I feel as if I am missing some top end power and I hope you guys can help me figure out what it is. I dynoed my 1995 maxima, its five speed and the mods are:
-00VI
-PR style CAI
-Y-pipe, high flow cat, 2.5" cat back
-JWT ecu w/ 7200 rev cut
-Fidanza flywheel, and fifth gen clutch
-tuned with VAFCII never more than +4 percent at any point
I am still waiting to have the files sent to me but I took a picture of my 190whp 190wtq graph.
I feel as if i am missing a good 15-20 peak horse power. I am hitting peak horsepower at ~6200. Could it be a VIAS problem? One thing that I have noticed is that when my VIAS hits the activation point at 4900 it does open, but when the RPMs drop after hitting the opening spot the valve is slow to close. It hangs in the open position for about 5 seconds and then will slowly close about 15 seconds after it opens. I am under the impression that this is not how it is supposed to opperate, but I am not sure what would cause this problem. The conditions on the dyno were 72.92 degrees F, 29.93 in-Hg, and 6% humidity, and a SAE correction factor was used of .97. All pulls were done in fourth gear on a dyno jet. Please ask questions if I left some important info out. Thanks for any help. I would like to find my power. Oh also it looks like an SAE smoothing of "3" was applied to the graphs.
*edit* why wont my graph show up using the regular [img] tags?
Carson, I think JSutter is more on point. As I noted in the PM, it REALLY does NOT look like a VIAS problem at all. The VIAS clearly opens at the correct point, and if it was broken you would have a DRASTIC power loss by 5000k...
Carson, I think JSutter is more on point. As I noted in the PM, it REALLY does NOT look like a VIAS problem at all. The VIAS clearly opens at the correct point, and if it was broken you would have a DRASTIC power loss by 5000k...
ok, I just went out and looked at everything. The vacuum canister for the car has what looks to be a check valve on top of it. There is a small vacuum hose on the top fitting and a larger one on the lower fitting. the hose on the lower fitting is not connected to anything. Where does this hose go and would it cause a drop in power?
I just replaced the two hoses going to the vacuum canister. I replaced the top smaller hose and put it in its factory location. I could not figure out where the bottom larger hose was supposed to go so i ran that one to the top of the intake neck to a factory fitting that I previously had blocked off. Will this work and would the lower vacuum hose being un hooked cause my loss in peak power, and also cause my VIAS to hang open for 15 seconds before it closes?
You should try a short ram intake to see if power is retained up top. The CAI can sometimes affect the amount of air into the TB b/c of the long path it takes.
Also, this bad vac can or check valve. I'm trying to look up the name in the FSM. Is it called something else?
You should try a short ram intake to see if power is retained up top. The CAI can sometimes affect the amount of air into the TB b/c of the long path it takes.
Also, this bad vac can or check valve. I'm trying to look up the name in the FSM. Is it called something else?
do you have any proof of how a cold air set up could possibly hurt my set up?
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Hey Karim, you still on Blackplanet?
so does anyone know where I should hook the larger vac canister line? As I stated before I hooked it to a fitting on the top of my upper intake manifold neck. Is that a good place for it? I am not sure where it should go. Also would this being un hooked cause me to have lower power? I am thinking with my set up I should be breaking 200 whp pretty easy. Am I wrong in expecting this?
Your VIAS is connected to vac source? It should be connected to fresh air source(before throttle body)
the hose connected to the one vac nipple on the front of the VIAS is hooked to a vac source. I will unplug that line and run the line else where or else plug it. I see a lot of people are just leaving that fitting open to the the atmosphere. What problems would the VIAS connected to a vac source cause?
If you have the hose connected to a vacuum source then the vacuums will be fighting against each other and it might not open completely. The VIAS system counts on the availability of atmospheric pressure.
yep, for your mods that's about average.
Fixing the "vacuum" source on the VIAS isn't going to yield a 10whp increase.
really? Maybe I am thinking of other people, but I have seen autos posting higher peak numbers than I am making with what I thought were less mods, and plenty of five speeds much closer or over 200 to the wheels.
So, you had to add fuel, or What did the cor %'s look like?
My normal wheels for this car are 18x8 Enkei RP02's...they only weigh 18 some pounds each, but I took them off and put on stock fourth gen 16" five spokes.
I'll look at my corrections later on but I added fuel, I never took any fuel out. All of my corrections were between +2-+4%
yep, for your mods that's about average.
Fixing the "vacuum" source on the VIAS isn't going to yield a 10whp increase.
If you look at the shape of the torque curve and compare it to other 00VI dyno's he's definitely missing some top-end power. And the HP curve peaking at 6100 then falling off? Something's not right. HP peak should be closer to redline.
If you look at the shape of the torque curve and compare it to other 00VI dyno's he's definitely missing some top-end power. And the HP curve peaking at 6100 then falling off? Something's not right. HP peak should be closer to redline.
I have those same bolt ons, 5spd with EU and stock clutch/flywheel made 193hp and 190tq. peak HP at 6100ish and holds fairly steady. But yeah the falling off is def VI issue
Edit: Just noticed that was a dynojet.. yeah those #s are a bit low then
What did the cor %'s look like?
Linear Mode
