350z twin turbo kit

[350zboost]

Hi there,

What twin turbo kit is best for my 2003 350z? I am looking for a reliable twin turbo kit that is capable of 400+hp and for a reasonable price.

[JETPILOT]

Hands down the Gredddy TT. You should sell the e-manage blue that comes with it and get a UTEC for tuning. The Blue really sucks. The kit should be good up to 625 whp with the right supporting modifications.

[phill Cosby]

I have no complaints about my APS system

[Burtonboarder950]

Hands down the Gredddy TT. You should sell the e-manage blue that comes with it and get a UTEC for tuning. The Blue really sucks. The kit should be good up to 625 whp with the right supporting modifications.

zerothread/359074
Modified by Burtonboarder950 at 3:47 PM 9/14/2008

[evildky]

I prefer the single turbo, fewer parts, cheaper to upgrade, less lag

[Marcus's Z]

I have no complaints about my APS system

I agree. Add the stroker kit with it and youll be pushing some crazy HP.

[R350Zz33]

cause every one has a spare 6 grand for a turbo and another 8 grand for a stroker just laying around lol

[dcz]

TT is good, but I am a single guy.. BUT if I had to do a TT kit, Id do greddy, too

[JETPILOT]

I prefer the single turbo, fewer parts, cheaper to upgrade, less lag

Single turbo = less lag? What color is the sky in your world?

[evildky]

ask a supra owner, how many of those crazy stupid fast twin turbo supras have done single turbo conversions? pretty much all of them, twins spooling faster is a myth, my L28ET and my Z31 both spool faster and make more power than my Z32TT

a propperly sized single will spool faster than duals flowing a comperable amount of ait

[R350Zz33]

but the supras turbos are set up diffrent thats why they have more lag one turbo spools up then that one helps the other spool up instead of spooling up at the same time from diffrent exhaust pipes idk

[Watermelonwarrior]

but the supras turbos are set up diffrent thats why they have more lag one turbo spools up then that one helps the other spool up instead of spooling up at the same time from diffrent exhaust pipes idk

The turbo dosn't help the other spool up.

In a sequential tt set up one turbo is used at lower rpms and both are used at higher rpms. Thats the type the 93-98 supra has. Where in a parallel tt set up each turbo is mounted to its own exhaust/turbo manifold. Which btw is what the 300zx tt has. And most people consider the sequential turbo set up to produce less lag. The only problem is that its costly and complex.

[xjmxstac]

I agree. My friend however had a 93 FD tt and did excatly the opposite. He turned his sequential tt to a non-sequential setup. Instead of having one turbo spool in the low rpm range he had both of them spooling at the same time at low rpm.

[JETPILOT]

ask a supra owner, how many of those crazy stupid fast twin turbo supras have done single turbo conversions? pretty much all of them, twins spooling faster is a myth, my L28ET and my Z31 both spool faster and make more power than my Z32TT

a propperly sized single will spool faster than duals flowing a comperable amount of ait

That's just plain wrong.

The Supra was a sequential turbo, not a twin turbo.

The 2jz is an inline motor with the exhaust manifold on one side so it would make sense to go with a large single to make power.

Big single turbo's have huge lag, but come on big time over 5000 RPM. If you building a drag car that would be what you would want if you were building a 2JZ motor.

On the Z the single setup isn't such a good idea. With the crossover pipe you lose exhaust gas velocity with the pipe bends, and there is also thermal/energy loss.

Twin turbo's will always spool up faster than a single.

[RCA]

The Supra was a sequential turbo, not a twin turbo.

The 2jz is an inline motor with the exhaust manifold on one side so it would make sense to go with a large single to make power.Big single turbo's have huge lag, but come on big time over 5000 RPM. If you building a drag car that would be what you would want if you were building a 2JZ motor.

On the Z the single setup isn't such a good idea. With the crossover pipe you lose exhaust gas velocity with the pipe bends, and there is also thermal/energy loss.

This statement is right. And on paper this is great info. But in pratice it isn't the same.

Exhaust gas velocity loss because of a crossover pipe is so insignificant that it won't be felt. And if designed correctly a longer exhaust manifold could be more effective then a short cast-iron manifold.

And interms of thermal/energy loss all that is needed is some header wrap and turbo insulator (exhaust side).Again wrap won't tottaly solve the issue completely but the diffrence won't be felt.

Twin turbo's will always spool up faster than a single.

Not always.

There are WAY to many factors and variables to make this statment absolute

[evildky]

so you think 2 30lb/min turbo's would be spooled up more quickly by a 3.0 v6, than if it were an inline with the same turbo's? but you think a 3.0 inline 6 will spool a single 60 lb/min turbo more quickly that a v6 of the same size?

keep in mind the mass of the 2 center sections, 2 compressors and 2 turbines is far greater than the single larger turbo, the single will take more initial effort but then will spool faster andhold more inertia between shifts

[R350Zz33]

battle of our turbo king (jetpilot) and our know it all nissan guy (evildky) lol good times who will be wrong tine in next time to find out

[rmezz13]

battle of our turbo king (jetpilot) and our know it all nissan guy (evildky) lol good times who will be wrong tine in next time to find out

I would call evildky the turbo Z guru and JETPILOT the 350Z TT guy.... But the funny thing is they are both arguing good points that are correct in different scenarios. You guys are both right and if you compare 2 turbos of equal size as a twin setup vs. one of the same size as a single setup, the single spools quicker everytime w/ less lag.... Bigger single has more lag but still spools faster once boost pressure is initiated, there for a TT would be less laggy VS. a single bigger turbo.

I would say go with the GReddy over the APS, purely based off the price of the two... Really which ever one you can achieve for the least amount of money.

[evildky]

turbo sizing is far more important than how many turbo's you have, and most people do nto understand how to size a turbo for their application, most people have no idea of the flow rate of their turbo and do nto understand that 14 psi form a 30lb/min turbo will make only half as much power as 14 psi form a 60 lb/min turbo

[RCA]

Yea this is a subject I always find my self thinking about...Small Twins vs Larger Single

So after reading every ones posts I decided to go to the only people I listen to when it comes to the mechanics of a car... EngineersEngineering Forum: Two Small Turbos Better Than One Big Turbo?

8th post Artsi states:

1.3.2 Sequential systemsA more extreme case of variable geometry is sequential turbocharging. Instead of varying the geometry of one charger the number of chargers is changed. The reason for using sequential turbocharging is to widen the flow range for the boost pressure required. Since still only one compressor stage is used it does not necessarily increase the boost pressure.Volvo tested sequential systems presented in an SAE paper in 1991 [1.26] as a part of a methanol engine program. The engine was a six-cylinder unit and the boost pressure target was as usual, slightly below 2 Bar abs.

They state that a parallel turbo system has around 30% lower inertia than a single turbo with the same top end flow characteristics, and thus should have a benefit in terms ofresponse.

Assuming ALL the different variables are the same (ex. PSI or flow awarded from each engine/turbo combo is the same, Turbo design, center cartridge type etc...)The general consensus is that turbo's inertia does not proportionatly shrink or grow with the size of the turbo. This causes twins to spool faster and provide more usable power then a single turbo.

EX)- 30 lb/min turbo has a given inertia of (x)- 60 lb/min WILL NOT have a given inertia of 2(x)- 60 lb/min turbo (using the quoted example above) will have a given inertia of 2.85(x)So running two 30 lb/min turbos would result in a 2(x) inertia And running a larger 60 lb/min turbo would result in a 2.85(x) inertia.

Extra inertia = extra lag

Now you also have to take into consideration that the quote was taken from Volvo in 1991. Turbo technology has changed dramatically since then, so the "30%" inertia difference quoted could now be 20%, 10% or less So I will agree that Twin-Turbos will spool faster (given the variables are all equal). BUT if it only spools slightly faster...Would the cost of a TT set-up justify the added performance?

We would need numbers from identical set-ups using updated technology to truly find the answer.

[NSRsheets]

If Your looking at staying around 400hp the Greddy should be fine for the price. The APS is great if you more power. I'm personally going to go with the Turbonetics single turbo kit when I get the money.

[R350Zz33]

when i go turbo i dont want high hp i just want usable hp. know what im sayin

[evildky]

I agree that the smaller turbo's are easier to spin but they recieve only half as much pressure to propel them but I still say it would take less force to spin the larer single turbine to 1000krpm than the 2 smaller ones to the same speed

and in a well engineered system the difference should be nearly undetectable

and a single will have less piping, and les piping = less pressure drop

[JETPILOT]

If you really want to get technical you need to look at the AR ratio on the turbine housing. That is the most important factory in spool time. Next... is the turbo a journal bearing or ball bearing turbo.. Ball bearing turbo's spool up a little faster. Look at the turbine whel itself, are the blades clipped? Look at the compressor discharge, is it dumping into a 2.5" or 3" downpipe? This all affects spooling. Compressor housing size is another important factor. Soooo many factors.

I had a turbonetics single turbo. It was at full boost at 4300RPM @ 10PSI. My greddy TT is at 16psi @ 3300 RPM and the Greddy uses Mitsu journal bearing turbo's vs Turbonetics ball bearing center section.

To simplify things maybe too much.... you will never see a properly sized single turbo capable of making equal power to a twin that spools faster on a Z.

BTW.... the Greddy TT kit can make over 600whp with the TD05H18G turbo's it comes with. I have yet to see a single turbo that will be at full boost at 3300 RPM and match the power. The only kit I know if is the Powerlab kit which reaches full boost at about 4600RPM for a 600WHP car. That kit uses the Garret GT3582.

[InjectedPerformance]

If interested we have a Greddy TT kit in stock w/intercooler. Price is 5899.00 shipped.

[rmezz13]

If interested we have a Greddy TT kit in stock w/intercooler. Price is 589.90 shipped.

i'll take one for that^^^, other than that - i have to wait.

[RCA]

When I go turbo I dont want high hp I just want usable hp. Know what im sayin

Yea for most people this is the case. But others like a little lag inorder to save some serious MPG.

I agree that the smaller turbo's are easier to spin but they recieve only half as much pressure to propel them

Yea but like I said a larger turbo will cost you 30% more lag then using 2 smaller turbos.

but I still say it would take less force to spin the larer single turbine to 1000krpm than the 2 smaller ones to the same speed

You can definitly "say" what ever you want. But I would rather KNOW. I have tried logic to come up with some car theroys but physics is a more solid platform of knowlege.

and in a well engineered system the difference should be nearly undetectable

This is true. I am also assuming both set-ups would produce the same HP and both engines are identical

and a single will have less piping, and les piping = less pressure drop

Well an engine (when on) is always producing exhaust so "pressure drop" isn't a real issue.I have seen guys running snails near their rear bumpers and the diffrence in the power curve between those who run snails in the rear of the car and in the engine bay is some thing like 500rpm.So running two manifolds instead of one won't make a diffrence and it defintly won't negate the extra inertia that a Single turbo system would bring to the table.

[evildky]

jetpilot, sounds like the turbo sizing was not optimal for your single, my L28ET spooled my T3O4E to 16 PSI at 3700 rpm (it used to spool faster but the engine was experiencing slow death so I can only state what I have dyno record of)(it hit 30 psi by 4250 rpm that wasn't good for the motor) and thats from my tiny ailing 7.3:1cr, 2.8 liter inecffiecient 12 valve, single cam 30 year old junk yard motor

rcabrita, I don't think you understand pressure drop, have a read:http://www.gnttype.org/techare....html

and here si a great single vs twin artical looks like the twins fow more air sooner but don't continue to spool as quickly as the singlehttp://www.turbomagazine.com/t....html

not seeing your "theory"of 30% come into play

I do appreciate the spirited debate, I am by no means an air flow engineer, just trying to pass what I have learend form my real world experience of boosting Nissan/Dtsuns for abotu 5 years now, I feared forced induction for too long, I wish I had given up on n/a and nitrous long before I did

[RCA]

rcabrita, I don't think you understand pressure drop, have a read:http://www.gnttype.org/techare....html

I am aware of pressure drop although I thought we were mentioning spooling characteristics so I assumed you were reffering to the exhaust side of things.But you know what they say about assuming...

Also that is a great link! I went through it and was fasinated. Also why is it on the top of the page it reads "theroy" hasnt this been proved allready?

Turbo Regals FTW

and here si a great single vs twin artical looks like the twins fow more air sooner but don't continue to spool as quickly as the singlehttp://www.turbomagazine.com/t....html

not seeing your "theory"of 30% come into play

I have read this article as well. But Even the writers mention that there will be variables that will affect the numbers.

Furthermore, low-end and mid-range tuning could play a role in the power output of the engines (which would only cloud the picture in a small "quick tech" style article).

Also it isn't my theroy. It's just some engineer's research.

I do appreciate the spirited debate, I am by no means an air flow engineer, just trying to pass what I have learend form my real world experience of boosting Nissan/Dtsuns for abotu 5 years now, I feared forced induction for too long, I wish I had given up on n/a and nitrous long before I did

Well I do still feel that what I wrote perviously still stands I do agree with you also. What an engineer calculates as true might not always work in real wold applications.

Maybe Volvo was testing a HUGE single and large twins which would explain the large diffrence between the two set-ups ("30%")Maybe Volvo was testing a twin GT42 set-up and a GT60 single set up.both are rated to 2000hp but the size diffrence between the two is enough to constitute the "30%" claim.

Also with this said, almost no one uses GT60 sized turbos. So seeing a "30%" diffrence in inertia for most normal sized turbos is laughable.EXTwin GT28RS vs Single GT35R (Both rated to 600hp)To spool the Twin GT28RS to full boost would be faster then the Single GT35R but not 30% faster. Maybe 5%-10% faster.I also do realize that the particular variables in this example I am useing. (Trim A/R of the turbo, exhaust manifold design, fuel delivery, intake manifold, tuning etc) affects the outcome. There are hundreds of variables.

But I stand by my statement of:"Twins will spool faster, but it wont justify its price tag"

But your the turbo expert.What two pratical turbo set-ups would match perfectly against each other??

EDIT: My Turbo Infohttp://www.capa.com.au/turbo_bb.htm

[evildky]

I am no expert, just a dork that had to learn enough to build the system that fit my needs, as for the dual 28's vs the 35, looks like the GT28RS flow about 37 lbs/min and the GT35 only flows about 62 lbs/min, so the 2 are going to outflow the single by about 12 lbs/min, which means they are capable of about an extra 120 hp, so I'd think they would take longer to spool given their increased potential, and I am no expert on thermodynamic's but in general you can get about 10 hp per lb/min or air, I know this is not exact but it's close enough to use as a rule of thumb

and you are absolutely correct, that the number of variables is nearly infinite, and finding a pair of turb's that combines match the total flow rate and VE of a single larger would be nearly impossible

here si a fun site to play withhttp://www.squirrelpf.com/turbocalc/