Intermediate NA Performance Mods

[Nardo_Z]

Hi all,

 

I've got an 05 DE, to date the power/drivetrain mod's I've got are (mixture of bought with and done myself):

• Full Intake
• Plenum Spacer
• Berk HFC
• Custom 3" cat-back
• Lightweight flywheel
• Fast road clutch

 

I will be going to Horsham over the summer to have dyno run and map done but I want to do as many upgrades as I can pre-that so I can have it mapped in final state. So my question is, where to go next?

 

What does a DE Z benefit from beyond the above? (I'm not in the price/effort range of stroker/high comp pistons range) The thoughts I have flying around in my head are:

• Port and polish
• Cams (expensive) - its a weekend car though so happy to go a touch more aggressive (but need to bare in mind light flywheel)

 

Does anyone have some suggestions about what might be my next step, not looking for huge gains obviously but a little here and there with some added "drive-ability" would be cool. Also looking to keep myself busy during lockdown. 

 

 

For context I also have: EBC discs & yellowstuff pads (all around), wider (275 rear 245 front) Michelin 4s tyres, HSD coilovers, braided lines, short shifter, strut braces - so these all add to the drive-ability question but more from a handling perspective

 

Thoughts and ideas from more experienced members would be greatly appreciated!

 

Cheers,

James

Edited April 16, 2020 by Nardo_Z

[msitpro]

You'll be around 245-250whp currently. Roughly 287-295bhp, just shy of a stock HR. (306bhp)

 

Equal length tubular headers like those on the HR (see DC sports) will take it to around 265-270whp with tune. About the same as a stock 370Z makes and about 15whp up on a stock HR on a dyno. Roughly 305-315bhp. Around £1200 all in job if you're paying for labour on top of parts.

 

264°-272° cams will see it to 290-305whp, roughly 330-350bhp. I guess £2000 for parts, labour and tuning.

 

Porting would then be worthwhile, opening the lower plenum collector and optimising the intake ports in the heads. Stock HR heads flow slightly better than the DE, but can be made better than stock HR after a good port job by somebody that knows what they're doing. That might see 310-320whp. Roughly 365-375 bhp.

 

Although, to realise the most benefit from the cams and head work, you'd need to be prepared to wring it out to 7.2k+ I suspect... Which isn't advised on a stock DE supposedly. (Rods, rod bolts and oil pump failures)

 

I'm one step ahead of you, with the same mods but with headers and a Kinetix plenum instead of the spacer and hit 270 @ hubs.... At 6800rpm, which is really high for a DE without cams. I've had redline set to 7100 currently.

 

If you or I went for cams, I would expect the peak power to then be pushed to 7200rpm-7500rpm mark, plus it'll still make power after that. Something I'd need to change rods, rod bolts and oil pump for.

Edited April 21, 2020 by msitpro

[Nardo_Z]

Hi msitpro!

 

Sorry for the slow response but many thanks for the detailed response and advice, much appreciated! 

 

On 21/04/2020 at 23:28, msitpro said:

Equal length tubular headers like those on the HR (see DC sports) will take it to around 265-270whp with tune. About the same as a stock 370Z makes and about 15whp up on a stock HR on a dyno. Roughly 305-315bhp. Around £1200 all in job if you're paying for labour on top of parts.

On the equal length tube headers do they fit with the standard CAT position or are you into custom CATs and y-pipe shapes/locations? It'll be a DIY job for me, I enjoy the process of constantly swearing at the car and cutting my hands to buggery, although looking at the manifold locations this could be a real tough one.

 

On 21/04/2020 at 23:28, msitpro said:

264°-272° cams will see it to 290-305whp, roughly 330-350bhp. I guess £2000 for parts, labour and tuning.

Question on this, do you know if there's significant overlap running on these durations? 

 

Cheers,

James

 

[Mark@Abbey m/s]

On 21/04/2020 at 23:28, msitpro said:

You'll be around 245-250whp currently. Roughly 287-295bhp, just shy of a stock HR. (306bhp)

 

Equal length tubular headers like those on the HR (see DC sports) will take it to around 265-270whp with tune. About the same as a stock 370Z makes and about 15whp up on a stock HR on a dyno. Roughly 305-315bhp. Around £1200 all in job if you're paying for labour on top of parts.

 

264°-272° cams will see it to 290-305whp, roughly 330-350bhp. I guess £2000 for parts, labour and tuning.

 

Porting would then be worthwhile, opening the lower plenum collector and optimising the intake ports in the heads. Stock HR heads flow slightly better than the DE, but can be made better than stock HR after a good port job by somebody that knows what they're doing. That might see 310-320whp. Roughly 365-375 bhp.

 

Although, to realise the most benefit from the cams and head work, you'd need to be prepared to wring it out to 7.2k+ I suspect... Which isn't advised on a stock DE supposedly. (Rods, rod bolts and oil pump failures)

 

I'm one step ahead of you, with the same mods but with headers and a Kinetix plenum instead of the spacer and hit 270 @ hubs.... At 6800rpm, which is really high for a DE without cams. I've had redline set to 7100 currently.

 

If you or I went for cams, I would expect the peak power to then be pushed to 7200rpm-7500rpm mark, plus it'll still make power after that. Something I'd need to change rods, rod bolts and oil pump for.

The only headers worth fitting are PPE long tube headers with the merge collectors, we tried the HR headers type on the DE they never give much more than 5 to 10 bhp which isn't good for the costs/time.

[Nardo_Z]

17 hours ago, Mark@Abbey m/s said:

The only headers worth fitting are PPE long tube headers with the merge collectors, we tried the HR headers type on the DE they never give much more than 5 to 10 bhp which isn't good for the costs/time.

 

Thanks AM!

 

With the long tubes where do you put the HFCs? Do you put them mid point somewhere with a custom fabricated pipe? 

 

When you tested the long tubes what power & driveability gains did you see?

[Mark@Abbey m/s]

the stuff we have with long tube are all race cars no cats no driven on the road and very aggressive builds I am afraid

 

 

[Ekona]

Silly question and perhaps a tad off topic, but have you done the brakes, tyres and suspension yet? They’ll make you go much quicker than another 20bhp will. 

[msitpro]

On 05/10/2020 at 15:43, Mark@Abbey m/s said:

The only headers worth fitting are PPE long tube headers with the merge collectors, we tried the HR headers type on the DE they never give much more than 5 to 10 bhp which isn't good for the costs/time.

Yeah I think we witnessed this with my car - probably only 5whp more than a DE with stock headers.

[msitpro]

On 05/10/2020 at 12:34, Nardo_Z said:

Hi msitpro!

 

Sorry for the slow response but many thanks for the detailed response and advice, much appreciated! 

 

On the equal length tube headers do they fit with the standard CAT position or are you into custom CATs and y-pipe shapes/locations? It'll be a DIY job for me, I enjoy the process of constantly swearing at the car and cutting my hands to buggery, although looking at the manifold locations this could be a real tough one.

 

Question on this, do you know if there's significant overlap running on these durations? 

 

Cheers,

James

 

As Mark has elaborated on - 'short' rather than long tube headers like my DC sports then fit standard DE cats (or HR if you buy HR compatible headers) - or DE HFC as I have. Beware that a single HFC cat on each branch will likely only just squeak past MOT limits on CO % for a year or two. I'm having a second HFC after the bend, as the OEM cat unit have - 2 mantles.

 

'Long tube' headers are designed for either no cats, or something custom fitment after that. (which isn't difficult for a custom exhaust place to do - order some Magnaflow or HJS if you feel fancy)

 

On the cams - a fair bit yeah - Mark might be best to answer better regards to emissions / MOT testing with cams. Although I suspect what he'll say is any customer he knows with higher duration cams are running without cats and pay off their tester if it's a road car

 

You can work out overlap versus OEM if that's your thing by Googling 'Jim Wolf VQ35 cam card' and look at the PDF that comes up.

[Nardo_Z]

5 hours ago, Mark@Abbey m/s said:

the stuff we have with long tube are all race cars no cats no driven on the road and very aggressive builds I am afraid

 

 

Fair, thanks for the advice though!

[Nardo_Z]

4 hours ago, Ekona said:

Silly question and perhaps a tad off topic, but have you done the brakes, tyres and suspension yet? They’ll make you go much quicker than another 20bhp will. 

Not a silly question mate. I've done these already to be honest. I've got wider stickier Michelin 4s, HSD coilovers, EBC pads & discs with some custom cooling ducting, and a pro alignment job. Lightweight flywheel and fast road clutch too. SO the driveability is good.

 

I'm not really specifically looking for HP gains as such, it's rapid in the bends but feels like it wanes a bit pulling out of mid speed corners and mid speed on straights. 

 

A diet is also on the cards for her.

 

12 minutes ago, msitpro said:

As Mark has elaborated on - 'short' rather than long tube headers like my DC sports then fit standard DE cats (or HR if you buy HR compatible headers) - or DE HFC as I have. Beware that a single HFC cat on each branch will likely only just squeak past MOT limits on CO % for a year or two. I'm having a second HFC after the bend, as the OEM cat unit have - 2 mantles.

 

'Long tube' headers are designed for either no cats, or something custom fitment after that. (which isn't difficult for a custom exhaust place to do - order some Magnaflow or HJS if you feel fancy)

 

On the cams - a fair bit yeah - Mark might be best to answer better regards to emissions / MOT testing with cams. Although I suspect what he'll say is any customer he knows with higher duration cams are running without cats and pay off their tester if it's a road car

 

You can work out overlap versus OEM if that's your thing by Googling 'Jim Wolf VQ35 cam card' and look at the PDF that comes up.

Thanks mistpro

 

I have a single HFC on each branch and I JUST get through MOTs and in the two years I've had it I've needed to replace them already. :-( 

 

Yeah that was my thinking I wonder if a set of long tubes then some custom HFC mid point would do the trick, wouldn't then necessarily be limited to those designed for 350s so could perhaps go for slightly bigger ones. But that has it's own implications. 

 

I know it's a potentially expensive option but if I'm serious about an intermediate NA build I could look to have an ECU that facilitates a "road" and a "track day" map that would allow me to run this kind of set up and still be able to do it on the road. Although I guess that could be super tricky to not run into issues and damaging said engine. I'm into the dark side well beyond my knowledge now......

 

18 minutes ago, msitpro said:

 

You can work out overlap versus OEM if that's your thing by Googling 'Jim Wolf VQ35 cam card' and look at the PDF that comes up.

Genius, thanks chap

 

[Mark@Abbey m/s]

13 minutes ago, Nardo_Z said:

Not a silly question mate. I've done these already to be honest. I've got wider stickier Michelin 4s, HSD coilovers, EBC pads & discs with some custom cooling ducting, and a pro alignment job. Lightweight flywheel and fast road clutch too. SO the driveability is good.

 

I'm not really specifically looking for HP gains as such, it's rapid in the bends but feels like it wanes a bit pulling out of mid speed corners and mid speed on straights. 

 

A diet is also on the cards for her.

 

Thanks mistpro

 

I have a single HFC on each branch and I JUST get through MOTs and in the two years I've had it I've needed to replace them already. :-( 

 

Yeah that was my thinking I wonder if a set of long tubes then some custom HFC mid point would do the trick, wouldn't then necessarily be limited to those designed for 350s so could perhaps go for slightly bigger ones. But that has it's own implications. 

 

I know it's a potentially expensive option but if I'm serious about an intermediate NA build I could look to have an ECU that facilitates a "road" and a "track day" map that would allow me to run this kind of set up and still be able to do it on the road. Although I guess that could be super tricky to not run into issues and damaging said engine. I'm into the dark side well beyond my knowledge now......

 

Genius, thanks chap

 

Road or Track map? what run 2 types of fuel? 

[msitpro]

@Mark@Abbey m/s Think he's referring to fast idle emissions, which isn't usually affected by map, because it's always a light load 14.7:1 fuel target part.

 

@Nardo_Z I'd go for dual HFCs on each branch like I will be... I have a 3rd cat currently after the Y-pipe area which has a 5" mantle/body and 3" in/out, the largest you can get off the shelf. (It's a Jetex Euro 5) This still only just passes emissions for me, due to the ones installed by a custom exhaust fab shop likely being terrible quality -  they wouldn't go less than 0.35% CO even when brand new. And the fact it's much further down the exhaust than it's designed for, so less hot/efficient -

 

 

Note that a single 3" in/out 5" brick/mantle is rated for around 350hp by HJS who make a lot of HFC for motorsport and supercar aftermarket systems. So my 3rd cat is also currently a potential bottleneck if I had an engine capable - https://www.hjs-motorsport.de/products/tuning/universal-catalysts.html 

Looks like they now do a 3.5" / 6" model with 500PS peak and 3" / 5.5" with 450PS peak since I last looked.

 

Note - picked HJS info above because they have diagrams and power estimates readily available - they are very expensive and I can't find any evidence whether they are more effective at removing CO and HC than other decent makes. Personally I've ordered a couple of Magnaflow 3"/5" off eBay to add to my existing upper cats.

 

I'm aiming to get my CO% at or below 0.15% for peace of mind once I have quad cats like OEM. For reference I think a stock Z does around 0.02% CO with it's quad cats. (each side/unit has 2 bricks/mantles)

Edited October 9, 2020 by msitpro

[RobPhoboS]

James, the only important thing here is how much money are you thinking about spending? 

 

And are you doing the work or paying someone else? 

 

That's the most important part. 

And just in case... 

 

Because I'm just in the process of putting my engine back together with cams/pistons/lth/ported heads etc etc 

I did my build in a weird way check my posts or look at 350Butcher's build thread (granted HR but still similar). 

 

And the figures being put out there are hubs if I'm reading that right, a little different from WHP. And with NA I really think that's irrelevant to concentrate on numbers, each dyno and day can be quite different too. 

 

We've got a few recent NA builds here and on the main US forum, there's a plethora of them, just ignore the bhp claims.