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Discussion Starter #1
Hi Guys and Girls,

Having had the opportunity to take my M6 out on the "track" for 40 minutes (Oran Park) I have found that the front end sticks to the track like glue, but the rear end oversteers (very controlably) way before the front end understeers.

Very unusual for a front wheel drive car who's design naturally favours understeer.

An inspection of the tyres Bridgestone Potonza RE 010 (17 inch) 45 psi for the track, shows the fronts working evenly but the rears are hardly scuffed.

Has anybody had the same experiences on the road or track ?

Can anybody in the suspension industry, recommend suspension adjustments to get the rear tyres working a little harder - increased front spring rates ?.

(I've found the same thing happening during a "fang" up the Old Pacific Highway).

The ride on the track and road shows very acceptable body roll control, even on 180kph high speed corners (track); with just the right amount of forward weight transfer during heavy braking from the same speed.
 

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Replying to Topic 'Rear Suspension during Hard Driving'

WOw, Test drive on the TRACK. Should we have a track day say in 6 months time when my car is run in my then? In and around Melb of course
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Interesting results
What spec is your M6?
Taking low gear corners during city driving I have also noticed the tendency to oversteer
Presumably this is because the rear springs are very stiff
Noticed my M6 sliding at lower speeds than my previous ride (Satria GTI) :( At least its overstter rather than understeer

What were your times at Oran park compared to other cars?
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Hi Sixman and Marckhor,

Thanks for your reply.

Sixman
I collected my M6 on 17th May, a Blue Pacific, 5 speed "Classic" sedan.
I factory optioned mine as follows, 17inch wheels with Bridgestone Potenza RE010, black leather gear knob and black floor mats from the "Sports", headlight and bonnet protectors, chrome exhaust extensions, sports grill and upgrade factory alarm (which now has the USA Tilt feature added). I'm not into rear spoilers or wings (the factory ones provide no downforce - only cost and increased fuel consumption through aerodynamic drag).

I had the dealer change a few of the fluid though on pre-delivery.

Engine Oil: Mobil 1 5w-50w (including filter)
Brake Fluid: Castrol "Response" Super DOT 4 (higher boiling point)
Brake Lines: Braided Stainless Steel - teflon lined (no brake line flex)
Transmission Fluid: Castrol Synthetic 75w-90w (smoother changes)
Tyres: Nitrogen filled (34 psi - street) stable temperatures and no wheel oxidisation
Fuel: BP Ultimate (far less Benzene than Optimax)

As you may have read in my other articles I have posted, I have done the airbox modifications.

If I can find a way to make the rear end behave like the front end during hard driving I'll be very happy.

Warren

(What is your spec)


Marckhor

My M6 is running in well, with just on 1600 kms.

Having been involved in drag racing, motorsport and aviation for many years, I don't believe in these extended "pussy foot" running in procedures.

The manufacturing tolerences and assembly techniques of the Japanese these days is a far cry of 20 years ago.

I give the engine 200 kms of below 3,000 rpm bedding in. From then on I increase the rpm limit by 1,000 rpm per additional 100 kms. So at 700-800 kms the full range of rpm is being used. Varying the rpm during run-in in the most important step. Your mainly varying piston speed to bed in the rings. At 3,000 rpm (100kms distance) each of the pistons has already travelled 180,000 strokes in 1 hour. You don't need to travel 1,000 kms to bed in pistons (1,800,000 strokes). Look at any racing application, and their run-in period and their engines are far more highly stress. (Yes they rebuild their engines at 3,000 kms - V8 Supercars mainly from abuse not poor running in).

These modern all alloy engines can't compare to the the old steel engines of the past.
 

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Reading Topic: Rear Suspension during Hard Driving

about tyres, i got RE050s on my 6, standard

my 6 is the lux/sport edition
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Hi Warren

My car is a manual luxury sports hatch
In my price range it was the best compromise between performance and comfort
Couldnt be happier :D
Man this oversteer thing is fun
Could it also have something to do with the relatively long wheel base?

Interesting that your dealer was willing to change so many fluids
Did you provide them?
I was also looking at upgrading the brake lines and fluid - did you do it yourself?

What airbox modification? Must have missed your other posts

Sorry for so many questions but I dare to say that your M6 may be the most modified in Australia :p
Havnt heard of anyone else taking their own private ride to a track yet....
 

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Reading Topic: Rear Suspension during Hard Driving

WRW, or if u have other preferred names, your a wealth of knowledge!

One thing i'd like to know is how u managed to oversteer a FWD? Did u use leftfoot braking? I'm seriously interested in advanced driving, but that'll be a while off - i'm 17 and still on my L's, but it doesnt stop me from being enthusiastic, eh?
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Correct tire pressure & camber can make a big difference. This explains it better than I can.

Tech Topic - Reading Tire Temperature

Road map to suspension tuning


"What tire pressure should I run?"


This is the most common question heard at the track. Unfortunately, the answer is different for every car due to suspension, driving style and tire differences.

The best tool for determining ideal tire pressure is the pyrometer. A pyrometer measures tire temperature. It's also a great tool for evaluating alignment settings, tire sizes and sway bar settings. Would you benefit from more negative camber? Are your tires too small? Too big? A pyrometer can tell you.

Tires get hot when they are loaded; acceleration, braking, cornering and steady state driving all deform tires and cause them to heat up. Tire temperature can tell much about how the load is carried and distributed over the tires.

Taking measurements -

Temperature readings should be taken when tires are fully warmed up, typically after 5 to 10 hot laps on the track. Readings should be taken immediately after the last hot lap, no cool down allowed.

Measurements are taken with a tire pyrometer. The best type of pyrometer has a probe that is inserted into the tire tread. By measuring temperature below the tread surface, the probe provides improved readings since the tread surface cools relatively rapidly.

Alternatively infrared (IR) thermometers may be used. However IR thermometers read surface temperature and therefore provide less reliable readings.

Three readings are taken on each tire; inner tread, center tread and outer tread. Inner and out readings are taken 1 inch from tread shoulder and in the center of a tread block. Write down the readings for evaluation.

Evaluating the readings -

We can draw useful conclusions by evaluating each tire individually and by comparing readings of the tires.

Tires have an ideal temperature range in which they produce maximum grip. When cooler than that range, tires loose grip. When hotter than that range the tires become "greasy", even hotter and they begin to break apart. Check with your tire manufacturer to find the recommended operating temperature for your tires. A typical operating range for a DOT-R tire is 180F to 200F. Street tires tend to run a bit cooler and racing tires a bit hotter.

Use the following table as a general guideline to evaluate readings:

Symptom Diagnosis:




Note that some symptoms have multiple diagnosis, one or more may apply. Sometimes multiple symptoms appear simultaneously. Making one change at a time is advisable to best evaluate the impact of the change.

It is wise to take and evaluate temperature readings frequently. Different tracks, changes in ambient and track temperature, tire wear, fuel level and more all affect ideal settings. Adjustment in pursuit of peak performance is a non-ending task.

Chuck Moreland - September 2002

http://www.elephantracing.com/techtopic/tiretemp.htm


Note:

You can only adjust the camber in the rear on a 6 (which may be all you need).
Toe is adjustable front and rear.
 

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Discussion Starter #9
Replying to Topic 'Rear Suspension during Hard Driving'

Hi Alexchu,

When driven at 9/10th's the M6's front end stays "put". Be it the tremendous grip of the RE 010's or whatever, its the rear end that begins to oversteer and it's very predictable.

I know its totally out of behaviour for a FWD car, but take it out for a drive and you'll find the rear end gentle letting loose - all controlable with a bit of opposite lock. Its really pronounced in say 35-45 kph corners taken at 80-90 kph. The front end just digs in and corners whilst the rear end gets loose.

I know the RE 050 are standard on "Sports" but mine was a "Classic" and I dealer optioned the factory 17inch wheels and choose the RE 010 as they are an OEM design and manufacture (hence the price tag) plus they achieve good mileage. I was looking at putting on S03's but the expected tyre life was a joke.

I told the tyre dealer 10,000 - 16,000 kms was a joke for S03's, as front wheel drive is pretty heavy on steer tyres, regardless of rotation schedule. Let me know how yours are wearing ?

Warren
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Hi Sixman,

Reference the airbox modifications, just go back through the pages and you'll find it.


Warren
 

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Reading Topic: Rear Suspension during Hard Driving

about the airbox, i've spoken with my friend about it, and he says you really shouldnt be mucking around with the airbox because you're increasing the chances of something unwanted getting into the engine which'll do it no good.

please comment
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Hi Warren,

Found the airbox modification thread
Thanks for the info
Look forward to playing around with it this weekend

Swapped drives with a mates Alfa Romeo 156 GTA yesterday
Sweet car:)
Like the M6 its also FWD and tends to oversteer rather than understeer
Feels like its on rails but very bumpy
Apparently it is to do with the stiffness of the rear springs in the GTA as compared to the standard 156
Wonder if its a similar thing with the M6

BTW how did you get access to a dyno?
 

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Replying to Topic 'Rear Suspension during Hard Driving'

Hi Alexchu,

All the airbox modifications are made prior to the airfilter - and are not made where the possibility of additional water could enter the system.

For Mazda to pass legal noise requirements in various countries, they have to pass static and dynamic drive-by noise tests. Induction noise thru the airbox can sometimes be a problem during static tests, especially the noise measurement taken at 3,000 rpm whilst stationary. Thus noise restrictors are placed over the intake trumpet and in the airbox to quieten down the powerplant.

Hope this helps

Warren
 

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Reading Topic: Rear Suspension during Hard Driving

you're making this modification very attractive!

prior to me doing it, i want to know whether it'll affect the car's warranty
 
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