A workmate is taking his 6G auto(CAI/catback) to dyno soon...just wondering what the verdict was on pulling the valve without modifying the inside of the intake manifold. Worthwhile? Does the butterfly valve easily come off the shaft or is this something that needs to be permanently modified..er damaged? Just curious if it could be quickly done for the dyno.



Also, has anyone tried closing the valve(zip tie or new vacuum source?) and seen a noticeable gain in torque from idle-1800rpm?

Drove the 6G for a few mins and the AEM CAI/Cattman catback sounded MEAN. It will be interesting to see how loud the ypipe makes it.

 

Just get the Kinetix manifold and call it a day!!!

 

I've got a set of Stillen headers I'll sell ya. J/K.

Would you mind taking a few closeups of the power valve for me? Thanks.

 

Hi Ice... long time...

The Alti guys have done this quite a bit recently, here's one thread:

http://www.nissanclub.com/forums/eng...nks-gbjna.html

 

Here's the valve:

This is a view facing the passenger side of the car, so left is the front of the engine bay.




This is a picture of the valve closed. You can get those screws off to remove the valve, like this guy:

http://www.nissanclub.com/forums/3124107-post89.html
.




Let me know if you need more pics or angles.

 

What does this mod do for those of us too lazy to register and search at the other forum....

 

i wantto know too

 

Hmm not sure but many many years ago , we did a mod for the 93-97 Altimas by taking the butterfly out and shaving the valve itself... that way the valve was as flat as the butterfly , not sure if this is what he is refering too...

 

I REALLY have a hard time seeing how doing this adds power. And i question the legitimacy of that dyno that was posted over on nissanclub that showed gains. It looked very similar to an SSIM dyno. I think they're confusing one with the other. Then they say they feel gains on the butt dyno when all that's happened is that their mid-range has gone to crap and the resulting surge in power after 3800 RPM feels like a net HP gain when it's not really there. I'm DYING to see a legitimate back-to-back dyno with this "mod".

 

Did anyone know that the new 07 Altima has 2 power valves

 

I agree for the most part, but you have to admit that theoretically, it could help top end. I'm just not sure how significant it is in practice given the small size of the valve, since a lot of the flow "constraint" is probably from the design of the shelf (hence the invention of the SSIM). Only back to back dynos will tell I guess.

And I think when people say it just "roars" up top, "sounds like a beast", or "just pulls like crazy", that's no different from when the valve is open in normal operation or with an intake. Its all psychological because you're expecting something to happen up top and hitting that part of the powerband more.

 

I dynod this. I didn't remove the thing, just didn't activate it. I saw no gains whatsoever just torque loss. nismology has the link where the pic is w/my dyno. Also, another member did the same and saw th same. Perhaps removing the valve would be more gain.

 

Thanks guys....definitely going to give it a shot. Will report back with the before/after dynos. As you guys said, I doubt just removing the valve will do much for 3600+rpm without removing the shelf in both the intake and collector.

Anybody lock it closed and notice a difference, since Nissan apparently wanted to LIMIT torque by having it open from idle-1800rpm(same as 3600rpm+)?

 

Also, anyone try one of these Altima blockoff plates or make them for Maxima.org members?

 

heres a crappy pic of my block off plate. i can get better pics if needed.

 

Thanks...yours is a 02-03 manifold, right?

If so, does the power valve look the same as the 04-05 one above?

 

Power valve on A34's are the same. IIRC, SE-R's powervalves are plastic, and the rest of the mani is still Al.

Found my dyno. Pay no attention to the lower green/blue lines. Only teh beefier ones. Those are the 2 runs, one activating, the other not.

 

Here's a pic of an Alti with the valve removed and a 1/4" aluminium piece in place:



From here: http://www.nissanclub.com/forums/eng...uestion-2.html

 

I wonder what their LIM looks like

I'm going to do this mod, but I'd like to get a new upper IM first. If I do that, I'll try to get dynos back to back swapping between the two IM's (unmodified/modified). I will also be removing the shelf though, because somehow I doubt any power is added from JUST removing the valve...my VIAS appears to be broken right now, so the thing does not pull at all until around 3800 and then it just feels the same as it did before...

 

A33B broken VIAS?

Not sure how the 07 LIM looks, BUT, here's this, shows the gasket, and it doesn't resemble what we have, or does it
http://forums.maxima.org/showthread.php?t=492413

 

IIRC, it has square ports, so do the heads, so if you were thinking about a swap, it may not be as straightforward as you'd hoped.

I may sell my spare upper IM and elbow in a few weeks, shoot me a PM if you're interested.

 

Thanks....

Just to make sure I'm on the same page, but there would be NO difference between those two dyno runs since the valve is already open 3600+.

OPEN ----- Idle-1800
CLOSED -- 1800-3600<~~~This is what you changed
OPEN----- 3600+

Disconnecting the valve or solenoid wouldn't cause any difference in the valve position/airflow/powerband besides the clear torque loss below 3600+(looks like 3800-3900 on your car) when the valve is open.

Removing the Power Valve, but leaving the PV housing wouldn't probably make much difference, but removing the whole unit like the Alti boys did would hopefully. Dyno will tell...I hope.

 

Puppetmaster

 

For those too lazy to go to the links:

 

I can't really tell but it appears that this image:



Is just the upper IM. AFAIK the head design is the same between our VQ35 and the new one, so do you think the LIM molds the runners into an oval shape as it meets the heads? Or did they change the head design?

 

07+ Altima heads = HR heads. You'd have to swap everything over.

 

ah, got it. I'll stick with modding mine

 

I've looked alot into swapping the 07 IM and the FSM show the lower intake manifold as having square ports up top and the same ports as ours down low with the same bolt pattern to install. I'm pretty sure it would fit if you got both however I wonder if you would run in to any problems with the electronics end of things. Also for that kind of money would you be better off getting the kinetixs(for add looks as well as performance).

Any one have pricing on both 07 manifolds?

 

I stand corrected...



http://www.my350z.com/forum/showthre...=264844&page=9

 

Still not convinced w/ Kinetix and their 1 dyno that doesn't even go past 6k. Yes, it was climbing, but the dyno should have been done correctly.

And it(stock 07Collector/IM) cannot be that expensive (vs Kinetix).

You can get a Z33 rev up collector for ~$230(BRAND NEW, OEM), add on a lower for $100 or so. And we all know those prices can be found other places for much lower.

 

So my research was correct. Perhaps I will do the 07 IM instead of kinetix. Anyone have any thoughts as to how much more power it should make. Also problems and complications due to the dual valve setup etc..

 

Check that FSM and see what RPM it's active and vice versa. Check the PCV diagram as well, and while you're at it, compare what ports (non intake ports, vacuum etc) are used and compare them to yours.

 

We'd also need to know about the activation mechanism; whether its vacuum, solenoid, etc driven. And the million dollar question, when it should be activated if the swap is possible/successful, since the "current" FWD IM design probably has a different activation point.

 

in so many words...

 

Darn, but not the second part...

 

. . . . . .

 

You're saying find out what RPM the 2007 Altis have it activated.

I'm saying you'd need to find out the optimal activation point of the 2007 VI on an older VQ, if it is ever installed, because the activation point could be different from the 2007, no? Because I would doubt that their VTCs and the flow characteristics of the IM are exactly the same, therefore the need for a different activation point if swapped onto a pre-2007 VQ.

Regardless, reminders are always good...

 

The FSM makes no mention of RPM specifications.

 

Yeah, I spent hours combing through it last night with on luck. Also it looks like the throttle bodies are different. Yet another part to pay for, looks less and less likely. The system is more complex than ours varying the valves independently for various conditions apart from the standard medium and high load indexs. It is controlled by solenoids and operates on the same premise as the 06 from what I can see. Despite dynos on the kinetixs not being proven, running an intake and agressive cams it will surely flow better than stock especially at higher rpm. Once you look at all the crap that has to be replaced and not having the ability to properly control the dual vias I think it's a better option.

On a side note has anyone else noticed the lack of EGR for 07's?

 

Dyno time.