hks 3037 on a rb20

[carl h]

hey all.

im looking into getting an hks 3037/gt30r turbo for use on my rb20.

i already have the hks cast iron manifold with a spot for the external gate so it shouldnt have any problems with this.

also i plan on getting one with a .63 turbine so it should spool fairly quick, what are your thoughts on this setup?

i also plan go get some tomei cams to help things along.

[RBsileighty]

Hey Carl,

What are your goals? Max power... max boost (race fuel or pump gas more or less)... most tolerated lag?

[Roy]

While i agree that a small A/R housing will help response, dont forget that the R stands for radius so even if the ratio is small, due to the size of the turbine the R is never going to be small enough to get great response. That said i think it would make a great setup....has anyone ever seen such a turbo on an RB20...surge problems?

Looking at my results with a smaller turbo, i think you would have to seriously consider cams if you want to make good power.ie the sort the 3037 should be capable of:)

[carl h]

well quite a few factors have gone into thinking about going this route.

i want a ballance of good power but not too much lag (3.8-4k max boost is tolerable).

its not going to be a drag car but more of a drift/highway car.

i also want to be able to make good power without having to run crazy boost as im not prepared to build up the engine internaly.

this being said and the car being a daily driver i would much rather have a slighly laggier turbo that doesnt make boost crazy early (IE: gt28rs, come on it makes boost revving the engine) so it will be decent on gas but also perform when i want it to.

by running that turbo i hope to have a decent power band with good overall power, just since i sit in traffic every day and its stop and go i dont need something that spools up hella quick when i dont want it to, the stock turbo did that and i found it kinda annoying in heavy trafic.

i think with some 260 cams on both sides and adj. cam gears/tuning i should be able to get good response and spool from the turbo.

[mokompri]

longer duration cams will bring boost on LATER... imo the 3037e is a bit too large for street use on a 2L engine

they have enough flow for around 320rwkw on 2L SR's, so you imagine its going to be a bit laggy

i cant understand why you would WANT some lag though, sure you dont want to be boosting at low speed traffic driving, but you can control that with your right foot !

[RBsileighty]

What do you plan on running for management? What kind of budget are you on?

Here are some flow rate numbers for you... you can use them on comp maps and check it out.

Lbs/min 12psi @3800 ~13.274

Lbs/min 15psi @3800 ~14.765

Lbs/min 17psi @3800 ~15.759

Lbs/min 17psi @7800 ~32.349

Lbs/min 20psi @7800 ~35.410

Lbs/min 22psi @7800 ~37.451

Lbs/min 17psi @8250 ~34.215

Lbs/min 20psi @8250 ~37.453

Lbs/min 22psi @8250 ~39.612

Hope this helps...

[Roy]

You will be doing well to get 1 bar out of an RB20 at 4,000rpm with a 3037. Dont know for sure, just a suspicion:confused: Mine makes 17psi at i think 4,600rpm and the power band is still very useable. As a daily driver you will want to be an old lady liek me because if you like some spirited street driving i think you will go crazy...use the revs and row the thing along and its all good fun

I still say go for it..us RB20 owners arent a very adventerous lot, so if you throw a 3037 at one plenty of ppl will be interested in the results:thumbsup:

[dangerous_daveo]

haha! Hell yeah! Maybe look at a different manifold desige to get a bit less lag, might work. Theres a few little things you can do if it is too lagy anyway.

And yeah, Highway stuff, just put your foot on the brake as well, load up the engine more

[discopotato03]

For the best possible result make sure you use a propper Garrett GT30 exhaust housing , these are available in .63 .82 and 1.06 ARR's in T3 flange . HKS do nice .61 .73 .87 etc housings but for the T28 flange . Just my 2c worth good luck !

Cheers A .

[RBsileighty]

You will be doing well to get 1 bar out of an RB20 at 4,000rpm with a 3037.  Dont know for sure, just a suspicion:confused:   Mine makes 17psi at i think 4,600rpm and the power band is still very useable. As a daily driver you will want to be an old lady liek me because if you like some spirited street driving i think you will go crazy...use the revs and row the thing along and its all good fun

I still say go for it..us RB20 owners arent a very adventerous lot, so if you throw a 3037 at one plenty of ppl will be interested in the results:thumbsup:

GT30R map

GT3071R Map

I posted the numbers so he could look at the map and see for himself... going by the GT30R map... max spool is going to be a bit after 3800 since both 12 and 15psi are on the left of the surge line at 3800. I'm going with the GT3071R for my RB20... nice map if I say so myself.

[DoughBoy]

That GT3071R map is bogus, I wouldn't put too much faith in a comp map ATP knocked up to sell their "new" turbo. Funny that ATP are merely copying the turbo matching from HKS and then marketing it as their own private concoction... the 3071R is a 2835R specc'd turbo.

FWIW the real Garrett comp map for that 71mm 56 trim compressor is floating around, it peaks at just past 40lbs/min.

[RBsileighty]

That GT3071R map is bogus, I wouldn't put too much faith in a comp map ATP knocked up to sell their "new" turbo. Funny that ATP are merely copying the turbo matching from HKS and then marketing it as their own private concoction... the 3071R is a 2835R specc'd turbo.

FWIW the real Garrett comp map for that 71mm 56 trim compressor is floating around, it peaks at just past 40lbs/min.

Good info... nice to have people out there watching out for others. When I spoke to HKS a while back they said the 2835R would be a good match for the RB20...

So are you saying their dyno graph with the "3071R" is bogus for their EVO8? That's a shame b/c it looked like a perfect turbo for a 2L... which is probably what they were trying to do.

[DoughBoy]

I think that the results they have shown in their dyno graphs is pretty realistic, B-Man was maxing out a 2835R with near 290rwkw so it could show 400hp at the wheels with some tweaking of the dyno or car.

Don't get me wrong, I think the 2835R/3071R turbo is a great combination, but if you think it's going to flow over 500hp worth of air (as per their map) you might be a bit disappointed.

[RBsileighty]

I think that the results they have shown in their dyno graphs is pretty realistic, B-Man was maxing out a 2835R with near 290rwkw so it could show 400hp at the wheels with some tweaking of the dyno or car.

Don't get me wrong, I think the 2835R/3071R turbo is a great combination, but if you think it's going to flow over 500hp worth of air (as per their map) you might be a bit disappointed.

I'm shooting for around 260-300rwkw so it looks like this is still a good option for me (and a lot less money than the 2835R). I was recommending it to Carl b/c it seems to support all that the RB20 is capable to streetably offer vs. the GT30R/3037.

Thanks again for the input... where did you get your info about ATP? Just wondering... my buddy with an Audi B5 series S4 had said to be questionable about ATP as well.

[Roy]

Good info... nice to have people out there watching out for others.  When I spoke to HKS a while back they said the 2835R would be a good match for the RB20...

So are you saying their dyno graph with the "3071R" is bogus for their EVO8?  That's a shame b/c it looked like a perfect turbo for a 2L... which is probably what they were trying to do.

When do you think you will be getting the turbo sorted for your car. Keen to see the results:)

As for making boost based on what the compressor map says...id be using it as a guideline as i cant see how the map accounts for compressor/ exhaust housing A/Rs, the turbine you use etc etc. Still it gets you in the ballpark:)

[DoughBoy]

where did you get your info about ATP?  Just wondering... my buddy with an Audi B5 series S4  had said to be questionable about ATP as well.

I'm not sure what information you're referring to, but ATP has released several unverified and questionable documents before. I don't know why they didn't just publish the Garrett comp map for that 71mm/56trim wheel, the only conclusion I can make is their one looks alot more impressive (and will sell alot more units). As for the dyno data you can cross reference what the 2835's have made on the dyno locally, and it appears to be believable.

Have to take everything with a grain of salt, and do some homework to back up data alot of the times..

[RBsileighty]

As for buying the turbo Roy... I just finished the car not to long ago and will be buying a house here in the next year... so my current T3/T4 is going to have to make due for a bit. I need brakes/wheels/tires before I sink money into a turbo and management (fuel is well taken care of, minus injectors). My list of mods is in my signature link along with pics of the car). I just wanted to pass on some of my calcs and research to other people since this is something I've looked into... hope this helps Carl.

Never figured a company would fake compressor data... but I guess your right DB... have to keep an eye out for such things. I think it's funny b/c it seems I've come full circle on my turbo choice. I started looking at the 2835R then looked everywhere else for every other option... and it looks like that what I ended on, the 3071R is the same thing. Maybe I can pick up a second hand 2835R at some point and do a rebuild.

[carl h]

wow i never expected this thread to generate this much interest.

rbsileighty i had considered the gt3071r over the gt30r but then thought about it some more and decided that a slighly later spool is worth more than the gt3071r had to offer.

also im not looking to run crazy boost on the car right now, so if i can get 10-12psi around 3.8k then i would be just happy.

looking at the hks japan website and the 3037 turbo kit for the sr it seems to really start to make power at 4k with a simmilar setup that i plan to run (260in/exhaust 8.5mm lift cams) but with a .84 ar so i think if i get a .63 ar turbine then it should spool fairly quickly but i guess we will all have to find out.

as for the lag, yes it is nicer to have a fast spooling turbo but i like to have power uphigh i just cant stand a turbo that makes good power down low but runs out of puff in the high rpms.

like i said before the idea of the car is to be a drift/highway car but im starting to get more into the track racing thing so having power in the high rpms would be benificial i think.

here in northcarolina in the mountains there is an 11mile streach of road that has like 300 some odd turns thru the mountains i drove it when i had the rb in my s13 and it was a blast but seeing as we were never under 3.5k revs it was all about high end power.

keep the info comming tho, it is educational to me as im still learning alot about sizing turbos and what goes where.

right now i know the basics and having driven turbo cars since ive owned a car (saab 8v tubo was my first car, crazy torque and a blast to drive) im going from experience as well as what im learning.

[RBsileighty]

Ahhh... are you talking about "The Dragon's Tail" Carl? I'm from the other side of NC (Wilmington) and haven't had a chance to head out there to the tail yet... but I've only heard good things, and I can't wait to get out there!

The other thing I like about the 3071/2835R is the internal gate option... and if you run a higher A/R on the hot side you can get your lag... I'm going to try the .8X A/R for either 2835 or 3071 since cams and maybe a set of 2.2 pistons are on the to buy list. Just some more food for thought.

[carl h]

yup yup.

tail of the dragon is an awesome route to go thru and the senery is awesome, least thats what my friend said as we were blasting thru the curves.

rbsileighty, your car looks almost exactly like my old car, i too had a hicas hatch and put the rb20 in it.

s13's are great lil cars with the rb20 in it.

as for the internal gate bit, i dont care much for the internal gate seems like it causes too many boost spikes.

i had bad spiking on my rb when i would crank the boost to 14, but i think the problem lies in the turbo elbow design.

when the wastegate opens up the exhaust gasses slam right into a wall, i cant imagine what kind of turbulance it causes.