dsm_mikey

I have been browsing the forums looking for problems with my NA build. Here is a background on the car and engine...

I purchased a 2005 Nissan 350Z track car that was built by someone else, NA.

-Engine was built by Import Part Pros with 11:1 Wiesco Pistons, Eagle Rods, JWT S2 Cams, Kinetix SSV Intake Manifold, Custom Intake Tube, Borla Exhaust Headers, it has a Tune from UPREV on it.

Custom tune allows the engine to rev to 7500 rpm...I figured this would be fine given that the internals are forged. Problem is car is not making power!!

It is putting down roughly the same power as a mostly stock VQ35DE.

I am not going to get into numbers because dynos differ.

-Did a timing check and all of the timing marks line up. EDIT...Incorrect-when we pulled the motor and front cover we discovered the exhaust cams are each 1 tooth off.
-Did a compression test and all numbers are 160 ish + or - 5 psi on a cold engine.
-Now I am thinking the Kinetix Intake manifold and shitty Borla Headers are costing serious hp... Could these really be costing 20 ish HP?

-I am contemplating a Motordyne MREV2 Manifold and stock upper manifold
-I am contemplating Z1 Motorsports VQ Headers
-I am contemplating a change of cams to the JWT Grand Am Cams

Will these changes net 20% HP gains...roughly 40+ HP?

I am starting to wonder if the car was built with the Wiesco 8.8:1 pistons instead of the 11:1 as requested!!! The car just does not seem happy to rev.

Please help!

-Looking for best possible intake manifold combination
-Looking to see if the Z1 Headers are the way to go...or if there is something better out there.

Thank you all in advance for the help!

Mike

Conway_160

iTrader: (1)

I would have some one look at your tune.

Conway_160

iTrader: (1)

Also do comp test on the block at normal operating temps not cold.

T-dizee

iTrader: (6)

If your talking about JWT grand am cams that I know your talking about.... you have to get the pistons as well as a combo. They are designed for those pistons and to work power wise... cams are so aggressive you will have no bottom end power at that compression. 11:1 wont cut it. You will also need to bump up your redline much high to take advantage of the aggressive cams... Just a heads up....

Toneloc

If all that checks out then you have a poorly tuned vehicle... Don't spend a dime on more mods.. Take it to a reputable tuner. With your mods you should be 285ish HP

DarkZ03

iTrader: (11)

I'm pretty sure the borla headers lose power, I'd swap them out. Either z1 or ppe, is that the ssv or the newer velocity manifold?

terrasmak

iTrader: (8)

For a forged and cammed motor I would bet a set of proper long tube headers will help.

What Kinetix manifold are you running?

dsm_mikey

Thanks for the replies...here are a couple answers/questions to your questions:

1. It is the Kinetic SSV intake manifold that is on my car.
2. The tune appears to be solid...steady afr across the entire Rev range.
3. Redline is set for 7500 rpm. Is this not high enough to take advantage of the higher JWT Grand Am cam powerband?
4. It was my understanding that the Grand Am cams were designed for the stock vq35de motors for the Koni Grand Am series?? Isn't 11:1 compression higher than stock?
5. Are long tube headers available for our cars?
6. Has anyone tried the Z1 headers? They appear to be the best available headers out there.

7. WHAT intake manifold setup should I run? (MREV2 lower, stock upper?, MREV2 lower, spacer, stock upper?, Stock lower, spacer, stock upper?, REV-UP Lower, stock upper, Any other uppers or other I take manifolds out there that work?
***Please keep in mind 7500 rpm redline (Eagle Rods, Wiesco Pistons), headers no cats, vq35de motor (non-rev up), JWT Grand Am or similar cams.

**Question...would a REV-UP lower intake manifold make substantial power gains vs. NON-REVUP above 7000 rpm on this set up?**

Thanks in advance for the help!!

Mike

1cockyZ

iTrader: (46)

afr could be fine but the cam or ignition timing maps could be ****. The borla headers aren't that bad, not the major cause of power loss. The early SSV not velocity Kinetix manifolds sucked, use a nonrevup lower with a spacer or contact Kinetix to trade up. The MREV2 is nothing more than a nonrevup lower, good dyno comparison on Motoiq.com for that. My build was incredibly similar, it now lives with PPE long tubes in its new home. They did not do much over the DC sports I had on it which are incredible similar to the Borlas.

Nathan

mikey
You will never get any serious power increase with the JWT S2 camshafts fitted
The S2's have a inlet cam duration only 5.5 degrees longer (@ .050) & less than half a mm more lift than the stock revup cam.
The revup motor never made as much HP as the original DE motor up to about 6200RPM
It did reach a peak hp of about 13 more at 6400K
At peak TQ the revup was down 14 ft/lb on the non revup.

So despite revup having 9.5 degrees extra cam duration & 1 full mm of extra lift over the non revup it made less power at every rpm below 6200K.
Also to achieve that small HP increase at the last 1000k the revup used shorter intake runners & a new short tube exhaust manifold.

Now to summarise. The S2 cams is very close in spec to the revup cams but you are using a SSV intake that has longer runners than the original DE motor so it is no surprise that the peak HP is no better than stock. The small increase in compression while certainly helpful, is not likely to add much to the current setup.

The original JWT GA cams (spec sheet no longer published on JWT site) was an early to mid 2000's cam that from memory had a long duration but small lift cam that met the Grand Am regs at the time. And those cars wern't running up the pointy end.
If your car is a dedicated track car, the new JWT piston/cam selection mentioned by T-dizee IMO is the way go.
You will need to shorten the runners on the SSV & enlarge the plenum. ( a good sheet metal worker should be able to do that fairly inexpensively) JWT may be able to give you an ideal runner length for the above cam.
If budget is a problem you can use a set of Ebay long tubes with the collectors cut off and replaced with Burns or similar collectors
With a Haltec and a good tune the above modifications will get you above your desired 20% increase in power

DarkZ03

iTrader: (11)

3. 7500 is not going to be a good zone for the S2 cams because they are mild cams.
5. Yes PPE and OBX sell long tube headers.
6. The Z1 headers are basically the same as the Momentum headers, they should be good, however, if I was to get shorty headers my money would go to Nismo due to them having a stepped design which should help with high end power.
I would recommend swapping out the cams for a set of Tomei 272s, as far as the plenum if you are not concerned about low and mid range go with the rev-up lower, 3/8" spacer and stock upper.

dsm_mikey

Thank you all for your input! Based on your recommendation :

1. Going with PPE Long tube headers
2. Ditching Kinetix SSV intake manifold.
3. I will call JWT and see what cam they recommend. This is a track car so looking for good top end without giving up the world in the middle of the power band.
4. Once the headers and cams are installed I will dyno test the REV UP and Non REV UP lower intake manifolds with and without a Motordyne spacer to see what works best with my set up. I will post the results once they are in. Dyno is a 4 wheel Mustang Dyno near Sheboygan, WI. The company doing installs and tuning is MMW (Mueller Motorwerks).

5. Another question...Is the NWP 75mm Throttle body worth doing? What is the inside diameter of the stock intake manifold? Is the opening in the Upper Manifold able to be ported?

6. Is going with the Agency Power Single Exhaust a good choice? Looking to shave some pounds off from this car as well. Does this exhaust make power?


Any other recommendations or ideas? Do you agree with my plan?

Thanks in advance !

Mike

The_Assassin

If you are looking to save weight I would go with agency power single or tomei ti exhaust. I would look into tomei 272 cams. Cams and full bolt ons De 350z usually dyno right around 300. With higher compression you should be over that.

DarkZ03

iTrader: (11)

I too like the specs Tomei over the JWT, I like the fact that they have a low and high lift for the 272s and they are cheaper, so wins all around. There is a Tomei titanium single for sale in the classified sections if you want to check it out. I think they have had mixed reviews with the NWP TB, I know the adapter outlet is 73mm, the stock manifold is probably close to that.

dsm_mikey

Is there a reason why people prefer the Tomei 272's over the JWT Grand Am cams?

-The JWT Grand Am cams specs:

Intake: Duration 297 Lift 11.5mm
Exhaust: Duration 289 Lift 11.0mm

Tomei 272 High Lift Cams (The smaller 272's are only 10.8mm lift on both intake and exhaust):

Intake: Duration 272 Lift 11.3mm
Exhaust: Duration 272 Lift 11.0mm

I pulled the above information from the cam cards for each cam...JWT emailed me the cam card for the Grand Am cam since it is no longer online. I pulled the specifications on the Tomei cams from the cam card on their website.


Isn't it better to have a longer duration cam? The intake cam lift on the Grand Am cam is 0.2mm more than the Tomei's. The exhaust lift is identical for both. Numbers can be misleading... so do the Tomei 272's provide better dyno proven results than the JWT Grand Am cams?

I am very new to this engine so I really want to put together a package that works. Wouldn't the Grand Am cam be better suited to a 5000 rpm-7500 RPM + power band than the Tomei 272's?

Any feedback would be great!!

Thanks!

Mike

1cockyZ

iTrader: (46)

Leave the cams.
Exhaust: PPE stepped headers(unless you can find a set of SG's), custom y pipe 2.5" to a 2:1 merge down to 3" and a transition cone to 3.5", y pipe back a 3.5" single.

Intake: Copy the Injen cold air but in 3.5", use a filter with an internal bellmouth, NWP throttle body(it works reliably with no ECU tuning), 1/2" spacer or APS tallboy, nonrevup lower plenum(I tested the revup on a dyno it sucked).

Find someone that can tune the hell out of it and use E85 if you can get it. Engine will still drop off badly after 6500 rpm because the upper plenum elbow is to small, fix that however you see fit. Kinetix velocity plenum will make more torque and carry the power to 7K better, this is all information I have found out from my own testing.

Those are my suggestions and feedback, hope it helps.

You get all that working and optimized then consider cams for a little more power, unless you have a crazy intake solution any large cam is unfortunately diminishing returns.

iideadeyeii

iTrader: (6)

I haven't seen one mention to AF/R. What are you running?

dsm_mikey

One more question:

1. I am currently running a REV UP oil pump. I was told by a reputable source that these REVUP pumps live on borrowed time past 7200 rpm.

-The NISMO pump is $1200 but is a solid choice to 8500 RPM (I won't be revving that high! Maybe 7800RPM if power is still there.)
-Is the COSWORTH Pump still available and is it good for 7500-7800 rpm on a consistent basis?
-Any other options?

Thanks!

Mike

dsm_mikey

Okay...

-PPE Engineering Long Tube Headers are ordered...
-Stepped Headers
-304 SS
-Merge Collector

-Motordyne 5/16" Spacer Ordered

-REV UP & Non-REV UP manifolds ordered

-Stock Crank Pulley Ordered (Removing lightweight aluminum pulley currently installed. Spoke with an engineer at JWT and he highly suggested this!)

1cockyZ

iTrader: (46)

I would have went fluidampr on the crank pulley.