Show or Go? Radiator Cooling Panels

22 01 2008

Hmm well you learn plenty in a week of having a blog. Technical pages get heaps of hits, opinion pieces go untouched. Well give the people what they want! Allow me to introduce my new column. Show or Go? Here I’ll be taking a hard look at some of the more dubious performance upgrades you can attach to your car and finding out if they actually make the car go faster, or if they’re just for show.

My first analysis will be an old favourite of mine. Radiator Cooling Panels.

Aka Hood Panels, Aka Bonnet blockers, Aka Mega happy cooling panel 3000!

I first came across these while working in my local tuning shop. A good earner, they sold well and were easy for modifiers to fit. Everybody wants their cars to run cooler and you’ll find these fitted to some seriously high performance machines in the D1 series. So they must work… right?

For those not in the know, a radiator cooling panel is a sheet of metal or carbon fiber that fits across the front of the car above the radiator. The idea is to prevent air from traveling over the top of the radiator, and instead force it through the radiator where it will have an actual cooling effect. A picture is worth a million words methinks.

Example of a Radiator Cooling Panel


The gap left open above the radiator that all the air escapes through 


All nice and plugged up now!

Ho ho ho, silly manufacturers. Don’t they know that leaving a big gap above the radiator means all the air will just flow past it? Whatever will we do with them.

Well of course they bloody well knew there was a gap there. Ladies and gentlemen, if I may direct your attention upwards. Have a long hard look at the bottom of your bonnet. You will notice, this:

OMG! Someone drew some badly photoshopped arrows underneath my bonnet!!1!

No as a matter of fact I’m pointing out the rubber seal that sits on the underside of your bonnet. And lets all look downwards again…


Got it yet? Hang on I’ll draw some lines that will explain a lot.

Ooooooh, anyone feeling like an idiot yet?

Yes in fact the manufacturers have blocked the top of the radiator using that rubber seal along the bonnet. Once air is forced into the front of the car it comes up against that rubber seal. It cant get past there so it finds another way out, by going through the radiator.

The reason cooling panels are popular in D1 is because they use carbon fiber hoods. These stripped out bonnets don’t have the rubber seal, so they need to make do with a cooling panel. But have a look at the pictures above, see all the gaps in the cooling panels to make room for the bonnet latch and so forth? Make no mistake, the near airtight seal of the rubber is a far better alternative that some chopped up tin.

So the Verdict. Unless your car is sporting a carbon fiber bonnet, cooling panels are definitely


How bad is the damage?

If you’ve got a full carbon fiber bonnet then your in the clear. It’d give you a better result if you had a rubber seal, but because that isn’t possible at least your cooling panel is of some use. 

If you have a stock bonnet with an aluminum Cooling panel your officially baby rice. Plenty of people have been in your shoes, don’t be to embarrassed, yes it has absolutely no use, but least you didn’t pay lots for it.

If you bought the $600 full carbon fiber cooling panel… Sorry buddy, you’ve paid through the nose for something that does little more than add weight. Rice king for you!




A review of Nissan’s Performance Engine Range.

18 01 2008

Nissans are hot right now, they’re topping the import lists and consistently placing well in motor sport. So whether you’re riding in one or racing against them, read on for the low down on the power plants driving them to success.

 Naming Structure 

Nissan uses a straightforward naming policy for engines. First a two letter family name, then the engine capacity in decilitres and finally the engine features are listed. So using the classic example the SR20DET engine. SR is the family name, 20 stands for 2 litres, then D for Dual Overhead Camshafts, E for Electronic Fuel Injection and T for Turbocharged. For a complete listing of the various features, check out the easy reference table below.


Engine Feature


Dual Overhead Camshafts or Direct Injection


Electronic Fuel Injection


High Revolution


Fuel Injected at Throttle Body




Electronically Controlled Carburettor




Twin Turbocharged


Variable Valve Timing

Enough background, onto the engines! When it comes to the performance versions there are four families you will be likely to encounter. The Inline four SR Family, the inline six RB family, the V6 VG family and the latest version, the V6 VQ Engines.

 SR Series Engines.

The successor to the CA series of engines, the SR’s improved on them in almost every way. Featuring in many of Nissans small to medium car line up, this engine truly earned its stripes in the turbocharged SR20DET format.


This legendary four cylinder engine first arrived in a bluebird of all places. But once paired up with the rear wheel drive S13 Silvia Chassis, history was made. N/A and turbocharged versions appeared, but it was the turbocharged SR20DET that became the sweetheart of the tuning workshops. Ranging from 150 kW in the original red top (named for the colour of the engine cover) the SR20DET slowly grew in power as it changed to the black top, and then was updated for the S14 and S15 versions of the Silvia. It finally peaked at 187 kW in the S15 Silvia.

The SR engines also appeared in the front wheel drive Pulsars and a special version was created for World Rally Championship homologation in the Pulsar GTI-R. The car was a flop on the rallying scene with over heating problems and a heavy chassis due to the addition of AWD. But the engine remained a favourite of the workshops.

Without serious modifications to the internals, the SR20DET engine are capable of 300+ horsepower with just bolt on components. This makes them an extremely potent, light weight engine and made them very popular for engine swaps. End result was the price of the engine skyrocketing. Expect to pay $3000 + for a good example.

 RB Series Engines.

Most people are well aware of the RB26DETT, the engine behind the legendary Nissan Skyline GTR, but there is also two other versions of note! The RB20DET and the RB25DET.


The baby of the family the RB20DET first appeared in the R31 Skyline as well as the R32. However later Skyline models switched to the larger capacity RB25DET for their performance variants. The RB20DET also found a home in Nissan’s Laurels and Cefiros. With 215 hp on tap this engine was no slouch, but mated to heavy car bodies it had a lot of work to do. If you’re looking for an engine swap you can pick one up for $2000, but be careful as they’re getting to be a bit long in the tooth and for a little more you could have the bigger brother.


The mainstay of Nissan’s performance inline six’s. The RB25DET was the engine powering high performance RWD R33 and R34 skylines. With 250 hp on tap it was well suited to the larger Skyline body shells, and from a modification perspective 550 hp has been recorded without modification to the bottom end. The engine can be sourced from $2500 and is my personal recommendation for an inline 6 engine swap.


The ultimate. This engine was built primarily for use in the GTR. The twin turbocharged inline six was originally going to be a 2.4 litre in order to qualify for the Group A category. However after fitting the GTR’s AWD system, the weight of the car resulted in poor performance from the small capacity engine. The decision was made to increase the size to 2.6 litres, and the rest as they say, is history. With 280 hp on tap and the quick response of the twin turbos this engine the ultimate version of Nissan’s inline six. So why do I recommend the RB25DET? The price. And RB26DETT can easily set you back $6000. The same money put into an RB25DET will get you far more performance. Unless your shooting for the moon with horsepower with an unlimited budget, you will simply get more from an RB25DET.

 VG Series Engines

Not well loved the VG series engines have been around in many versions since 1984. Nowadays the only model that isn’t ready for the retirement home is the VG30DETT


Found in the 300ZX this twin turbocharged V6 never found particular success with the modifiers, despite coming from the factory with 300hp. Noted for its overheating problems when pushed past stock performance, this could be traced to casting faults with the cooling channels for the rear two cylinders. A shame, because once remedied the block was proven to withstand more than 1000hp. Still the fact remained that it needed to be stripped down in order to fix the cooling problem before it could be improved. This made the engine undesirable to modifiers who preferred to simply bolt on components. Engines can be sourced from $3500, but be aware of the cooling problems before tinkering with them.

 VQ Series Engines

The successor to the VG engine the VQ family have won a string of awards, including making Ward’s 10 best engines list since its inception. There are several variants in its capacity as well as turbocharged versions, however locally the VQ35DE remains the only performance version sold.


The VQ35 travelled to Australia under the bonnet of the 350Z. Producing between 287 to 306 hp it’s an extremely attractive option and has won a string of awards. Widely regarded as the current world benchmark for a production V6 engine it will no doubt attract a following. Unfortunately its extremely hard to source one of these blocks currently due to their newness.

 VR Series Engines, the Future. 

Finally there is one last arrival due soon from Nissan. The twin turbocharged V6 VR38DETT, Nissan’s most powerful performance engine yet. This engine is slated for the all new GTR. With 473 hp from the factory one can only imagine what will happen when the aftermarket community get their hands on this beast. However I wouldn’t hold your breath waiting for one to appear second hand. They will attract a premium price tag and will be as rare as hens teeth… five years from now though? Well we’ll just have to wait and see.