It’s been a few days now since my IVA test, so I thought it was about time to discuss the test process.

I firmly believe that as a kit builder, you should consider presenting your car yourself, or at least attend the test. In my mind the test marks the point when the kit becomes a car.

I also would strongly recommend following the standard Caterham process of PBC before IVA, especially if you are a first-time builder. You have to be fairly confident in your skills to ignore the reassurance of a second pair of eyes checking your work before the test.

I wish I could say I was as confident as I appeared when I formulated my plan to IVA before PBC. Sleepless nights and worries, all unfounded, built up to the big day.

You have a choice of test centre, all will have seen Caterhams over the years, but some will be more familiar with them than others. The familiarity brings positives as negatives. It’s worth checking with the Caterham community (Facebook, The Lotus 7 Club forum or blogs) on experiences at these centres before booking. I had been to Norwich with a friend for his car’s IVA, and had my 360R tested at Gillingham (where the Caterham factory send their cars). I preferred the Norwich experience, so that was my first choice for my 420R.

The day started with a get-up-time of 4am, to make the actual appointment time of 8am. It was 2 hours driving and the spare time was allocated for any unexpected eventualities, for example a road side adjustment of the speed sensor. My wife followed me in the ‘support car’, which was carrying tools and spares.

At this time of the morning it is possible to attempt the first of the tasks needed during the drive to the centre, and that is to use the brakes as much as possible. The IVA brake-efficiency tests leave little in the way of margin for new brakes, so a bedding-in procedure needs to be performed during the drive. You have two options: perform a series of stops multiple times in a row, or do some left foot braking. I was mainly using the series of stops, building intensity as I went. Certainly you could smell the brakes.

The second task of the drive was speedo calibration and testing. Because my car hadn’t been through PBC, I was reliant on the factory setting my speedometer calibration correctly. The good news here was the calibration was spot on compared to the support car, and the speedo worked up to the required 70mph that it will be tested at.

Cars have to be inspected full of fuel, so just before the test centre I stopped to fill up, and to set the recommended IVA tyre pressures: 20 psi rear and 40 psi front. I strongly recommend you take this advice, even though it’s way off the typical Caterham tyre pressure settings. I am assuming they help with the dynamic brake test, where the front wheels need to lock before the rears.

With the car behaving well, I was able to afford the time for a quick breakfast and arrive in plenty of time. The side screens were removed and stowed in the support car, and the rubber covers for the bonnet latches were fitted. My car was now ready as it will ever be for the IVA test.

The test starts with the emissions test, I was given plenty of time to warm the Catalytic Converter, a few minutes at 3,000 rpm saw a pass. First hurdle taken, and onto the next.

The bonnet came off and it was time for a good poke around, followed by a trip up on the ramps and more poking around, checking the build and all the bits a normal road-worthy-test would involve.

Lights and headlights alignment next: I had done my homework, and the headlight alignment was spot on for one of the headlights, but other was a little high, so some adjustment was needed. You are allowed to make small adjustments and minor corrections, after all this is an amateur built car.

On to the external extremities tests: I only missed two nut covers on my isolator switch cover, and again I was given the opportunity to reactivity it there and then.

Brake testing next – at this point not even the inspector knows, if your car passes or not. The figures are recorded and entered into a spreadsheet, after the car has been weighed, which will determine a pass or a fail. So at this point I started to question, if I had done enough on the way to the test centre.

Speedometer testing followed, and I felt confident after checking the speed on the drive to the test centre. When my speedo reads 70mph, my road speed is 66mph. Chatting to the inspectors a speed of 57mph is still a pass.

Then the car goes off for the dynamic braking test, the inspector is looking for the fronts to lock before the rears. Obviously the recommended IVA tyre pressures help here. They also check they can adjust the mirrors to see specific objects behind them from the drivers seat. The then onto the weight bridge for the all important figures which need to be feed into the brake test results.

The final test was and the one I was most concerned about, noise. 3/4 max rpm your car need to be below 99db. The problem with noise is there are a lot of factors that can effect the result like humidity, reflections from the environment, etc. My car peeked at 97db, and you can’t believe the relief I felt at that point.

But what does the brake spreadsheet say, a few more agonising moments wait, before the inspector returned with a spreadsheet printout full of green “passes”.

The only thing now to wait for is the hand written IVA pass certificate.

And that’s the IVA test done. I am one step closer to being on the road, and I have had the luxury of driving my Caterham.