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-7/9s Or -5s Garretts


Adz2332

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Ok im going through an engine rebuild at the moment for my 33 gtr.

I have narrowed down the turbo choice on reading through the engine build up to either the Garrett -7s/9s or -5s....

ANd have been told they make roughly -

-7s/-9s are 330rwkw or so.

-5's are 380rwkw or so.

My thing is the -5s are laggier then the other 2 but just how much laggier?

When do each spool up roughly and then hit full boost?

Mines just a road car so mayb i should have the quicker spool of the -7s over the 5s?

But then 380kws does sound quite nice!!

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im also keen to find out this info, my 32 has forged engine set up, big porting and cams, its making 280rwkw (limited by stock afm's) but should make 300rwkw with z32's and bigger fuel set up (running r34 gtr turbos), so upgraded turbos just for a extra 30kw at there limit wouldnt be worth it, i want around 350-360rwkw

Edited by shy_s6
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i am currently getting a set of 2860 -5's fitted to my R. so i will let you know how it turns out.

it used to have the standard n1's so it will be interesting to see the difference. :(

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take it from me as gospel, PLEASE GO THE 5's PLEASE.

I was umming and ahhhing and was told to go the SS's and they would be good for 450 rwhp

BUULLLLLLLLLLSSSSSHHHHHHHHIIIIIIIIIIITTTTTTTT

any more than 400 rwhp (on a proper dynodynamics not a hub dyno!!) and the GTSS's are out of their efficiency range and you are having to run 20 plus PSI.

I have all the supporting mods, cams, dumps, full turbo back exhaust (Mines stainless front pro, decat and kakimoto mega N1 rear), tomei manifolds, evc, djetro, Sard 700's, HKS fuel pump and AFR etc etc etc and 400 rwhp on x-speed's dyno is about it. My motor is new as too.

GO THE 5's, the lag??? psssttt you are talking about 500 rpm MAX, my SS's hit full boost by 4,000 rpm, the 5's would be on by 4,500 max and probably still pushing more power at 4,000 even at a lower boost, so go the 5's. A decent tuner will be able to minimise lag by properly dialing in the cams anyway.

All this bullshit about SS's are good for 330rwkw (465 hp) is just that IMHO and if you got that much out of them it would be a time bomb. The only way to truly tell is to put all turbos on the same dyno under the same conditions but I doubt very much a true reading dyno would show anywhere over 300rwkw for the SS's.

GO THE 5's, otherwise, buy the 5's, ill swap you my 500km old SS's and give you $500

Edited by R33GTRKid
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... any more than 400 rwhp (on a proper dynodynamics not a hub dyno!!) ...

All this bullshit about SS's are good for 330rwkw (465 hp) is just that IMHO and if you got that much out of them it would be a time bomb. The only way to truly tell is to put all turbos on the same dyno under the same conditions but I doubt very much a true reading dyno would show anywhere over 300rwkw for the SS's.

Do you have -5s now? Did you get a gain? Have you done cams? Hypothetically speaking would you come back and eat your hat if you changed to -5s and got a result within a few kw of with the GT-SS and it turns out that you were running stock cams/timing and weren't getting the most out out the turbos because of other things in your setup?

And what is this bollux about "proper Dyno Dynamics dyno" or "True reading dyno"? I guess in Oz Dyno Dynamics are the majority used at the moment, albeit some workshops are catching up with the rest of the world and upgrading to Hub dynos - but globally speaking most dynos used read within a couple of % of each other (Dynapack, Dynojet, etc) so if you hear results you just need to take into account that Oz dynos don't read consistant with the rest of the world and take that into account yourself.

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take it from me as gospel, PLEASE GO THE 5's PLEASE.

I was umming and ahhhing and was told to go the SS's and they would be good for 450 rwhp

BUULLLLLLLLLLSSSSSHHHHHHHHIIIIIIIIIIITTTTTTTT

any more than 400 rwhp (on a proper dynodynamics not a hub dyno!!) and the GTSS's are out of their efficiency range and you are having to run 20 plus PSI.

I have all the supporting mods, cams, dumps, full turbo back exhaust (Mines stainless front pro, decat and kakimoto mega N1 rear), tomei manifolds, evc, djetro, Sard 700's, HKS fuel pump and AFR etc etc etc and 400 rwhp on x-speed's dyno is about it. My motor is new as too.

GO THE 5's, the lag??? psssttt you are talking about 500 rpm MAX, my SS's hit full boost by 4,000 rpm, the 5's would be on by 4,500 max and probably still pushing more power at 4,000 even at a lower boost, so go the 5's. A decent tuner will be able to minimise lag by properly dialing in the cams anyway.

All this bullshit about SS's are good for 330rwkw (465 hp) is just that IMHO and if you got that much out of them it would be a time bomb. The only way to truly tell is to put all turbos on the same dyno under the same conditions but I doubt very much a true reading dyno would show anywhere over 300rwkw for the SS's.

GO THE 5's, otherwise, buy the 5's, ill swap you my 500km old SS's and give you $500

Gospel huh?

Considering im making a lazy 250rwkw @ 12psi with GT-SS, and I know of at least another 10 cars making over 300rwkw (between 300-330rwkw) on 20-22psi… On various dynos to boot (more on the dyno racing later)

Not one of them has blown up yet, so much for a 'time bomb' huh?

Consulting the RB26 dyno sticky for the other results, which I don’t think you've done... also back up that over 300rwkw is easily do able as have many, on many different dynos. Now, if that’s not a good enough spread of results vs your ONE, I dunno what is.

Your seriously gonna try and say that over 600hp worth of turbo cant make more than 300rwkw???

Simple logic would tell you that’s wrong.

Please post the actual compressor map and highlight the fact they are out of their efficiency range flowing 300rwkw worth of air.

Because quite simply they are not.

Also what I find most interesting is you have all these 'fancy' parts (what I would call uneccesary in reality), manifolds, cams and so on… yet all the cars in the results threads and so on have factory just about everything, and are still going better, interesting no?

As for the rest of your post with regards to response and so on, on a loaded up dyno fair enough.

Take it too the street, 1st/2nd/3rd and so on. You'll soon see where the smaller turbos perform best, and what the OP after… ?

A street setup. SURPRISE!!!!

A RB26 is bad enough to have fun with under 150km/h as it is, and you loose your license before the end of 2nd gear.

So what does going bigger/less responsive achieve??? Nothing.

Better off to have blistering response upto 160-180km/h and a car that’s a street rocketship as opposed to a car that cant be enjoyed until you've lost your license.

If you were circuit racing and after every 10th, then ye you might considering the larger more powerful option, but this is a street car.

Ill take the results of many as gospel over the results of one.

As should everyone else.

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I knew there would have been a bit of debate over what was said lol...

SO your saying 7s or 9s over the 5s??

will it 100% see over 300kws?

Also whats the difference between the 7 and 9s?

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I knew there would have been a bit of debate over what was said lol...

SO your saying 7s or 9s over the 5s??

will it 100% see over 300kws?

Also whats the difference between the 7 and 9s?

You really want 300kw atw? personally the novelty wore off quite quickly and im happy with about 255 so im going the

-7 route and running just under 1 bar. Response is what i miss on the street for instance when i drove my friends dc5 type r and jumped back into mine; response is just better, i know its only 500-700rpm but in the first few gears or being in a higher gear and wanting to overtake etc

I dont like to redline mine, 4000-4500rpm changes with the stockers are more than enough to make the car feel alive.

this is just my impression

-9's are a little bigger than the -7's right? like n1 to gt-ss and -5 is more 2530 which would benefit with some headwork.

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well all I can say is that one of the most experienced tuners in WA disagrees with you Nismoid and I have spoken with three other shops over here and had the same response that 400rwhp is about max for GTSS's but you obviously must know better.

Oh and HKS rate the GTSS at 280hp each which makes them 560 combined!

Yes I have read the rb26 dyno post, I have posted in it. I have also posted up my dyno results after expecting the world (you were one of the pro GTSS's) from the GTSS's, spending a shit load of money and only getting 390 rwhp and asking for help as to what could be the issue to cause a lower than expected (after listening to you and others in the rb26 dyno thread). I got 2 replies, maybe you could have a look over them and shed some of your allknowing light into the thread, if you search dyno result posted by my username it should come right up.

What all three workshops over here have said is that dont listen to all these blokes quoting higher than 400 rwhp figures on dynos that are likely to be out by at least 10%.

250rwkw at 12 psi is not unusual, it is 350hp which is what I am also getting at about 12 psi, it is just after that you are not getting much more and they are just too small to hold much more than 15psi through the higher rev ranges (or at least that is what I have been told x 3 by x 3 different workshops here). I did say anything more than 400rwhp and you have to run 20 psi plus which is out of their efficiency range - I dont know if I would be putting 22psi through GTSS's (which will be running pretty damn hot) over a stock RB26 bottom end, which is where I was talking about it being dangerous.

At the end of the day, all I can go on is my experience with my car and my mods which is what I said I was referring to along with three of the most reputable (including possible the most) rb26 tuners in WA saying the same thing. 400rwhp is approx max for a safe tune on a RB26 running GTSS'.

I wish I had gone the 2530's (-5's) because I would not be still waiting for the top end rush that does not come with the GTSS's, yes they are fun to drive, yes they are very responsive on the street, yes they are fun on the track also, but they do not give me the punch I was hoping for and certainly no where near the 330rwkw everyone else is talking about.

2 over here have tuned it now and I am going to try a third next week to see if we can go any further. Both so far have performed leakdown and compression tests and they came back perfect. You say my supporting mods are unnecessary, I call them insurance to allow the motor to perform with less stress but still no 330rwkw, in fact I am not even on 300 rwkw but you know best!@

Edited by R33GTRKid
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Gospel huh?

Considering im making a lazy 250rwkw @ 12psi with GT-SS, and I know of at least another 10 cars making over 300rwkw (between 300-330rwkw) on 20-22psi… On various dynos to boot (more on the dyno racing later)

Not one of them has blown up yet, so much for a 'time bomb' huh?

Consulting the RB26 dyno sticky for the other results, which I don’t think you've done... also back up that over 300rwkw is easily do able as have many, on many different dynos. Now, if that’s not a good enough spread of results vs your ONE, I dunno what is.

Your seriously gonna try and say that over 600hp worth of turbo cant make more than 300rwkw???

Simple logic would tell you that’s wrong.

Please post the actual compressor map and highlight the fact they are out of their efficiency range flowing 300rwkw worth of air.

Because quite simply they are not.

Also what I find most interesting is you have all these 'fancy' parts (what I would call uneccesary in reality), manifolds, cams and so on… yet all the cars in the results threads and so on have factory just about everything, and are still going better, interesting no?

As for the rest of your post with regards to response and so on, on a loaded up dyno fair enough.

Take it too the street, 1st/2nd/3rd and so on. You'll soon see where the smaller turbos perform best, and what the OP after… ?

A street setup. SURPRISE!!!!

A RB26 is bad enough to have fun with under 150km/h as it is, and you loose your license before the end of 2nd gear.

So what does going bigger/less responsive achieve??? Nothing.

Better off to have blistering response upto 160-180km/h and a car that’s a street rocketship as opposed to a car that cant be enjoyed until you've lost your license.

If you were circuit racing and after every 10th, then ye you might considering the larger more powerful option, but this is a street car.

Ill take the results of many as gospel over the results of one.

As should everyone else.

Don't tell him that! someone could pick up a bargain pair of GT-SS for $500 less than a pair of garretts LOL :)

Nah - i agree with the above - response is what you want for a street GTR. Adz

Take him up on the offer of the swap :D get the Genuine HKS article!

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Rather than enter into a pissing competition about whos dyno operator is better & how many rwhp people may need why don't people simply refer to the compressor maps supplied by Garrett? They have been created for a reason.

Perth & its *%ing tuner wars. :)

See here for the -7

http://www.turbobygarrett.com/turbobygarre...0R_707160_7.htm

-9

http://www.turbobygarrett.com/turbobygarre...9R_707160_9.htm

-5

http://www.turbobygarrett.com/turbobygarre...0R_707160_5.htm

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Rather than enter into a pissing competition about whos dyno operator is better & how many rwhp people may need why don't people simply refer to the compressor maps supplied by Garrett? They have been created for a reason.

Perth & its *%ing tuner wars. :)

See here for the -7

http://www.turbobygarrett.com/turbobygarre...0R_707160_7.htm

-9

http://www.turbobygarrett.com/turbobygarre...9R_707160_9.htm

-5

http://www.turbobygarrett.com/turbobygarre...0R_707160_5.htm

lol that meant nothing to me llol!

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Meh - I have HKS GT2530's and am totally satisfied with them. spent a lot of time ensuring I got decent response from them + they are still pulling hard at the top end.

I HAVE NOT driven an R32 GTR with GT-SS, but after changing up from the stockers, didn't notice a notworthy difference in respone, but DID notice the mid - top end.

Be happy with what you have regardless everyones setup is different - if you want more top end look to swap for larger set, or more response - swap for a smaller set.

I have found EBC setup and engine tune makes a huge difference, but that is just me.

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I've got 2860-5 now make 500hp at 21psi, come on early and pull hard. Had 2530's before, which were 1000rpm laggier but had alittle more top end. Good turbo and bang for buck, with the yen at the moment you can't go wrong with the garret range.

Edited by monga
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lol that meant nothing to me llol!

Well then rather than lolling try the rest of the Garrett website.

There are some good tutorials on it which explain what all the various terms mean & importantly how to read compressor maps.

The important thing to note is this:

THERE IS A DIRECT CORRELATION BETWEEN THE AIRFLOW IN LB/MIN AND THE OUTPUT OF THE MOTOR.

This holds true over a very wide range of motors & any number of modifications to the same motor.

So a 350hp turbo (for the sake of the argument) will have a capability of flowing 35lb/min of air (assuming 10:1 ratio I can't remember the exact number but it is about that)

Anyway the point is once you understand this & understand the nature of the efficiency islands on the compressor map you will then understand why a marked increase in pressure ratio is needed for a turbo to eek out the last few lb/min airflow. You may further understand why this is usually a bad idea & why a boost reading can be regarded as a measure of failure of the turbo/motor combination to work efficiently (As opposed to something to brag about)

Sorry if that sounds harsh but please take the time to read what Garrett have written. It is much more usefull than p!ssing competitions between keyboard warriors.

Anyway love to all, etc.... :)

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I've got 2860-5 now make 500hp at 21psi, come on early and pull hard. Had 2530's before, which were 1000rpm laggier but had alittle more top end. Good turbo and bang for buck, with the yen at the moment you can't go wrong with the garret range.

Where in the rev range does boost start coming on? and when does it hit full boost?

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Well then rather than lolling try the rest of the Garrett website.

There are some good tutorials on it which explain what all the various terms mean & importantly how to read compressor maps.

The important thing to note is this:

THERE IS A DIRECT CORRELATION BETWEEN THE AIRFLOW IN LB/MIN AND THE OUTPUT OF THE MOTOR.

This holds true over a very wide range of motors & any number of modifications to the same motor.

So a 350hp turbo (for the sake of the argument) will have a capability of flowing 35lb/min of air (assuming 10:1 ratio I can't remember the exact number but it is about that)

Anyway the point is once you understand this & understand the nature of the efficiency islands on the compressor map you will then understand why a marked increase in pressure ratio is needed for a turbo to eek out the last few lb/min airflow. You may further understand why this is usually a bad idea & why a boost reading can be regarded as a measure of failure of the turbo/motor combination to work efficiently (As opposed to something to brag about)

Sorry if that sounds harsh but please take the time to read what Garrett have written. It is much more usefull than p!ssing competitions between keyboard warriors.

Anyway love to all, etc.... :P

If im doing it right, which is highly likely i am not... being its the first time ive tried it all & im not getting all the variables exactly right (VE. BSFC, peak torque RPM etc etc)...

I just used a rough estimate going off what the doco said, and the notepad im using is now 3 pages long with numbers :D

But... if by some stroke i was near enough to correct then 550hp (the figure i picked) with a 12:1 AFR... it is certainly able to be done by both turbos, running over 20psi of course, which is what ive seen as per the comp map.

Albeit its right near the top, but still within the boundaries none the less. The -7s are at the limit, -9's similar but bit more room to move around.

How does two turbos affect things though, i guess you half it as two turbos flow air

If not, then my calcs are definately up the shitter somewhere, and i wouldnt be surprised if that was the case :)

Perhaps you could enlighten on some of the things for a more accurate result for people? (VE, BSFC etc)

Ill redo the numbers again, but i think the guide might have a typo too

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ok...Garrett smarrett...

everyone bags out HKS...expensive...not required etc...but I seem to always make the rated power at the tyres...not the engine. Why is that ? Is it because the Garrett's run out of puff when pushed ? It seems like it...not trying to start a war but it seems most times the 'equivalent' Garrett items are not up to it when pushed for power.

HKS 2530's 450KW at the tyres = 705hp at the engine 30psi

HKS GT-RS 500KW at the tyres = 785hp at the engine 25psi

Try doing that with 'equivalents' it just doesnt happen

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