Beat the roll

[Dubs00]

Hi all

Trip to the Nurburgring last week was great and the s3 did its job in fine style accept for the sloppy back end. My chassis upgrades are so far as follows

Bilstein shocks/Eibach springs
Poly bushes all round
Yellow stuff pads/Bilstein discs
Yoko ad08s which I can't recomend enough.

Managed to put in a couple sub 10 minute laps but come back thinking if only the car conered a little better it could do at least a 9.30!!

Has anyone used updated anti roll bars on a track with any success?

Have been looking at these so far but have also seen people mentioning r32 jobs which are a bit thinner. The car is not my daily so I'm not to bothered if it's stiff as a rsj as long as it looses the sloppy *** end.

EIBACH 26MM FRONT & 24MM REAR ANTI ROLL BARS

S3 8L 1.8T Quattro 01/99>

Part Number: E40-85-001-01-11



H&R 25MM FRONT & 21MM REAR ANTI ROLL BARS

S3 8L 1.8T Quattro 01/99>

Part Number: 33431-1

OUR PRICE
£309.95
INC. VAT & DELIVERY

Any recommendations would be greatly appricated!

Thanks in advance

 

[superkarl]

Try an R32 rear bar and see how you like that.
Have you changed the trailing arm bushes?

 

[Dubs00]

Heard that can make the back end a bit twitchy if you just swap the rear and not the front at the same time??

Haven't no, I might have a look underneath on Saturday see what they're like.

Cheers for reply

 

[superkarl]

Heard that can make the back end a bit twitchy if you just swap the rear and not the front at the same time??

Haven't no, I might have a look underneath on Saturday see what they're like.

Cheers for reply

Generally, increasing the rear combats under steer. Increasing the front combats oversteer.

It should not be twitchy

Changing the trailing arm bush is the best thing you can do at this stage. HIUUGE difference to stability and how it handles

 

[Dubs00]

Generally, increasing the rear combats under steer. Increasing the front combats oversteer.

It should not be twitchy

Changing the trailing arm bush is the best thing you can do at this stage. HIUUGE difference to stability and how it handles

Batter take a look at those at weekend then thanks.....

Sure I read somewhere a guy said fitting a rear r32 bar made the car unstable at high speed but I could just be imagining it!

 

[Madmax199]

Well, for starters there are many ways to attack the 'problem' that you have. Larger ARBs being one of them, but not necessarily the best or most effective approach. I would also preface by saying that a larger than factory front ARB is the worst thing you could do to this platform. Forget about that one unless you fancy understeer!

Anti roll bars act as secondary springs whenever there is lateral load. Therefore they can contribute to the overall roll stiffness in a significant way. However, there is a catch! ARB work by the bar's ability to resist twisting, and that works because they attach both side of the suspension (removing independence). Less independence means less grip on the respective axle and that could be a blessing (when done in moderation) or a curse due the lack of grip that comes with stiff ARBs.

From experience, the platform already have way too much front ARB from the factory, if anything you want to reduce the rate (or totally delete the front bar if possible). There is some wiggle room in the rear for increasing the ARB rate -- but go overboard, like most people tend to do, and you have more cons than pros (tripod and low grip levels). The most I recommend in the back is a 16mm bar... and even then you are already unloading the inside rear at low G-forces. For example I run a modified 14mm factory bar with extra holes drilled in it to increase the rate and provide adjustability.

Pic of the modified factory bar I mentioned above.

As I mentioned earlier, there are other things worth attacking as well. In order of importance:

- Stiffer springs/coilovers. That is actually the proper way to improve the roll control on the car. Matched with proper damper valving, this will give the best results as it doesn't have the negative byproducts that are attached to stiffer ARBs.

- Increase front camber compensation. This platform start to come alive around -3 deg (or more) of static camber compensation. I run -4.4 deg in my track car as a reference.

In the front of my car

- Increase track (especially in the front). Increasing track acts as better geometry on the axle that it's performed. You will roll less, and improve the rate of weight transfer by increasing the track. There is a point of diminishing returns though as too much track increase will mess with the scrub radius. So it's a balancing act. I'd say you're fine at 30mm or under (per side).

There is more, but I will venture saying that this are basic mods that will get you the most return for your effort.

 

[Madmax199]

Changing the trailing arm bush is the best thing you can do at this stage. HIUUGE difference to stability and how it handles

^^^ While I am not in disagreement, I think that it should pointed out that this will make the aforementioned improvement provided that the existing ones were past their prime. Otherwise, it's not that drastic!

 

[Madmax199]

Here are some actual numbers for the common rear ARB "upgrades" (copied and pasted from another post I made somewbere else on the topic).

Stock 14mm bar:
158 lbs/in Static rate
133 lbs/in dynamic rate (the dynamic rate is with body roll and the effective rate)

Modified 14mm bar (1" spacing between bolt holes):
268 lbs/in Static rate
226 lbs/in dynamic rate ===> a 70% increase in effective rate

19mm Euro-spec R32 bar (seems to be a poular upgrade in the UK):
537 lbs/in static rate
454 lbs/in dynamic rate

19mm Modified Euro-spec R32 bar:
910 lbs/in static rate
769 lbs/in dynamic rate ====> a 69.4 increase in effective rate

For comparison's sake, a 21mm bar with stock-location bolt hole:
802 lbs/in static rate
678 lbs/in dynamic rate ====> this bar is softer in effective rate than a modified R32 bar

A stock 14mm rear bar will see a 70% increase by drilling new holes 1" inboard of the factory ones. The increase in stiffness by just doing this free mod is substantial. The 19mm Euro-spec bar that is a common mod here will be stiffer than a 21mm aftermarket bar at its center hole.

For those that might care about that kind of stuff . A 21mm bar is a staggering 409% increase over the standard 14mm bar -- therefore even more if going with bigger than 21 mm. With increase that excessive, the bar is basically doing all the work (might as well run on bar only). All independence is out of the window, and while a car like that may feel flat while due to the lack of body roll, it is obviously not going to actually handle better than a car where the spring is the main player and the bar is complementary.

 

[Madmax199]

Just so the 16mm rear ARB lovers don't feel left out, your typical 16mm bar has the following data:

270 lbs/in static rate
228 lbs/in dynamic rate ===> the effective rate on this bar is basically identical to a standard 14mm bar with the drilled mod

If you were to mod your 16mm bar, this what you'd have at a 69.2% increase :
457 lbs/in static rate
386 lbs/in dynamic rate ===> which is not far trailing an unmodified 19mm bar from an R32

 

[Dubs00]

There's so much information there I had to read it three times....thanks!!

So looks like I'll be drilling a couple holes in my original bar then which sounds much much cheaper than a £320 h&r set of chunky bars

 

[superkarl]

^^^ While I am not in disagreement, I think that it should pointed out that this will make the aforementioned improvement provided that the existing ones were past their prime. Otherwise, it's not that drastic!

Absolutely. But with these cars being as old as they are, and British roads, they are bound to be way past their best


Sent from my iPhone using Tapatalk

 

[snowy]

Stiffer springs/coilovers. That is actually the proper way to improve the roll control on the car. Matched with proper damper valving, this will give the best results as it doesn't have the negative byproducts that are attached to stiffer ARBs

Linear vs progressive setups though

Softer progressive springs rates, less unloading, more wheel contact with road
Requires better damper units doing more work
ARBs still used

Its what VAG did when taking this chassis to motorsport

eg Octavia WRC, Octavia Kit Car & Leon Supacopa all retained front and rear arbs with progressive springs

There isn't a proper way, there's the old method and the new

 

[Madmax199]

Linear vs progressive setups though

Softer progressive springs rates, less unloading, more wheel contact with road
Requires better damper units doing more work
ARBs still used

Its what VAG did when taking this chassis to motorsport

eg Octavia WRC, Octavia Kit Car & Leon Supacopa all retained front and rear arbs with progressive springs

There isn't a proper way, there's the old method and the new

All else equal, progressive springs are a compromise. And they're a compromise in the streets or at the track. That debate is very old btw. The reason why they're in use is because compromising a bit of performance is not necessarily a bad thing. You give away some performance to gain some compliance. On a street car, this is definitely good -- on a track car that runs on various or changing surfaces they can be acceptable (but in no way ideal for one specific environment).

So why are progressive considered not as good a linear springs in terms of pure performance or track use? Mainly because of the way conventional damper valving works. Typically you have your low speed valving (1-3 Hz/sec) and you have your high speed valving (3 Hz-up). You will valve both separately (low and high speed) to be at a chosen percentage of a critical damping. With an infinitely changing rate of most progressive springs (popular rising rate kind), nailing a valving setup that would be ideal through the entire stroke is impossible. For the dual rate kind of progressive springs (more rare), valving is still problematic as you're dealing with dead zones in the transitions phases between the rates, and still have two main rates to valve).

As you may know, there are more than one way to skin a cat. But with that said, progressive springs are a tradeoff approach to setup a track car vs linear springs. If you look at all tarmac racing series, you won't find much outside of linears springs unless a compromise is absolutely necessary. I can't comment on the reasoning behind the use of progressive springs by VAG on the platform in Motorpsorts, but I can tell you that they did so knowing that it is a tradeoff (maybe a favorable one for the conditions).

 

[snowy]

As you may know, there are more than one way to skin a cat

This is what I was pointing out to you

But with that said, progressive springs are a tradeoff approach to setup a track car vs linear springs

*everything* suspension wise is a compromise, and you neatly stepped round the major flaw in linear rates:

various or changing surfaces

The little effect of floation

nailing a valving setup that would be ideal through the entire stroke is impossible

Been done, perfected even
Check out folks like Ohlins, exe-tc, Reiger
Even KW v3 does a pretty good imitation of serious damper

If you look at all tarmac racing series

Formula 1 ?
They use ARBs' too

 

[Dubs00]

Madnax99 are you using standards shocks with your modified bar?

 

[Prawn]

Trip to the Nurburgring last week was great and the s3 did its job in fine style accept for the sloppy back end. My chassis upgrades are so far as follows


Managed to put in a couple sub 10 minute laps but come back thinking if only the car conered a little better it could do at least a 9.30!!



Any recommendations would be greatly appricated!

Recommendation: practice makes perfect. My old A3 with 200bhp would do 08:50's all day long on normal road tyres

You car would do an 8:30 exactly as it is, it's the driver that needs upgrading (I joke I joke)

All joking aside though, I'm glad you had a great time. the Nurburgring is a truly epic place, and it's a trip you will NEVER forget.

Max has gone into a lot of detail, so I won't go over that ground again, but needless to say, most aftermarket ARB kits available are wholly inadequate and do nothing to alter the terrible factory balance of the car front to rear.

If going down a more traditional UK route of modifying, you want the rear bar to be closer to the front bar in terms of size, but not to exceed it. You also need to remember that ARB's actually REDUCE grip on the axle overall, so should be kept to a minimum where possible.

Massive ARB's on your spring setup will not work either, as the spring rates will not be high enough to control them.

there is plenty more to add, but it's all probably too in depth. if sticking with your current spring / damper setup, the best thing you can do is retain the stock front bar, and modify or go up in size slightly at the back.

 

[Dubs00]

Recommendation: practice makes perfect. My old A3 with 200bhp would do 08:50's all day long on normal road tyres

You car would do an 8:30 exactly as it is, it's the driver that needs upgrading (I joke I joke)

All joking aside though, I'm glad you had a great time. the Nurburgring is a truly epic place, and it's a trip you will NEVER forget.

Max has gone into a lot of detail, so I won't go over that ground again, but needless to say, most aftermarket ARB kits available are wholly inadequate and do nothing to alter the terrible factory balance of the car front to rear.

If going down a more traditional UK route of modifying, you want the rear bar to be closer to the front bar in terms of size, but not to exceed it. You also need to remember that ARB's actually REDUCE grip on the axle overall, so should be kept to a minimum where possible.

Massive ARB's on your spring setup will not work either, as the spring rates will not be high enough to control them.

there is plenty more to add, but it's all probably too in depth. if sticking with your current spring / damper setup, the best thing you can do is retain the stock front bar, and modify or go up in size slightly at the back.

4th time over there gets better every time! Just learning the track is a nightmare there's 70 odd corners

Your doing pretty well with 8.50s the standard s3 8l lap with a pro driver is 8.42 I believe.

Im going to try out the extra hole on the bar check rear trailing arm bushes and if all still fails maybe just live with the loose *** end.....I don't fancy forking out a couple k on some decent track coilovers may as well buy a Clio 197

 

[Prawn]

4th time over there gets better every time! Just learning the track is a nightmare there's 70 odd corners

Your doing pretty well with 8.50s the standard s3 8l lap with a pro driver is 8.42 I believe.

Im going to try out the extra hole on the bar check rear trailing arm bushes and if all still fails maybe just live with the loose *** end.....I don't fancy forking out a couple k on some decent track coilovers may as well buy a Clio 197

8:42 time for the car will be a full lap. BTG is minus roughly 27-30 seconds depending on max speed down DH, so that 8:42 translates to about an 08:10 BTG for the stock car.

All the above aside though, upping a rear ARB in size isn't going to tame a loose back end, it's going to increase it!

Chances are, if you're suffering from the back end being too mobile, you've got some sort of geometry issues causing it. S3's are dull as dish water standard and the rear end doesn't come into play unless you REALLY provoke it.

 

[Dubs00]

8:42 time for the car will be a full lap. BTG is minus roughly 27-30 seconds depending on max speed down DH, so that 8:42 translates to about an 08:10 BTG for the stock car.

All the above aside though, upping a rear ARB in size isn't going to tame a loose back end, it's going to increase it!

Chances are, if you're suffering from the back end being too mobile, you've got some sort of geometry issues causing it. S3's are dull as dish water standard and the rear end doesn't come into play unless you REALLY provoke it.

 

[Dubs00]

......good point that's very true.

My bad, when I mean loose in the wobbly sort of way not lack of traction .....only time I've had the back out with an s3 was a previous car which the owner before me had fitted Nankangs to the rear. Was crazy In the wet would just let go at 60mph mid corner went through many many pairs of underpants every time it was even slightly damp!!

 

[Dubs00]

Ps thanks for the help guys you've been more than helpful!

 

[Madmax199]

This is what I was pointing out to you

*everything* suspension wise is a compromise, and you neatly stepped round the major flaw in linear rates:

The little effect of floation

Been done, perfected even
Check out folks like Ohlins, exe-tc, Reiger
Even KW v3 does a pretty good imitation of serious damper

Formula 1 ?
They use ARBs' too

There is really no point in arguing this, but I love a good technical banter. You're the one that introduced spring design into the convo. What I elaborated on was the use of ARBs vs the use of the main springs to control body roll.

A few undeniable facts:

F1 uses linear springs (cars from different eras)

You mentioned KW, Ohlins, and Rieger coilovers... they all use linear spring in their top motorpsort offerings for tarmac use.

I know you'll likely try to mention the secondary springs in use in some of these coilovers. Well, they're not really effective springs. They are zero-rate tender springs that are just there to take up slacks from main spring on full droop. They totally collapse with the car on the ground and do absolutely nothing to the ride or damping characteristics.

These little springs in these coilovers are not secondary springs, but zero rate tenders.

So, if any of these things that you introduced to the conversation (F1 and a few coilover brands) are any indication of anything, they're living proof that the use of linear spring is the better/ideal approach for all out performance. You will only see progressive rates used in Motorsports with off-road type environment... which is irrelevant to the OP.

To come back to the discussion, Nick, said it best. ARB remove grip and are consequently not the best way to do things if possible (the springs are). I will agree you that most things with suspension tuning are compromises, but some compromises are less compromising than others!

 

[Madmax199]

Madnax99 are you using standards shocks with your modified bar?

No, I run a modified set of H&R RSS Clubsports coilovers (revalved to my specs, and running custom springs 850/1300 lbs/in).

 

[snowy]

F1 uses linear springs (cars from different eras)

Red Bull F1 2016 Car
3 stage progressive thrust spring

You mentioned KW, Ohlins, and Rieger coilovers... they all use linear spring in their top motorpsort offerings for tarmac use

they *used* too
past tense

Everyone offers progressive options these days

I know you'll likely try to mention the secondary springs in use in some of these coilovers. Well, they're not really effective springs

You're straight wrong there I'm afraid

Secondary (or 3rd, 4th) springs can be used anyway you/the manufacturer likes

On some setups yes they are used only as slang absorbers, on others they form the progressive element of a combined progressive/linear system (as used by KW on v3 and Clubsports on their front coilovers)

Progressive springs can also be single spring systems, with no helpers

You can't tell whether a setup is progressive or linear just from appearance

You will only see progressive rates used in Motorsports with off-road type environment...

Read up on a chap called Graham Gleason

I first came across Exe-TC when I was a senior race engineer at Prodrive back in 1997. We tested them first on the Honda BTCC Touring Cars after they offered a free test and they proved to be fractionally quicker than the Penske dampers we used at the time. Their basic philosophy was to run loads of low speed bump and very little rebound, almost the exact opposite of a conventional valved damper. I remember the owner was a chap called Graham Gleason, an ex bike racer turned entrepreneur. As you say they ended up on the WRC Subaru shortly afterwards.

"The EXE-TC engineering philosophy translates into higher driver confidence on track..... especially on notably uneven racing surfaces like Sebring. I'd never use anything else"
Rob Blake, 2010 Porsche Cup Car

 

[Madmax199]

Don't have too much time now to elaborate on a proper answer (on the road), but I'll leave this here so you have a chance to properly research and retract the incorrectness of what you have posted. BTW, it's not a ******* contest or battle on who's right, to me it's about technical correctness. But couldn't get pass the first statement and pic that's flawed.

Redbull 2016 RB12 suspension. FYI they use the hypercoil carbon stack spring technology that are BTW the future.

I'll also save you the hassle of researching, educating, and correcting your fail by providing an overview of the RB12 from a reputable source:
http://www.racecar-engineering.com/cars/red-bull-rb12/

 

[snowy]

Redbull 2016 RB12 suspension. FYI they use the hypercoil carbon stack spring technology that are BTW the future.

That's the front suspension

The 3 stage progressive unit is the rear setup

BTW, it's not a ******* contest or battle on who's right, to me it's about technical correctness

I'm not having a ******* contesting, just telling you of what folk out the world of racing are actually upto

 

[Madmax199]

I'm not having a ******* contesting, just telling you of what folk out the world of racing are actually upto

Sure, like quoting some random post on Porsche coilover convo which has nothing to do with progressive and linear springs and proves nothing. EXE-TC makes coilovers for all sorts of use Rally, street cars and tarmac racing.

http://www.pistonheads.com/gassing/topic.asp?h=0&f=48&t=997387&i=40

I am realizing that this discussion is going nowhere, and I'm not into ******* contests much. Was a pleasure.

 

[snowy]

FYI Chris Harris setup was progressive, that's why I quoted from, and because he's someone well known in the UK
eg someone from whom info can easily be referenced - not someone I could possibly invent - ie "my mate who you don't know blah blah ..."

I am realizing that this discussion is going nowhere

Still wonder what your thoughts on the little issue of floation (oscillation caused by lumps and bumps)

This has alway been the achilles heel of stiff linear setups

This was the major problem being faced by the VLN racers at the Nordschleife, problem sovled by changing approach

For anyone thinking road+track: Uk/european roads and hyper stiff spring rates = floatiness + skating

Been there, done that

 

[Dubs00]

Well, for starters there are many ways to attack the 'problem' that you have. Larger ARBs being one of them, but not necessarily the best or most effective approach. I would also preface by saying that a larger than factory front ARB is the worst thing you could do to this platform. Forget about that one unless you fancy understeer!

Anti roll bars act as secondary springs whenever there is lateral load. Therefore they can contribute to the overall roll stiffness in a significant way. However, there is a catch! ARB work by the bar's ability to resist twisting, and that works because they attach both side of the suspension (removing independence). Less independence means less grip on the respective axle and that could be a blessing (when done in moderation) or a curse due the lack of grip that comes with stiff ARBs.

From experience, the platform already have way too much front ARB from the factory, if anything you want to reduce the rate (or totally delete the front bar if possible). There is some wiggle room in the rear for increasing the ARB rate -- but go overboard, like most people tend to do, and you have more cons than pros (tripod and low grip levels). The most I recommend in the back is a 16mm bar... and even then you are already unloading the inside rear at low G-forces. For example I run a modified 14mm factory bar with extra holes drilled in it to increase the rate and provide adjustability.

Pic of the modified factory bar I mentioned above.

As I mentioned earlier, there are other things worth attacking as well. In order of importance:

- Stiffer springs/coilovers. That is actually the proper way to improve the roll control on the car. Matched with proper damper valving, this will give the best results as it doesn't have the negative byproducts that are attached to stiffer ARBs.

- Increase front camber compensation. This platform start to come alive around -3 deg (or more) of static camber compensation. I run -4.4 deg in my track car as a reference.

In the front of my car

- Increase track (especially in the front). Increasing track acts as better geometry on the axle that it's performed. You will roll less, and improve the rate of weight transfer by increasing the track. There is a point of diminishing returns though as too much track increase will mess with the scrub radius. So it's a balancing act. I'd say you're fine at 30mm or under (per side).

There is more, but I will venture saying that this are basic mods that will get you the most return for your effort.

Don't seem to have the space for another hole on my bar so maybe an r32 one it will have to be.

Bushes have seen better days on the rear arms.

 

[Madmax199]

FYI Chris Harris setup was progressive, that's why I quoted from, and because he's someone well known in the UK
eg someone from whom info can easily be referenced - not someone I could possibly invent - ie "my mate who you don't know blah blah ..."



Still wonder what your thoughts on the little issue of floation (oscillation caused by lumps and bumps)

This has alway been the achilles heel of stiff linear setups

This was the major problem being faced by the VLN racers at the Nordschleife, problem sovled by changing approach

For anyone thinking road+track: Uk/european roads and hyper stiff spring rates = floatiness + skating

Been there, done that

My thoughts are that it comes down to setup, and setting it up properly. For example the Natural Frequency (aka ride frequency) chosen for the car or specific track. Secondly, the valving in the dampers (especially the high speed valving and amount of digression in the curves).

A bit of background, I was on Mitsubishi's payroll for 8 years, and volunteered in the North American Motorsports program when it was running. We never used the same Natural Frequency (NF) and spring rate on two tracks. The Front NF was alway picked for the surface, then the rear NF chosen based on a percentage off the front (say 1.5 times the front depending on rear wing AoA etc.). Therefore each track or type or surface had their ideal spring rates (influenced by the Natural Frequencies we wanted to run).

But we always say, springs are dumb, and dampers are smart. The spring does the work, the damper valving controls that work. You can easily control the valving for stiff springs or rough surfaces. For example I run 850 lbs/in front springs and 1,300 lbs/in springs in my TT (same chassis). It would seem excessive to most, but because of how I valved the damping curves, it feels better (even over bumps and ondulations) than the street vesrion of the same coilover.

The caveat is that not every car can be setup and tailored to every conditions/track they're going to. Therefore an all-around compromised approach is often taken. Something that is not perfected for any conditions, but will do well enough on most. Enter the world of progressive springs. They do allow comfort and some compliance, but never IMO ideal or best for a specific use.

The OP is building for circuit racing. I think he should focus on that. With what is available at his disposal hardware wise, a good set of coilovers with linear rates is his best option (AST, GAZ, H&R Clubsport, KW Clubsport, Koni true choice, Ground Control Advance Design, or the sick set of Moton that is always in my wish list). All of those are with linear springs (some with zero-rate helpers that do nothing but take up droop slack. Ditched them in mine).

Here is video of the rear of my car driving around with 1,300 lbs/in springs. You wouldn't know from inside the cabin, plenty of compliance over bumps, no bouncing, and not crashing or skipping.


How my Clubsport started (long convetional spring that places the collar next to the tyre and limit clearance, unnecessary unsprung weight with the helpers, collars and spring).

What they evolved into (revalved, much lighter without collars, helper springs, and short swift springs that created tons of clearance for rubber).

I think that's what the OP should be aiming for... what has been proven and where there are others to compare notes with. Thoughts?

 

[snowy]

The caveat is that not every car can be setup and tailored to every conditions/track they're going to. Therefore an all-around compromised approach is often taken. Something that is not perfected for any conditions, but will do well enough on most. Enter the world of progressive springs. They do allow comfort and some compliance, but never IMO ideal or best for a specific use.

Core this the core question - general or specific

When starting out with a any form of motorsport going for a general all round setup would seem sensisble
Something that allows you concentrate on driving and building experience
A more compliant setup will be more forgiving of mistakes, and encountering the unexpected

Moving into the proper racing, I guess you could sumarise as using progressive as a 'planning for the worst' policy, and going linear as 'planning for the best'
At the end of the day its consistency that wins races
So if by using a progressive setup you can get more consistent times and win your series, case proven, imho

Here is video of the rear of my car driving around

If only UK roads where that smooth
Our roads are really quite dangerous in many places, heavy core damage that justs gets a fresh top layer every few yrs
But even without that, we get alot of sh1t3 quality workmanship with cheap ready mix tarmac - leading to rippled paving that cracks within a few days of freezing weather