Mods

[John M]

Sorry not a Bravo but a Brava specifically a 1.8 ELX

I am currently embarking on a bit of a modding spree after origanally getting the bug to save money in the form of a powerflow custom fit stainless steel exhaust (plug to ALPHA Cars in Leeds for an excellent job)

I would like to know if any of readers of this most excellent forum have had any experiances or would like to pass comments on the following mods:-

1) Black diamond combi discs and pads £200
2) Sparco Strut Brace
3) OMP Shocks and lowering Springs (-40mm)
4) Powerflex Polyurathane front Suspension Brushes (£100 + fitting, a new product that is apperantly the same as Alfa 145-146-147, 155-156, spider GTV, Fiat Coupe and all Fiat Bravo/a's and Marea's. Part numbers are PFF1-801 for Front lower wishbone front bush and PFF1-802 for the front lower wishbone rear bush (2 of each required @ £24.95 per item for anybody else that is interested)

Also I am, due to slight rear end modifcations resulting from my girlfriends attempt at reversing and some scrote with a key, requring a new boot lid and a nearside respray, any suggetions for garages in the Leeds area capable of an excellent job at a reasonable price would be appreciated, also I would like to get a hold of a primed boot lid to modify (read delock, dehandle, de high-level-brake light and add spoiler of the raised variety prior to spraying) at a non fiat dealer price (a price that does not require the sale of car/granny/mother/sister/dogs/computer etc.etc.)

 

[Dug]

Polyurethane bushes

I've not tried those bushes on a Bravo, but I've used them on other cars. You have to be a bit careful.

The bushes do improve the steering to a remarkable degree, and even aid braking and handling (there's less play in the front suspension, which stops the wheels wandering around). However, the ride becomes terrible. Every thump and bump is passed straight through the steering wheel to the driver. It can become really tiring even on a moderate journey. I'd leave these to race tracks.

However, I've had great success in using harder rubber bushes: they're a great compromise. Alternatively, you can use a mixture of rubber and polyurethane: just replace the centre anti-roll bar bushes with the polyurethane, and leave the end bushes as rubber. I noticed a slight improvement when I tried this on two cars, but potholes didn't shatter my elbows.

I don't know if anyone makes such bushes for the Bravo...

 

[Nigel]

Bushes

I agree totally with Dug. I used them on an Alfa Sprint and while the tautness of the front end was a joy, the transfer of cats eye shake was unbeleiveable.

Make sure your brake system works in compatability with your ABS (those who know me here will roll their eyes to the heavens as I once again go on about my favourite subject!) as quicker grab means the ABS will cut in quicker and braking distances will be longer, especialy in the wet. Insurance companies are not stupid on this one and will hike accordingly.


Nige

 

[John M]

Which is the best type of iduction kit?

Green Cotton Filter P123 1.8 16v £78.50 Single cone
Green Cotton Filter P123BC 1.8 16v £97.50 Dual Cone
K&N 57-0160 (Can't find a price dor it)
Pipercross PK164b (this is for the HGT will it fit?)

or if anybdy knows of anyothers please advise

 

[rowanskinner]

i originly lowerd my car with the OMP springs and shocks, and diddnt get well with them, they improved the handling no end, but vibrated the fu*k out of me, and as i do a lot of long journies it pissed me of loads.
So i got rid of them and got some apex springs and shocks, and they only lowerd it by 35mm, and the ride was a lot nicer i found, and they were nicer handling.
Although i did fit roll bars when i brought the apex suspentation, so that may of changed the handling a bit?

 

[JohnM]

Brakes

I'm not 100% I am sure what your saying on the Brake side of things Nige.

Surly the ABS sensors in the Braking system sense if the wheel is locking up (a Skid) and then release or increase the braking in relevant wheels to prevent an uncontrolled skid. So therfore, as the brake discs will remain the same diametre (257mm I beleive) the wheels will only lock up if I apply an excessive amount of brake pressure.

Everyone should Brake early and anticipate hazards. I drive wagons for a living and the number of people I see racing towards red lights then digging the tarmac up with their front splitter makes me laugh, you can beat them everytime if you reduce speed on the approach and anticipate the green light, I do it all the time and embarrass the drivers of much more powerfull vehicles than either my car or my truck. (I enjoy the game in both vehicles though the wagon is more fun)

Also increased breaking response will increase the effectiveness of an ABS system as the wheels will lock (and therefore unlock) quicker while still maintaining breaking forces on the wheels that are not locked/locking up. But that is more down to the upgrading of the DOT rating of the brake fluid and as Fiat recommends Dot 4 or 5 so I can't see that being a problem.

 

[Tom]

Re: Brakes

DOT5 fluid is generally slightly more compressable that DOT4. (Yes, you CAN compress a fluid, just not very much)

ABS systems MUST, and I cannot stress this hard enough, be used with EXACTLY the right fluids, hoses etc.

Don't expect it to work as Fiat intended when you are using DOT5 fluid, overbraid hoses, grooved disks and hot pads.

When it all goes wrong I just hope its not my car infront.

 

[Tom]

Re: Bushes

Just rosejoint the front end! Polly bushes are for wimps!

You'll end up with split suspension mountings, RSI and a mega dental bill after the first 10 motorway miles.

A friend of mine put 250lb springs on the front of his rally car and wondered why after a couple of stages the front struts had come through the bonnet.

 

[John M]

Brakes

I'll keep you informed, though I doubt I will be getting up close and personal with any cars in front of me.

The hoses are staying the same, though as long as the hoses are designed to withstand extreamly high internal pressures what exactley would be the problem???? I would really appriciate the technical explanation.

As I understand the Fiat ABS system:-

It has an individual sensor on each wheel, when the system senses that a wheel is about to lock up it releases the breaking pressure to that wheel OR increases breaking pressure to other wheels to prevent the said wheel locking. For this to work the sensor must be able to prosses the braking pressure between pad and rotor and the rotation of the wheel or hub.

Then there must be some sort of actuator for the system its self allowing the brake fluid pressure to be variated at each caliper (as calipers only work on fluid pressure).

.....sod this I have just found this link read it

http://www.howstuffworks.com/question451.htm

Ok now we are back

How does a grooved (or drilled) rotor alter the parameters required for a mechanical or electrical ABS system to work?

 

[Nigel]

ABS

Righty ho, if you put uprated pads and discs on the car the idea is to basically grab one another harder and faster without overheating.

You ABS counteracts this by sensing as soon as the wheel locks up to apply a very quick form of cadence braking (i.e. on off very quickly)

Therefore with you uprated brakes working a operational temperature they will grab the disc faster than standard set up, but the ABS will cut in quicker. Problem is that ABS is not an aid to stopping in shorter distances, it does allow you to steer under heavy braking without skidding. In fact, the distance is increased. My note was to ensure that you do not upset the balance between grab and ABS so that you endager yourself and to make you aware of why insurance comapines hike fees up.

Please drop me line if you want more info, as I know a number of people at AP (look up F1 brakes!) including design engineers.

Nige

 

[JohnM]

Brakes

Ok,

Uprated discs/pads/fluid/lines = increased friction between pad and rotor = stop faster.

ABS - Antilock Breaking System

Prevents wheels from locking under heavy breaking

X = pressure @ Disc/Pad reqired to lock wheels

X is variable

Conditions ie friction beween road surface and tyre

Road surface = dry tarmac
Breaks Standard
Tyre VR rated 185/65/14

Friction = 10 X = 140 psi

ABS interveans when wheel locks at 140psi pressure

In this example, say the vechicle is travelling at 50mph, the car begins to respond to your break input at 75psi pressure, you require to stop in less time you increase the input to the braking system that increases pressre between pad and rotor say 110psi as the speed reduces you require less pressure on the rotor to reduce speed so you release the brake pedal (progressive breaking)

Keep everything the same except uprate brake system componants.

X now = 110psi due to the increase in friction between pad and rotor (less gas build up pad deglazed) Breaking is now felt at 40psi but you require the car to slow down more you increase brake input until pressure = 65psi as you slow you release the pressure in the breaking system, that in turn releases the pressure between pad and rotor

Wheels Still didn't lock ABS still did not intervene

 

[JohnM]

Breaks

In laymans terms

Better brakes means less breaking effort is required to stop the car, the ABS doesn't care about pressure it works by sensing road wheel speed. So By increasing brake pad/rotor performance you reduce the pressure required to stop, this in turn increases the life of calipers, brake fluid, hoses and lines, but you may find that the Pads and rotor wear increases. Pads particulally as the Rotors will probably still last longer than the rest of the car.

ABS will not intervene unless a very complicated fomula is met, this takes into account the input from available sensors and on Road cars these are limited. Usually to Speed sensors at each road wheel and data regarding velocity received from EMU Engine speed, gearbox speed, flywheel velocity, etc etc. Brake system modifications will only affect the ABS if the sensors are in anyway interferred with or if the programming of the ABS control system is altered.

Breaking distances will only be improved because the driver feels more confident with the breaking system.

If you can lock the wheels on the car then the brake system is sufficiant to stop the vehicle. Distance it takes is decided by the friction coefficiant of your tryes and the road surface.

 

[Nigel]

Nice Explenation

I know what you are saying and am not arguing in any way, what I was saying sort of ties in, if you stand on the brakes they will lock quicker on the "uprated setup" than the "standard" set up and therefore increase the distance for the car to stop.

I took the driver to be an "On the limit" one because of the other mods and to even contemplate these sort of changes, which is where I aimed it at.

However, you did say

"Brake system modifications will only affect the ABS if the sensors are in anyway interferred with or if the programming of the ABS control system is altered."

Surely by altering the componenets, the programming of the ABS would need to be altered as it no longer matches part of the equation, and therefore if it isn't reprogrammed the ABS will be affected. Or am I going off at a tangent here?

Cheers

N

 

[Dug]

misleading

John, several of your points are very misleading.

First of all, improving your brake discs and pads will NOT improve the life of the calipers, hoses and fluids: far from it. The improved discs and pads will allow the brakes to work at higher temperatures (less fade), which is the enemy of the fluid, calipers and hoses.

Secondly, brake discs rarely last the life of the car. 30,000 miles is a damn good innings for most brake discs.

Thirdly, I don't get yuor comments about pressure. Surely if the new discs and pads have the same surface area, they'll need pretty much the same pressure to slow down the car? Unless we're talking carbon fibre on carbon fibre, the feel of the brake pedal won't really be altered, and the pressure in the system will have a similar effect.

Fourthly, I was under the impression that 'progressive braking' calls for the driver to gradually INCREASE the pressure on the brake pedal, not the other way round! As you slow down, you can apply more pressure, as the friction between the tyres and the road is still roughly the same, but the car has less kinetic energy. That's the way I've always braked, anyway! If you did it the other way round, you'd never stop...

I'm not sure of the ins and outs of ABS operation (I've never had it), but I'd want to be very sure I wasn't upsetting the system if I was using different pads and discs.

 

[cliff]

abs

improving brakes will not affect abs* as the chap said it works off sensors on each wheel, so if a wheel lock's it decreases the pressure to the wheel and therefore gets it rotating again reducing slip. improving the brake will not affect this action unless the sensors or rotors are modified. *However the only problem is that in severe weather you will only have to touch the breaks (with improved breaking equipment) to lock the wheels so while youre stamping on your £200 brakes the old lady in the panda in the next lane may!!!! have stopped and your'e heading for the vehicle in front of you.. it's 10 years since i worked on fiats as a mechanic the systems have changed but i dont think that the abs sysytem on fiats has intelligent capabilities so improving the brakes should not affect the abs system.. and im picking up my 3 yr old bravo today hence me being nosey here.. see you again ..

 

[JohnM]

Brake Discs

30K, if I only got 30k out of a set of discs i would cry, thats only 18mths motoring, i have had mine on for 56k and they are still sevicable exept the fact that one of them has warped

 

[John M]

Breaking

Progressive braking is the inrease then the decrease, if you kept your foot down the same all the way to the stop your passengers would not be happy as whiplash would result, as speed decreases kinetic energy is reduced proportionatly. You can actually di an emergency stop quite smoothly with practice, when I trained for VIP duties in the army we had to do emergency stops with a glass of water in the passenger foot well, we practiced untill the water stayed in the cup (that was supported so it didn't fall over).

PS Is it still the case that u fail your driving test if you lock up on the emergency stop? What about if you have ABS fitted?

 

[Nick]

Closed loop

Nigel

ABS is a closed loop system, and the beauty of closed loop systems is that they can automatically compensate for parameters within the loop, leaving the overall system performance the same.
As someone else has said, the limiting factor in car breaking systems is the coefficient of friction between the tyre and the road, and this is what controls the stopping distance in the limit. This can be affected by suspension age/set up, tyre pressures, make of tyre and whether or not you are going in a straight line. And the surface of the road.

As an extreme example of this, a brake engineer told me that large vehicles such as lorries can take up to 60% longer to stop than cars due entirely to the tyres. This was a long time ago so hopefully this is no longer true!

My 2 pence worth.

 

[Anonymous]

Re: Brake Discs

"30K, if I only got 30k out of a set of discs i would cry, thats only 18mths motoring, i have had mine on for 56k and they are still sevicable exept the fact that one of them has warped"

Doing that high mileage each year you obviously travel on motorways a lot, you dont need brakes on motorways very much. My dad almost bought a vaxhall senator about 5 years ago that was on the original pads after 60000 miles!!! The guy lived right on the motorway and so barely needed to use brakes.

Try living near me in the middle of the pennines in west yorkshire. A set of discs lasts 2 sets of pads, and a set of pads last under a year!

 

[Rob D]

Hello John, Good to see a fellow West Yorkshire man on the board!

As far as paint work go's I use a company in Wakefield called "C+S" They do all the paint work for Fiat Piccadily (Wakefield near Leeds). They have done a fantastic job on my car. Bypassing the Fiat middle man has saved £500 Which is always a bonus.

If you want to give them a try please post again.

Rob D