mojo powered

iTrader: (2)

I personally am a fan of single turbo kits for the Z and here's what I was thinking..

with the TN and APS single turbo kits out there (twins are worse), you get so much midrange torque so quick that it's nearly impossible to get traction unless you drive on drag radials all the time.

My theory is that with a larger turbo that spools slower then either of the single turbo kits and running lower boost for the same peak whp and wtq, we could maybe get more useable horsepower without spinning all the way thru 1st, 2nd and 3rd.

Now, I don't mean so much larger to make the hp and tq curve similar to a supercharged Z's. We all know that although superchargers might be the solution for some, they do not offer anything near the torque turbo kits can. I mean large enough to move the full boost from say 3500 to 4200rpm. Everybody is raving about how quickly the turbo spools etc, which is really good. But to me, traction is more important on a daily driver, hence more useable horsepower.

We could even run say 6psi instead of 8psi. Such a setup not only would offer daily driving capability, it could also offer much higher whp and wtq figures if the engine were to be built and the boost to be raised.

All that being said, I was thinking of a possible 62-1 version of the Turbonetics kit (rumors? yeah I've heard some ha!) or a big GT35 or even small GT40 version of the APS kit.

What do you guys think? Do you think spool would suffer that much?

In my thinking, all I am trying to do is to shift the powerband a little closer to redline, and increasing the full spool RPM.

tig488

iTrader: (18)

youre right, no lie, right now, i can spin the tires (these are 275/35-19s BFG KDWs) all the way thru third and a little in 4th, when boost kicks in. feels great! usually at about 4psi is when it starts.

failsafe306

iTrader: (38)

Why not just get taller gears?

mojo powered

iTrader: (2)

you could do that, too.. but the rear end from the auto doesn't make that much of a difference and any other solution would be very expensive..

a larger turbo is usually a couple hundred more (sometimes less) than the one that already comes in the turbo kits.

Also, larger turbo's advantage wouldn't be *just* traction.. I also mentioned running lower boost and bigger potential for a built engine/high boost.

MIAPLAYA

iTrader: (3)

I agree with traction. I can also spin through third. Turbonetics is doing Stage II which will include a T61 turbo and the goal of 550 RWHP out of box. You could go with that on 6-7 PSI of boost but the numbers certainly arent going to be the same. You could possibly switch to a bigger turbine size to slow the spool up time if you want. Personally I think using a boost controller with gear based boost control can help with this and I will be testing my theory soon.

overZealous1

iTrader: (27)

i think the best way to go about it is to adjust the boost controller to knock the curve down abit, or get good with the throttle feathering, lol.
i have absolutely no problem spinning the tires and usually it is just a slight punch on pedal away. i am going to be looking at the rear suspension and see if anything can be done to make the car hook better. i'm thinking of having my 20x10 axis widened so i can fit 335's on the back. should look pretty sick!

aaronlosey

iTrader: (1)

you can get a boost controller with "gain", which slows down the spool of the turbo. i had this on my old rx7 fd, and it did exactly what you want. slows down the building of boost and smooths it out at the same time. i like spinning the tires though, if i didn't want to spin the tires, i wouldn't have gotten my tt kit ( which still is half finished )

i've had fast cars before though, and i like power delivery as fast as possible, and as aggressive as possible. remember a larger turbo will spool several hundred rpm later, sometimes a thousand later. this means you get to use the turbo less. and sometimes, a larger turbo actually takes a long time to spool, then you instantly hit redline it builds power so damn fast. that will mean you have lag and your slow, then all at once loose traction and still go slow. thats kinda what my rb25 hks2835 car is like.

mojo powered

iTrader: (2)

so let's get something straight here..

if you have a 8psi wastegate and run 9psi with a boost controller, the minimum boost you can run is 8psi as soon as the turbo is spooled, even with bc turned all the way down.

But if you run a say 5psi wastegate and run 9psi via a gear based bc, then what MIA is saying could be done?

Also, I'm looking at people with the APS kit and how they put a higher number of torque than hp, which to me is a sign of easy spooling turbo. I'm wondering what would happen if there were a GT40R instead of that for instance... to fully spool at 4k instead. Anyway, I have this perception that small turbo for such a large displacement engine will spool quick and provide insane torque too quick, whereas a larger turbo could give higher whp while making wtq later in the powerband.

damen

well i'm running a GT35R on my G35 coupe and i've hit 8.5 psi. at 2800rpms. so this turbo spools very early also. the kit now make 9psi. producing 383hp and 416tq. with a stock muffler. i've hit full tq. at around 4000rpms so yes this turbo spools very early and is great turbo.(those numbers are on a dyna pak and this is an Eternal Motorsports single turbo kit)

InSaNeZ

iTrader: (9)

I've heard something about the "BIGGER" turbos now being made to spool just as quick.
Anyone else hear anything about this?

damen

that very well may be true being a dual ball bearing turbo

Gman2004

iTrader: (8)

having higher tq vs hp number is a sign of a restrictive exhaust.

Netko350Z

iTrader: (8)

Any more info on Stage II???

Exta_Z

overall, you can't not expect the VQ35 to not produce HUGE torque from forced induction...especially turbos. I mean, look at previous Japanese turbo motors, they have all had at most 3.0 liter displacement engines and under thats why they never had problems with traction, turbos never "got up there as quick." Yeah i know, 0.5 liters does make a difference in hp/torque. Then again, Porsche can do it with its 3.6 liter twin turbo motors. What i always wondered was, will the car go crazy in traction if there is slightly more "turbo lag" in 1st and then come on strong midrange in 1st?

damen

now knowing that, i wonder if it's worth me changing out the stock muffler. i have a 3" exhaust running to the stock muffler. i was wondering if i would loose some of the throttle response. the tq feels so good though.

MIAPLAYA

iTrader: (3)

For now I just have the parts list and goals R&D hasn't been started yet.
Turbonetics T61 turbo
NewGen or dual Evolutions (most likely one of these) wastegates
Raptor BOV my remain but a chance of the Godzilla
550 cc injectors
alternate engine management AEM EMS has been talked about alone with others but nothing has been finalized there yet.

Goal is 550 RWHP at ~15 PSI on pump gas. Recommended for built motors ONLY.

taurran

iTrader: (18)

Hear anything on a fuel return line and regulator included in that?

I'd be interested in if it would be cheaper to go with this stage 2 kit on the stock block at lower boost, or just upgrade the basic kit with engine management, injectors, and a fuel return system.

MIAPLAYA

iTrader: (3)

No word on that. Like I said R&D has not yet begun. I just know the projected parts and goals. There was also talk of possibly using a T66 turbo too. We'll see what happens.

plumpzz

iTrader: (10)

My friends huge *** turbo supra spools slow but for the last 6 or 7 lbs of spooling is only over about 500 rpm. and it hits HARD= traction issues thru 4th gear.

sentry65

iTrader: (11)

the torque is what's causing wheel spin. Torque is great, but only if you're able to use it.

Sounds like people are wanting less midrange torque and more torque towards redline