Alex_V

So I have a cheap VQ for said project in the sig. I want to make it as fast as possible, and that means top end power. Other motors use insanely high rpm and velocity stacks or ITB's. So why not my VQ30?

I heard the power falls off at about 7000rpm on a VI engine. My idea was a custom intake with velocity stacks connected to a plenum as big as I could make, with a forward facing intake, and then a ram air box on the bottom of the car pretty much the entire width of the bumper, with a good amount of frontal area to pressurize the intake. of course the one time Im dragging in the GRM challenge Ill run w/o a filter and use mesh. It'll be fine for 1/2 a mile of driving.

For actual TB's I could use 2 VGs as I have them out my ar$. And they are insanely cheap as well. Id port them as well. With all that high flow parts all custom made together a suitable exaust would be needed.

Id probably start off with 350z stock headers if I found them, or maybe make them my self. If I make them my self they could be long headers for even more top end. Say I got the 350z stockers, Id make a true dual exaust with random pipe I have laying around or get a hold of. It may be kinda small diamiter if I went back to the mufflers, but I would have cutouts some where under the front doors. Not eletric mind you but bolt on, so they'd be like $20 or less in hardware (ok pretty much free, as Im sure I have bolts that will work).

Lets see, since theres a $2006 cams are outta the question. unless some one wants to donate some VQ35 cams for like $20.

Oh and with all these high end parts I figured Id make alot more top end and I could bump up the redline. But then comes oil and water pump durability. I just read about some one that put JWT cams and a 350z oil pump for reliability. I figured I could do the same w/o the cams and be set. Then the WP might be a restriction, but no biggie its only a half mile. I can turn the limiter back down. I figured on a 7500 or so redline. Id have to get it dynod of course and see where the tq/hp fell off.

Any way if I missed any thing plmk as I have some thing like 4-6 months to build this perfect budget VQ-Screamer

~Alex

JClaw

iTrader: (17)

I could get you stock VQ30 cams for cheap if you want to look into modifying them (like some companies do for the VQ35). [/shameless plug]

You could look into Travis' idea of a VQ38 stroker. You could have him buy you a new VQ40 crank (300$ straight from Nissan according to him), then have him prep the crank (I think he needs to grind the main journals) and then use your stock VQ30 pistons and rods but with the modified VQ40 crank, effectively bumping displacement from 2988 cc to 3751 cc.

That's all theory though. Might wanna check his thread (Search for VQ38/VQ40 stroker).

If I were to build an "all motor screamer" I'd probably look into this but with my VQ35 block/pistons/rods and better heads. It'd bump up compression (not sure by how much, maybe 11.5-12:1) and raise displacement to 3954 cc. Then I'd put in super aggressive cams, and maybe some headwork, extrude honed lower and custom homemade ITB's. That last part I'm doing to my stock VQ35 engine this year.

If Travis' theory is true, we could build a budget stroker with high compression and aftermarket cams for maybe 1500-1800$. And we wouldn't have to rev the crap out of it to make big power. I'd keep it south of 7000 rpms.

michaelnyden

iTrader: (15)

I'd say just a de-k with jwt cams, upgraded valves and valve springs, intake and full exhaust including headers and a good amount of timing advance including A/F tuned up there should make a vq screamer up to about 8 grand, the limit of the tachometer...well atleast the last # they put on there...
I would probably get new head bolts though...

GodFather

iTrader: (10)

michaelnyden is right, dek with jwt cams will do the job fine. i'm almost done there, but mevi just took all my low end torque away already, but on the other hand, it literally pulls from 4k rpms and up, and at around 6700rpms, i can hear a sharp, ear piercing scream from the cold air intake at the intake compartment (placeracing style intake). At one point, I even think I should reset the VI opening to a different rpm, heh.

I am experiencing a sudden power drop at 7100 rpms, but i don't know what that is, prolly just fuel map running out. but other than that, jwt cams is the way to go. for my case, i'm gauging interest in putting together a set of dek-vi so i can take it further to my oncoming jwt 8k rpm cammed ecu. I really have to admit mevi is good, but it seem so that 00vi can take it even higher while not loosing so much low end torque. with my mods, i am safely capable of reving up to 8k+ rpms. so your ideal screamer is already in progress under my hood. for more details, click my sig and check mods on page 2.

as for the jwt cams, I'm sure lots of guys would like to know more. I got it installed and running, i really didn't want to talk much about it till i get some dyno numbers, but i can assure you one thing that with these cams, whatever VI you slap on that vq, those power gains and losses in different rpm ranges are very evident. whatever everyone had talked about in the VI characteristics, with a jwt cammed VQ, you can but feel those differences right on.

I'll set a bottom line here:
with stock cams, I can slightly tell the torque loss from the mevi over the stock manifold; and of course a moderately notice of a high end gain of Mevi over the stock manifold.
but with jwt cams, torque loss is very evident from mevi over the stock manifold; and high end gain is extremely evident from mevi over the stock manifold. what i want to say is, with jwt cams, "butt-dyno" is felt obviously over the behavior of the different manifold. With that said, I strongly believe that 00vi is going to ship up a real screamer N/A VQ30de...

Alex_V

Thats great guys, and Id love to do them, but my budget is going to be eaten up by rwd parts. No money for cams or internal engine upgrades other then pumps. Im really asking, with a velocity stack style intake and a air scoop, something like 2sq ft front area or some thing like that. I hve to make due with AC delete, an UDP, and a lightened car, and the mods I talked about before. Any way would I run into oil or water pump issues when running 7500rpm?

~Alex

michaelnyden

iTrader: (15)

I would think more the oil pump then anything else...but even so...it probably wouldn't be an issue until later on down the road and only if you were keeping it there for an extended period of time...

godfather...I would like to know more about what your car is like since the cam install since I might consider that route...

is there a definite kick in the pants at a certain rpm...or is the power a really seamless increase....? what rpm range do you feel them really kicking in at? did the cams increase your top end as much as your mevi did? ie. same feel on the "butt-dyno"...

what things did jwt recommend to you about revving to 8K....anything else besides just upgrading your valvetrain which you already did...?

does the top end sound any different with the addition of the cams? how's the idle? did you raise it?

perhaps it's best to start a new thread or pm...since I don't want to jack this guys thread...

nismology

iTrader: (8)

I'm seeing a whole lot of nothing in this thread...lol...sigh

GodFather

iTrader: (10)

It's a very harsh journey I went thru to finally pull it altogether. Did you read my mod history in my homepage? check out what I put down on November and December of 2005.

Yes, kick in the pants at 4k rpms and all the way up. I noticed a hint of the kick from 3500 rpms then up. I also went back and forth switching the stock and mevi manifolds, the result is very intersting like I said before:

the cams also increased mid range to top end more than mevi did alone. Yes, "butt-dyno" is very evident with cams, much more evident than mevi with stock cams. and just cams with stock manifold, I can assure you that I felt an evident increase of mid range to top end power much more apparent than I did with mevi alone without jwt cams. It pulls up hard to 6800 rpms. I noticed power drop after 6800 rpms. It's not that bad, but the sound of my intake changed with a day-night difference. It went from a tuned intake suction sound to a !Sharp! ear peircing sound like a high pitched honda fart cannon exhaust. I didn't like that too much, but lot's of people told me that they love that sound. it is mean...


Jwt recommend and assured an 8k rev with their valvesprings alone. They didn't even doubt that our 4th gen oil pump will hinder that assurance. However, I heard a 3.5L oil pump is a heavier duty and direct bolt-on, I didn't hesitate to get one for my valvetrain. Oh yea, I got a new water pump, too. It's actually that water pump that started this whole JWT mess I'm in.
I did take off my cat-converter to listen to the idle sounds, it's like that iron lung's video but much louder and crsipier. but after putting the cat back, I barely noticed that "grin-grin" except the harmonic stomping vibrations like the car's got a heart beat. Idle is fine at 700 rpms, I didn't even have to raise. Jwt modded their idle characteristics over these cams, and idle wasn't rough at all for a warmed up engine. However, on cold idle while the rpm is around 1400-ish, the idle comes with almost-rattling vibrations. I dont' know what to make of that, but my engine was re-built with the cams' installation. Could be a bad rebuild job. Or the Cam's idle is that bad alone on cold starts. I really don't know. But after it drops below 1000 rpms, idle's fine without vibrations except that heartbeat I felt. Also, I never liked a loud-azz exhaust at all, and I thought with cams and a full exhaust system, I was going to have to live with a loud exhaust tune. But miraculously, Cattman's full exhaust coupled with jwt cams gave me the most ideal sound I wanted. The idle sound isn't loud at all, just a decent hint of low-tuned p-p-p-p-put. going from 1k-3k, it's a fine tuned exhaust note at a very low noise level. Then 3k-almost 5k rpms, It's the same sound but with increasing intake suction sound coupled with a noticeable sound of "pure air flow" right around the middle of the headers to flex section area. I dont' know what to make of it. Then 5k-6800 rpms with stock manifold, it is a grouchy leapord's attack sound. Very loud and mean. Then 6800-7200 rpms, it's a bad azz but sharp ear peircing sound that I did't like at all, it's tooooooo loud. Back to 5k-6k rpms with mevi manifold, it's a slightly louder sound than it was with the stock manifold. Then from 6k-redline, It's a loud growl sound and it didn't switch to that sharp intake sound from stock manifold's 68k+rpms sound I experienced. Mevi is a much more fine tuned intake than stock manifold under the cams, but there's barely any torque left down low, the kick in at 4k is when mevi is moderately acceptable, and you all know what's after that in a legendary mevi. I am really wondering if I should reset my VI opening since the cams. But it is yet to come. i need more knowledge about doing all that.

I think it's all good. It's a screamer thread and our posts pertains to lots of things he'd asked for. It's not a bad jack. Besides, I'm in a bad debt right now, and I wont' dyno till prolly late this year or early next year. So I wouldn't want to start a new thread and fart too much about these cams. I want numbers to back up my snit. You know what I mean.