N/A 350Z - How far have you taken it?

[Teardropz98]

Concidering that twins or SC are not relatively cheap either to install for decent HP. Has anyone really considered doing a N/A upgrade. Without any FI whats so ever to see what type of potential this engine plant has to offer. From Cat-back system to the front Cold-Air Intake and everything in-between? I've started the engine build of this type. Thinking that life expectancy would reach further if I left out FI, that being the main reason but to also keep the engine true to its roots sorta speak.

List of mods and keeping it short for an Idea of power output:

High Compression PistonsCams5 angle Port and polished headsStraight Test-down pipesTrue Dual exhaustCold Air IntakeKentix PlenumheadersSpring and Lifter upgradeJimWolf Flywheel/clutch upgradeTurbo XS UTEC CPUUnorthodox Pulley Set

Just and idea of what I'm doing to it. So tell me what have you guys done and what power potential will this bring the car too??

Modified by Teardropz98 at 11:24 PM 7/18/2006
Modified by Teardropz98 at 11:25 PM 7/18/2006

[C-Kwik]

My question is how much does all of that cost vs how much HP will you get? There are a few labor intensive items you listed and could cost a lot of money/time. I would imagine you might spend at least a few grand on parts alone(probably even more than 5,000) with that list. I would expect total peak power gains to be relatively small as well. For the money, you might actually be better off going with a low boost FI kit.

Having spent plenty of money on NA mods for an S13 I owned and seeing no results and then turbocharging an S14 I owned and seeing huge gains, the money for an FI kit is well worth it as long as it is reliable. You will feel more satisfied with the money you put into it as the results will be much more noticable.

[joe603]

I agree with C-Kwik...Those mods are very expensive, plus the VQ35 for the 350/G35 is already pushing the blocks limits. Spend the money on a decent forced air mod and a good exhaust-you'll be very happy with the results.

[idriveaTTz32]

Nismo managed 350crank on the RS concept and that was all NA...im sure you are aware that you wont reach the same numbers as a FI setup so I give you props for treading where few are willing to go. To truly take advantage of an NA set up you will need a shorter rear end and a reallyu good weight loss program with added chassis bracing.

I suggest you check out the brief article on the Opera 350z thats in the current Sport Compact Car magazine as they too went NA, but focused more on the chassis of the car.

With a built NA setup I think you will loose more of the cars streetability (loudness, rev range if you shorten gears, ride harshness if you go crazy with chassis weight loss mods etc).

If done properly I can imagine a 350-375 wheel hp range would be feasible. If you really have the money to spend on it, I'd look into getting the Nismo head packages as they are built a lot better than stock obviously an probably better than what other companies can do or look to Cosworth for some help (rumor has it they will be releasing VQ crate engines soon).

I do agree with above though, bang for buck you're not going to beat a turbo kit, but NA hp is awesome in its own right so I say go for it.

What cp ratio, displacement and bore/stroke do you plan to run?

[C-Kwik]

If done properly I can imagine a 350-375 wheel hp range would be feasible.

Getting into this HP range NA would probably mean some serious revving(8000+ RPM) and some wild cams. This means low to mid drivability may suffer and may require a high idle. The variable cam timing may be able to help if tuned right, but still may need a bump in idle RPM. Attaining more than 100HP Liter is not terribly difficult in a race motor, but it becomes harder when trying to combine it with everyday drivability. Revving this high would require strong lightweight pistons and rods to keep tensile loads in control.

[Teardropz98]

I totally understand the concept, more bang for the buck with a FI system. Dont get me wrong, after doing research and looking and the Pros and Cons of each of the 2. In the long run, even if i went FI the internals would probably need a stiffer more reliable tuning. I felt that going N/A gives me something Different to brag about, safer in the long run and comes to me in a more reliable longer lasting block. Maybe one day in the near future I'll stick in a SC with low boost and space the heads to free some space (to compensate for the HighCompresionPistons) to really boost its power level. I'm not limiting my options, just mearly setting this up in a safer direction. I might even like the power output of this N/A setup who knows. Be good to play in a different field from the rest of the crowd no?BTW CR is set at 11:1, bored to 96mm vise OEM of 95.5mm. I'll let you guys know the outcome of it as soon as its back from the shop. Hoping in a week PICS will be posted soon as well. Thanks for the advise and opinions. Will shoot you guys the detials as soon as I know more.

[C-Kwik]

I'm all for being different, but depending on your power goals, going FI with a low boost set-up can be less stressful on the engine. I'd maintain the OE redline. This will probably be the biggest factor as far as reliability is concerned. But don't expect much of a difference in HP without being able to rev higher.

As far as going SC later, don't use any method of spacing the heads. You can actually do more harm then good. Combustion chambers are designed with quench areas where at TDC, the piston edges come very close to the top of the combustion chamber. This pushes a large amount of the mixutre to the center of the chamber for a more efficient burn. The quench area has such a small amount of space that any air/fuel in it is too cool to burn due to the proximity of the cooler surface of the metals surrounding it. This helps prevent detonation with the high compressions modern motors run. Opening this area up can allow detonation to occur more easily. Add in FI and you could end up with a recipe for disaster. While the quench area can still be more than the factory setting and still prevent detonation at TDC, bear in mind that TDC only occurs for a moment in the combustion process. The moments just before and after TDC still have very high pressures and heat and you want to make sure detonation doesn't propogate during these crucial times.

Moving to a lower CR piston is a much better way to lower CR.

Personally, I'd be concerned with trying to run 11:1 compression in the first place. Especially on a factory ROM tune. The VQ in the Z is pretty high strung already. Pushing the envelope here may not be wise. I'm not saying it won't work, but I don't see this as setting out in a safer direction.

Either way, let us know how it turns out.