IVA Brake performance what does it actually mean
Discussion
Hi,
Getting my cars brakes set up at the weekend in preparation for IVA, mainly because I have a bias bar fitted. Finding it hard to understand what the brakes actually need to be set to.
Can the below be simplified for a simple person like me, so that I can tell the garage what figures they should be looking for on the brake tester.
2. The service brake performance must be at least 60%, (of the CLW
or DGW as determined to be the highest) or more than half the
road wheels lock.
3. The secondary brake performance must be at least 25%,(of the
CLW or DGW as determined to be the highest) for:
? each half of the split system or
? the park brake if used as secondary. (see Note 6)
12. Where a vehicle is fitted with a full power hydraulic system, the
calculated service brake efficiency after four full applications must
be at least 25%. (See Note 2).
14. The parking brake performance must be at least 18%, (of the CLW
or DGW as determined to be the highest) unless more than half of
the wheels lock as operated by the park brake.Decelerometer Test (see Note 3)
15. The service brake performance must be a minimum of 60%
16. The parking brake performance must be a minimum of 18%
Thanks
Nick
Getting my cars brakes set up at the weekend in preparation for IVA, mainly because I have a bias bar fitted. Finding it hard to understand what the brakes actually need to be set to.
Can the below be simplified for a simple person like me, so that I can tell the garage what figures they should be looking for on the brake tester.
2. The service brake performance must be at least 60%, (of the CLW
or DGW as determined to be the highest) or more than half the
road wheels lock.
3. The secondary brake performance must be at least 25%,(of the
CLW or DGW as determined to be the highest) for:
? each half of the split system or
? the park brake if used as secondary. (see Note 6)
12. Where a vehicle is fitted with a full power hydraulic system, the
calculated service brake efficiency after four full applications must
be at least 25%. (See Note 2).
14. The parking brake performance must be at least 18%, (of the CLW
or DGW as determined to be the highest) unless more than half of
the wheels lock as operated by the park brake.Decelerometer Test (see Note 3)
15. The service brake performance must be a minimum of 60%
16. The parking brake performance must be a minimum of 18%
Thanks
Nick
Edited by Nick Brough on Thursday 10th November 06:23
Don't worry about the numbers.
1. Does the handbrake work well? If it does you will be fine. If not fix it.
2. Set the brakes so that travelling at 30mph and emergency stop the fronts must lock before the rear.
Job done.
Don't forget the bias bar needs to be pinned or wire locked. Also you need the warning label...the one which says the world will stop rotating if you adjust the bias after the test.
At the test you will be amazed at the amount of test data the examiner has to compile onto the test sheet having started by measuring the wheelbase and the position of the engine. Then weighing the car and all this before it goes anywhere near the brake test rollers.
Steve
1. Does the handbrake work well? If it does you will be fine. If not fix it.
2. Set the brakes so that travelling at 30mph and emergency stop the fronts must lock before the rear.
Job done.
Don't forget the bias bar needs to be pinned or wire locked. Also you need the warning label...the one which says the world will stop rotating if you adjust the bias after the test.
At the test you will be amazed at the amount of test data the examiner has to compile onto the test sheet having started by measuring the wheelbase and the position of the engine. Then weighing the car and all this before it goes anywhere near the brake test rollers.
Steve
Having just done the IVA test on my Westfield I just built, as long as all components match each other and its all bled well, then you hopefully should be fine. One thing that was an issue with mine, was that, although I set the handbrake at 3 clicks, it was never used, so was about 10 clicks that the end, due to cable and cable outer stretch. So put the handbrake on tight in your garage for a while to allow this stretch to come out. The guy uses a lot of lever to test for wheel locking and to get the required figures to allow a pass. Also, I helped the guy with the test and the IVA manual in another thread is definately worth reading. It gave me some information about self centreing and demisting which helped. By being helpful with the guy, sped up my test and he then spent additional time bedding my brakes on the rollers before the test figures were done. Its pretty daunting and the guy was black and white with everything ( even laying out his lunch on the desk was done with precision !!) but gave me confidence in knowing the car I had built met the required build level that was required. Good luck with it !
Steve_D said:
Don't worry about the numbers.
1. Does the handbrake work well? If it does you will be fine. If not fix it.
2. Set the brakes so that travelling at 30mph and emergency stop the fronts must lock before the rear.
Job done.
Don't forget the bias bar needs to be pinned or wire locked. Also you need the warning label...the one which says the world will stop rotating if you adjust the bias after the test.
At the test you will be amazed at the amount of test data the examiner has to compile onto the test sheet having started by measuring the wheelbase and the position of the engine. Then weighing the car and all this before it goes anywhere near the brake test rollers.
Steve
Thanks for the advice.1. Does the handbrake work well? If it does you will be fine. If not fix it.
2. Set the brakes so that travelling at 30mph and emergency stop the fronts must lock before the rear.
Job done.
Don't forget the bias bar needs to be pinned or wire locked. Also you need the warning label...the one which says the world will stop rotating if you adjust the bias after the test.
At the test you will be amazed at the amount of test data the examiner has to compile onto the test sheet having started by measuring the wheelbase and the position of the engine. Then weighing the car and all this before it goes anywhere near the brake test rollers.
Steve
Handbrake is now excellent ex Lamborghini ebay bargain and apparently one of the few up to the job of getting a GT40 replica a pass.
bar already drilled in perpetration, and anti tamper warranty invalidation type sticker in place.
Justin S said:
It gave me some information about self centreing and demisting which helped.
I have a heated windscreen fitted but not sure it is actually working well enough. What self centreing / demisting info do you have.Regards
Nick
Edited by Nick Brough on Saturday 12th November 22:28
Nick Brough said:
I have a heated windscreen fitted but not sure it is actually working well enough. What self centreing / demisting info do you have.
Squirt a mist of water onto the screen then turn on the heat. You should see it start to dry out.The tester will drive your car in a figure of 8 pattern (space permitting). As he comes out of each turn he will expect the car to straighten up before he turns again.
Steve
Steve_D said:
Squirt a mist of water onto the screen then turn on the heat. You should see it start to dry out.
The tester will drive your car in a figure of 8 pattern (space permitting). As he comes out of each turn he will expect the car to straighten up before he turns again.
Steve
Thanks Steve,The tester will drive your car in a figure of 8 pattern (space permitting). As he comes out of each turn he will expect the car to straighten up before he turns again.
Steve
"The tester will drive my car" eek
The tester said to me, that this was his bonus, being able to drive the car round the site. It was a pretty big site and took about a minute to re-appear , which was making me nervous. As said, he tested the self centreing, but the IVA rules stipulate 'it must show signs of', rather than 'it will snap the wheel straight' .
As for the windscreen, I had a heater, but it wasnt working , long story and also a heated screen. Luckily it was a damn chilly morning that I trailered my car to the test. When I was taking the car off the trailer, I showed the tester the screen clearing , while the car was running and driving to the test area, so passed before it even started for demisting.
As for the windscreen, I had a heater, but it wasnt working , long story and also a heated screen. Luckily it was a damn chilly morning that I trailered my car to the test. When I was taking the car off the trailer, I showed the tester the screen clearing , while the car was running and driving to the test area, so passed before it even started for demisting.
The brake test machine at IVA flashed so many different numbers I had no idea until I passed
I have been to several SVA/IVA with friends and club members in the end it's about the fronts locking before the rears.
Self entering can be a problem with some kit cars so for IVA pump up the front tyres and run a bit of toe out of you have issues on the day
I have been to several SVA/IVA with friends and club members in the end it's about the fronts locking before the rears.
Self entering can be a problem with some kit cars so for IVA pump up the front tyres and run a bit of toe out of you have issues on the day
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