WE are in the process of developing a TUrbo Kit for the 350Z. we are using my (axis 350Z as the platform) we have experince good results previousl in my Axis MR2 Spyder.

We like some inputs from 350Z owners.

Option 1
Single turbo
about 400hp at the wheels
about $5,000.00

Option 2
Twin turbo
about 400hp at the wheels
about $7,500.00

using stock internals, all bolt on, on pump gas.

which option would you choose,

would you buy it?

thanks for your input

 

Axis,

What would be the relative advantages and disadvantages of each system? Currently you are estimating the same power out of each one, but with a significantly reduced cost for the single?

Would the twin turbo be sequential with different sized units, or two of the same sized units, but one for each bank of cylinders?

Would the biggest difference (other than cost) between the two systems be turbo lag?

I personally plan to do mainly AutoX and circuit type tracks, so I would probably be staying away from turbos all together. However, if I were looking at a turbo setup, my biggest concern would be to have as small a turbo lag as possible, and have a very linear rise in boost and torque in order to reduce the chances of upsetting the car during cornering.

I have a feeling that a twin or sequential setup would be best for me (but like I said, I will most likely go N/A or stay stock)

-D'oh!

 

I believe a twin turbo setup will have much less turbo lag then one big turbo.

 

The added cost is because of the added Turbo. The smaller ones cost a little more. Twin would be same size, one for the left and one for the right. There wouldn't be any noticeable Turbo lag. If the Turbos are sized properly there is very minimal Turbo lag. The HP is based on boost. We are not going to use any more boost single or twin. It will be the same.

 

i might go for option 2 IF there is a good fuel management solution, not some piggy-back bandaid.

 

I have a twin turbo Audi 2.7T right now, and it still has lag, but much less so than one bigger turbo.

So I would go with the twin turbo set up.

HOWEVER, for the money, and $7.5k is a LOT, I'd expect installation to be included, and some sort of powertrain warranty up to 75-100k mi.

There is a 500 hp supercharger for the H2 Hummer. It's 10k, but it has a 100k mi powertrain warranty.

I'm a little skeptical the Z's drivetrain could take 400 rwhp for the long term. Please prove me wrong!

 

I'll take option one. Are you guys using a ball-bearing turbo (please say yes)? What's the size of it? What brand? I would think a 3.5 liter v6 should be able to spool a decent sized ball bearing turbo (18g maybe even 20g) at a low rpm. Keep us informed. BTW do you have a website link?

 

What kind of turbos?

 

I think some clarification is in order regarding the Pricing you submitted.

Personally, I would want the Twin-Turbo option, simply to minimize the Turbo lag that you get with 1 bigger single turbo option.

Secondly, as someone asked, the Drivetrain can handle a tremendous amount of HP. Nissan service technicians have commented that the Drivetrain is much more durable than the older 300zx, and in fact could handle at least 600HP. Not sure how the VQ35 engine will handle more than 400HP on stock internals.

SO questions on the pricing, all relating to the twin turbo:
1. Pricing includes what? Wastegates, Blow off valves, Intercooler?
2. What type of Intercooler, and what version/type of Turbo
3. Pricing assumes Installation? 7500 is quite expensive if it does not include Install.

That's about it

 

OPTION 1.

 

several key factors when it comes down to payin' BIG money like a turbo kit.

1. Which type of turbos? K03/04?T03/04? ball bearing? fluid?
2. does it include:
a) fuel pump? new fuel rails?
b) bov?
c) a/f controller?
d) boost gauge/controller?
e) warranty?
f) exhaust system?
g) intercooler?
h) is piping included?

3. how will it compare to other companies turbo kits, pros and cons..

yea. i would like to put a twin turbo kit on the Z. by all means, life without boost is like... life w/o ice cream. Yea its ok for a while. but you eventually gotta have some.

i wouldnt mind a single ball bearing turbo... that would cure the lag issues. as long as all parts made for it. like the piping and wastegate, are all nicely manufactured and correctly welded...


just a suggestion...

is yours the yellow Axis car with the fake HKS intercooler?



--cheston

 

how much boost can you feed to the stock internals without lowering compression? also can the 350z handle boost on the stock ecu or are you planning on somekind of piggyback computer.

thanks,

 

the stock internals on the VQ30 can hold up to around 11

VQ35, maybe around the same. ..


where's Mardigrax?

 

Option 1

Cost less, easier to maintain, and less costly to upgrade.

 

I agree with that. Today's ball bearing turbos do pretty well with lag and regain boost after shifting instantly. I figure that the single turbo kit would spool quickly because the turbo won't need to be very big to support 400 hp. If you figure a small 16g can support 350hp, a big 16g or 16g killer can support 400hp and a 20g supports around 500hp. I would guess a size around 20g would be close to correct and should spool at a pretty low rpm. This is speculation of course.

 

Well, I would "prefer" a twin turbo set up.... but if it would cost $2500 extra, I would definitely have to drive two cars, one with single turbo, one with twin turbos. For me to pay that extra $2500, that twin set up would have to be lag free, as if it came from the factory.
Just out of curiousity, how much boost would you plan on running? Just looking at the compression ratio alone, I speculated that this engine would be able to easily handle 8 psi, probably 10 with an intercooler.

 

I will be going FI or NA. It all deppends on these key factors:

1. Reliability
2. Tuning
3. Design and Quality
4. HP
5. Cost

I had an Impreza 2.5 RS that I turbocharged. I had a Spearco Top mount intercooler, greddy blowoff, HKS EV4, Apex-i ITC and S-AFC, Holly fuel pump 255lph, Stock injectors, 3 inch down pipe and exhaust, No Cat, Turbonetics T3/T4 OE ported, polished and clipped, Lightweight flywheel and pulleys. I ran between 12 and 26 psi on the car. I didn't blowup anything because of the tuning. The shop that installed it on the car had done another 2.5RS before. They knew exactly how to tune it. My best time in 1/4 mile was 12.8@108. The kit was designed by a small company in BC, Vancover. The kit worked great. I didn't have a single problem.

thanks,
Greg

 

I gotta say, all this non-sense about a twin-turbo vs a single having the same horsepower, with almost NO-LAG for either setup makes absolutely NO SENSE.

Why spend an extra $2500 on a twin turbo, if the single outputs the same HP, and as people have said on this thread, there won't be much lag with either setup.....Almost like its not noticable between either setup.

The arguement just doesn't hold water. Greddy and PE are designing twin-turbo kits for a reason. What is the reason? I assume to reduce lag in the lower RPM ranges.

Axis007,
Can you please give us the pros and cons for both setups?
thanks

 

joeshow750,

You must be a former DSMer or current DSMer to talk about 16Gs and 20Gs.

My 16G on the 4G63 motor (2.0 Liters) make full boost at about 3000 rpm, this is on 7.8 compression.

If I slap on the bigger 20G onto my VQ3.5 with 10.5 compression... hum... I think it can spool a little lower.

 

Cintel7
Guilty as charged, DSMer here ...my fourth vehicle is a 95 talon. Do you mean you think a 20g would spool at a lower rpm on the VQ35?