05 Z's with Crawford plenum?
 

I heard that some 05 Zs were actually loosing power with the crawford plenum because of the lower plenum on the 05s? Is this true for all 05s? Or just the new 300hp Track/35th Anniv. Engines? I have a 05 Touring, so it should just be like the 04 engines right? Does anyone with a 05 Z, thats not track or 35th anniv, have the Crawford plenum, and what are the results?

And after i put the plenum on, should i drive around for 300miles before dyno'ing? Or does it even matter?

Its the other way around . . . the 05 track engine lower plenum does not work well on an 03-05 non exhaust VCT engines.

The new 300hp Track/35th Anniv. engines do quite well with the Crawford plenum. Just goes to prove how the lower plenums are designed for their respective application.

Hrm ok, so once i install the plenum on my car, how many miles should i put on the car before dynoing?

You can dyno right away.

Ok sounds good, thanks for the help man.

pardon me?

the 05 track engine lower plenumd DOES WORK well on 03-05 non Variable EXHAUST Cam Timing engines. We all have Variable Intake Timing...

The 05 Lower Track Plenum doesnt begin to shine until a reflash is done. But even with out, if you are in the Higher RPM's the majority of the time (Tracking) the 05 lower track plenum is best reflash or not...

Jason,

I have no personal experience, but I've seen more than one post about the '05 plenum on an earlier car with the variable timing exhaust, and they all lost low end torque. You are the only one that is claiming success. Here's a well done post from another site:


I have now flow tested my original 2003 lower plenum. One note is I did polish the inside to remove major casting roughness, but did no porting. So the total airflow is probably up 10 to 15 CFM. I wanted to test the AAM spacer so could not justify the expensive of doing three more runs.
2003 polished lower plenum
The front flowed 232 CFM @ 28" H2O
The back flowed 255 CFM @ 28" H2O

Bottom line is you can take a 2003 lower plenum and polish it and the upper and get just about the same airflow as a stock 2005 lower plenum.

Now for the spacer results.
2003 polished lower plenum with AAM angled spacer
The front flowed 250 CFM @ 28" H2O
The back flowed 255 CFM @ 28" H2O

AS you can see it does a great job of balancing the front to rear airflow. The interesting thing is it did nothing for the back airflow even though it raises the back a little also. Makes me wonder if having it angled is important or not.

"If you get the AAM I recommend you buy some extra bolts. They only supply new bolts for the front of the plenum where it is raised the most and do nothing with the studs (they say to leave the nuts off since they don't reach and not to worry about it). The bolts in the back have very little bite and are really too short IMHO. Buy 11 stainless or grade 8 M6 x 35mm bolts and you will be better off. I would also remove the two studs and put the 35mm bolts in their place (need 11 if you do this).

I put my 2003 lower plenum back on the car and can really tell a difference. The 2005 just kills the torque. My Stillen upgraded valve body had not turned out as well as I expected, but I put it in at the same time that I switched out the lower plenum. Now that I have my 2003 lower plenum back in I can really tell a difference. The valve body upgrade was well worth the money.

If you have forced induction, the 2005 lower plenum may be a good fit. It flows more air, but without dyno testing and forced induction I just am not sure."

Yep, I fugured - These two sites are feuding, so I can't paste the link. But, I did paste the text.

As I said, every post I've read about this transplant, has meant lost power on the low end.

Lou

might just want to go spacer instead as the 05 lower intake plenum already sorts the leaning front cylinders

u cant go AAM though as the angle would throw the balance off again, a constant width like the ME is ideal for the 05 cars

just my opinion though

Thats kinda what I was saying . . .The real benefit of the 05 lower plenum comes with the addition of the VCT on the exhaust side. We all know the 05 300hp engine lost a little TQ but gained top end, but it would have been worse had it not been for the cam timing. The low end was dismal when we tried the 05 lower on an 04 motor. It goes without saying . . .we try so many things and positive results are harder to come by. The key as you said will be tuning, which is the biggest challenge at this point. IMO, the 300 HP is a little underrated by Nissan . . . I would call it more around 305. That engine is gonna be sick once tuners have full control of the VCT on both sides. :D

The guy originally said:

I was trying to set the record straight on what I think cloudy was referencing. I know somewhere it was posted or referenced the fact "crawford lost power with 05 plenum" as we get emails and calls asking the same question. In reality we lost power with the 05 lower plenum, but because the company name was included it gets miscommunicated on what was being said.

Post back with results, this is most likely my next mod.

Will do.

'05 w/Crawford
 

I know we are talking about Zs here, but I have an '05 G35 sedan (6MT) and just wanted to chime in about the Crawford plenum on my car...

Granted, I did some finishing work to my plenum (smoothed out most of the casting marks polished the inlet), did some minor work to my throttlebody (knife-edged the lip and polished the bore but did not increase bore size), followed that up with a Z-tube and a JWT pop-charger...

The seat of the pants difference is quite amazing. Very very noticeable gains across the powerband, especially above 5000 rpm this thing just rips. I may dyno my car ina few days to get an idea before I add the cats and headers.

Awesome!

I have had the Crawford Plenum on my 05 for a week now and my 1/8 time has already improved and it is a noticable power increase

mrtomcat,

Is your car a 300hp version?

no, it's the Enthusiast 287hp