John Brett

John is a professional engineer with 50 years experience.

John has designed and built many cars, trucks, and vehicle assembly facilities.

John has worked on design of roads, bridges, cranes, transmission towers, and buildings, and operation, maintenance and upgrade of hydro and gas turbine power stations.

John was a LVV Certifier for 13 years. John has long been a whistle-blower, expressing the view that the LVV system is dangerously deficient. John's authority was revoked in December 2012.

John rides a 1992 Yamaha FJ1200ABS, and is also a keen road and off road cyclist.


“The LVVTA has brought it to my attention that statements I have made in relation to it and its employees may have been perceived as defamatory.

I sincerely regret that and apologise for any harm caused. I have taken down the statements identified by the LVVTA of concern to it.

I have strong views about the low volume vehicle certification process and intend in the future to direct my energies into the public inquiry now being held in relation to it.”

John Brett 7th October 2015


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Classic Nissan

The rear wheel drive Nissans are absolute classics in their own right, and a gold-mine for anyone wanting to build a fast, reliable, good-handling car, either for road, track or drifting.

Nissan RB25DET

Nissan RB25DET

Nissan SR20DET

Nissan SR20DET

There are the six cylinder cars- Skyline, Laurel and Cefiro, and the four cylinder cars – Sylvia, 200SX, 180 SX, all available with and without turbo.
The sixes (the RB’s) come on 2 litre 2.5 litre, 2.6 litre (the Godzilla) and 3 litre (Aussie Nissans and Holdens) It is possible to build a RB30DET by taking an aussie 3 litre block and fitting an RB25DET head. It is common to fir bigger turbos, and some phenomenal power outputs can be achieved.
The fours (SR’s) are no slouches either- conversions of a DE to a DET by fitting a turbo are common, as is fitting bigger turbos.

The suspensions on all of these cars is basically sound from the get-go, and respond well to fitment of adjustable platform struts (coil-overs), adjustable camber arms, caster bars, etc.

The braking systems can generally be interchanged- the bigger brakes come with 5 stud hubs.

Front Intercoolers are commonly fitted, and often holes cut in the inner guards for Intercooler ducts.
There is a problem with later, “frontal impact” cars- no LVV Certifier can test the crash performance of a car, so cannot approve anything that affects frontal impact. We heard of a man who bought an intercooler kit from Japan, and followed the instructions to modify the front siderails to make it fit. He ended up having to have the whole front of his car re-built with new side-rails. If your car is fitted with airbags, or is later than about 1997, check FIRST with your LVV Certifier

John Brett Technology Ltd. Ph 0800 LOWVOLUME (0800 569865)

177 comments to Classic Nissan

  • jordan

    hi cheers for the quick reply john. ok i will upgrade the fronts only will put bigger brakes from a newer skyline i also need somewhere for my intercooler piping to go my batery bracket has been removed due to batery going in boot but is it ok to cut a round hole in where it was ? i see someone else has asked this to but didnt quite get the answer something to do with a crash test or something i have seen holes cut before but is it just better to try and find another way for the piping to run?
    cheers for the info

  • johnbrett

    Hi Jordan- Hole for I/C pipe is OK. Issue is with ‘Frontal Impact’ cars (from about 1995 on). On those cars you can STILL make a hole in the inner guard, but NOT change any of the front structure such as trimming the chassis rails or bumber beam. You are OK with what you are going to do. Cheers John

  • Val

    Hey John.
    I am going to buy a 3L 5 speed vl gts and it has a rb25det in it.I was just wondering whether I needed a cert for it?


  • johnbrett

    Yes you would need a Cert.

  • Craig

    Hi John, great site you are running here!
    I have a R32 GTR, which came from Japan with a few modifications. One is that it is fitted with the front brakes off a R34 GTR (324mm disc, Brembo 4 pot vs standard 296mm disc, Sumitomo 4 pot) with the matching master cylinder. The brakes fit unmodified. The same Brembo brake setup also came on the R32 GTR V-Spec (obviously mine is a non V-Spec). Does this require a cert? From what i was told it came through compliance like this, only requiring a cert for the adjustable suspension.
    Thanks, Craig

  • johnbrett

    Hi Craig- what wonderful cars these are! This sort of swap can be carried out easily, without any problems. The Entry Certification inspector probably did not notice the brake change. Any brake change DOES need a LVV Cert- because the potential for people to do something stupid and dangerous is high. We couold arrange for the Cert if you wanted. Regards


  • Craig

    Thanks John! I may as well add a few more mods to the list then and get it all certed together, shall be in touch when shes done! Thanks for your help.

  • jordan

    hey again john i had a read up on the aftermarket seats bit thats up here but i just want to check….so if i put my aftermarket seats on my factory rails then its fine?? as they fit on fine and i havent had to move any seat buckles or anything and how many drive shaft hoops are required? is it 1 or 2 ? cheers


  • johnbrett

    Hi Jordan- for a two piece driveshaft, two driveshaft hoops. New seats on factory rails are fine. Seatbelt buckle is not affected, so no problem there.

  • Tex

    Hi John, i have got a 1990 skyline R32 Coupe factory N/A RB20 De, i have done some extensive work to it so far and i would like to convert it to a RB20 Det,i have been tidying it up etc, it has had 15 previous owners and i have taken my time restoring it as i would like to keep it, so far the car has got Certs for kings lowering springs, Hicas removed, gearbox X mounts from the previous owner. I have converted it to 5 stud and the big 4 pot caliper brakes & brake lines and put LSD diff in it done by proffesionals do i need Certs for my Diff?, my DET motor is getting rebuild at the moment as i would like to have a peace of mind once i put it in, what’s bothering me at the moment is that the previous owner cut a hole(square) approx 20x20cm by where the factory airbox used to be just below the inner left guard as he ran a pod filter,far off from the side rail/wall and hasn’t modified the front iron bumper bar at all, would this be scrutinised when i take my car in for Certs?? as i would like to run my intercooler pipings through gearbox and engine should be ready next week to be put in and i have been eliminating faults just from your replies to the questions on here(many thanks to you!)..but yep i dont wana muck around and take it in for Certs straight away as this is my daily driver,as i cant afford to get it PINK stickered and any other advice would be appreciated,many thanks in advance.

  • johnbrett

    Hi – sounds like a very worthwhile project, and a good car at the end. All the mods sound good, except the holes for the intercooler piping. Yours is not what they call a “Frontal Impact Compliant” car so its not such a big deal, but we need to keep to a ‘General Safety’ standard. Can you email me photos of the hole, to I can come out and do a site visit if you like. Regards John

  • Tex

    Sure and thanks for the prompt reply, i will email you pictures when i finish my shift tonight, Cheers.

  • johnbrett

    Those holes will not be a problem. Just tidy them up a bit, smooth the edges and put some paint on them. Regards


  • JT

    Hi, I have a 1984 300zx and i want coilover suspension problem is it has seperate spring/shock semi trailing arm rear suspension, is it certfiable to replace seperate spring/shock set up to a single coilover unit in the original shock mount? as for the front is it legit to cut strut tubes and weld on coilovers?

  • johnbrett

    Hi Jarrod- At the rear, the shock mount is not strong enough for the spring loads. You can get adjustable spring setups for similar setups, they have an adjusable base, and spring to fit on top.
    On the front, you can get ‘slip over’ adjustable units- no need to weld anything. Welding causes too many problems. Also remember if you are fitting stiffer springs, you need stiffer dampers (shock absorbers)
    Hope this helps


  • Tex

    Hi again John, I got in contact with you couple of months ago about my R32 Skyline coupe, I have now upgraded and installed a Rb25 det motor in it note that is was only running a Rb20de, well just and update as I saw a lot of dodgy work done by the previous owner, I have installed brand new hanger bearings for the driveshaft and now waiting for the loops to turn up and installed b4 I book you in for the Certs. Below is a list of work I have done and has been certed, if you could point out what else I need to be sorted before we set a date for cert, please bare in mind that this is my daily driver and im currently off the road as I am on work leave :).

    Certed – Superlows, gearbox crossmembers, Hicas removed(will you be running over these again?)
    Mods : LSD tight differentials(shimmed)
    – 5 stud conversion
    – Bigger GTST brakes(just installed brake booster this morning)
    – 17 inch ROTA mags – 9.5 inch wide(not rubbing the guards)
    – Side mount intercooler(unseen from the front as I would like to keep it a sleeper) ps iv tidied those holes.
    – running factory turbo (custom plumbed back in turbo dump pipe)
    – Exhaust is 3 inch from the turbo(CAT converter installed) to the rear factory GTR exhaust

    Now I haven’t run the exhaust yet, im assuming that the CAT converter is all I need for certs, if you can point out anything else I needed to be done I would really appreciate it, Cheers.

  • johnbrett

    Hi Tex- it all sounds good- I can’t think of anything you have missed. I could come out to have a look if you like.

  • Car enthusiast

    Hi i have a few cars(5) few need to have certs but i do not like being raped by the prices for an example

    i have 3 cars that need a cert do i get a cert or do i wait till everything is done then get a cert as every thing that will need to be re-certed will cost me or will it?

    I have a 1982 ford falcon was 4.1L now it has a 351c v8 all factory XD v8 mounts and xmembers i have done a lot of mods to it 15″ wide wheels, disc rear end just to name some

    I also have a nissan bluebird hnu12 1990 sss attesa 4wd manual sr20de i have added a turbo kit from a s15 silvia, the setup looks stock(passes wofs LOL) and r33 gts front discs(gts have larger 4 stud disc’s) i have 4 pot r33 gts25t calipers with bolt on spacers and then

    I have a 1990 nissan skyline r32 4door it was a 1.8L 4 cylinder gxi now i have my old rebuilt 4.1L xflow motor with ford falcon XY hydraulic bell houseing and xd 3 speed manual box(all this to keep the hydraulic clutch setup) xf 1 piece driveshaft, it has a t04e turbo, megasquirt ecu, all sitting in its place,

    I am now seriously thinking of converting the skyline into a ute by welding rear doors up putting a datsun 720 rear roof/window in and welding support bars in for the rear doors, the only problem is
    to get a cert for big jobs like turning it into a ute do i have to see the cert guy for progress updates or do i have to sketch/write what im planing to do on paper prior to doing it? can i do the work then go for a cert?


  • johnbrett

    Where are you?? could you contact us directly please.

  • mark

    hi took my car in for wof, its fail on my (heim joint) steering bump steer ends. its lowered so am I able to put some reputable angled tie rod ends on and will they need a cert considering they are identical to OEM tie rods but with the angle in them. thanks

  • johnbrett

    The vehicle, the suspension, and the tie rod ends will all need to be certified. Normal tie rod ends will cope with any lowering of a Nissan that can be certified, so no point in spending the money on angled joints.

  • CALE

    Hi there I was jus woundering , i have a 89 r32 rb20de that the engine has now blown and have another 89 r32 but rb20det that had a previous lvv cert but rego has lapsed , if I was to do a engine swap would I have to get it cert’d again?

  • johnbrett

    If the rego has lapsed, the LVV Cert does not have to be re-done. If you put the DET motor into another car that had a DE, you need a new cert for the car. Hope this helps. John

  • kev

    hi i have an old datsun and i am doing a and engine conversion and was wondering if iam allowed to replace my hard fuel line with some braided lines? thanks

  • johnbrett

    Yes you can, provided it is fuel grade. You will need more clips to secure it. Why would you want to use a flexible line?

  • Linds

    Hi, I’ve recently bought a 1989 hr32 skyline. It had a rb20e and auto trans standard. No air bags or abs. Someone has converted it to a rb20det manual.
    I think I’ve got it all sussed to pass a cert except i just noticed they’ve cut the whole front bumper beam out to fit the front mount intercooler. Just want to know if that’s ok or if i should get it replaced by a pannel beater and just cut enough to fit?
    Cheers Lindsay

  • johnbrett

    Hi Lins- OK so your skyline is not officially a ‘frontal impact compliant’ car, so we are just looking at general safety requirements. If it was frontal impact NO cutting would be allowed. As it is, it will depend on the LVV Certifier’s opinion as to whether the vehicle’s safety is compromised. I think the beam you mean is a steel channel, bolted onto the bumper mounts. Other skylines can fit an inter-cooler without having to remove or cut it- I would recommend replacing the beam, and re-positioning the intercooler. Regards- John

  • Linds

    Hi, thanks, thats what I’ll do, great. Also one more question, it has a (I think) 3 inch exhaust, I’m getting a catalatic converter but will It be looked at, it’s pretty loud? I’ll have it checked for a wof before the cert…

  • Car enthusiast

    Hi John

    Sorry i have not rung you but i have been very busy
    Do i call you on 0800 569865 ? During the week?

    I am in Palmerston North

    Cheers Phil

  • johnbrett

    Hi Car enthusiast

    You can call us on 0800 569865 almost any time, look forward to talking to you- Cheers, John

  • Thomas

    Hey John,

    I’ve recently put a Evo 6 engine/gearbox/transfer case into a 4WD mirage hatchback (CL2A), they come 4WD from factory and are very rare. The front of the car is basically an Evo 4+ and the rear is Evo 123 so all Evo parts bolt straight in which is handy

    I have also changed the front and rear lower control arms to Evo items and also the front and rear hubs to 5 x 114.3 Evo items. The brake calipers and discs are also Evo items. I presume all of the above needs to be certified?

    Also I want to confirm, I will need 2 x drive shaft hoops and also a cat converted installed for certification? What would the cost be to certify all the above?

    Many thanks!

  • Thomas

    Hi again John,

    I do have an external wastegate too which I understand needs to be certified too


  • johnbrett

    Hi Thomas- This is a big revenue earner for the NZ Police. I have learnt that YES- it is considered an ENGINE MODIFICATION REQUIRING CERTIFICATION! Make sure that the waste gate is plumbed back into the exhaust, or has a compliant exhaust and silencer.

  • johnbrett

    Hi Thomas- I have done these before- they make an awesome little car, shorter, lighter, and more agile than an Evo saloon.
    Yes, you need driveshaft safety loops
    Yes, you need a cat IF the original car AND the new engine had a cat.
    ALL the mods need to go on the Cert- I expect your brakes will be no problem.
    We would charge $570.00 for that Cert, all inclusive



  • Simi

    Hi john

    Just wondering, I just brought a 95 Nissan navara which has been fitted with a td27t engine from a terrano, which bolted straight in!! Does this need to be certed?? And if so how much am I looking at??


  • johnbrett

    What was the original engine? If an engine is changed to a different type, or modified it would need a Cert.
    You need to phone us for a quote
    Regards John

  • Lenon

    Hi, I have a non turbo r32 skyline and was planning to put in a 20det motor with the factory side mount and everything. What would be needed for a Cert?

  • johnbrett

    Hi- I’m busy preparing for the Court Case right now. I’ll reply properly in early December

  • johnbrett

    Hi Lenon. Sorry to be so slow in replying. Your car will be a straight forward certification. Items to do are: Driveshaft loops (2), Crankcase ventilation- standard PCV Valve not an external vent. Vehicle will otherwise need to be in WOF condition. Hope this helps John

  • Lenon

    Many Thanks for the reply john.

  • karl

    Hi John,
    I have a 1988 holden vl vacationer 2l which now has a rb25 det in it all factory stuff except the intercooler. Will this need to be certed? An roughly how much would it be?

  • johnbrett

    Hi karl- This is certainly going to have to certified. The brakes are likely to be an issue- it will have to do 5 hard stops from 100kph. Holdens usually fail unless they have the V8 brakes fitted. Our phone No is 0800 569865

  • Matthew

    Hi John,

    Im planning on buying a 1999 C35 Nissan Laurel that will be manual converted and repowered with an RB20DET engine. I plan to add a frontmount Intercooler which would require cutting the inner guard to fit. Because it is a frontal impact car, this would not be allowed for certification. How would i go about adding the front mount intercooler? Would i need to make a custom piping setup to fit without cutting an metal?


  • johnbrett

    I have Certified many frontal impact Nissans, (Skylines and Silvias), with the hole in the inner guard. Now these sort of decisions are made by the LVVTA in Wellington. It might pay to phone them first. Cheers, John

  • Jared

    Hi John

    Done a complete rebuild and transplanted a 1jzgte into toyota supra 1994. How much for a lvv certification on fuel system running under the car surge tank is up under the diff and the 044 pump is also mounted under the car, The motor itself 1jzgte single turbo is completely rebuilt by a reputable engine builder putting out a lot more power than the factory engine 2jzge ( to be confirmed at dyno ), Transmission is the original but has been made to be manually shifted auto, Brakes have been upgrade to the supra 4 pot front 2 pot rears off the 2jzgte model, wheel adaptors are on the front only to clear the bigger brakes, rear seat bottom part has been removed as installed a pair of subs and amps instead just want to make as a 2 seater car, battery relocated to the boot, and anything else you would think that needs to be done please advise as want the car to be completely legal and not have any issues with police. Many thanks Jared.

  • johnbrett

    Hi Jared- it sounds like an amazing project. Would you please phone us on 0800 LOWVOLUME (0800569865), or email at thanks

  • Jacob

    Hi there
    i am currently working on my r32 skyline it now has a rb20det with external wastegate (plumbed in) frount mount. full 2.5inch straight through with a coby half way. also have the loops to put in. currently still has 4 stud hubs and non turbo brakes and im wondering if they’ll pass a cert like that or if ill have to convert to 5 stud bigger brakes. any info about things ill have to do will be greatly appreciated

  • johnbrett

    Should pass the LVV Brake test with existing brakes (Skylines are good cars). If you WANT to upgrade the brakes later, you would need another cert though. Hope this helps Cheers John

  • Sam Game

    Hey I have an r32 and it had a ca18 in it and now it has a rb20det in it and has a manual conversion, 5 stud conversion, adjustable suspension and front mount intercooler, does it need anything else to pass the cert? And where do I get the cert done?

  • johnbrett

    Hi Sam- We have done many Certifications for similar mods. You will need- 1 Driveshaft loops (2), a recent WOF Failsheet, a full wheel-alignment report. If you are in Auckland, phone us to arrange when and where for the Cert. Thanks John

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