Im new to the 350z, Ive been tuning Hondas, but its time to grow up. Hah!!

So Ive been reading everything about Forced Induction, with all my Hondas, they were all motor, and I would love to build an all motor 350, but I want to feel boost!!! Especially from the 3.5ltr. Im just an average Joe, Full time college student, and I work full time aswell. So I dont have alot of money at this time, but do have a little to play with after rent is paid.

So Im not going to pay 8gs for a twin turbo kit, which would be fun, but i dont have it like that yet. So, Im leaning towards a Vortech. Im not looking for anything extraordinary yet, maybe 350-380whp. I will be rebuilding the motor with eagle rods, which I already have, and forged pistons, havent decided which company, but probably around 9:1 comp.

So the question that I have is if I were to throw a 3.91 gear, just so I can rev through the gears faster, would it be to much overkill?? From what Ive seen people with supercharged vehicles, the power is very linear, and Im thinking, with not that much Hp, you could get out of the hole quick with the torque, with not to much tire spin, im thinking a 295 BFGs on stock touring 18s. Im not looking to drag this car either, just a nice all around car, maybe a little drag, little highway runs, and maybe some autox. Let me know if Im in way over my head, or if im on the right track.

 

I'm running the 3.9 final drive with a vortech and IMO it's one of the best things you can do to a vortech Z as long as you can get traction, which given the tires you mentioned, sounds like you'll have that taken care of.

Really it's the perfect mod for the vortech because not only does it give you more gear torque, but it'll put you 10.7% (3.917/3.538) higher in the rpms compared to the stock final drive which means you're that much higher into the boost since the vortech makes its boost up high

You won't be disappointed, especially at the power levels you're talking about.

For me, someday when I build my block (probably 4.2 GTM stroker kit) and making more power than I currently am, only then would I consider going back to the 3.5 final drive. But that's after I've exhausted every other option for getting better traction

The only time I wouldn't recommend the 3.9 with the vortech is if someone wants to run something less than 295 size tires and not go with tires that are all that sticky. Otherwise I think going above 400whp with the 3.9 you really need a tire at least like the 295 bfg KD

 

There is a guy on here running 3.9 fd with 2.87 pulley. (sentry65) He is probably at a power level that makes the fd a pain to deal with I would think, but a bigger pulley like 3.12 would probably marry up nicely with the sc. You would not only get to your tq quicker, but into boost quicker too. I will likely end up with the same setup as sc is in my own plans down the road.

edit to add: heh, he posts as I type, he would know

 

Well that is good to hear that you are running this set up, I will definitly be in touch with you when I have questions, do you still have the stock drivetrain?? I was thinking about a light flywheel, on my Hondas I always wanted the lightest one, which was an ACT prolite, again just for the Revs to come quickly. But with a boosted 3.5ltr, I believe I will not need to do this, but I want this thing to rev pretty quickly, so I can keep up with those turbo 350s, and I think it would sound amazing. Also, stock differential??

 

I have a carbonetics twin disc clutch and nismo LSD. You can check anything else I have here:
http://www.geocities.com/sentry65/350z/mods.txt

I'm going through a growing pain right now with my car, but from how it's driven in the past to how it drives now, I'm extremely sure I'll have 100% traction in 2nd gear. I'm not sure about 1st gear though because I can't drive the car past 5500 rpms right now due to a fuel pressure issue that I'm working on fixing soon.

However, I just modified the rear of my car to have dramatically stiffer bushings which makes a big difference on independent rear suspension cars. I also run competition tires and an aftermarket LSD. Like I said, I'll exhaust everything before I switch back to the 3.5 final drive and so far I think my efforts have been paying off

 

Thanks Sentry, and your exhaust, from what Ive read, you do need some back pressure with a charger, but 3inches would be overkill, so Im leaning towards the Borla RD 2.5 inch, again let me know. Thanks for all your help.

 

Would be interested in "need for backpressure".. Where did you find the info??

 

probably whatever you want to run will be fine since you don't have cams and headers etc. If you had cams, headers, HF cats/test pipes then you might not consider a dual 2.5 exhaust with only running the 3.12 pulley.

I dunno, it's a sorta mixed bag, but if your overall exhaust is really open, then your low and possibly midrange power will suffer

IMO no vortech Z should ever need a dual 3 inch exhaust until you're getting into crazy amounts of power like 600+whp. That's a huge exhaust even for turbo cars. The turbo cars have an extra restriction that superchargers don't have which is the turbine sitting in the path right after the exhaust manifolds.

 

it's not so much backpressure as it's exhaust velocity. If the exhaust is too huge for the amount of power you run, the gasses won't move very fast - which has a kind of suction effect as the velocity will actually help suck the gasses out instead of them slowly moving along with a an exhaust that's too big

 

I am running a 2.75" exhaust with my vortech with no problems at all, it actually feels better than my old 3".

 

vash, is it a single 2.75 inch or dual?

 

Single, Tanabe Titanium, however, my y-pipe is 3inch.

 

Vash are you on TR.com?? Your name looks familiar.

But thanks for all your help guys, I was pretty sure that would be a great setup, Now I just want to get this motor rebuilt, and then starting buying everything, I dont even want to try my chances with the stock block, as Ive had bad expierences in the past, and Im a firm believer of the saying, "do right the first time."

Look for my posts to come, keep you guys updated.

Take a look at my old Honda, I am an **** individual when it comes to the motor builds, everything clean and brand new: http://www.cardomain.com/ride/601679

 

nothing wrong with building it, but the vortech, especially at 380whp or less is pretty safe IMO

 

Well some spray might be needed for the highway runs.

 

Wow. Extremely clean. Do you have a parts cleaner? Those headers are sick. I don't know about that tap at the oil pressure sender for your VTEC solenoid supply, though. I would have worried that vibrations might break it (being that long).

 

Yes sir, glad to see you made it over to my350z. If you are going with the vortech you dont really need to build the motor, the linear power delivery is quite gentle on the motor, especially with the 3.33 pulley.

 

I tend to think with over 400whp , any thing more than a stock rear end . Makes your first two gears useless . I have a AT5 and the 3.5 rear and I cant go WOT in 1st or 2nd with out losing the car side ways . The stickiest and widest tires may help a little . But I still say its to much gear for that power level

edit....I should really say...I cant go more than 1/3 throttle with out losing the car sideways in 1st and 2nd

 

Had everything hot tanked and bead blasted, it was a brand new motor, that was an AN-R header, one of the best at the time for all motor. The tap was good, held out very well, that was not going anywhere.

 

Cool, you ever been out to any meets or anything, Ive never seen a SC in person, like to hear it, and maybe feel it until I get mine done.