MilleniumZ03

I'm sure this question has been asked numerous times. What is a safe amount of boost to run on these engines in the new 350z. Would it differ between turbo boost and s/c boost? I really want a Z but I hate to have to spend thousands extra on a turbo or s/c to meet my wants. I have also considered a WRX which is about 5k cheaper depending on the model. Already turbocharged but only comes with 227 stock. It is a cool car but NOTHING compares to that 350z. I want it not only b/c of the looks but I know mods will keep on coming as this car gets more popular. But the WRX is cheaper, but, but , but.............. There are so many but's involved. What is the compression the the engine in the Z? I see so many posts on turbo charging or super charging this engine? Which one is better? Is one really better than the other one or does it come down to which one is more cost effective? I'm confuzed! HELP!

G3po

iTrader: (8)

Factory Z compression is 10.5:1.
Yes it's higher than optimal for FI , hence more the reason to make sure the FI you may use has a good intercooler.

To safely run higher boost levels , good gas >91 and lower compression will be needed. Good forged rods and ~8.5:1
pistons would allow significantly higher and "safer" boost levels.
But for most people this "bottom end" upgrade is a little much.
So ~7-9psi is probably good enough for most, and this should push near 400rwhp with a little tuning.

One thing to note comparing a WRX to the Z, since the Z has some cubes in it's favor , TQ is better and more useable as a daily driver. It doen't need to be "manic" to perform.
You won't have to turn up the psi nearly as high to match an sTI's output.

This should equate , generally to a more reliable , driveable platform. just my $.02

OCG35Coupe

iTrader: (3)

Compression is 10.3:1 for the 350Z.

Greddy's Twin Turbo i believe is at 7 psi making around 350 HP

ATI's Procharger is also at 7 PSI and making between 430-450 HP depending on other mods.

G3po

iTrader: (8)

Sorry , I stand corrected , the stock Z is 10.3:1.

I haven't seen the final Greddy TT rwhp curves yet @ 7psi,
but 350 seems reasonable for "rwp".

The ATI numbers @ 7psi are for hp @ the "flywheel" .

multiple ATI systems already dynoed @ 7psi have measured >360rwhp without other mods such as catbacks. Witout saying the TT system must later the exhaust system for mounting and to offset the addtional backpressure insert by the turbines.

At this point I prefer the ATI setup since it is simpler and much easier to tune. But I'm not building a race-car , but a pumped daily driver. But I am sitting on a purchase till other get a few k miles as alpha testers.

MilleniumZ03

Well I saw the cover of a magazine a month back and it had the Z with the TT Greddy kit and said something like 334 rwhp at 5 psi. Not bad but how much is a TT setup going to cost vs. a S/C? Aren't there generally more mods you can do to a turbo charged engine than a S/C? But then the more mods you run the higher the boost and that raises the question of running too much boost doesnt it? What are all of the factors that effect boost? I know I probably know most of them but maybe not all. When you talk about tuning up to 9 psi, how much are we talking here? What kind of tuning? Also, when you talk about 400 rwhp, are we talking about pretty much the simple bolt ons with the TT or S/C or with just adding one of the systems? Sorry for all of the questions. I am new to the Sport Compact world. I have always been into muscle and classics and never really paid much attention to non N/A engines(such as a lot of compacts). This car is what got me interested in your vehicle niche. I am learning a lot and hope to learn more. Thanks guys!

G3po

iTrader: (8)

Well one thing for certain , installation of any TT kit is much more involved than an ATI kit. From all appearances the ATI kit is about the simplest FI installation yet seen.. One poster ,some time back, made the comment that it looked like a" trained chimp" could install it . Well he could probably install it , but adjusting the fuel map to A/F ratio probably not .

No doubt the highest potential gains could be had by a well made TT kit, but it is by far a more comitted effort. Ifyou are new to auto mods and tuning you would definately want a reputable installer. So if Greddy sells the "base-kit" for $6k you can count on another few grand for installtion and tuning.

To get 400rwp out of the ATI kit on pump gas ( I imply 91 Ca gas) , you would probably need at least a cat back system an ECU optimization. I don't know if 8-10 PSI is necessary to push beyond 400rwp, but several people are experimenting and we'll know within the next few months. Generaly you may expect >10rwp per psi, "to a point" . Eventually the ECU should "de-time" and reduce power in order to protect the engine from detructive detonation. A point to make about the ATI setup, it couln be removed as easily as installed ( definately over a weekend), so any warranty disputes could be avoided if necessary.

I would expect that any push beyond ~450rwhp will start to turn up weak links in the engine and chassis such as Rods , clutch , half shafts etc. Much depends on how the car is driven.

For huge boosts such as 18psi , you would most definately need to beef up the bottom end (forged Rods and lower lower comp pistons (~8.5:1) and probably improve the intercooler (ie 3 core rather than 2. etc. This is clearly the realm of a veteran tuner.
And if you cna't re-build the long block yourself , you are talking an extra few k.


drive the car.

MilleniumZ03

Do you know where I can read up more on the ATI Procharger? Sounds very interesting. Now where and how do you get the ECU tweaked? What kind of things do they do to tweak it? What are the factors that can lower the compression of the engine?

Spencer@AAM

You can visit www.procharger.com to read up on the design and features of the kit. It really is an excellent kit.

As far as the ECU, we will be offering ECU reflashing for the 350Z here at Altered Atmosphere in about 2 weeks. We are still working out the details as far as pricing and shipping time go. But we can adjust the fuel maps and timing maps as well as raise the rev limiter and adjust other parameters. More details to come in a couple weeks.

In order to lower the engine compression, you have to replace bottom end components, like G3po said. Lower compression pistons will need to be installed. And while you're in there, you might as well upgrade the con rods as well.

The Greddy turbo kit is going to be really nice once it is released. But at 5.6 psi, those TD-05s are not even tapping into their power capability. But in order to crank up the boost you will have to lower the comp ratio in the motor. In NA form it is just too high to safely run high boost without breaking stuff.

nonmature

just so you guys know... the greddy TT is still being screwed with but they made 345 rwhp at like 6.4 PSI

-non

G3po

iTrader: (8)

As you guys probably know "SRP" is already selling forged 8.5:1 pistons and forged rods ( I will wait til Eagle puts out a set of good I-beams.. But this path is for deep pockets and those that can afford warranty dis-qualification.


Spencer , so it sounds like you are flashing ECU specifically with FI in mind. What is your business model? Will you accept a "core" ,
sell new ECUs pre-flashed etc?

My personal plans in sequence ( G35 6MT streeter, fall delivery) after ~5k brake-in and baseline:

a) Borla TD, etc.
b) Maybe Borla headers , but I have had quality issues with the
collector weld cracking i other vehicles, plus not sure if it's worth the marginal HP increase at top end over stock.
c) Intake plenum , ie Crawford,etc . I expect it to help some with FI
d) ATI @7psi, if the feedback(reliablity) for other Alpha testers is good thru next year.
e) Add 2-3 PSI (smaller pulley) , usually requires Water injection / octane booster with crappy Ca. 91 gas. Need to know if the factory injectors and ATI provide FMU are adequate.

If these get me reliable +400rwhp , I'll be pretty happy for a while, Since these mods can easily be backed out for serious drivetrain warranty concerns or resale.

Longer term after ~10-20k miles , if I still like the platform

f) Rods , pistons (.2 over etc.), reasonalbe CAMs, retainers etc.

g) lightened flywheel, clutch upgrade half shaft etc to handle the extra TQ.

However I want to keep it keep Ca. emmissions legit. Don't know if the lower compression and cams will allow that.

Spencer@AAM

Those are the "details" we are still working out. We can flash the ECu for FI or optimally tune it for NA operation as well. And we can flash it to suit whatever mods you have. Mike put over 40 runs on his before adding any mods (other than maybe the CAI).

I will definately post when we have nailed down the procedure and have the serice available.

Sounds like you have quite a plan in mind! Let us know if we can help you in any way

G3po

iTrader: (8)

The ATI kit appears like it's going to be very popular for many reasons. One of them being weekend installable without speciallized tools, so perfect for the "shade-tree mechanic".

So it looks like a "ripe market" if you guys resold the ATI "tuner" components @ ~10psi along with your own calibrated FMU, ECU etc.

The Ca. crowd may be interested in a setup specificaly for the 91 gas, catbacks, CARB.

Spencer@AAM

Absolutely. And from what I have heard directly from ATI, they have been getting slammed with orders. There really seems to be a huge market for FI out there for this car.

Another HUGE plus for ATI is that there is no hood modification needed. I know that Stillens kit detered a lot of people for that simple reason.

It makes me wonder if Nissan has taken notice and may think about a factory FI model at some point in the future. The demand and market is definately there. Could be interesting to see.

Thats a good point about the CA 91 water. We may have to do sometuning with 91 in the car and set some ECU parameters for it. It wouldn't be a problem at all. Thanks for the suggestion!

G3po

iTrader: (8)

Just curious , do you tune the ECU maps for a 160 degree thermostat? If you do , I'm not sure about Nissan, but other ECUs control the cooling fan trip points. If you run a ~160 , and the ECU controls the Fans, it is desirable to lower the fan set point as well. Some tuners seem to forget this point.