-7/9s Or -5s Garretts

[R31Nismoid]

- 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

Dave has a R34, so 10 years give/take - not a clapped out R32 RB26

[Marko R1]

LOL

an aust r32 with genuine 90000km, and its last 4000km of life @ 19psi...is that "clapped out"

when the rb26 is strained on boost, generally a ring land will collapse with stock pistons. regardless if its a 32, 33 or 34.

so how do u explain my mates 34 with 50000km which let go on the same boost?

i learned the hard way

[R31Nismoid]

Could be in the tune, could be a lot of things.

Plenty of stocker motors running around 300-330rwkw safely with the N1's/GT-SS's. You've gotta ask yourself how they are doing it if they are so fragile.

Im not saying the RB26 is bulletproof. Once you get to 350-370rwkw you are on borrowed time no question.

However 300-330rwkw is looking to be the sweetest spot for them

[Marko R1]

point taken.

however my current gtr had gtss's on 325awkw tuned by crd, would be good if ur theory was true

[R31Nismoid]

Proof is in the pudding though unfortunately. Nothing to do with a theory when the RB26 dyno sticky and various threads are living proof of it all

If a large percentage of people do not have problems, just because you do means you were in an unlucky minority.

So basically - sucks to be you. You had to foot a new motor bill when the majority have not. Just how it goes sometimes.

Doesn't mean for a second everyone else is going to have the same drama's as you, far from it

[donkeypunch]

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

nicely put.

[Marko R1]

dave, u might fall in the minority group like myself.

seriously be prepared to fork out money with high boost if it doesnt hold, i was hence why i pushed the boundary twice.

[Phil 34GTR]

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!

Guys, great thread, and the best I have found so far on SAU when searching for info on the elusive "-9's". As Dave questions above, has anyone seen any dyno results of -9's, or more fundamentally, know of anyone who has first hand experience on how they perform? Prior to getting serious about upgrading my stockies, I was more or less sure that -7's were the right choice for me (looking for no more than 400RWHP and more low end response that my current set-up) but based albeit upon somewhat sketchy info, maybe -9's would give me a better bang for my buck!

[silva33]

I went in Shepo's car today (thanks Matt I really appreciate it) and although lag is subjective let me tell you that only running 16psi on -5's it was not laggy (in my opinion) and went pretty hard! Yes my stock R34 came on boost earlier but I have been concentrating on the power bands when I give it the business in my gtr and in all honesty the -5's dont look to bad at all.

I am still super keen to see what -7's are like as all my previous modded cars have been super resonsive hence the reason for hesitating with the -5's over the -7's.

I am just so curious as to why no one has tried the -9's, I would try them myself but I dont really want to be the first one to say 'yeah i tried them and they are crap'...

I am torn between the two but I also respect the reasoning behind the -7's and the people puishing the -7's are the people in the know! i will keep on doing my research and if anything pops up I will be the first to post...

As good as the -5's are, I just cant get over how resonsive the stock 34 GTR turbos are and how they pull you out of any corner and every corner, its just the drop off up top that worries me. The fact that the -7 can pull xxxrwkw and the -5's can do xxx+rwkw doesnt really bother me at all.

[rev210]

-9's have the exact same part number as the HKS GT-SS cartridge. I checked some time ago.

-9's/SS are the only choice if you want smaller than the -5's. They are as responsive as -7's but with more guts.

[Phil 34GTR]

-9's have the exact same part number as the HKS GT-SS cartridge. I checked some time ago.

-9's/SS are the only choice if you want smaller than the -5's. They are as responsive as -7's but with more guts.

Ta Rev. I have found a turbo comparison sheet on a previous thread that confirms the specs for -9's and GT-SS are identical. Think I will be going -9's.

[rtune]

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.

way late to the topic ..

Here is what a tuner - who gets probably the most respect on SAU judging from others posts over

the last year - said to me this week in regards to stock but prepped (for oil, sump pickup, etc) rb26s ..

"Crank will do over 600kw @ wheels...yes, we have tried

Rods will do over 450 @ wheels... tried that too.

Most track failures are usually tune related or oil/water temp induced."

so there you go. I believe him that problems with stock parts

are not the headline power figures,

but the possibility that goes hand in hand with those: that the car is being abused

either through a dodgy tune or driving on through high temps .. which induce detonation

which cause failure which in turn can be easily blamed on "stock rods" or some such.

so if your tune is good and the temps & oil are under control it doesn't matter what

the boost is, up to and including 400 awkw ..

[Brezza]

i've got -5's on my GTR and they spool up really quick atm, got a rebuild done and theyre making boost @ 3,500 rpm. pretty punchy.

love them

runing stock ecu, stock injectors, 3in exhaust and pods.

and engine has recon head, thicker head gasket, forged pistons, race bearings, std cams

i would recomend the -5's, plus i think they're a little louder on the "woosh" than the others, but its just my opinion

[GTRKat]

Bit late but I have to say -7s ftw! I wish this thread was around when I was looking and had to make the decision!

They were ok before my rebuild (Tomei 2.8 stroker) but ever since it's made it a totally different car! Very happy with my choice and I would go the same way if I had to make it over again.

There's some really good info on the GTR UK forums about the -7 -9 and -5 debate!

[Mr GTR-32]

I have the -9 turbos on my R32 GTR, they are awesome with Apexi PFC, 3.5 inch full exhaust, cams, cams wheels, 044 intank, 700cc sard injectors, stock exhaust & inlet manifolds, on 18psi made 362Rwkw.

Very responsive minimal lag. They are rated at 320hp just under the -5s 350hp, i will have to post up the dyno chart but seat in pants feel is great i guess from what i have been reading they are in between the -7 and -5s for response but do pull hard all the way to 7750rpm so i dont feel them dying out at all till then.

My 2 cents worth.

Dave.

[Juan]

anyone else got experience with the -9

Did a search:

this is the same turbo as a -1 but the -1 comes with an actuator

[R31Nismoid]

-9s = GT-SS.

Plenty of GT-SS results around

[longex]

Correct me if im wrong but aren't -7s Equivalent to GT-SS

-9s are more similar to a -5s with different exhaust housing and turbine

[Lippo]

Huh ????

[some_cs_student]

Correct me if im wrong but aren't -7s Equivalent to GT-SS

-9s are more similar to a -5s with different exhaust housing and turbine

Incorrect, AFAIK -7's are N1 equivalent, -9 GTSS equivalent.

Read the Garett's specs page to confirm.