I was wondering, we have all seen/heard of the Z being limited to around 450 rwhp (or there abouts) before any engine blowups and problems. Well, I was wondering, these TT kits like the PE are coming out with like 400 rwhp at the wheels. Now, alot more than that is said to put you in danger. So what if you add a free flowing exhaust, high flow cats, flywheel, etc, that would put you up in the danger zone, would you need to start worrying about rods and such even though you haven't turned up the boost or anything like that in the engine???

Would be nice to know in what order these engine mods must be made, maybe we will find that out when/if manufactors start putting out stage kits.

 

Its the stock drive shaft that is limited...

Anything above that would probably be best to put a new tranny in all together w/ drive shaft etc...

 

I don't think the driveshaft is the limiting factor.

Fuel rails, connecting rods are some of the limiters from what I've read.

I've never read about the driveshaft failing.

Victor

 

We haven't had any drivetrain failures because no one has hit the drivetrain that hard with enough power enough times. Yeah the motor will probably go first in this car. I doubt you will need aftermarket rods for any NA mods. You will probably want to beef the top end with ti retainers, springs, etc. when you get bigger cams to help resist valve float and avoid damaging some of those small parts on top during your 8K RPM jaunts. I don't think you need rods until you install a power adder (nitrous, FI, etc.).

I think the clutch will need some beefing and I am not positive about how our halfshafts and ring and pinion will hold up to high torque. Did Smithtown ever launch on a full hit of nitrous? Wasn't it always progressive on launch? If they did launch on a full shot wasn't it one time (the time they blew it up)?

 

Are you guys thinking that if you stay between 360-400rwhp that besides putting in a heavier clutch, everything else should hold together?

I know it is speculation at this point to a degree because no one is putting out 400rwhp is there?

Jeff

 

carbon fiber driveshaft should be able to handle some solid power. garbage trucks use them and they have some massive torque going into the shaft. gotta figure the power the shaft has to hold is the amount of traction the tires can provide.

 

i thought i read some where that the drive shaft couldnt handle more then 450... hrmm.. never mind then...

definatly a stronger clutch!

im getting the clutch and light weight fly wheel from www.performancenissanparts.com very soon!

ill post review!

 

Cool info, but not what I was asking about, lol. Really, I am asking about a kit like the PE kit coming out. It quotes 400 rwhp, and I was really wondering what other mods that increase HP would do to the max safe HP for the engine (around 450 rwhp). I mean, if you add free flowing exhaust, flywheel, high flow cats, etc., then you could be in that danger area.

BTW, if anyone does have info on main things to replace in order to increase HP to a certain level, then by all means post it as we don't have any concrete info on this other than rods. Haven't heard anything about the driveshaft being a problem.

 

First of all our driveshaft is not carbon fiber. It is plastic. It has a little layer of carbon fiber wrapped around it. But it is still plastic. Also, if a turbo kit puts 400 HP out and you add something like exhaust to help it breathe, I don't think you have to worry about surpassing reliability levels as the exhaust does not FORCE the motor to make more power, it allows it to run more efficiently/easily and could ease some strain from it. Same with a flywheel and cats. They are not stressing the motor.

Zland, I think that's accurate. As long as the halfshafts and R&P can hold, I think it's cool. But I also think we won't see those numbers NA/streetable so FI comes to play which is a different type of stress on the motor.

 

I'm not positive, but after breaking into 400rwhp, all mods you do will help the car "breath", but will not take too much strain off the engine. The biggest problem in our car is our rods. I know once the rods, and possible piston work, fuel rails, new injectors, possibly a fuel pump, and definatly a new clutch, the car should be able to handle much more than 400rwhp without a problem. As many of you saw, I'm selling a PE TT kit, and that has safely put 400rwhp down to the ground without blowing the engine. Of course thats running it close, but that is 100% safe according to PE, or they wouldn't release their kits. No company would risk mass-marketing a kit which can potentially "blow" an engine. In my opinion, if I boost 7.35, I'd be safe and never run more than 6.5 just to be safe. Daily driving I'd run no more than 3-3.5psi. If you look at PE's TT kit, they got 160 (based on 240hp baseline average) gain at 7.35psi, which translate to 21hp/psi. Even running 3psi, you're going to be dynoing around 305hp (359hp flywheel based at 15% loss). Do you really need more than 360hp for daily?

Yes I know I got a little off topic, sorry =)

 

Also, if don't plan to swap out your pistons to lower the compression, I know a lot of people just bump up their headgasket size. On an IS300 stage 3 kit by PFS, they use a 3mm steel headgasket and 2.5 SS piping to drop the compression to 8.6:1, from a high factory compression of 11.3:1. With a new gasket on the Z, and the other mods listed above, I think you should be fine.. but then again I'm not a car expert, and only base my knowledge off what other people who went FI have done.

 

The drive-train is rated at 600hp, now the connecting rods we know of are definately not rated to handle say ~620 (275 shot of nos in one gulp) cause that blew the rods to say the least. But in terms of power, the PE kit has been running reliable at the 460 chp power level so I wouldnt worry about that more about just tuning it right, but a new clutch would be in order sooner than later.

 

Ricky, I know what you are saying, but if I spent all that money on the turbo kit, it would be hard for me to leave it at 3psi. 6.5psi is pretty reasonable. I do know, we are talking like, "this won't blow the engine". But if we want to keep our car for a while, on the limit of not blowing the engine is not where we would want to be.

 

Guys guys - the misinformation that gets posted here is making it worse than Club Si

Noone knows what the limiting factors are in the motor - simply becuase noones car is making all that much power.

How is the drivetrain rated to 600 hp exactly? How does anyone know this - they don;t they are simply reposting internet babble, which does not help any of us learn more about our cars.

Jut because someone did a 275 shot to their car (albeit without engine management of any kind) does not mean the stock bottom end cannot handle 550 hp.

Again noone knows, becuase short of a tiny (can count on one hand) number of people, no one has truly started tapping the limits yet, as everyone is sticking to basic bolt ons (understandable!). Give it time - plenty of people will try, blow it up, try again, blow it up, and 2 years from now, we'll all look back and see what a bunch of ***** we were for thinking th stock motor could not handle "x" or the stock tranny could not handle "y".

I have yet to hear about 1 car needing a clutch replacement yet too, and given that Nissan does not even release the info around their "performance clutch", how do we all know its truly any better (or at least, worth the money).

While we sell stuff on this site, and other sites, all too often I see people eager to please others, by posting more mods in their singature line than the other guy. It seems very few people really are interested in learning how to divide the BS from the facts - people are all to eager to take an idea posted by a person with a keyboard, and preach it as if its gospel.

Be smart guys - learn what it takes to make a quick and reliable car. 450 may turn out to be the practical limit of this car without going to internal work - it may be 550, and then again, it may be 325. Noone knows yet, so until you do, why bother guessing?

 

Yeah, of course, some of the numbers that are out right now have been leaked out of manufactors. Really, the only one that I have seen/heard to have the most truth to it is the mid 400 rwhp rod thing. Cheston, among others, have reported this on several occasions. Other than that, we really know nothing at all cause noone is making that much HP. Now, if anyone has reliable numbers for us by all means share it, like I said before.

I would be real hesistant to lower the compression of the engine, rather just go with lower boost levels, but that is just me.

 

depends how you lower compression - thicker headgasket - works great on some cars, stinks on others. I ahve not seen one offered yet for the Z.

If I were building a true high HP FI car, I'd run in the 8.5 :1 CR area, and pick my snail carefully (GT30 would do wonders), as would twin 2835's

 

Thanks for posting that. I've often felt the same thing. Not just on this forum, but on just about any car forum.

On that note, there is another thing that's been bothering me regarding drivetrain questions: isn't the capacity of a drivetrain rated in torque handling capacity... *not* horsepower? For example, excessive torque is what snaps a driveshaft or makes your clutch slip or breaks your tranny. Right??

 

Thanks for trying to answer my question potato. What do you think of this Z1?? If cats, exhaust, and such are added to the PE kit, would that put the kit in the danger zone of the engine's supposed mid 400 rwhp output??