-7/9s Or -5s Garretts

[Marko R1]

what are the -5's, -7's, -9's & -10's rated at hp each?

[R33GTRKid]

I am pretty sure as follows:

-5's 350hp,

-7's 280hp, (maybe 300hp)

-9's 300hp (maybe 320hp)

-10's 400hp

[shepo]

Ah, so that was your black GTR @ Sabbaddin Automotive? Mine is under the blue cover, lol.

Yarp, that was mine. yours was the charcol grey one right? getting the whole rebuild and the works... should be pretty sweat when its all done, we should get together and go for a cruise when its up and running.

[silva33]

I have read this thread a few times and like everyone else I am so confused! I want to go -7 or -9's but I am tempted to go -5's!

Why don't more people go for the -9's I dont think I have seen any dyno results of -9's, if so many people are confused like me about choosing between -7's and -5's then why don't more people go for the -9's?

Do the -9's not perform well? on paper they seem like a good compromise if you are worried about lag and want a street car.

I think that lag is also very subjective, My 34 GTR for a stockish car is great for response and I would be happy to lose a little response but the -5's some people say are alggy and others not at all.

decisions decisons!

[Travis Trayhern]

with the -5 i was looking ordering some but they have two rear housing option a/r.64 or .86 ? what one do i pick i want around the 350-400rwkw some one help out here

my setup full built engine, cams, head work, the works really, mainly circut and some weekend driving

Edited May 6, 2009 by Travis Trayhern

[R31Nismoid]

I have read this thread a few times and like everyone else I am so confused! I want to go -7 or -9's but I am tempted to go -5's!

Why don't more people go for the -9's I dont think I have seen any dyno results of -9's, if so many people are confused like me about choosing between -7's and -5's then why don't more people go for the -9's?

Do the -9's not perform well? on paper they seem like a good compromise if you are worried about lag and want a street car.

I think that lag is also very subjective, My 34 GTR for a stockish car is great for response and I would be happy to lose a little response but the -5's some people say are alggy and others not at all.

decisions decisons!

Its easy Dave

Just go for a ride in a few cars

RPMZ, Scotsman, Ferni, myself - all running the smaller ones.

JAGR33, archie01 etc are running the larger.

Try get into those guys cars for a spin and decide for yourself, they all come from racepace with similar motors/tunes so its all in the turbos for the most part.

Street = smaller

Circuit = bigger (if you need the power)

I'd choose by seeing them in action

[silva33]

Thanks Ash a ride in different cars would sell me in a second I think,

But out of the smaller ones which are the better options? -7's or -9's as I think that the -9's also have the rear housing option at .64 and .86?

This is where I can not find much info, if the -9's are equiv to GTSS then which rear housing option is the way to go? is the .86 to big for the smaller turbo?

I appreciate everyones help

[Marko R1]

in regards to rear housing dont go for the larger .86 as these are suited for a single application and is overkill, as told by gcg turbos and others in the know how. will be a lag monsta!

for this reason i stuck with .64

[discopotato03]

Silva I did a bit of digging around last year and PMd a few people in the US that have genuine HKS GTSS turbos (RB26 spec ones , there is an SR 20 spec one as well which is different) .

The cartridge (center section and both wheels) has the same part number as the 707160-9 turbo and I think from memory the housings are the same as well .

Usually HKS only has unique model specific turbine and or compressor housings made if there isn't a Garrett one available to do the job .

I'm told the situation is that if HKS get Garrett to develop a unique turbo (or cartridge) combination for a specific purpose HKS has the rights to it for around 6 years . Then it's open slather and Garrett can sell it through their on distributors if they like .

If you want to go through the process ask someone who has RB26 HKS GTSS turbos to pass on the turbos ID tag numbers , then compare these with the Garrett 707160-9 turbos ID details .

I'm pretty sure they are one and the same thing but please double check , I'd hate to see you buy the wrong thing because of my fallible memory .

Cheers A .

[Bakes]

Here are my results: R34 GTR, stock turbos vs -5s

At 0.9Bar, the -5s are behind in response till 4400RPM. The most they are behind at any point is ~600RPM. In a six speed, below 4000RPM is just for cruising in traffic anyway.

I really cant tell that it is laggier or anything, especially when it comes on boost at the higher boost setting

[R31Nismoid]

Here are my results: R34 GTR, stock turbos vs -5s

At 0.9Bar, the -5s are behind in response till 4400RPM. The most they are behind at any point is ~600RPM. In a six speed, below 4000RPM is just for cruising in traffic anyway.

I really cant tell that it is laggier or anything, especially when it comes on boost at the higher boost setting

I can tell

You basically have nothing till 4400rpm, thats fairly laggy.

Mainly because the GT-SS i have are making 15-16psi (280rwkw) a lot earlier. Im making positive pressure and a fast moving gauge from 3300rpm.

So not quite 'as stock', but very close too it.

[silva33]

I must agree with Ash here, those -5's on the graph look laggy, I quite like the way the stock turbos kick in nice and low and find myslef never really wanting or needing to push it over 6,000rpm...

I think Ill chuck my car on my mechanics dyno and compare it to his other customers who have the -5's that way I can have an accurate comparission between the two, as we will be using same computers and tuner.

To me those -5's look laggier than just 600rpm behind, as getting to .9 bar they are much laggier than that, they look like they feel very progressive in the lower rev range where the stockies look very punchy and responsive, the -5's don't come on boost like the stockies until 4100ish rpm

[NickR33]

the T517z's on my car come on hard at about 4000rpm but go on to make 360rwkw... on 20psi... they are old school plain bearing turbos too... I think only go for the bigger (-5's) if you intend on pushing them... no point sacrificing the bottom end response if your not going to work them really hard up high

I have NOTHING below 4000rpm... big cams make sure of that lol... then again if I wanted low revs performance I would have stuck with the ol' GTSt... RB25 + 2835Pro S + baby cams combo, that was super progressive

I do like how you can get away with light switch delivery on a GTR though, just grips and goes! (and has passengers looking for something to hold onto)

I just reckon there is not much point having turbos that your not running decent boost through... you may as well so as small as possible and try and get the most out of them... otherwise you'll always be talking about how much you 'could' make if you wound them up... whilst not having the response of smaller turbs

[Bakes]

Each to their own, I dont notice the lag when Im gear changing at 8000RPM

[Swiper the Fox]

Each to their own, I dont notice the lag when Im gear changing at 8000RPM

great post Bakes.

[Marko R1]

Each to their own, I dont notice the lag when Im gear changing at 8000RPM

i was criticized on lag when i ran gtrs's 5yrs ago, depends on driving style as i too like the gtr howling revs :-)

[silva33]

Everyone makes valid points, I think the only way to decide is to hop into a car with both setup and see what I think.

Do we all agree that max boost on a stock bottom end would be approx 18-20 psi (20 at the absolute max only for -7's) I am not looking to build my engine unless it goes bang, and it is quite healthy so unless I do something stupid i think it should be fine.

[Marko R1]

Everyone makes valid points, I think the only way to decide is to hop into a car with both setup and see what I think.

Do we all agree that max boost on a stock bottom end would be approx 18-20 psi (20 at the absolute max only for -7's) I am not looking to build my engine unless it goes bang, and it is quite healthy so unless I do something stupid i think it should be fine.

- my 1st engine was running 19-20psi, after 6 mths ring land collapsed (that was a genuine 90,000km engine, aust delivered gtr with full history)

- my current was running 19-20psi, after 9 mths same thing

dont expect it to last long - dont forget these engines are pushing 20yrs now

[Bakes]

Yeah, I didnt want to push mine either. Im happy with the power its making considering its running ~17.5 Psi, 18 max

Better safe than sorry

[Roy]

Each to their own, I dont notice the lag when Im gear changing at 8000RPM

I say the same thing. Only need to go so quick when going to the video shop of bottle-o. WHen you need to go fast you arent driving under 4,500rpm