Rb25 Hks 2835 Pro S 56t With A T2 3037 .74 Rear

[LaurelPWR]

I'm thinking of putting a sr HKS 3037 pro S .74 a/r external gate rear housing on my current internal gate t3 .87 a/r 2835 pro S and putting the gt30 rear wheel on as well obviously.... I was going to use a mamba t3-t2 flange adaptor so I can maintain all my piping and have the external gate flange welded into the .74 rear and just a new dump made... Can anyone see any problems in this idea?

[LaurelPWR]

[LaurelPWR]

Anyone??

[Dale FZ1]

It's not just a simple matter to change the turbine rotor on a BB cartridge.

Effectively you want to completely change the turbine spec while retaining the compressor spec.

Consider just purchasing a GTX3071 and adding a T3 housing of your spec. Cost effective, and you'll recoup a fair bit by selling off the 2835.

All this assumes you are not prepared to look beyond Garrett/Honeywell product.

[LaurelPWR]

It's not just a simple matter to change the turbine rotor on a BB cartridge.

Effectively you want to completely change the turbine spec while retaining the compressor spec.

Consider just purchasing a GTX3071 and adding a T3 housing of your spec. Cost effective, and you'll recoup a fair bit by selling off the 2835.

All this assumes you are not prepared to look beyond Garrett/Honeywell product.

I should have added that I've had trouble with this turbo since i bought it... Apparently "new" ..... it's never held boost properly... Always drops off at around 12-14psi starts to drop drastically even with 21psi springs in a turbo smart actuator.... It's going to mr turbo to get looked at in the next months so if it turns out there's a fault with the cartridge of blades or something then I will rebuild with the bigger rear wheel and use the t2 housing

[discopotato03]

From memory .

HKS Pro S housings came in 0.68 or 0.87 AR ratios for the 2835 and 3037 turbos .

IMO it isn't practical to change turbines in a 2835 cartridge , probably better off just using a GT3076R (Garrett speak for GT3037) in the GT30 spec HKS Pro S turbine housing .

Generally the GT2835 Pro S turbos came with the 0.68AR turbine housings but the 0.87 version was an option .

The cropped GT30 turbine in the "2835" turbos was a special by Garrett for HKS back around 1990 to try to squeeze a modified GT30 turbine into GT28 turbine housings . It was a failure which somehow made it to the market for RB26 and SR20 applications . Basically the nozzle angle in a GT28 turbine housing is all wrong for GT30 turbines - even cropped ones .

HKS were the only ones to make GT30 turbine housings profile machined to suit the cropped GT30 turbine that did work . The GT Pro S turbine housings were for a time the ONLY T3 flanged GT30 integral waste gate housings available , later Garrett got around to making their own version but never machined to suit the cropped GT30 turbine .

Also have to remember that the compressor wheel in the GT2835R is a 71mm 52 trim GT (Garrett Technology) family and not exactly a high volume wheel for say a 2.5 lire engine .

To get the most out of it you need to spin it fairly fast and a GT30 turbine isn't going to want to do that without a smallish ratio turbine housing . This was why HKS opted for a custom Garrett version of the GT30 turbine , shorter blades and a bit less mass to spin the wheel up faster .

Garrett tried the 71mm GT compressor wheel + GT30 turbine wheel combination in turbo called GT3071R . People tried them in GT30 0.63 and 0.82 AR Garrett turbine housings and many were never happy with either . I think the smaller housing brought it on a bit quick and made the compressor surge and the larger one seemed to add unacceptable lag .

I reckon HKS knew all this and got around these issues with their unique turbine housings and port shrouded compressor housings .

The situation is a bit different with GT3076Rs and GTX3071Rs , Garretts GT30 IW turbine housings work fine and the compressor housings sold with them are port shrouded as well .

Garrett has never successfully bridged the gap between the GT28 NS111 turbine and their GT30 UHP turbine . The cropped GT30 was a band aid for specific HKS applications but not a real fix . Shortening the length of the blades really leaves you with too much wheel hub area and mass and it only kind of works in turbine housing made specifically to suit it .

There are a few 60mm versions of the NS111 turbine but they were only ever used in competition turbos of the TR30R family which again are application specific and very very expensive . Also made of different materials not necessarily suitable for general aftermarket use . Basically dead end .

IMO if you have a HKS GT30 Pro S turbine housing , and the unique dump pipe , get a GT3076R or GTX3071R cartridge compressor housing combination and fit them together . You should be able to sell the complete 2835 Pro S easily if its in good working order .

I think trying to customise the 2835 could owe you a lot of money and net you a lack lustre result .

Your call cheers A .

[LaurelPWR]

From memory .

HKS Pro S housings came in 0.68 or 0.87 AR ratios for the 2835 and 3037 turbos .

IMO it isn't practical to change turbines in a 2835 cartridge , probably better off just using a GT3076R (Garrett speak for GT3037) in the GT30 spec HKS Pro S turbine housing .

Generally the GT2835 Pro S turbos came with the 0.68AR turbine housings but the 0.87 version was an option .

The cropped GT30 turbine in the "2835" turbos was a special by Garrett for HKS back around 1990 to try to squeeze a modified GT30 turbine into GT28 turbine housings . It was a failure which somehow made it to the market for RB26 and SR20 applications . Basically the nozzle angle in a GT28 turbine housing is all wrong for GT30 turbines - even cropped ones .

HKS were the only ones to make GT30 turbine housings profile machined to suit the cropped GT30 turbine that did work . The GT Pro S turbine housings were for a time the ONLY T3 flanged GT30 integral waste gate housings available , later Garrett got around to making their own version but never machined to suit the cropped GT30 turbine .

Also have to remember that the compressor wheel in the GT2835R is a 71mm 52 trim GT (Garrett Technology) family and not exactly a high volume wheel for say a 2.5 lire engine .

To get the most out of it you need to spin it fairly fast and a GT30 turbine isn't going to want to do that without a smallish ratio turbine housing . This was why HKS opted for a custom Garrett version of the GT30 turbine , shorter blades and a bit less mass to spin the wheel up faster .

Garrett tried the 71mm GT compressor wheel + GT30 turbine wheel combination in turbo called GT3071R . People tried them in GT30 0.63 and 0.82 AR Garrett turbine housings and many were never happy with either . I think the smaller housing brought it on a bit quick and made the compressor surge and the larger one seemed to add unacceptable lag .

I reckon HKS knew all this and got around these issues with their unique turbine housings and port shrouded compressor housings .

The situation is a bit different with GT3076Rs and GTX3071Rs , Garretts GT30 IW turbine housings work fine and the compressor housings sold with them are port shrouded as well .

Garrett has never successfully bridged the gap between the GT28 NS111 turbine and their GT30 UHP turbine . The cropped GT30 was a band aid for specific HKS applications but not a real fix . Shortening the length of the blades really leaves you with too much wheel hub area and mass and it only kind of works in turbine housing made specifically to suit it .

There are a few 60mm versions of the NS111 turbine but they were only ever used in competition turbos of the TR30R family which again are application specific and very very expensive . Also made of different materials not necessarily suitable for general aftermarket use . Basically dead end .

IMO if you have a HKS GT30 Pro S turbine housing , and the unique dump pipe , get a GT3076R or GTX3071R cartridge compressor housing combination and fit them together . You should be able to sell the complete 2835 Pro S easily if its in good working order .

I think trying to customise the 2835 could owe you a lot of money and net you a lack lustre result .

Your call cheers A .

Thanks for the epic reply man! Your a wealth of professional information and as always a credit to the RB community!

I'm not actually trying to make a freakish custom 2835 turbo but I am trying to, from what I understand, turn a t3 internal gate HKS 2835 pro s into a t2 external HKS 3037 pro s and fit it to a t3 manifold using a flange adaptor... The 56t compressor side appears to be identical on both 2835 and 3037 Pro S

[discopotato03]

No , the 3037 in HKS speak uses the same cartridge (centre section and wheels) as the Garrett marketed GT3076R - 76mm 52 trim compressor wheel .

The 2835 in HKS speak uses a smaller diameter 71mm 56 trim compressor wheel .

Really if you have a turbine housing from a HKS 3037 Pro S adding a Garrett GT3076R and its compressor housing basically gets you the full 3037 Pro S .

Garrett sells the cartridge and compressor housing combo and if you want the complete unit the turbine housing is added to it . Garrett GT turbine housings are mostly made of the expensive Ni resist material and add considerably to the cost of a complete turbo .

Also I don't know if its possible to machine a HKS Pro S turbine housing out to 3037/GT3076R turbine dimensions if your housing is from a 2835 Pro S .

From memory HKS used the same T housing castings but offset machined the 3037 ones so they didn't break into the waste gates passage with the larger turbines profile . I remember looking at pics of the hot sides of GT Pro S 2835s and 3037s and the gap between the two outlets isn't very big nor very different from each other .

A .

[LaurelPWR]

No , the 3037 in HKS speak uses the same cartridge (centre section and wheels) as the Garrett marketed GT3076R - 76mm 52 trim compressor wheel .

The 2835 in HKS speak uses a smaller diameter 71mm 56 trim compressor wheel .

Really if you have a turbine housing from a HKS 3037 Pro S adding a Garrett GT3076R and its compressor housing basically gets you the full 3037 Pro S .

Garrett sells the cartridge and compressor housing combo and if you want the complete unit the turbine housing is added to it . Garrett GT turbine housings are mostly made of the expensive Ni resist material and add considerably to the cost of a complete turbo .

Also I don't know if its possible to machine a HKS Pro S turbine housing out to 3037/GT3076R turbine dimensions if your housing is from a 2835 Pro S .

From memory HKS used the same T housing castings but offset machined the 3037 ones so they didn't break into the waste gates passage with the larger turbines profile . I remember looking at pics of the hot sides of GT Pro S 2835s and 3037s and the gap between the two outlets isn't very big nor very different from each other .

A .

Ahhhh yes i see... I always assumed the compressor was the same on both 2835 and 3037 pro s....

Well if I'm already making 460whp now so my next aim will be 500-550whp so instead of f**king around, I'm now contemplating a trust/greddy t67...

Can I have your opinion on this one please disco -

https://www.ebay.com.au/itm/252438374637

[LaurelPWR]

I reckon it's a greddy compressor housing on a chinabay core and rear housing .... Can't find one other t67 with this rear. Not to mention it has no markings whatsoever on the rear and a 7 blade comp wheel when the t67 has a 6 blade wheel..

[discopotato03]

Personally I would stay with Garrett GT or GTX units , eg a GTX3071R should put you in the power range you mentioned .

 

[Dale FZ1]

Given Mick-o achieved one of the bigger proven results with a GTX3071 on E85 @450rwhp, I'll be the skeptic on a HKS 2835 making a comparable 460rwhp with its lower flow potential through both compressor and turbine.

If the target has now been elevated to a 550rwhp ceiling, he's in GTX3576 or 3582 territory if Garrett is the brand.

I'd be looking a bit harder at some BW literature too.

 

[Dose Pipe Sutututu]

Slightly on topic, slightly off topic...

Last Saturday I tuned a non-VCT SR20 with basic Poncams, a proper twin scroll setup using a GTX3071 with 0.83 rear housing. Car made a healthy 351kW @ 27psi with more room in it.. I had to stop because I wasn't confident the motor would hold up (i.e. bang, snap rod, basic rebuild by Forced Motorworx about 7 years ago).

22psi by 4050rpm and 27psi by 4200rpm.

Now imagine that same setup on a RB25DET with VCT.

https://www.facebook.com/traklifeofficial/photos/a.604327549596378.1073741827.555908561104944/1316197368409389/?type=3&theater

[LaurelPWR]

Slightly on topic, slightly off topic...

Last Saturday I tuned a non-VCT SR20 with basic Poncams, a proper twin scroll setup using a GTX3071 with 0.83 rear housing. Car made a healthy 351kW @ 27psi with more room in it.. I had to stop because I wasn't confident the motor would hold up (i.e. bang, snap rod, basic rebuild by Forced Motorworx about 7 years ago).

22psi by 4050rpm and 27psi by 4200rpm.

Now imagine that same setup on a RB25DET with VCT.

https://www.facebook.com/traklifeofficial/photos/a.604327549596378.1073741827.555908561104944/1316197368409389/?type=3&theater

Woweee! I'm not an SR fan by any means BUT That's an impressive result! If you happen to do an RB25 please share those results with [emoji16]

[LaurelPWR]

I think I've finally gotten over my HKS / Trust brand name obsession and am looking at a hta instead ... I been reading thru the hta thread and all I can say is f**king wow.!! Any you lads used them?