Sorry for the lack of searching, i'm sure this topic has been already adressed,

I have a completely stock block 91k miles, 2nd owner,

I have done regular scheduled maintenance, complete fluid flush, spark plugs, aftermarket radiator headers test pipes exhaust intake throttle body coolant bypass mod BLAH BLAH BLAH

I am wondering if it can take the 8000 RPM first off, I know regularly N/A there is no point to rev this high due to torque/hp falloff,

but with the addition first off is it safe to spray that high?

Secondly I will be on 4.08 gears so I just want to know is it safe/worth it to tune for 8k?

 

Stock is 7500 I have only ran with volvo motors and My stock redline was 6500 and I had it tuned for 7k on stock block, and it took it,

I guess Im just wondering how well balanced these blocks are?

 

there is 0 reason to, you can make the power needed without revving it and you still need cams to supplement, only spraying high rpm isnt going to do a ton, sure it will help but your still not going to even be close to flat. thats not even touching on the subject that you WILL float the valves, since you are going to have to pull the cams to change springs and retainers just do the cams. search a little this is stuff that is easily available on google.

plus the rods arnt likely to take it since at that rpm its going to take less torque to break them vs boosted at a lower rpm, its not just the boom that stresses them, rpm is just as stressful.

 

Why would you want to rev that high

 

first of all, stock rods at that rpm are already in the danger zone. adding a good shot of spray on top of that is only asking for trouble. as a lot of other people have already said, you are gonna need a **** ton and a half of supporting hardware to rev that high once you get a built shortblock in the car. now, i am a relatively experienced nitrous user (going on about 15 years now)... on my g, i run 150 shot, and have for a while. i spray between 3000 and 6800. my fuel cutoff is set to 7200. to illustrate how rpm and nitrous are related lets first consider just the single nozzle and its operation irrespective of the motor. when it comes on with a given jet it sprays a constant amount of nitrous and fuel. the reason nitrous makes more torque down low is because the intake valve is open longer (in terms of time, not duration) and allows more nitrous into the cylinder (since it sprays at a constant rate). with a nitrous motor, the torque and cylinder pressure reach their peak values right after the system turns on. the tq begins to fall off from there and the hp continues to climb. as you increase the low rpm set point, you reduce the peak torque of the motor. thus the car wont feel as strong when you activate it at 4000 rpm as opposed to 3000 rpm. if you are using stock internals you can reach the limits of the shortblock without increasing rpm or getting all the high rpm hardware if you spray in the 150hp neighborhood (not recommended for novices). that said, the only reason to increase rpm when spraying is to increase the amount of nitrous that the motor injests, and vise versa. you can run a much larger shot (assuming appropriate octane fuel is present) and get the tq gains at a higher rpm than you would have had at a lower rpm with a smaller shot. say for example you had a 300 ftlb increase at 3000 rpm and sprayed to around 6800, if you raised that range to 4000-7800 it would take more nitrous to produce the same peak tq gain when the system turns on. a lot of people use progressive controllers for traction out of the hole. an alternative use for a progressive controller is to bring in more nitrous up top (again assuming good gas) and flatten the tq curve out and make the car pull harder in the higher rpms. ive gone way, way to far into this to answer your question but what the hell. my recommendation is that you spray a larger shot in the stock rpm range. if you want to do something special and beneficial, get an auxillary fuel system like the one im building and run race gas in that all the time (for the nitrous fuel supply). you can use a progressive controller and dial in a good curve for your car. good luck with it, stay away from the juice at 8000 rpm on a stock shortblock

 

+1 very informative haha

 

Fuccckk yea! I love good answers, thanks bro,

Just supporting mods on the G? Are you 91 octane still to?

 

I do it on my car... but it's an HR. I wouldn't want to twist a DE that hard without upgrading the other parts to handle the rpms first, then worry about the nitrous. I still don't need to shift that high, mainly on the 1-2 shift to keep the car closer to the powerband in 2nd. Every gear after that can be shifted around 74-7500 and still stay in the thickest part of the curve.

 

this thread makes me want to add the fog to my car lol.. yes good answers from very bored or just very generous pros ( lol) are always rad.

+1 for leaving a stock internal DE alone. google vq35 de rods... take alook at the dinky little things that are in your engine.. HR has better ones.. torque is what breaks them, and NO2 is torque.

This is the SCARIEST 350z picture ive ever seen.. its a cautionary tale lol.
DE rods.. and one dont look too hot.

 

HR

Since my tune I take it to 7800 +/- all the time...

There is no real advantage unless racing another Z/Gs due to similar gears! The extra RPM
just gives you a jump into the next gear at a higher RPM.

It's very noticeable against non HRs, and still noticeable on HR with tunes yet the driver isn't willing to rev that high.

If you're spraying a high enough shot no point in stressing the motor over another 1000 RPM. Especially if it's not built!


Keep us posted on what you do.

 

relevant mods: custom nx nitrous system i put together, nano 3000psi sport system (might upgrade to 4500psi one i dunno), motordyne tdx2, mrev2, isothermal 5/16" spacer, z-tube, 350z airbox modified for ram air, osiris tuner version (i tune myself with help and guidance from a few others on here... i have a nitrous map and an na map), 1 step colder copper plugs, ppe longtube headers, nwp thermal spacers between lower intake runners and heads and tb to plenum, i have been working on an 09 maxima throttle body swap and finally have everything ready to put on after i finish porting the plenum inlet this weekend, also i just got my 4.083 gears and quaife installed in my extra pumpkin. that rearend, my nismo cover, injected performance diff brace, sikky solid bushings and dss pro axles are going in very soon. depending on the type of racing you do, the 4.083 gears might or might not be a good thing... for me its a win. if you do a lot of highway racing i wouldnt go that route. i am running 91 octane but i am also in the process of setting up an nx s.a.f.e. fuel cell in the trunk to hold race gas and feed the nitrous fuel solenoids. this way i can go back to completely stock revup timing and maybe add two degrees. once i do that i am going to swap in the direct port setup ive been building and go up to about a 180whp shot that doesnt turn on until 3500-3800 as opposed to my 125whp single nozzle setup i am currently running.

 

^ Sounds like a pretty slick set up. Post more info and pics in a separate thread. I'd be interested to see what all's going on.

I need to start messing with my nitrous system again one of these days.

 

thanks man! im out there now mocking up the maf sensor placement on the new 3.5" intake pipe. when i get it back from the welder and powdercoater im gonna shine the engine bay up real good and post some pics up. pm me and ill give you a link to my fb and u can see the pics i already have up there.

 

Why would 4.08 gears be a problem on the highway? From my understanding its only top speed your missing out on..

Acceleration would be improved upon yes?

 

More time shifting = Less time going faster

The advantage of more gearing becomes less obvious as power increases and speeds are higher. In theory, as long as it has grip, the car with higher numerical gearing will accellerate harder over any given course but will reach a lower top speed. In the real world, sometimes one extra shift in a given speed range can even out the advantage and too much gear down low just means more tire spin. With good tires i'm borderline on trying to spin second, go from a 3.5 to a 4.08 and i'll be roasting the tires instead of going forward.

 

amongst the z/g car owners, gears and nitrous seems to be a very touchy subject with very little actual information to back up either argument. not very many people are doing it. i agree with Italianjoe1 for the most part.his point about sometimes its that one shift that makes a difference is very valid. im sure a lot of us have experienced that at one time or another with a really close race. i feel that the real disadvantage is in racing from a pull against a car with highway gears with similar power curves because he might start at the middle of third (high power at a greater rpm and more torque multiplication and in the gear longer) where as you are starting at the bottom of 4th (less power lower at a lower rpm and less torque multiplication and not in the gear as long). on the 1/4 mile track the 4.08 car is going to be faster. ive heard people on here talk about it, but ive never yet seen a 4.08 car lose to a 3.53 car due to gearing. ive had 4.10's and 150 shot in most of the 15 cars that ive owned and they were always faster than the stock 3.20ish to 3.50ish gears, always. the z/g is not a unique case although some seem to think so and treat it as such. a lot of people on here encouraged me not to go 4.08 with nitrous but i know what works. ive been doing this too long. also, its like i said before, it really depends on the kind of racing you do as to whether or not its a benefit or a hindrance . in my g, dont have the traction issues a lot of guys seem to have in their z's. i dont know if its the longer wheel base or added weight or what. ive driven my buddy's hr 350z a lot and it breaks traction a lot easier than my revup g and im a little faster than he is, driver differences aside (ive been drag racing various cars for 15 years). with the gears i should be able to put several more cars on him in a drag race. on the highway, things might turn in his favor at speed, but we dont highway race here. that is why i went with the 4.08's. its only 15% more torque multiplication at the wheels. nitrous is like 200% at 300 when it kicks on lol. sure i spin in first, but im going forward and im fine with that. 15% wont break the bank on my setup. i expect the quaife to greatly aid in managing the additional torque on the bottle with the new rearend. ill let you know how it works out when i get around to installing them next weekend or the weekend after that. all i need for the swap is the sikky solid diff bushings.

 

^ What Italianjoe1 is absolutely correct, but you're also right. It's really about acceleration vs top speed. More acceleration (from shorter gears) means you'll be quicker out of the hole and at lower speeds but you'll also run out of steam sooner. Longer gears will give you a higher top end for a slight hit on acceleration. Given that you're only going from 3.5 to 4.0, assuming 6MT, the acceleration gain outweighs the loss in top speed (which most will never ever see). This is because most races, on and off the track, are don't require you to go deep into the triple digits. Unless you're doing a highway race starting from 100+, the one with shorter gears will win.


Gears and nitrous together will be useless on street tires only due to lack of traction, particularly at lower speeds, keyword being street tires and lower speeds. Nitrous alone will break the tires loose without hesitation and gears will only exacerbate the problem. On slicks, or where traction isn't an issue, greater acceleration will always be better. This is what the older posts about gears & nitrous was referring to, not the fact that gears is bad when used in conjunction with nitrous. And I think there's a few reasons why there aren't too many topics on gears & nitrous:

1. most people don't stick around with nitrous for too long and move onto more power adders, where you want longer gears to be able to put your power down better (because acceleration isn't really an issue anymore)
2. people eventually stop spraying just because ______
3. people aren't that devoted to drag racing to get every little acceleration mod
4. many people get nitrous because it's a cheap power adder and gears aren't cheap (much less tangible gains/$)

As far as having to shift one more time with shorter gears on the 1/4 mile, it won't really slow you down much if you can shift quick enough and if you aren't being forced to upshift right at the end of the 1320'. That is, sometimes, maintaining a (somewhat) consistent acceleration by hitting the rev limiter will be equal to or faster than the time you lose shifting (and therefore time spent decelerating; acceleration after the upshift may only make up the lost time).


This is just simple math with a little bit of logic and reasoning.

 

i couldn't agree more. you nailed it on the four reasons. i would even go so far as to say that there isnt one answer to the "should i get gears/nitrous" question. a lot of guys get on here and ask about it and expect there to just be some general, definitive answer to the question, when really, there isnt. successful builds are all about the combination. a lot of guys really dont get this. they just expect to keep bolting on parts and throwing money at it and it magically just coming together at some point. ive had a lot of people ask me if they should do the gears thing and i tell almost all of them no, after finding out their goals/intentions. ive got about $2800 in my new rearend (and other supporting parts) sitting right here, not counting the $2100 axles. going back to my application... mild cams are in the near future as well (264's probably). thats one of many reasons i went this route. 3hree you are right though... its a fact, traction is definitely going to be worse than before, but how much worse remains to be seen. i still think the slightly longer wheelbase of the g helps, and is probably one of the only advantages to that platform over the z. i also feel like the quaife is the most appropriately suited lsd for this application. i think its torque biasing characteristics will do a lot to keep the forward momentum up, spinning or not. the tires are always the limiting factor... and thats good because then you usually break less parts. you can better believe ill report on the newfound traction and acceleration characteristics as soon as i get a chance to swap the pumpkin/axles out for the new pieces. you mentioned lower gear (1 & 2) traction being the issue, not really traction in general. we have both sprayed enough to know this is true. ive thought about the issue a lot. its worth noting that i have a few methods of dealing with it on street tires that i am going to experiment with.

1) launch in first and hit the bottle in second. ive done this several times with the stock gears and i find it to be effective. however, i personally dont prefer this method because it is human error prone and i dont like taking my eyes off the road to find the switch when im spraying, especially in low gears. nonetheless, it works well enough.

2) i am going to double up on my solenoids soon and switch my electronics over to an nx maximizer 4 soon. this is more to deal with the complications of the nano system on a daily driver than it is traction, but i can experiment with the various progressive algorithms to see what works the best. i think they have a gear based one but you have to start in first every time for it to work.

i think the best thing about it though is that finally, we will put some real experimental data on the board. thats what is important. you also mentioned shifting and gearing at the 1/4 track. i think joe and i were referring more to the street applications of the extra shift effect. in the past, on my other cars, ive always tailored my drag race tire size to the cars performance on the track and chosen gears that put my cars in the sweet spot on the street. ive found them to be very different on some cars and just about the same on others, you never can tell until you run it. they ruined our 1/4 track when they repaved it so now its just an 1/8 track. i have to drive north 2 hours to get to a track where i can run a full 1/4 now... sucks... 140 miles on ET streets is sketch.

 

Launching in 1st and spraying in 2nd is a good idea when you lack traction on street tires. And since you don't like doing that manually, you should look into gear lock outs (standard feature on many) as it does just that for you. The only problem is that if you want to spray right away, you'll have to either wait until the next gear or hit the max set rpm value first to trick into thinking it's the next year. Alternatively, you could put the switch on the steering wheel.

As for the extra shift with shorter gears vs stock FD, given that the difference is so small (3.5 vs 4.0), it doesn't really matter if it's at the drag strip or not. As long as you're not having to shift an extra time vs stock FD and the race doesn't end right as you shift (time loss), the acceleration benefit should be apparent. If the difference of the 2 FDs becomes big enough, the acceleration difference, starting/ending mph, and the gearing ratio of the tranny will determine the outcome -- again, this is just math.

BTW, I definitely feel you on the long drives. I used to drive about 120 miles each way to get to the 1/4 drag strip until they built a new one, which was still 100 miles each way.