Hks Gt-ss Vs. Gt-rs

[SkylineT04Z]

I would like to say, when we fitted my GT2530's ( HKS mind you ) there was no lag differnce compared to the standard ones, we had the head off, shaved it 20thou to bump the compression slightly more /give it a clean up. They came onto boost around ~2800 properly in 2nd and hit you hard bout ~3800rpm all the way tilll 7500rpm which is redline on the R32 GT-R engines.

We used step 1 camshafts from HKS to give us the EXTRA midrange torque/power as we felt it was needed to increase the midrange response of the 2530's and give them the extra topend flow!

I think whoever used the 2530's and said they are MUCH noticebly laggier then the standard units is a complete idiot,moron,loser,wanker you name it!

There are many track monsters in japan using these turbos that hold LAP RECORDS on various types of tracks.

If anything, now they will all be changing there turbo selection to the GT-RS / GT-ZZ when it releases as they will be 420PS rated each turbo and hve the same response as a GT-RS.

For now, bye bye

[discopotato03]

Hi all , is there any information available on HKS's GT-ZZ . Have seen the odd mention but no specs .

Cheers Adrian .

[lwells]

There are many track monsters in japan using these turbos that hold LAP RECORDS on various types of tracks.

I think most everyone is aware of the potential of the HKS 2530s, but being realistic for a second, very few are going to have anywhere near the resources to exploit the turbos to the level shown by demonstrator cars from aftermarket tuners. Even increasing the compression ratio and minor headwork as you did is a rather serious step for some people who don't have the skill to do the work themselves or the funds to pay someone else.

So in the real world where benefits are weighed heavily against costs, I can understand why some people find the 2530s too laggy. All of this also ignore the crucial element of exactly what you plan to do with your car anyway.

Getting semi back on topic for a second, what about camshaft choices for the GT-SSs? I have spoken to my trusted mechanic who was suprisingly opposed to installing aftermarket cams with these turbos as he feels they tend to rob the engine of low-down torque/power, even if there are benefits in the mid-range and upper-range. I say "suprisingly" because their is such overwhelming love for the poncam range on here. I have tried searching for a dyno before/after results with just cams changed to type-b poncams (260/260 9.15) or an equivalent with no luck, so if anyone has them lying about I would love to see them.

Edit: The mechanic obviously suggested cam wheels on the stock cams.

[ferni]

Getting semi back on topic for a second, what about camshaft choices for the GT-SSs? I have spoken to my trusted mechanic who was suprisingly opposed to installing aftermarket cams with these turbos as he feels they tend to rob the engine of low-down torque/power, even if there are benefits in the mid-range and upper-range. I say "suprisingly" because their is such overwhelming love for the poncam range on here. I have tried searching for a dyno before/after results with just cams changed to type-b poncams (260/260 9.15) or an equivalent with no luck, so if anyone has them lying about I would love to see them.

I was told the same thing.. the stock cams are fine with these turbos.. you can change them and maybe gain a little but not worth it... Unless you were really trying to squeeze every kw out of them...

[R31Nismoid]

Agree with the above two aobut the cams. But then i take my car to the same place ferni does

Although i'm going to be using stock cams...

We will also try some other cams once i get sorted and just have a play around.

That will be after july though i think so results wont be in for a while

I like to fiddle with my setups so i might try one or two different tyres (not large ones either) and see what results are given.

Cam get is a definate however... rule numbers on with an RB26

[lwells]

Interestingly the dyno graphs on HKS's website for the GT-SS kit show that the car was running 264/264 camshafts (no mentioned of lift)

http://www.hks-power.co.jp/products/turbo/...ss/ac_gtss.html

However, on their page about the variable intake cam solution they make for the RB26 they suggest a 256 ex camshaft for GT-SS turbos and 264 with 2530s:

http://64.233.179.104/translate_c?u=http:/...vcamsystem.html

[gdogzgtr]

On topic of cams choices I have been told to look at 252/252 pon cams for better down low response and almost as much up top as 260/260. Don't really hear about many people with them but advised this through racepace who would have one of the best reputations on here. This advice for use with R34N1's and street set up other set ups better for other applications.

[SkylineT04Z]

Sorry, but whoever told you the step1 cams will increase lag... is a fibber and has never really done this themselves. step 1 camshafts from HKS will not increase low down lag, althou they will feel exactly same and once on fullboost they will increase power..

I dont believe there is such thing as " you dont need camshafts" yes that might be true, but you also dont need bigger turbos on your car

Step 1 camshafts will INCREASE power across the entire rev range and get your head flowing more and push more exhaust gases too! exhausts gases - more rpm to play with.

The GT-ZZ i had a read up on whilst i was in japan last month, they are suppose to be " new technology trims chosen by HKS" from garrett. just like how the T04Z is a "SUPER TURBO" now, i think the response aim is similar to HKS GT2530's (if not less ) and produce 420PS per turbo.. Dont quote me it was on the GTR magazine.

[lwells]

Sorry, but whoever told you the step1 cams will increase lag... is a fibber and has never really done this themselves. step 1 camshafts from HKS will not increase low down lag, althou they will feel exactly same and once on fullboost they will increase power..

I dont believe there is such thing as " you dont need camshafts" yes that might be true, but you also dont need bigger turbos on your car

Step 1 camshafts will INCREASE power across the entire rev range and get your head flowing more and push more exhaust gases too! exhausts gases - more rpm to play with.

For starters, its not simply about turbo "lag", but low down engine torque/power (or "response" if you prefer) which encompasses a part of the rev range where the turbos aren't necessarily in play. Secondly, I would watch who you call a "fibber" and accuse of "never really done this" because you're talking about workshops that together have done hundreds (thousands?) of camshaft installs and are well known for their expertise with Skylines.

Also, I don't think talking about "step 1" is particularly useful given that encompasses choices from 256 through 272 duration on both intake and exhaust camshaft (in the HKS range); the only similarities are that they are drop-in and in the case of HKS feature 8.7 lift (whilst other manufactures equivalents are different again: eg. Tomei uses 9.15 and has options of 260 and 252 duration). If it were the case that there was no downside to any of the "step 1" choices, then they wouldn't bother offering any choices and just provide one set of camshafts with the optimal duration lift possible.

Its clearly a question of choosing the right camshafts for the right application. So the question is which option is best: standard cams adjusted or which aftermarket option.

Just my 0.02c

[SkylineT04Z]

For starters, its not simply about turbo "lag", but low down engine torque/power (or "response" if you prefer) which encompasses a part of the rev range where the turbos aren't necessarily in play. Secondly, I would watch who you call a "fibber" and accuse of "never really done this" because you're talking about workshops that together have done hundreds (thousands?) of camshaft installs and are well known for their expertise with Skylines.

Also, I don't think talking about "step 1" is particularly useful given that encompasses choices from 256 through 272 duration on both intake and exhaust camshaft (in the HKS range); the only similarities are that they are drop-in and in the case of HKS feature 8.7 lift (whilst other manufactures equivalents are different again: eg. Tomei uses 9.15 and has options of 260 and 252 duration). If it were the case that there was no downside to any of the "step 1" choices, then they wouldn't bother offering any choices and just provide one set of camshafts with the optimal duration lift possible.

Its clearly a question of choosing the right camshafts for the right application. So the question is which option is best: standard cams adjusted or which aftermarket option.

Just my 0.02c

I can garuntee you will BENEFIT from using 256/264 on the street and track with lowdown POWER and RESPONSE also gain lots more useable RPM uptop too.

[gdogzgtr]

That's the advice I got for my set up everyone wants different things. I'm not going to race car or change gears at 8000rpm each time and car making power all way to there on standard cams. That was advice for low down response and reduce lag which is what I was looking at and this thread also about low down reponse etc. I'm not telling anyone else what to do but what I was advised as best for me. They never said anything about other set ups just advised on this. They are one of the best engine builder workshops in Aust and would definitely know what they are talking about.

[Roy]

I would like to say, when we fitted my GT2530's ( HKS mind you ) there was no lag differnce compared to the standard ones, we had the head off, shaved it 20thou to bump the compression slightly more /give it a clean up. They came onto boost around ~2800 properly in 2nd and hit you hard bout ~3800rpm all the way tilll 7500rpm which is redline on the R32 GT-R engines.

We used step 1 camshafts from HKS to give us the EXTRA midrange torque/power as we felt it was needed to increase the midrange response of the 2530's and give them the extra topend flow!

I think whoever used the 2530's and said they are MUCH noticebly laggier then the standard units is a complete idiot,moron,loser,wanker you name it!

There are many track monsters in japan using these turbos that hold LAP RECORDS on various types of tracks.

If anything, now they will all be changing there turbo selection to the GT-RS / GT-ZZ when it releases as they will be 420PS rated each turbo and hve the same response as a GT-RS.

Its always great to hear the experiences of others...but you can go about posting any info ina better way. Calling ppl wankers whatever????

As for the cars using 2530s in Japan, the quickest GTRs are using T88s...a turbo i read you dont rate

Also, i have been in a couple of cars with 2530s, and they are responsive, and make good mid, but they are still not as punchy down low as std turbos...especially noticeable at motorkhanas etc. You also noted that your engine which has similar response to std had head work, and increased compression...and cams so how can you use your engine as a comparison to a person that noted increased lag with 2530s on their std engine?

Anyway, Fernis car is awesome. IF his engine builder doesnt feel cams make much difference with these turbos, what are they $1000 installed? Then having been in his thing its an absolute hoot and abviously a handfull on a dry skidpan with road tyres

[lwells]

I can garuntee you will BENEFIT from using 256/264 on the street and track with lowdown POWER and RESPONSE also gain lots more useable RPM uptop too.

You'll have to forgive me for not racing out and purchasing based upon your "garuntee" since your username was registered yesterday, you've provided no information to back up what you're saying, and you haven't provided a blank cheque that I can fill out for the cost of camshafts, installation and tuning should your advice prove incorrect

Don't get me wrong, I am not necessarily doubting what you are saying, but as Roy has pointed out the way you have said it doesn't exactly inspire confidence.

[R31Nismoid]

I can garuntee you will BENEFIT from using 256/264 on the street and track with lowdown POWER and RESPONSE also gain lots more useable RPM uptop too.

I find that hard to believe if the GT-SS run out of flow uptop.

Cams are not going to make a turbo work any better once they are running our of flow.

Once they are out, thats it

[SkylineT04Z]

Yes cars at central circuit use the T88

but im saying, for a street car, you would WANT cams for the midrange PUNCH!

[BU5TER]

Yes cars at central circuit use the T88

but im saying, for a street car, you would WANT cams for the midrange PUNCH!

Who are you?

[SkylineT04Z]

Who are you?

Ricky, but what do you mean?

I am a fellow skyline enthousiest who is just having a talk from experience/physics.

[Blitz]

Ricky, but what do you mean?

I am a fellow skyline enthousiest who is just having a talk from experience/physics.

I think whoever used the 2530's and said they are MUCH noticebly laggier then the standard units is a complete idiot,moron,loser,wanker you name it!

There are ways to and ways not to say things, "Ricky"

[pnblight]

Pete GTSS's are much smaller than 2530's , they are baby turbos and will run out of puff at top . I run 16psi in my 34 ( totaly stock, unopened engine ) and it drops to 15 psi above 7000 but they spool up almat like my stockers. Actualy the only reason i replaced them was the ceramic wheels, i dont want them to let go and destroy my donk .

Unless you are thinking of the bigger housing GTSS's like the ones used in SR20's, not sure on them and all but one set of the twins ( RB26 sets) i have seen are the small comp housings .

the gt-ss is smaller but not by a great deal and if you have a poor responce from a rb26 with 2530's i don't believe changing to gt-ss will not make a great difference (small but not great) things like intake and exhaust system and cams and cam timing will play a much great roll in reducing lag

HKS2530

trim 63

47.7mm

60.1mm

0.60a/r

trim 76

53.8mm

47.0mm

0.64a/r

GT-SS

trim 56

44.46mm

59.41mm

0.42a/r

trim 62

53.85mm

42.40mm

0.64a/r

and for real life expirence i got better responce and early power from rb26 with GT2560R garrets(very simliar to 2530's) than i could from a Rb26 with HKS2510's (same cams and injector and ecu) i believe the difference was more in exhaust system and cam timing. And when i mean responce and early power i mean below 4000rpm. The hks 2510 still made 456rwhp so it was no lemon.

My opinion is if your got the money to buy and try such turbo's you should have to money to tune and fit the equipment required to run them correctly or your wasting your money and time. And i think the person how think his 2530hks are to laggy has got other issues cause his problems with lag.

pete

[pnblight]

I find that hard to believe if the GT-SS run out of flow uptop.

Cams are not going to make a turbo work any better once they are running our of flow.

Once they are out, thats it

That’s not entirely true

Because well sized and setup cams can reduce the restriction to airflow of a motor dramatically meaning as SK would state you can make the same or more horse power with less boost and the less boost pressure the turbos have to product the more air volume they can pump. So cams can help get much more out of a give set of turbo regardless.

On similar lines it bugs me that people get so concerned about what boost is made by what rpm. As it no true guide to response and performance of an engine setup. For example a motor that makes 1 bar at 3500rpm and 200rwhp is not more responsive then a motor making .5bar boost at 3500rpm and 250rwhp the first motor is just more restrictive and making the turbos work harder earlier. We should be more concerned with torque and hp by what rpm rather than boost as it is what you'll feel and what will make a real difference. So when i see a motor making boost very early it’s normally tell me there some thing wrong and the motor does not want to flow well.

pete(only my 2c)