-7/9s Or -5s Garretts

[Phatboy]

Have a look at my new thread with my dyno just above. There are others who have posted similar threads.

I just got my GTR back with -5's. Reasonably happy with them. Not much steam below 3.5-4k, but a pure wall of speed from then until redline. Never drove -7s or -9s, so can't compare. I guess it really depends on your driving style and where in the rev range you usually are. -7 and -9s appear to come on slightly earlier but lose a bit of puff at the top end, so should be more fun in city driving where you hardly go above 60 km/h.

[im late]

For the sake of this thread I will post my personal experience with -5's once I get my car back.

My BNR32 is getting tuned tomorrow or Monday. It has a built/forged/balanced 26 (motor parts list too much to list here) 10.5mm Jun cams, Tomei cam gears, 6 Boost, Trust Extention Dumps/Front ( thanks Ash ), Apexi PFC D-Jetro, etc.....

Everything that benifits from ceramic coating was done.

Once I get it back I will scan the dyno figure sheet.

Then I will take it for a good long drive and describe when boost kicks in, etc.....

[Adz2332]

I went in and spoke to my tuner today had he defiantly recommends some -7s. He said tuned and set to around 20 PSI it will see 330kws without a prob mayb a touch more....

He said 5s would get there easier but wouldnt recommend them for the street at all....

[Bakes]

Who is your tuner?

[Adz2332]

Boostworxs....

He said he has tuned many very fast skylines equiped with -7s...

is 20 psi streatching it a bit far?

[GTR1993]

tell you in a week or 2 what the -5 is like just putting the car back together

-5s

tomei 260s

cam gears

sard 700s / 044

nismo afm

tomei dumps, blitz front pipe, custom 3.5" rest of exhaust

power fc

Going to run 20 psi.

Edited February 10, 2009 by GTR1993

[Bakes]

Boostworxs....

He said he has tuned many very fast skylines equiped with -7s...

is 20 psi streatching it a bit far?

If youre worried about running 20Psi, get the -5s and run less boost and make the same power. A good tuner will have the response only 500rpm behind the -7s

[R33GTRKid]

which is what my tuner is saying

[im late]

For the sake of this thread I will post my personal experience with -5's once I get my car back.

My BNR32 is getting tuned tomorrow or Monday. It has a built/forged/balanced 26 (motor parts list too much to list here) 10.5mm Jun cams, Tomei cam gears, 6 Boost, Trust Extention Dumps/Front ( thanks Ash ), Apexi PFC D-Jetro, etc.....

Everything that benifits from ceramic coating was done.

Once I get it back I will scan the dyno figure sheet.

Then I will take it for a good long drive and describe when boost kicks in, etc.....

As promised,

Dyno sheet. See here: http://www.skylinesaustralia.com/forums/Rb...80#entry4418655

Took it for a nice drive. Boost builds quite low (around 3600) then once it hits 4000 it pulls VERY hard all the way to my 8300 redline. Power delivery is linier (to be expected) not like a "on/off" effect like a big single. My knock snesors are faulty so it is currently tuned to 20PSI. Once they are replaced I'll be able to run higher boost and be able to monitor detotnation (in case I get a bad batch of fuel).

Overall I think they are ok for they street but I agree that if you are happy with 330RWKW they you may be better off with -7's or GT-SS's.

As my motor is built for a lot more power I am going to push higher later.

[Phatboy]

Boostworxs....

He said he has tuned many very fast skylines equiped with -7s...

is 20 psi streatching it a bit far?

I'd be VERY interested to see your dyno, just to have a look at what kind of job they do with the -7s.

If you want to know more, PM me for details on my experience with the tuning from that workshop.

[shy_s6]

As promised,

Dyno sheet. See here: http://www.skylinesaustralia.com/forums/Rb...80#entry4418655

Took it for a nice drive. Boost builds quite low (around 3600) then once it hits 4000 it pulls VERY hard all the way to my 8300 redline. Power delivery is linier (to be expected) not like a "on/off" effect like a big single. My knock snesors are faulty so it is currently tuned to 20PSI. Once they are replaced I'll be able to run higher boost and be able to monitor detotnation (in case I get a bad batch of fuel).

Overall I think they are ok for they street but I agree that if you are happy with 330RWKW they you may be better off with -7's or GT-SS's.

As my motor is built for a lot more power I am going to push higher later.

is that rw or all wheel hp? thats around the 330rwkw mark anyway at 20psi i would have expected more??

[R33GTRKid]

so there you have (2.5 rwhp more than) 330rwkw from -5's at 20psi on a built motor, so how are you able to get the same from an standard internal RB26 with the smaller GTSS's (-9's) or 7's without pushing them way outside their efficiency range?

[djr81]

so there you have (2.5 rwhp more than) 330rwkw from -5's at 20psi on a built motor, so how are you able to get the same from an standard internal RB26 with the smaller GTSS's (-9's) or 7's without pushing them way outside their efficiency range?

330rwkw for 20psi is an awful lot of boost for that reading from a -5.

My RB26 is within a few rwkw using 15psi.

[R31Nismoid]

so there you have (2.5 rwhp more than) 330rwkw from -5's at 20psi on a built motor, so how are you able to get the same from an standard internal RB26 with the smaller GTSS's (-9's) or 7's without pushing them way outside their efficiency range?

Ever thought that 330rwkw on 20psi from -5's is LOW for a built motor ...?

I mean, seeing as though there are built motor results in the dyno sticky and all...

And, once again for the record, the GT-SS are NOT outside thier efficiency range for 330rwkw. We have been over this, done the actual calculations, seen results...

Yet you still post up factually wrong information... i wish it would stop as it does nothing but mislead users

[R33GTRKid]

I am sorry but I asked a question not made any factually incorrect statement

Edited February 11, 2009 by R33GTRKid

[im late]

is that rw or all wheel hp? thats around the 330rwkw mark anyway at 20psi i would have expected more??

That is rear wheel HP.

Why would you have expected more? Have you had personal experience with GT2860R-5's?

Once I increase the boost to 24PSI then the turbos will come 'alive'.

Once I replaced my faulty knock sensors I will tune and increase boost.

We are expecting over 500 All Wheel HP once done.

I will keep you all posted.

[im late]

330rwkw for 20psi is an awful lot of boost for that reading from a -5.

My RB26 is within a few rwkw using 15psi.

What are your turbos?

[im late]

so there you have (2.5 rwhp more than) 330rwkw from -5's at 20psi on a built motor, so how are you able to get the same from an standard internal RB26 with the smaller GTSS's (-9's) or 7's without pushing them way outside their efficiency range?

Hi Simon,

You do not need a built motor to work GT-SS's to their peak. You just need the essentials (Aftermarket ECU, Injectors, Fuel Pump, Exhaust).

There are heaps of cars in Australia with stock motors running the essential mods mentioned above producing around 330RWKW all day every day.

You do need a built motor if you want to run -5's to their peak.

If you saw my dyno post I stated I had to stop at 20PSI during my tune because my knock sensors are faulty and in case I get a bad batch of fuel I won't know about detonation until it may be too late.

Once the knock sensors are replaced then I will up the boost to 24 (maybe 25) PSI and then we will see why -5's are the choice if you want higher HP than what -7's or GT-SS's can do.

I'll say this again.

GT-SS or -7's are THE turbos to have for the street if you have a stock motor.

I have a built motor so my turbo choice is greater. For now I choose -5's.

Later...... who knows?

[R33GTRKid]

thanks mate,

but what I am saying is that you ran 20psi through -5's and only got 330rwkw. How much boost would you need to run through GTSS's (9's) to get the same 330rwkw, and is that level of boost required then not out of their efficiency range and dangerous for a stock bottom end.

[im late]

thanks mate,

but what I am saying is that you ran 20psi through -5's and only got 330rwkw. How much boost would you need to run through GTSS's (9's) to get the same 330rwkw, and is that level of boost required then not out of their efficiency range and dangerous for a stock bottom end.

Although I have never personally had GT-SS's I have read the whole Dyno thread and have found a common pattern:

Stock Motor + GT-SS (7's) at 18PSI is around 300 - 310 RWKW

Stock Motor + GT-SS (7's) at 20PSI is around 310 - 340 RWKW

These turbos run fine at those boost settings

If you push past 22PSI the turbos would start to be less efficient and run out of huff over 6000rpm.

There are some cars doing up to 350RWKW on GT-SS's with a stock motor (and the essential supporting hardware).

It has been proven many times in japan (and here for that matter) that a stock RB26 can produce up to 400RWKW with the required supporting hardware.

For this to be true the following would need to apply.

1. The stock motor must be in an excellent condition (i.e. good leak down and compression tests)

2. Hoses, belts must not be the original ones (they are over 15+ years now)!!

3. The water and oil pumps must be in tip top working order (they would be questionable after that many years)!!

Basically if you have a stock 15+ year old motor don't expect it to last as long pushing 300+RWKW than if it was just running stock turbos.

Hope this helps.