Why does the VX sound

[Luna X]

like an F15 fighter jet on the runway?

I have an aftermarket air filter on it, and I recently replaced the fan clutch. But this thing is loud! My 350Z (same size engine btw) creates a beautiful growl but doesn't have anywhere near the loud, whirring noise that comes from the engine of the VX...

... that leads me to another question.

How does Nissan get 75 more horses from their 3.5 than what Isuzu produces? Is it mostly in the computer? Would remapping work? (If it can even be done)
I'd love to get a little more power, but since the supercharger is no longer available, and turbo kits are more of a piece together, it seems like choices are quite limited.

any idears?... :_shrug:

[Gussie2000]

It's all about engine specs luna.

The VX 3.5L is a low compresion engine,that's why it use 87 regular octane gas & produce 215 hp which if fact was a lot of power back in the late 90's according to my mech the VX was one of the most powerfull V6 SUV world wide,just after the nissan pathfinder which had 240 hp ( all 2001 edition ) even more then few V8 SUV's out there back in those days.

The nissan Z350 which is a high performace car with a high compresion ratio that requires higher octane gas,plus both vehicules have different gross weight,ground clearance,etc.

Don't forget that the VX engine is a 13 years old engine,if the latest version of isuzu 3.5L that you find in the 2004 axiom can the use in the VX you'll definately have more power.

The 2004 isuzu 3.5L engine kicks 250 HP with direct injection technology. Unfortunately isn't compatible with the VX :(

[Luna X]

That's a great little tid-bit of info, Gussie. thanks!

I have yet another querie about these VX's...

We got rid of a 2WD 2000 Rodeo (3.2L) that seemed to have much more "oomph" from a standstill.
Does the TOD sap some of the linear power in exchange for more stability? I have to admit, the VX feels almost like the Z while zippin' around corners (and slow people)... gotta love the handling!

[Gussie2000]

That's a great little tid-bit of info, Gussie. thanks!

I have yet another querie about these VX's...

We got rid of a 2WD 2000 Rodeo (3.2L) that seemed to have much more "oomph" from a standstill.
Does the TOD sap some of the linear power in exchange for more stability? I have to admit, the VX feels almost like the Z while zippin' around corners (and slow people)... gotta love the handling!

I believe that the rodeo had more standstill power because of the 2wd ,the engine only had to focus on delivering the power to the rear axle,instead the TOD have to deal with two axles all the time so the load is more.

For a vehicule with 4000+ pounds & only 215HP the VX take off is acceptable.

[Bob Barker]

I had no idea they weighed that much.

I remember reading though that the factory transmissions can only hold around 300hp before they grenade. Maybe that's some of the reason why they didn't put a stronger motor in there.:_confused

[Luna X]

my Z is no lite-weight either... gvw is over 3800lbs!! It's more of a cruiser, not a rocket-ship. (It's actually longer & wider than the VX)

[SlowPro48]

The variable valve timing in your Z's engine also contributes a great deal to the increase in hp/liter. Don't know why the VX has so much fan noise/roar but I've noticed that too. Ah well... just part of the "character"!

[Triathlete]

Just turn the volume knob on your audio entertainment device clockwise a few notches and those noise's amazingly disappear!http://forum.planetisuzoo.com/images/smiles/headbang.gif

[Gussie2000]

I had no idea they weighed that much.

I remember reading though that the factory transmissions can only hold around 300hp before they grenade. Maybe that's some of the reason why they didn't put a stronger motor in there.:_confused

Isuzu just don't wanna spend more cash to design & develope an stronger and better engine for the VX,

[Triathlete]

Isuzu just don't wanna spend more cash to design & develope an stronger and better engine for the VX,

In '99 215HP from the factory was pretty good. Compare it to other vehicles of that era.
(for comparison...1999 Mustang GT 260HP, 1999 Corvette C5 345HP and those were V8's)

[Luna X]

Just turn the volume knob on your audio entertainment device clockwise a few notches and those noise's amazingly disappear!http://forum.planetisuzoo.com/images/smiles/headbang.gif

Back in my autobody repair days, that's exactly what I wished I could tell customers who came in and said,,, "I have this rattle/buzzing sound coming from so and so..."
No fair using that on me... :bgwo:

[Gussie2000]

[quote=Triathlete;200687]In '99 215HP from the factory was pretty good. Compare it to other vehicles of that era.

No doubts about that tri but we all agree that a bit more wouldn't hurt at all :winky:

[Triathlete]

No doubts about that tri but we all agree that a bit more wouldn't hurt at all :winky:

No dought more is better.:bwgy:

[JHarris1385]

You might want to check into that claim that the axiom engine does not work. I believe there was a swap on here.

[Ldub]

You might want to check into that claim that the axiom engine does not work. I believe there was a swap on here.

IIRC, He swapped in the lower end, but had to use the 6VE1 intake/throttle body/injectors because the ECU couldn't be adapted to the DI & fly by wire.

[Anita]

like an F15 fighter jet on the runway?

I have an aftermarket air filter on it, and I recently replaced the fan clutch. But this thing is loud! My 350Z (same size engine btw) creates a beautiful growl but doesn't have anywhere near the loud, whirring noise that comes from the engine of the VX...

any idears?... :_shrug:

Though not coming from the engine compartment, I wonder if you have a PV2 muffler on. Power Vault made mufflers specifically for our VX and the second generation PV was VERY loud. Too loud for many.

[JHarris1385]

Mine got louder after taking the restrictive elbow off.

[Marlin]

I had no idea they weighed that much.

I remember reading though that the factory transmissions can only hold around 300hp before they grenade. Maybe that's some of the reason why they didn't put a stronger motor in there.:_confused

If it makes you feel better, the 4l30e tranny we have is the same that is used in the Chevy Aveo. High quality...

[Luna X]

Does the JDM version of the VX use the same trans.?

[deermagnet]

I don't know about the JDM version, but we don't have the same 4L30-E tranny as all those other makes and models. We don't even have the same 4L30-E that's used in most other Isuzu's. The 4L30-E has been around a long time and it gets changes almost every year. Our version of this tranny is only used in a '98+ 3.5L Trooper, that's it. It gets different components based on what specific vehicle it's gonna be used in. So they're not all the same.

This is what Isuzu says about our tranny-
"Though similar to the 4L30-E transmission used in other Isuzu models, the 4L30-E in the Vehicross has been modified to deal with the added horsepower and torque."

My tranny is rock solid at 234,000 miles and I wouldn't be surprised if I get 400,000 miles out of it.

Mark Griffin

[djmdma02]

like an F15 fighter jet on the runway?
\

Is the not a good thing :)

[BigSwede]

Isuzu just don't wanna spend more cash to design & develope an stronger and better engine for the VX,
That's not entirely true...Isuzu was working on a V8 for the Trooper, but when it became clear the US market was a no-go, they dropped the program.

[RamAirZ]

like an F15 fighter jet on the runway?

I have an aftermarket air filter on it, and I recently replaced the fan clutch. But this thing is loud! My 350Z (same size engine btw) creates a beautiful growl but doesn't have anywhere near the loud, whirring noise that comes from the engine of the VX...

... that leads me to another question.

How does Nissan get 75 more horses from their 3.5 than what Isuzu produces? Is it mostly in the computer? Would remapping work? (If it can even be done)
I'd love to get a little more power, but since the supercharger is no longer available, and turbo kits are more of a piece together, it seems like choices are quite limited.

any idears?... :_shrug:


Also the 350Z has about 10.3:1 compression and the Isuzu 3.5 is a bit over 9:1, just increasing the compression ratio and nothing else, you're only looking at maybe a 10-15hp increase at the engine at most. Also there is no tuning software for our trucks that we can just plug in and mess around with which sucks and I wouldn't trust a JET computer on anything I own. You can wire up a megasquirt to control the fuel/timing on our engines though which will help, HP Heaven can custom grind cams for the Isuzu V6's but they are in australia and the price will be a little expensive. Also, engine design plays a big part, just because one engine puts out the same displacement as another, doesn't mean they should be equal. Valve timing, ignition/fuel curves, stroke/bore, etc. The Nissan engine uses a shorter stroke and larger bore. We really have no "bolt-on" ways of making alot more HP out of these things so it's all going to be a custom [project until someone decides to start producing stuff. You can send your piston/rod off to someone who will make forged/billet versions of them, slap them in there, slap a turbocharger on it, megasquirt computer and tune it with 10-15psi of boost and you'll have a pretty peppy engine lol

[Ldub]

Also the 350Z has about 10.3:1 compression and the Isuzu 3.5 is a bit over 9:1, just increasing the compression ratio and nothing else, you're only looking at maybe a 10-15hp increase at the engine at most. Also there is no tuning software for our trucks that we can just plug in and mess around with which sucks and I wouldn't trust a JET computer on anything I own. You can wire up a megasquirt to control the fuel/timing on our engines though which will help, HP Heaven can custom grind cams for the Isuzu V6's but they are in australia and the price will be a little expensive. Also, engine design plays a big part, just because one engine puts out the same displacement as another, doesn't mean they should be equal. Valve timing, ignition/fuel curves, stroke/bore, etc. The Nissan engine uses a shorter stroke and larger bore. We really have no "bolt-on" ways of making alot more HP out of these things so it's all going to be a custom [project until someone decides to start producing stuff. You can send your piston/rod off to someone who will make forged/billet versions of them, slap them in there, slap a turbocharger on it, megasquirt computer and tune it with 10-15psi of boost and you'll have a pretty peppy engine lol

The answer to all of lifes problems can be found here...:yesgray:

You're results may vary.

http://www.facebook.com/pages/Nitrous-The-Squeeze-The-Juice-Spray-NAWZZZ-HP-in-a-Bottle/270465350733

[Luna X]

that's like, all crazy, and stuff.... :yesgray:

[RamAirZ]

Tis true Dub, and I have used it many times. Probably going to run it on the 68' too. Just wouldn't run it on the VX for anything over a 50hp shot without better internals and a way to retard the timing + colder plugs. Nitrous is the cure for all things slow lol

[crotchrocket]

You got to think of the VX engine as an agricultural setup. It just aint a performance engine, also sounds pretty crap for a V6!!!! But hey, it still grumbles!

[Luna X]

thanks for backing me up, c-r... ;)

[Triathlete]

Tone ran Nos on his VX before the supercgarger....unfortunately all those threads are on the old board which no longer exists.

I am hopeing that by the time my VX engine gives up the ghost that there will be a few of those 2011 mustang v6's floating around the parts yards. Similar small package, 30mph (probably a bit less in the heavy VX) and 305hp stock. Would make a nice swap me thinks!:bwgy:

[RamAirZ]

Backing you up for what lol, don't think most of us actually consider the 3.5 to be a performance engine, but it gets the job done for what it was intended for, and you can always make it faster, just takes time, money and effort, like with anything else in this world. Also my VX doesn't make the sounds yours seems to, I actually like the sound of mine until the AC compressor bearing started going out. Oh and CR has the 3.2 so it'd be all the 6VD1 and 6VE1's that must sound like crap to some.

[Cobrajet]

...2011 mustang v6's ... 30mph (probably a bit less in the heavy VX) and 305hp stock...I recently rented a 2011 Mustang from Hertz. I can actually go faster than 30 mph... :)

[Triathlete]

In this new universe h=g!:rotate:

[Luna X]

ok, here's what I'm gettin' at...
Under heavy acceleration, the VX sounds good. But if I'm just coming off idle, say just doin' 5 mph, the engine is quite loud. (not exhaust) It's as if you are holding a stethescope up to it and you can hear the internal workings.
I'm just tryin' to figure out if other VX owners hear this with theirs. I have owned probably 15 vehicles plus I worked in body shops for over 20 years, so I've heard my share of engines... just not this one.

I really appreciate those who responded with some tech regarding the main difference between the low compression (the VX) and high compression (the 350Z) enigines.

Since I've been made aware that there are no simple performance mods, I'll just drive it as is... worry about more power if/when engine goes kaput.

[IndianaVX]

Hey luna,
I'm not around much, but welcome to VX ownership! Something that came to mind reading your post
Is thhi...actually 2 things. You might check the nut under the EGR valve. I know that if that thing is loose, or completly off,
The VX gets loud.2ndly, in my best tommy chong voice...."Did you check the air in the tires, man?"
Seriously....if even one tire is low on pressure (often caused by peeling chrome wheels) this causes the TOD to whine and moan
As you speed up and slow down. And yes, makes it sound like you hear everything going on in the engine.
Just a thought. And its real cheap to fix! Just add air! Preferably from a free sourse, and not one of those 1.00 air pumps.
So you might just check it out.
Again, welcome to the family!
Live long and enjoy your vx!

[Ldub]

ok, here's what I'm gettin' at...
Under heavy acceleration, the VX sounds good. But if I'm just coming off idle, say just doin' 5 mph, the engine is quite loud. (not exhaust) It's as if you are holding a stethescope up to it and you can hear the internal workings.
I'm just tryin' to figure out if other VX owners hear this with theirs. I have owned probably 15 vehicles plus I worked in body shops for over 20 years, so I've heard my share of engines... just not this one.

Oh THAT noise...:yesgray:

Kinda hard to describe, not exactly a whirring, not a knock, not really grinding, not exactly hissing either...:_thinking

I've got the same thing, it did get a little better when I modded my trans mount by through drilling it & installing some 1/2" gr 8 bolts. (making it, for the most part, a solid mount)


http://www.vehicross.info/gallery/data/500/DSC02863.JPG

http://www.vehicross.info/gallery/data/500/DSC02877.JPG

These pics show the first attempt with 1/4" hardware, which wasn't up to the task.(sheared off)

[RallyDude]

I think there is a member on this site in Michigan who was selling his S/C'ed VX. He said the midwest weather had taken its toll, so he was asking $5,000. The S/C part alone was sold for $3500, and I'd bet as there isn't a replacement, a used S/C in good condition, if available, would probably sell for about the same as new, as its a highly sought after part.

Anyway, you could buy the car, get the S/C and any other parts you may need. You could get upwards of 2 grand or more to part it out after its done. Kind of a pain in the butt, but if you're in the need for speed, it's at least an option. It sounds like the car is probably better for parts, or drive it till it dies type of thing. I bought an East coast VX, however the rust hadn't taken over yet. It needed the timing belt, tune-up, lowered to stock, CV joint and both boots, all fluids and filters changed and exhaust. Some of the bolts were hard to break free; my mechanic had to use the plasma cutters several times to free things up. But now we won't have those problems as most items that have to be serviced have been and worn fasteners replaced. The maintenance cost about half as much as I paid for the truck, but I had (almost) budgeted for it, and I'm very happy with my S/C VX.

I too had thought the Axiom Direct Injection motor had been swapped in by more than 1 member, but I may be wrong. That motor not only developed more power and torque, it used less gas, and was a quieter, reliable, more refined motor. I wish it was more straight forward to install. Combined with the S/C would be very interesting.

I know that the tranny is kind of the weakest link, but wasn't the tranny designed by Borg Warner? Or is that just the electronic TOD that they were involved with?

[crotchrocket]

I was in a rush when i posted, what i meant was i had a Nissan 300zx before the VX which is a 3.0 V6 and it sounded awesome (as im sure Luna VX' 350Z does) The VX has never really sounded like a V6 to me, i guess its just the way it fires the cylinders but i was quite dissapointed when i put a straight through exhaust on it as it sounded like a tracktor, so i took it back to the shop for one with a bit more silencing, now it has a low down grumble and not too much rasp etc.

From what i've heard on youtube the 3.2 sounds the same as the 3.5

[RamAirZ]

I think Luna may be talking about the "lifter" sound most of these motors make. I will agree all the Isuzu V6's I have owned you can hear the valves going up and down at low engine speeds and light acceleration. Never bothered me since I've daily driven some primitive engines (solid valvetrain small block comes to mind lol) but yes you can hear all that going on up there. Also I wouldn't consider 9:1 a "low" compression motor, it's average, and if it was an iron block iron head engine it would be kinda high, the aluminum dissipates the heat alot better so you can run higher compression on pump gas (like 10.3:1 on the 3.5 Z motor, 10.3:1 would not be happy on pump gas with an iron block/iron head engine)

[BigSwede]

Heh, you should get a 92-97 SOHC 3.2 and take a listen...your motor's valvetrain noise will sound blissfully quiet by comparison. I tell the SOHC Trooper guys to just pretend it's a diesel.

[SlowPro48]

Ldub stop taking pictures with your leisure suit as the background - I'm going into seizures here man!

[Ldub]

Ldub stop taking pictures with your leisure suit as the background - I'm going into seizures here man!

When they're induced by "dubware" they're called "Liesures"...not siezures...:laughing:

[RickOKC]

Ldub stop taking pictures with your leisure suit as the background - I'm going into seizures here man!LMAO! Thanks for saving me the trouble of typing that! :laughing:

[Luna X]

Guess what I found out!?

All along, that mysterious noise I was hearing is the a.c. compressor clutch... It makes more noise than it should, which means one of these days it will quit altogether, but I did make it through another ridiculous AZ summer!... ;)

And in better news, yesterday's oil change was first since June, and she was just barely 1/2qt low... seems to be holding up quite well compared to some other stories I've read here.

Also changed the transfer case oil and outfitted her with a pair of new running shoes...

Now........ if I could just get geared up to give her a much needed paint job, things will be all good in VX-land!!

[Gussie2000]

That's not entirely true...Isuzu was working on a V8 for the Trooper, but when it became clear the US market was a no-go, they dropped the program.

I have no clue if isuzu did ever had thoughts of going V8 on any passenger vehicule.

As far as my mech told me isuzu wasn't eager to build any V8 passenger truck.
I neither believe that the VX shall came with a V8 engine,but rather with an stronger,more powerfull V6 engine.

Nissan was able to develope an special 3.5L V6 for the pathfinder kicking 240 PH.

[vt_maverick]

Seems like a V8 would be hard to shove into the VX engine bay...

[Gussie2000]

I think Luna may be talking about the "lifter" sound most of these motors make. I will agree all the Isuzu V6's I have owned you can hear the valves going up and down at low engine speeds and light acceleration. Never bothered me since I've daily driven some primitive engines (solid valvetrain small block comes to mind lol) but yes you can hear all that going on up there. Also I wouldn't consider 9:1 a "low" compression motor, it's average, and if it was an iron block iron head engine it would be kinda high, the aluminum dissipates the heat alot better so you can run higher compression on pump gas (like 10.3:1 on the 3.5 Z motor, 10.3:1 would not be happy on pump gas with an iron block/iron head engine)

My VX got a lifter noise which is very common on these engines,sounds like an diesel.

My mech told me that the VX will run just perfect so i didn't bother to fix any thing.
Last year i went up state NY with my brother-in-law.Back on my way to NYC i told him hey ! Hold on tight,i am gonna floor the gas pedal,let me put to the test this engine.
On the I-78 i drove over 110 mph,told my self if this VX is that good we'll make it back home,otherwise i gonna call my warranty company and let them fix it all.

For my dissapoitment we make it back home in one piece, minutes later i called my mech and told him man,you were right,the VX will run just fine.

Many people asked me if "that" runs with an diesel engine. my replay is Yes,it does....

[crotchrocket]

Seems like a V8 would be hard to shove into the VX engine bay...

But oh so worth it!!! :D