Which mods and what power gain?

[350z_Dan88]

Can anyone shed any light for me...have recently bought a 350z totally standard, what are the best mods for me to do? i was thinking exhaust cat back...but also thinking of just taking the cat off as mot isnt a problem for me, have ordered air filter. Not sure though if i have a de cat if it will spoil the sound of the car and just make it stupidly loud...which i dont want, but i do want the extra bit of power.

[Ekona]

ECU will adapt to any mod you make power-wise, so pointless unless you want the noise or benefits of less weight.

[350z_Dan88]

so im guessing will get a 10-15bhp gain off cat back exhaust and air filter?

[Jp606]

Will need an UpRev remap to get gains from any mods, do all breathing mods first then get it mapped. So filters, HFCs/decats, y pipe and mid pipe and backbox. Looking at anything from 10-30bhp gain with all of this.

 

You won't get any gains without a remap, as above the ECU will adapt to anything you add.

Edited February 23, 2014 by Jp606

[RafsZed]

I'm going for an uprev, high flow cats and two cosworth air filters, I'm told that should do the trick for now, maybe in the future a Miltek exhaust system which would be lovely with the hfc's.

[350z_Dan88]

im reading a lot of posts on here saying stick with panel air filter rather than a hks mushroom etc...surely an external filter would be more benefit to the engine hmm

[Lexx]

so im guessing will get a 10-15bhp gain off cat back exhaust and air filter?

 

Not unless you remap afterwards.

 

350 has an intelligent ECU and it adapts to dial back power to it's OEM setting.

And UpRev remap is the way to get around this. But if you are spending money on that then you may as well go the whole hog prior to it - Panel filters in OEM housing, exhaust, HFC's, and a plenum spacer.

[Lexx]

As for external filters - heat soak will kill any gains you would possibly get. The OEM system with a performance panel filter is proven to be the best

[Jp606]

Panel filters give the best gain, some Zs benefit from a modified/upgraded air box depending on which model you have.

[KyleR]

Even without heat soak they make little to no power compared to a standard box.

[350z_Dan88]

ok so best to stick with standard airbox then...which is the best panel filter to go for?

[Lexx]

This has all been covered many times and can be found using the search button.

 

But in answer to your question - Cosworth filters are generally thought to be one of the best.

[Stutopia]

I've got a cosworth panel filter, more worried about filtration than gains TBH, it's dry so it doesn't risk any oil sneaking out. So far it seems to work fine but I can't say if it makes any bhp.

[Tricky-Ricky]

Where does the heat soak bit come from? heat soak only takes place when the car is stationary or slow moving and the airflow is slow, once the car is at normal speeds (providing that you don't have a cone filter that doesn't have a decent cold air feed directly to it from the outside air)

The airflow will prevent any detrimental effect from heat.

The std air box with a decent filter will be far better, as it has a reasonable cold air feed, which can be improved with a little ingenuity.

[350zPhil]

I have plenum spacer, de cat, cat back system done by longlife, cosworth filter and remap and have 310 hp on a DE engine to give you a rough gains estimate, the bloke at h-dev said i have the same setup as him and have about 4 more bhp with decat instead of berks hfc's

[Rock_Steady]

Doesn't heat soak only happen when you're in slow moving traffic or at a stand still? Surely if you're on the move there is flow and you're not getting heat soak? I thought that was the logic.

Edited March 6, 2014 by Rock_Steady

[Stutopia]

IIRC from GCSE physics, heat can transfer by conduction, convection and radiation. So when the car is moving I'd expect heat soak to be reduced for conduction and convection, but not eliminated. Also as radiation heat travels through a vacuum (sun's heat to earth) the heat 'reflectivity', as well as the specific heat capacity, of the materials must also be a factor in heat soak, whilst in motion.

 

It's been a while since I did GCSE physics, so that could be wildly apocryphal

 

Edit: typos, sorry for sub GCSE English skills

Edited March 6, 2014 by SuperStu

[KyleR]

IIRC from GCSE heat can transfer by conduction, convection and radiation. So when the car is moving I'd expect heat soak to be reduced, but not eliminated. Also the radiation as left travels through a vacuum (sun's heat to earth) so the 'reflectivity' as well as the specific heat capacity of the materials must also be a factor in heat soak whilst in motion.

 

It's been a while since I did GCSE physics, so that could be wildly apocryphal

 

Exactly, thats the reason I polished up my Pop Chargers heat shield, not because it looks pretty

[Rock_Steady]

Aha! well explained. I too will polish anything I can to death!

[Stutopia]

The real questions are:

 

Do aftermarket bits weigh more and negatively impact power to weight ratio?

Even if they weigh less, do they impact weight distribution and balance negatively?

Do they impact airflow, air pressure or turbulence and increase drag at all?

Or negatively impact any intended air flow efficiencies nissan intentionally designed in?

 

I fear we may never know

 

I just buy shiny things and loud things