BJH_360S Posted March 17 Share Posted March 17 I am preparing for my IVA. One of the build blogs strongly suggests changing the brake bias by raising the front tyre pressure to 40psi and reducing the rears to 20psi. Is this standard practice? I will be driving 60 miles to the IVA so that should give me opportunity to bed in the brake pads. I would have thought that this tyre pressure jiggery-pokery was unnecessary but what is your experience? Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted March 17 Area Representative Share Posted March 17 Could be an interesting drive with that pressure imbalance. Not standard practice as far as I am concerned. 18psi all round is the norm. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 17 Member Share Posted March 17 How do they test the brakes at an IVA? One end at a time? Jonathan Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted March 17 Area Representative Share Posted March 17 9 minutes ago, Jonathan Kay said: How do they test the brakes at an IVA? One end at a time? Jonathan At Gillingham it was one end then the other. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 17 Member Share Posted March 17 Just now, Geoff Brown said: At Gillingham it was one end then the other. Thanks Jonathan Link to comment Share on other sites More sharing options...
7 wonders of the world Posted March 17 Share Posted March 17 That's the norm using brake rollers and a pressure transducer on the pedal. Link to comment Share on other sites More sharing options...
BigCol Posted March 17 Share Posted March 17 At the Yeading test centre for mine, they said they couldn’t use the rollers as the sump would ground getting the car on, so they “road” tested it - and identified that the rears locked-up first. Link to comment Share on other sites More sharing options...
SteWi Posted March 17 Share Posted March 17 Road test for mine at Leighton Buzzard. Link to comment Share on other sites More sharing options...
BJH_360S Posted March 18 Author Share Posted March 18 20 hours ago, BigCol said: so they “road” tested it - and identified that the rears locked-up first. My understanding is that the pressure imbalance is aimed at ensuring that the front locks up first. Was your road test a problem at the IVA? Link to comment Share on other sites More sharing options...
SM25T Posted March 18 Share Posted March 18 I wouldn't like to drive it on the road with 40/20 pressures !! Link to comment Share on other sites More sharing options...
Graham Hutton Posted March 18 Share Posted March 18 I think the LSD means they can't test the brakes properly on the rollers so at my IVA they did a test by blatting it around the yard and getting the fronts to lock. They used a decelerometer device in the car. I turned up with 18psi all around and it worked fine. The handbrake was a bit marginal though and after 3 years it only just scraped through it's first MOT too. Worth bedding in the rears with a few handbrake runs on the way to the test I reckon Link to comment Share on other sites More sharing options...
BJH_360S Posted March 18 Author Share Posted March 18 2 hours ago, SM25T said: I wouldn't like to drive it on the road with 40/20 pressures !! Yes, that was my thinking. I think I will stick with 18psi all round. If it is unsafe for some reason then that is good to know. Link to comment Share on other sites More sharing options...
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