HKS Turbo's vs Garrett Turbo's...

[Steve]

Attached is an intitial dyno of the HKS 3037S 56T I just had fitted.

I got him to keep the boost to 1 bar, and the AF ratios on the conservative side, as I was a bit paranoid about the plenum and the fact that I still havent fitted a head gasket.

Torque is very linear, the lower run was on 10lbs the upper on 1 bar, which comes up under 3krpm. Boost starts building at just over 2krpm. Also the car feels more responsive off boost, which could be due to the manifold that was done at the same time as the turbo, also had a front facing throttle body and plenum done.

All up it is awesome on the road, totally different car to drive. Top power was only 230kw @ 1 bar - cant wait to wind in some boost and get let the turbo show its true colours:D

[rob77]

That is impressive boost spoolup time. 1 bar at under 3000rpm... must have something to do with the exhaust manifold

[Steve]

That and the 0.61 turbine AR ratio;)

[rob77]

The trust turbo is definately a lot laggier but at 13psi on the stock ecu I'm making 256kw Weird how it makes a lot more power and lower boost... complete different type of turbo.

[GTS-t VSPEC]

Steve, Nice response, I'm looking forward to seeing what power you get out of it:D

[Guest INASNT]

Originally posted by Steve

Attached is an intitial dyno of the HKS 3037S 56T I just had fitted.

I got him to keep the boost to 1 bar, and the AF ratios on the conservative side, as I was a bit paranoid about the plenum and the fact that I still havent fitted a head gasket.

Torque is very linear, the lower run was on 10lbs the upper on 1 bar, which comes up under 3krpm.  Boost starts building at just over 2krpm.  Also the car feels more responsive off boost, which could be due to the manifold that was done at the same time as the turbo, also had a front facing throttle body and plenum done.

All up it is awesome on the road, totally different car to drive.  Top power was only 230kw @ 1 bar - cant wait to wind in some boost and get let the turbo show its true colours:D

sweet results steve, when the cams and head gasket going in?

[Steve]

Rob, generally the amount of air flow will vary from trubo to turbo. Some turbos will make 200kw at the same boost another turbo will make 250kw. If I am not mistaken, the TD06 is acutally rated higher than the 3037, but give me an earlier spoolup anyday - personal preferance.

Also, your dyno was in shootout mode wasnt it? which will give a different figure to if its not in shootout mode.

Anyways, the part that truely impresses me is the long flat torque curve - thats the fun zone:)

paul, I have already tried bumping the boost to 1.2bar, but couldnt find anywhere local to really open her up. I sort of tried it, but got very sideways very quickly and there were a few cars about so I thought I would back off until I can find a nice open piece of road - just need a leave pass from the wife for the afternoon:)

It will be interesting to see how the GT30 you are fitting goes in comparsion - hurry up:D

INASNT, not putting cams and gasket in until I get the plenum sorted so probably a couple of months off unfortunately:( It will be interesting to see how it goes at 1.5-1.6 bar.

[EVOIV]

Steve: Is that the smallest turbine housing? 0.61A/R? I have the 0.73A/R. Yours is the 56T trim right?

rob77: Your TD06 would be a much larger than the GT3037S seeing that you have the 20G and the turbine housing of Steve's is 0.61A/R. Hence lower in rated horsepower, but a lot more responsive. It would be interesting to compare your TD06 to a GT3037S with a 1.12A/R turbine housing...both are comparable in size. I think the results would be very similar.

[RS500]

Steve, EVOIV,

fyi, the TD06SH L2 20G is actually rated at less power than the 56T GT3037S.

although, i guess the difference in exhaust housing A/Rs is what is making the difference b/w power/response on these two engines.

Steve,

with an A/R .73 exhaust housing, you'll definitely pick up atleast 10-15rwkw on the same boost.

good stuff btw, nice power/torque curve.

[EVOIV]

Yeah, I always wondered how manufacturers "rated" their turbos. Does anyone know? I also get confused as to how a GT3037S 56T turbo can be rated at 480PS, regardless of the turbine housing A/R used? I know the A/R makes a difference in lag, and I would expect the top end power to be higher with a larger A/R? Same goes for all other turbos. Confusing. I guess power also depends upon other things, like tuning and what others mods you may have.

[Steve]

RS500, where did you get the info about the TD06 being rated lower?

I wouldnt mind trying a larger AR, but I am not sure I want to loose the response which is pretty awesome, much better than I had hoped. HKS actually use the 0.87 AR on the 3037 they sell for skyline in complete bolt on kit form. I am just not sure I want to spend the $$ to find out that I prefer the 0.61 housing.

Why would just putting a larger housing pick up more power at the same boost?

EVOIV, 0.61 is the smallest, and yes its a 56T.

[EVOIV]

I am not sure...I know that a larger A/R turbo can flow more, but when does this actually come into play? Does this mean that a larger A/R turbo has more potential...eg when at 2bar?

[RS500]

Originally posted by Steve

RS500, where did you get the info about the TD06 being rated lower?  

I wouldnt mind trying a larger AR, but I am not sure I want to loose the response which is pretty awesome, much better than I had hoped.  HKS actually use the 0.87 AR on the 3037 they sell for skyline in complete bolt on kit form.  I am just not sure I want  

to spend the $$ to find out that I prefer the 0.61 housing.  

Why would just putting a larger housing pick up more power at the same boost?  

EVOIV, 0.61 is the smallest, and yes its a 56T.

Steve,

check out the following turbo comparison table and you'll see that the GT3037S is actually rated at higher hp than the largest of the Trust TD06 20G.

http://fangartists.com/pics/turbo_comparison.jpg

the larger housing will decrease the amount of back-pressure in the exhaust housing allowing exhaust gasses to flow more freely giving higher hp at the cost low-down turbo response.

Actually, the .61 would be perfect for my 2L cossie

btw, would any of you guys care to part with any of these GT3037S' that you have in your possession??

EVOIV,

having the larger exhaust housing will bring the compressor into it's efficiency range of air-flow at a higher rpm but given the decrease in back-pressure, it will flow more gas hence more power, especially at higher boost.

the rule of thumb generally is that the bigger you go in the exhaust housing, the more you air/gas flow you get at higher rpm while sacrificing down low air-flow and response, whereas going smaller will allow more air/gas flow at lower rpm while sacrificing air/gas flow at higher rpm, hence loss of power.

[EVOIV]

I still don't understand why the A/R does not affect the "rated horsepower"? I thought the larger A/R would have a bigger rated horsepower?

RS500: Have you decided which turbo to go for?

I still have not yet repaired my other GT3037S. Been pretty lazy lately...

[GTS-t VSPEC]

Steve, With luck mine will be ready by the end of this week, so we can do a comparison:D

(Take me for a ride in yours when we come over for the JMS drift day?)

[RS500]

EVOIV,

actually, a turbo's "rated hp" is affected by the different A/R sizes of an exhaust housing.

fyi, we'll take Ray Hall's GT series website as the prime example as to illustrate what we are talking about.

http://www.turbofast.com.au/GTseries.html

when looking at the CHRA assemble section, the following GT30 core is rated at 600hp (700177-0014).

that's all nice, although when this turbo is bought complete with an A/R .84 exhaust housing, it is only rated at 550hp (SB8006A) and infact it needs the A/R 1.06 housing to make the rated 600hp.

does this make sense??

yeah, i've made up my mind, i want a HKS GT3037S

why don't u just give me the 3037 that's on your EVO, then that'll prompt you to fix the other one so that you can get your car on the road

[EVOIV]

Yes, I had always thought that the A/R affected the rated horsepower. The GT3037S is rated at 480PS (56T), so I am guessing that is with the largest A/R which I believe is 1.12? Considering this, I would expect my turbo to be rated around 400PS, which seems quite reasonable giving the power it produced.

Both turbos are off my car and I have the stock one back on. Don't worry, I am going to get the turbo sent to Sydney very soon. So when that happens, and hopefully if/when it's repaired...I'll let you know asap

[Guest INASNT]

Steve i am getting the 56 trim 3037S like yours and i was recommended the 0.87 turbine housing. I've seen the 56 trim with 0.73 housing on a internally stock SR20 make 300rwkw at around 25psi and not 2 laggy.

[RS500]

EVOIV,

how about you give me your good turbo until you get the other one fixed

[EVOIV]

INASNT: What car do you have? Guessing a Skyline R33? I think a 0.87 housing would be perfect for the RB25...not too laggy, and a heap of top end power.