OEM GT4(revup) airbox spotted

[GT4 Zed]

Grab a bargain on ebay. Best breathing mod for a DE engined zed. All you need is a good panel filter like cosworth, Apexi or HKS to go with it

 

http://cgi.ebay.co.uk/Nissan-350Z-GT4-A ... 414fa7fbbb

[Roo]

How does it actually differ from a stock 03 airbox for example?

 

Does anyone know if it uses a different size filter and will fit without modification in to an 03 engine bay.?

[narcotix]

Grab a bargain on ebay. Best breathing mod for a DE engined zed. All you need is a good panel filter like cosworth, Apexi or HKS to go with it

 

http://cgi.ebay.co.uk/Nissan-350Z-GT4-A ... 414fa7fbbb

 

I did see this a few days ago actually ... but I wasn't sure if the GT4 airbox was the same as the post 06 airboxes ....

 

I asked the seller and he seems to think it came from a 2005 GT4 Zed ....

[maz77]

How does it actually differ from a stock 03 airbox for example?

 

Does anyone know if it uses a different size filter and will fit without modification in to an 03 engine bay.?

 

 

 

 

the internal design is slightly different (on the engine side of the filtre) the rest is the same. it is better than an 03 box.

 

no sure 05 GT4's had it though. worth checking

[andlid]

only difference is that the + box has a ring that funnels air into the air pipe... there is a thread here about it... lets see what a search can find!

[andlid]

viewtopic.php?f=25&t=33613&hilit=difference+airbox&start=0

>06

<06

[Aust350z]

A bit clearer shot of the velocity stacks..

 

[andlid]

crazy to think that makes 5hp... best phantom gain ever Will need to go to halfords and see if one of the sub reflex ports rings would fit in there

[GT4 Zed]

It will be a direct fit between DE and Revup

 

The GT4 was the first revup car

 

Its amazing how should a little difference in design can achieve so much. But this has all t do with fluid dynamics

 

Mark was able to confirm the gains consistently on the dyno

[captain]

So how much should anybody pay for this and will it fit my '03 JDM??

[Steve Watts]

Neither of these designs are efficient, but then neither need to be, its not a restricting factor. I doubt there would even be a single hp difference.

[captain]

Neither of these designs are efficient, but then neither need to be, its not a restricting factor. I doubt there would even be a single hp difference.

 

What's your credentials for stating this Steve or are you just guessing?

 

Mark at Abbey has said measured gains via before and after tests.

 

Thanks.

[Ian]

How does it actually differ from a stock 03 airbox for example?

 

Does anyone know if it uses a different size filter and will fit without modification in to an 03 engine bay.?

 

 

 

 

the internal design is slightly different (on the engine side of the filtre) the rest is the same. it is better than an 03 box.

 

no sure 05 GT4's had it though. worth checking

 

Of course they do, all GT4s had the Revup engine, this is the intake from the Revup engine

[Steve Watts]

The most efficient design of bellmouth, an elliptical profile with a height equal to the intake diameter and entry diameter slightly over twice the intake diameter, only yeilds 1.5% maximum mass flow over a simple radius design. The '06 design would gain maybe 0.5-1.0% maximum flow over the earlier design, so the maximum power gain could only be 1.4-2.8 bhp if maximum power was being limited by the flow of the entry, which it is clearly not.

 

As it has not reached maximum flow, any gain in power will be from reducing drag at the entry and the amount of energy required to draw air through the entry point. This would be in the region of 0.05 hp.

[Sarnie]

The most efficient design of bellmouth, an elliptical profile with a height equal to the intake diameter and entry diameter slightly over twice the intake diameter, only yeilds 1.5% maximum mass flow over a simple radius design. The '06 design would gain maybe 0.5-1.0% maximum flow over the earlier design, so the maximum power gain could only be 1.4-2.8 bhp if maximum power was being limited by the flow of the entry, which it is clearly not.

 

As it has not reached maximum flow, any gain in power will be from reducing drag at the entry and the amount of energy required to draw air through the entry point. This would be in the region of 0.05 hp.

 

Yeah, what he said

[andlid]

The most efficient design of bellmouth, an elliptical profile with a height equal to the intake diameter and entry diameter slightly over twice the intake diameter, only yeilds 1.5% maximum mass flow over a simple radius design. The '06 design would gain maybe 0.5-1.0% maximum flow over the earlier design, so the maximum power gain could only be 1.4-2.8 bhp if maximum power was being limited by the flow of the entry, which it is clearly not.

 

As it has not reached maximum flow, any gain in power will be from reducing drag at the entry and the amount of energy required to draw air through the entry point. This would be in the region of 0.05 hp.

I think there was actual proof on the 06+ box doing consistent 5hp increase though. Above looks good in theory but practice and theory are two different things really. Would be interesting to see with your theory background on what the optimum box would look like and what type of increases you would see...

 

A

[Steve Watts]

A redesign of the airbox isn't required unless you are going to do considerable work on the intake, throttle body and plenum. A clean, low resistance filter in the standard box will be best. Even a clean standard filter will yeild a couple of bhp over a very dirty one.

[captain]

I think what Steve is saying is that when people (Abbey maybe) have done the comparisons in the past they've measured a pre-'06 airbox and got XXX bhp. This is then removed and a post-'06 airbox is fitted, probably with a sparkling new Cosworth or similar upgraded filter and they get XXX plus 4-5 bhp.

 

The "experiment" is unscientific as it doesn't compare all the variables. 4 measures need to be taken on the same day.

 

1 - Old airbox with old filter.

2 - Old airbox with performance filter.

3 - New airbox with old filter.

4 - New airbox with performance filter.

 

Have I got your drift Steve.

[Chris`I]

To be fair, I think when the numbers have been stated, its been a case of an 06+ airbox with performance filter will give you a few HP over the standard pre-06 box. Most likely mainly from a clean free flowing filter and a little bit from the intake

[andlid]

I read it in the past as the box itself = 5hp no discussion of the tests been done in the way captain describes it. What Steve's talking about is that the 'lungs' of the car (egine) doesn't need a better design of the 'mouth' (air filter/canal) unless you do work to the lungs... (make e'm bigger say or increase the muscles around the lungs = cam change). In my case with my car it's breathing fine through the mouth and ass so the restriction isn't there... I've got a torq drop though somewhere... (looking at the ssv box)... It's so much harder to get ponies out of a N/A build and I'm not going to spend any more monies or time trying to get 1-5hp every time I mod... FI all the way! (the we can do away with the standard airbox all together!)

 

[MattG]

Mine made 7bhp and some torque (can't remember exactly how much) after fitting an 06+ airbox. The exact same cosworth air filter was used for both tests and the dyno runs were done before and after fitting the airbox on the same day. This was at TDI North, not Abbey, and I supplied the airbox so it's another independent test. In the US the gains from this mod are common knowledge.

 

It would have cost Nissan time and money to change the design of the airbox so they must have done it for a reason. I'm assuming it's more to do with the timing of air pulses rather than total air flow, possibly optimised for the different cams and higher top end of the Rev-up engine (but fortunately benefiting early cars too). Perhaps Nissan were scratching around for gains to try and make back some of the torque they lost compared to the earlier engine?

[Steve Watts]

Not a good advert for TDI's testing then, other than for people who want to achieve high numbers (I'm not aiming that at you Matt - it just makes commercial sense for dyno ops to promote modding). The intake runners and plenum control pressure waves in to the cylinders, the airbox bellmouth would not effect this. The 06 design is better, but it could have been done by an undergraduate placement student - the cost of the change would be neglible compared with the other developments to the rev-up.

[Steve Watts]

There is loads of test data on bellmouths and air flow, there is even some quite detailed analysis of different profiles in the public domain that have been conducted under proper test conditions.

[captain]

Went for £93

[andlid]

Went for £93

now thats expensive...