Finally, re-dyno'd after my variable intake was replaced.

The results are below. It is clear that my vias is now working!

My stock numbers are very close to my original (although they are a couple hp lower across the board - probably due to the heat and the extra 25,000 miles).

The only set of results I didn't get printed was my old stock numbers against my new stock numbers.

We did two new runs and one old run on the plot.

Run 14 - Old run: VIAS not working
Run 15 - New run Vias enabled
Run 16 - New run Vias disabled.

Variable Intake Dynos

Clearly, the run with the VIAS not working and the run with the VIAS disconnected are very close. No doubt that was the problem. Also, the difference between run 15 and 16 shows what the VIAS is worth in our cars.

Comparison of vias enabled and disabled.

Vias on vs. Vias off

Lots of thanks to Madmax2k, 2k2DEMAX, and maxfreak 98 for all their help!!

 

The link doesn't work.

Glad to hear all is better now!

 

Max_Gator:

Did you see my post to you? It is here http://forums.maxima.org/showthread....hreadid=116405

Maxi_overdose has given me some excellent pointers, but I want your input as well. Thanks!

 

Good News! I am gonna book an appointment at my dealer next week.

 

 

Its fixed. I fixed it last night when I posted but for some reason it didn't take.

 

hey you owned a fat 4th Gen for a couple of weeks there

 

He's right on. But an intermittent problem is not good news.

You ought to follow the steps I outlined here:

Vias steps

The dealer will do the diagnostic in the manual. There is a diagnostic for an intermittent problem but it really is just a matter of checking all of the connections. That would be a worse problem than mine.

 

Wow for a stock 5th gen your car makes alot of torque compared to 4th gens. I wonder if nissan bumped the timing more in the 5th gens for the midrange torque gain. Either way you need more rpm .

 

Max_Gator - thanks for the info...I didn't see the thread you just refered me to. I will get the dyno down soon and let you all know what happens. Thanks again to everyone who helped.

 

Glad to hear everything is back to normal.

 

Max_Gator Check your PM's.

 

Does this VIAS problem apply to 2K2 Maximas or only 2K to 2K1? I have a 2K2 6 speed that seems to me to be down on power, but the the dealer thinks it is okay.

 

the 3.5 in the 2k2/2k3 has a vias but its operation is different than the 3.0's vias. the 3.5 vias does not have the power valve which along with the cup that holds it is the root problem for the 3.0 vias.

 

Thanks, SM.

Any suggestions as to other likely causes that might have been overlooked by the dealer?

 

it is a possibility that your 2k2 has the weaker maf which has a tendency to fail even with stock components. in some cases they die without any warning signs or it could also take a while to go out. is your acceleration lessened cruising around or at wide open throttle?

 

I think it is down all round. It feels as if I am driving one gear higher than I am. It is particularly noticeable at full throttle though. For instance, until recently accelerating moderately hard from a stop with the wheel turned would cause quite violent torque steer to the point where I had to be cautious making the left from the stop sign at the end of the street. Now it feels more like an Accord.

 

Hey Gator,

Was your cup completly worn through allowing the shaft to just spin, or did it just have a little play? The power you got back is pretty impressive.

 

i thought that the 2000/01's should have those dyno#'s stock?? w/ your mods shouldnt it be a little higher? maybe i'm mistaking

 

I kinda thought the same Glad it's working again though!

 

He wouldn't know, since the dealer replaced the whole manifold long before we knew what was the problem.

 

IT'S ALIVE. . . ..

Yep. Ice is correct as usual. I have no clue what the problem was but it was total failure.

As for the dyno # comments - I don't know if you are referring to my dynos or something else. When I had the vias fixed, I brought the car back to stock and tested it that way.

As far as I know any of my dynos with mods are where they should be - I've never dyno'd "low" for any reason other than vias.

 

So do you guys think that 190 hp with intake and y-pipe on an 01 is a about right or is that low. In edition to that i am not sure if my vias is working but with 190 hp SAE corrected would that mean it has to be working

 

look at the date of the original post.....he probably didn't have all those mods that are in his signature now, 3 years ago. Remember, if you change your sig, it changes on all your old posts too!

 

I have to go back and look at my dynos - and clean up everything and repost on my site.

But, you can't just take the # 190hp and make any conclusion. You have to look at the curve after 5000 rpms. If it keeps going to redline then your vias is probably fine. If, on the other hand, your peak hp is at 4-5k, then you might have a problem. You only lose power after 5k with a broken vias.

I think my stock hp was in the 190 neighborhood. (222*.85= 187) That's assuming a 15% driveline loss so that's about right.

And yeah, I've got more mods in my sig now.

 

How do you know you're losing power? Like...the needle will continue to climb but the car just won't pull after 5k? What do you feel when you have a broken VIAS? I'm certain that my VIAS is more than fine, especially since I can hear the engine absolutely roar (with the intake on) once it gets to the 5k mark. I'm just curious.

 

I think my vias is fine as well, its an auto , it revs past 5k mark to red line.
If you dont rev past 5 k often does that mean ur hardly using the vias and therefore it is less likely to break?

 

Thats what i have gathered from all the threads over the past couple of years. The valve never opens unless you go past 5k rpm and therefore there is no wear if you stay under 5k.