 in both 20 and 30 offset

On same ride heights the 20 caught on the rear outer arch on fast track use.

I did not specify a set ride height, I just used my man Chris @ centre gravity (who is the best geo guy I think about), he corner weighted and dialled in my settings, it was a tad lower than yours iirc.

I also noted that other set-ups where lower rear to front, my car had more rake the other way, which is open to personal preference.

My advice try it yourself, change heights- one mans perfect set-up is shit for another. :thumbs:

ET30 and 20mm spacers at the rear, seems perfect from the point of filling the width of the arches. I can only imagine ET20 would need some serious camber to squeeze in, or rub ;-)

I think generally, if you lower the front too much you also need to stiffen it up and this introduces understeer.

I also increased the camber at the front this weekend (not tested on track yet, just the road) and found that in the dry its a more positive turn in, but in the wet understeers more. Clearly horses for courses in all conditions.

[AlexGTT]

Cheers, thats useful. So I'm comparing apples with apples - from top of arch to wheel centre ?

No mate, that's top of arch to ground or surface plates if on set up rig.;)

What cambers are you using for dry at the mo?

[shimmy]

Cheers, thats useful. So I'm comparing apples with apples - from top of arch to wheel centre ?

I think that is the proper way to easier I but Simpsons measure top of arch to floor (which introduces two errors in wheels size and tyre size) so if you are running 640 to wheel centre you are driving a TRACTOR

Just measured and top of arch to wheels centre looks like 330F and 325R

[titan]

340F and 325R. Although thats a best guess at looking past the tape to the wheel centre, if I bend/follow the tape into the wheel centre you can add another 5mm.

Simpson set the camber at 1.5 and said that a little trick is to ignore the adjusters on the topmounts, but instead slacken the turret bolts and the play between outside and inside was equivalent to another degree (and also made a little toe-out). Not having a camber gauge I cannot say.

[daniel]

2.5"-3" front camber is what you need:thumbs:

[shimmy]

2.5"-3" front camber is what you need:thumbs:

He will have -2.5 when top mounts are adjusted

You prob will want -3 or more for the correct camber on track Tyres depending on circuit but running more than -1.5 on road for long distances will knacker the insides

[shane@mbtech]

I set mine to -3.5* front on the inners of the turrets, then slacken off and move out to approx -2.5* on the outer of the turrets using the 3 13mm nuts. Takes 2 secs and saves tyre wear, although I used to forget and my tyres still worn perfectly even too.

As you say, moving the camber in takes the toe back to near 0, from the slight toe out I was running.

I never had any understeer issues either, I will try to dig out my spec sheets for my ride heights.

But as I said Lee, experiment and find what suits YOU. Thats what I did.

I tried simpsons Geo, but I actually prefered the way Chris set mine up, I was faster on Chris's setup too. Not taking anything away from The simpsons lads, because they know their onions. I just prefered a different set-up. I think Chris set my car up more aggressive than Simpsons did, and it suited me more.

[s.mac]

Tom posted this sometime ago for a standard reference

I just had my geo done today on the BMW Kinematic Diagnosis System (KDS) and the print out states the factory ride height spec as follows:

Measure from the bottom of the rim to the top of the wheel arch through the centre of the wheel:

Factory Spec:
Front Target: 607mm+/-10mm
Rear Target: 602mm+/-10mm

[titan]

I don't really use the car much apart from trackdays so running high camber isn't the same kind of issue as it would be for a daily driver.

Its a good point to find out what suits.

I've only ever gauged correct/incorrect camber by looking for wear on the sidewalls or specific areas on the contact patch, and ensuring that heat across the entire contact patch is more or less constant. After all, isn't the purpose of camber to ensure that when cornering the roll of the car just "corrects" the negative camber to ensure the tyre is then "flat" against the track surface? I believe stickier tyres esp slicks demand more camber because their grip is so much more, hence the roll of the car is so much more.

Interesting to know what happens in the wet though. Too much camber and surely you're running on the insides, therefore unable to get the grip required to force body roll onto the entireity of the tyre...so less camber in the wet ?

Currently I've got the hankook rs2s on the car.

[shimmy]

You should be able to feel the corner grip with more camber but otherwise pyro readings is by far the best way.

We did Snett last year with full pyro and actually wound the camber in on the right side of the car.

DONT FORGET TYRE PRESSURES, what you running hot?

[titan]

Thats another good question which I can't answer. I set tyres to 30 when cold, at oulton was doing about 5 to 7 laps in a session, doubt they got significantly hot but really should invest in a decent and quick gauge.

the gt2rs has a realtime pressure display on the dash !!

We looked into these last year:
http://www.tyresave.co.uk/smartire.html

but never bothered in the end.

[DuncanR]

Run the fronts too low and all you'll get is understeer ;)Absolutely spot on Tom ... Henk at Intrax will tell you this also. I hope all family and friends are ok out there Tom after recent events mate.

[shimmy]

Thats another good question which I can't answer. I set tyres to 30 when cold, at oulton was doing about 5 to 7 laps in a session, doubt they got significantly hot but really should invest in a decent and quick gauge.

the gt2rs has a realtime pressure display on the dash !!

We looked into these last year:
http://www.tyresave.co.uk/smartire.html

but never bothered in the end.


Feck me you are dangerous :thumbs:

Not sure on the weather but at 30 cold you could have got the Tyres up to 36 hot at the back I would guess, no wonder they felt a bit squirmy. Before you buy new Tyres and suspension you might wanna buy a pressure gauge :thumbs:

[glendog74]

Feck me you are dangerous :thumbs:

Not sure on the weather but at 30 cold you could have got the Tyres up to 36 hot at the back I would guess, no wonder they felt a bit squirmy. Before you buy new Tyres and suspension you might wanna buy a pressure gauge :thumbs:

:hahaha::hahaha::bigcry::hahaha:

[titan]

heh, shall I just give up ?

OK its a reasonably fair point but having played with tyre pressures in the past (albeit different cars) I can't say I've noticed a huge amount of difference.

In fairness I do check pressures in the summer as bone dry trackdays tend to heat things up nicely.

What pressures (hot) would you recommend ?

[AlexGTT]

Feck me you are dangerous :thumbs:

Not sure on the weather but at 30 cold you could have got the Tyres up to 36 hot at the back I would guess, no wonder they felt a bit squirmy. Before you buy new Tyres and suspension you might wanna buy a pressure gauge :thumbs:

:hahaha: Indeed.

Slightly lower ride height all round (Shimmy's measurements give you a decent start point), more camber (at least -3 front -1 rear), decent tyres :whistle: and keep an eye on tyre pressures. I run at least 28psi cold and usually take quite a bit more out once hot.

[AlexGTT]

heh, shall I just give up ?

OK its a reasonably fair point but having played with tyre pressures in the past (albeit different cars) I can't say I've noticed a huge amount of difference.

In fairness I do check pressures in the summer as bone dry trackdays tend to heat things up nicely.

What pressures (hot) would you recommend ?

Believe me, BIG difference on E46 M3/CSL. Cups are quite sensitive to pressures.

Hot I run 30ish front 32ish rear.

You will find you wear out the centre of the trye running Cups with pressures to high.

[shimmy]

heh, shall I just give up ?

OK its a reasonably fair point but having played with tyre pressures in the past (albeit different cars) I can't say I've noticed a huge amount of difference.

In fairness I do check pressures in the summer as bone dry trackdays tend to heat things up nicely.

What pressures (hot) would you recommend ?


On the CSl tyre pressures will make a massive difference, more than suspension and nearly as much as geo.

If you aim for 32 HOT you won go far wrong at first then adjust down as you feel the ride altering. Like Alex says, starting around 28 cold then you will
Need to let out 2-3 more psi to get them 32 hot immediately after a good session

I am sure with assume pyro advice you could fine tune the pressures down to optimum for each corner of the car on each track.

[uncle benz]

I start at 26 psi cold, with Toyo R888's

Usually end up 30ish hot.

[shimmy]

I start at 26 psi cold, with Toyo R888's

Usually end up 30ish hot.

So do I but just need to be a bit careful on running low pressures too agressively on 19 inch tyres

[uncle benz]

I can't afford 19's.

[shimmy]

I can't afford 19's.


I'd have though Titan was keeping you in sheepskin slippers:thumbs:

[uncle benz]

I have a nasty AMG habit that's keeping me poor.

I'd like to talk about it, but I've started crying already...

[titan]

Believe me, BIG difference on E46 M3/CSL. Cups are quite sensitive to pressures.

Hot I run 30ish front 32ish rear.

Odd, shouldn't you run a higher pressure on the wheels that support the engine weight. 32 front, 30 rear ?

[glendog74]

On track I run:

Fronts 31/32 hot

Rear 30/31 hot

this normally equates to a cold starting temp of around 26 during the warmer months.

[mattCSLnut]

I have a nasty AMG habit that's keeping me poor.

I'd like to talk about it, but I've started crying already...

There, there :smt056 we understand ;) :whistle:

http://www.youtube.com/watch?v=5Nq4xyHQb7o&feature=related

[shimmy]

Odd, shouldn't you run a higher pressure on the wheels that support the engine weight. 32 front, 30 rear ?


No not necessarily. Don't forget the CsL has near perfect weight distribution.

You run pressures that give you the best grip levels and balance for your car.

Pyro tests at Snett for me last year showed that hot pressures should be around 26RL, 29RR, 31FL, 33FR although my camber wasn't perfect so these may have altered slightly when adjusted.

[_Nathan_]

"Don't forget the CsL has near perfect weight distribution"

:bigcry:

26 hot rear left seems low?

[shimmy]

"Don't forget the CsL has near perfect weight distribution"

:bigcry:

26 hot rear left seems low?

Very low I agree and I was loathed to go that low, but it worked and gave the right temp across the tyre. Snett does work that side very hard. Well the old track used to.

[TANKSLAPPER]

Copied from Michelin website


Note: Michelin ® Pilot® Sport Cup tires are designed to operate at pressures ranging from 32 psi to 36 psi hot. A cold pressure of around 25 psi (front) and 28 psi (rear) should be a good starting point, which can then be fine-tuned to your car’s setup and your driving style. You should never go below 20 psi cold, to avoid any risk of bead unseating.

T$

[AlexGTT]

Odd, shouldn't you run a higher pressure on the wheels that support the engine weight. 32 front, 30 rear ?

Not necessarily. Remember the fronts load up and heat up quickly in the braking zones, more so than rears.