I got my maxima dyno'd yesterday. I wasn't going to but i got a deal I couldn't refuse.

The end result was 117WHP, and 150WTQ. The dyno started at 1800 and went to 6000. It made great torque from 1800-4000ish then just died off. Is that typical?

I'm not sure if my "power valve", or w/e the butterfly in the plenum is, is working properly. Didn't even occur to me to check before I went. I need to go through the FSM now and check other VG dyno's.

~Alex

 

That seems pretty low, Alex...That's some serious driveline loss for a FWD car.

 

well my dyno results didnt make me very happy... but that actually seems right
VE
factory crank hp = 190
factory tq = 190

my Whp = 162
my tq = 181
VG
factory crank hp = 160
factory tq = 160

your Whp = 117
your tq = 150

seems like a close ratio... but the power drop off... should be way diff... i havent studied them at all actually

but mine dropped off at about 5500? redline at 6800

 

My TQ starts dropping off at 3750 and keeps steadily dropping from then on. I make peak HP at 5100 and thats when i have 117WHP and 120WTQ at that point. I make peak TQ at 3100rpm.

I should be making 136WHP and 154wtq with a 15% loss. Im right there at 15% loss but if you only loose 12% with a FWD tranny I should be close to 140WHP/161WTQ. Thats a far cry from 117WHP/150WTQ....

Im basically down about 10HP in the top end, with the bottom end TQ being normal. Tomorrow Im going to see if my power valve works, I hope it doesn't.

My mods consist of a HAI (just a filter and no box), some 8.5mm wires (not really a power adder) and time has given me broken exhaust studs, a leak between the cat/y pipe and a 1/2 dime size hole after the cat.

I tried looking for other VG dynos and I couldn't find any...

~Alex

 

Yea I think perhaps having your car properly maintained might help you out a bit, I'm saying this because you've had your car for quite a while and still got the original PCV valve in.

Anyway I'm guessing our cars are pretty close if we were fairly close when we did mad crazy street racing y0...unless you just simply cant drive for shizzle.


Hey Chris better getchur VG torque numbers straight before I drive down there...

 

Umm...VG factory torque is more like 180...

 

well WHP should be about 136 on a stick VG with no mods in perfect shape (160 - 15% powertrain loss for a stick) so based on the driver I'm not surprised that you dynoed a bit less

 

my old VG auto dyno...
http://blehmco.com/pics/old_max/dyno.jpg

 

I will be interested to see what my car dynos at Maxus...

 

What mods did you have on it at the time of dyno?

 

Here's a 210,000 mile stock VG in a Datsun 510, which should have more drivetrain losses:

http://www.datsuns.com/Tech/dyno/VG3...0-jwaalkes.gif

Something is definitely holding you back.

 

182. i've read it to be at either 2800 or 3200rpm, sources disagree. but they always say 182. it's supposed to be because of the power valve being closed I think, that adds torque on the low end, and then the power valve flips open under highRPM high load to help maintain that torque once the airflow demands are very high. if his is stuck closed, that would explain a crappy top end.

but don't quote me on that, I'm just going of memory from what i read in the FSM or something.

EDIT: it's closed for intake efficiency under high-load low/med RPM, and flips open at all other times, for reduced suction resistance.

 

Thanks for the torque correction capedcadaver

 

this power valve talk is new to me... i thoiught the VE's have the PV....
im guessing the VG SE's do also... or just VG's in general?

 

all VGs have a power valve. only the VE-5 has one, IIRC.

a pic on a sec.

 

more or less, the VG power valve setup

 

So how would one make it so the power valve is open all of the time? Seem like it might be beneficiary.

 

keeping it open would kill your low end. it'd drop it (EDIT: it = torque) to ~175 at the crank, as per the SOHC 300ZX configuration...

http://en.wikipedia.org/wiki/Nissan_VG_engine#VG30E it mentions it here. "Variable intake plenum" they call it

so for drag racing, sure, leave it open. you're only in the lows for the first half of first gear, then you're redlining your way down the strip and never seeing a shift-in RPM of lower than 4000RPM... so it won't hurt you there. but it will in everyday driving.

 

If you ever go with some boost you'll actually want to keep the valve closed. One of the boosted VG members found that it made a little more power with it closed under boost. N.A. it'd be best to just leave it be.

 

that makes sense, actually, because opening it reduces suction drag, but if you're pushing air into it, suction isn't an issue.

 

my vg has more than 250k on it and according to my G-tech pro it has a close to the same hp as yours maybe a little more. the g tech measures hp differently than the dyno would though. since the car is actually moving and moving against wind. the g tech is really accurate though.

 

Just noticed that Fram oil filter, capecadaver...
Try using Napa Gold...

 

that came with the car, but that's not on there anymore. however, i have an equally-ghey STP filter. but then again, when i was doing the oil, I didn't know about the ORG, thus I didn't know i could swap in a 5spd, thus I wanted to sell my car and get something else with a 5spd. Like many others on here, the Org is the only reason I still have my maxima, because it opened up a whole new world of possibility for my car. Thus i did a cheapo oil change, with STP filter and Valvoline Jurassic 10W30.

Next time... next time i'm using some energy-conserving full-synth and a good filter (everyone seems to disagree on filters... i've heard to use pureones, napa golds, toyota filters, etc etc)

 

VG engines are old technology, there is no need to use synthetic oil.