Maximum Boost On -9s With Standard Headgasket And Studs.

[r32-25t]

The -9 has a smaller front wheel then the -7, so size wise it's 9 7 5 10, flow potential in usually considered to be 7 9 5 10

[r32-25t]

20 minutes ago, TXSquirrel said:

I'm okay if -9's flow less power than -7's, but if -9's are more responsive then I will stick with -9's.

So with -9's on stock 440cc injectors, can I run 16psi?  I believe 16psi is the base setting for Garrett actuators.

Not without a tune and even then you may run out of injector and pump 

[Hadouken]

Should keep it simple otherwise the forum will once again be bombarded with the same questions.

7s make less power than 9s. Only a little bit.

7s are slightly more responsive than 9s.

[TXSquirrel]

20 minutes ago, r32-25t said:

The -9 has a smaller front wheel then the -7, so size wise it's 9 7 5 10, flow potential in usually considered to be 7 9 5 10

So what makes -9's flow more with smaller compressor wheel?  Are -7's and -9's different on turbine side?

20 minutes ago, r32-25t said:

Not without a tune and even then you may run out of injector and pump 

I already have Nismo pump and I will get Nistune.  Sounds like at same psi setting the -9's will flow more air than stock turbos?

[TXSquirrel]

5 minutes ago, Hadouken said:

Should keep it simple otherwise the forum will once again be bombarded with the same questions.

7s make less power than 9s. Only a little bit.

7s are slightly more responsive than 9s.

Right... as if the nicknames are not confusing enough for us newbies...  

[r32-25t]

Yes 9 and 7s have the same housings and exhaust wheel, it's only the compressor wheel that's slightly different.

yes the -9 will flow more power per psi compared to the standard turbos 

[No Crust Racing]

In terms of power it goes 7, 9, 5, 10

Yes it makes no sense when listed that way. 

As the power goes up, response goes down more or less. 

I neded up with a touch over 25psi in the midrange tapering off a little in the top end and a 354rwkw, I ended up putting ARP studs in for safety. 

 

[Roy]

I have been trying to tell folk here that if you are running E85 than the -7s will make more power.

The smaller, later model -9 compressor seems to do the same job with a smidgen better response on 98-100.

But generally when bolted to an engine and I have observed the difference is usually in the tune, health of engine and quality of bolt ons....not a night and day difference due one or the other turbo. ON 98-100

On E85 they seem to make a bit more power when you wind the extra psi in where as the -9s hit a wall sooner. I guess its to do with E85 masking as few little things and ultimately the little bit of extra flow that is in the different trim/aero compressoris realied with the -7s. I have seen far more 340-360 rwkws results with -7s then I have on -9s and generally 330-350rwkws with E85

One thing i think I can safely say is I have never seen -7s that are more responsive than -9s. I am curious to know how this has come to be summised as a reliable rule of thumb. Not to say its not true, I am just kicking around my experience, most reliable being two identical R34 N1 engines with the same Jap workshop ported head, same cams and near identical pipes etc and -7s and -9s with the same Sydney tuner. The trend observed with those cars is generally what I see play out with other setups. 

Too many supposed N1s arent N1s and people then equate N1s to being -7s yadda yadda yadda

 

Either way bang on 350awkws is a stout-one of the better result for a -9 setup!

 

[sneakey pete]

there's a bees dick of difference in the size of the -9 and -7 compressor, and the exhaust turbine is identical. The -7's are 44.6 and the -9's have a 44.45mm diameter compressor inlet size, and the outlet is 60 v 59.4mm.

People get 350kw with -9's, people get 350kw with -7's. The -9's theoretically have a fraction less inertia but in reality the difference isn't going to be noticeable. Personal preference would probably be whatever is cheaper, or even what is in stock at the time, but wouldn't side-grade from one to the other.

 

[No Crust Racing]

Yeah I've seen -7 setups do 360 on 85.

Mine is a flex setup and I wanted best power on both fuels, as you cant get 85 at the pump here, so -9s it was.

It's no single but it goes ok.

[Hadouken]

-7's aren't n1's?!

That's news to me

[TXSquirrel]

I realize this is a very general question, but how many psi can I run on -9's with factory injector?  Let's say at a safe 85% duty cycle.

My only current mods are Nismo fuel pump and Reimax exhaust system; 60mm front pipe, no cat, and 80mm cat back.  Plan to get Nistune, Tomei dump, and have factory manifold ported to match -9's.

[No Crust Racing]

For the cost of injectors, just replace them. 

Factory injectors will limit you to well under the capability of -9s, I think they max out around 250-260rwkw from my very vague memory, if not sooner. 

 

[TXSquirrel]

I plan to do this in phases.  I want to get Garrett's 15.5 psi actuator and I want to know if I can run 15.5 psi with factory injector.  If not I will try another actuator because I need to run this setup for a while before I can collect all the parts for next phase.

Next phase will obviously include larger injectors, but problem is all the other support mods.  I will need ARP head studs, a better clutch, a proper boost controller, and switch to MAP sensor.  So yeah the injectors are 'only' about $750, all the other parts needed to make them injectors worthwhile will cost another $1800.

[No Crust Racing]

Dyno thread shows stock injector pulling 288kw with -7s on 18psi but maxed duty cycle so it will be around there as max limit with -9s on stock injectors. 

 

 

[Dose Pipe Sutututu]

You live in America, get an Borg Warner EFR... will leave any twins for dead.

[Count Grantleyish]

I made 302 at 18 with stock injectors at 87-93% injector duty - not recommended but had no issues.

These with -9s. Never get to push it further.

Another GTR have same turbos, different dumps, injectors, tuner and it did 314 at 18.

Really should wick the boost up on this one!

[No Crust Racing]

Surely that can't be at standard fuel pressure? 

314 on stock injectors and stock fuel pressure? 

Sure you're not talking horsepower

[Count Grantleyish]

The 314 is with ID1000's

302 was with stock injectors and both are killerwasps cos I'm not murcian

Both on dinosaur fuel.

[Count Grantleyish]

And stock pressure too.