Turbo Trim

[adgey]

Hey

Wanting to buy a HKS 3037 turbo with external gate. I've decided on going with a 0.73 A/R but have no idea what i should be going for with the trim.

Any help would be appreciated

[T04GTR]

56. 52 is significantly smaller

[adgey]

thank you

[discopotato03]

Nope , the GT3037 series turbos used 3 different trim versions of the 76.2mm GT37 BCI-18C series comp family . The inducer sizes are ~ 2mm different ie 56T = 57mm , 52T = 55mm , 48T = 52.8mm .

From their compressor maps the choke flow in corrected Lbs/min for the 56 and 52T versions is ~ 53 and 50 lbs/min .

Cheers A .

[sweetr33]

do hks sell them with a surge slotted comp cover?? running bigger trim with surge slotted comp cover should be an issue hey?/

[discopotato03]

Port shrouded compressor housings do zip for you provided the compressor is operating outside its surge zone . The things that make these turbos surge are small A/R ratio turbine housings and large trim compressors .

People have to understand that small exhaust housings help to get the turbine up to speed BUT if the compressor tries to pump more air than the engine can swallow you get pressure fluctations - surge . The propper way to do it IMO is to use less than the largest compressor trim option if you must use smallish exhaust housings . Big trim compressors create more turbine lag than medium or smaller trim wheels because they take more energy to drive .

Specifically to HKS's GT3037's . The normal or "straight" GT3037 uses the std form 0.60 A/R TO4E compressor housing ie 2.75" inlet and 2" outlet . These are easiest to package because of the smaller inlet boss ie 2.75" vs 4" . As I said if you don't need the port shrouded comp housing this is the way to have it . The port shroud actually costs a little bit of compressor efficiency (and screams its head off) but thats preferable to surge .

The GT3037 "S" variant are the ones with the ported inlet shroud and HKS intended them to have large A/R exhaust housings ie 1.01 for the 52T version and 1.12 for the 56T one .

By the way I believe most of HKS's turbine or exhaust housings were a hybrid GT30 housing with the T28 mounting flange . Your call but I would never use that flange size on an RB 6 cylinder . I don't think its possible to merge 6 exhaust manifold runners into a flange of that size and not get an unacceptable exhaust pressure rise . The RB26 is different because it has two turbos meaning only three manifold runners and three cylinders to handle . Nissan went with the divided T3 flange on single turbo RB's almost certainly for this reason .

The easiest GT3037 you'll ever fit to a single turbo RB is the Pro S Version , the reason being that HKS has a model specific one that goes on the std exhaust manifold and includes ALL the plumbing and a dedicated dump pipe . Expensive yes but when you add up all the fiddlies needed and the running round to find them its probably not so different .

Cheers .

[sweetr33]

ah ok, i wasnt sure, just the 35/82R i ordered i got the port shrouded comp cover, ah well.

[discopotato03]

That would not be one you'd see very often , a port shrouded GT3582R . You see the odd one in the US but its not a version Garrett market out here too often - this asumes it has a T04S comp cover and not some other oddball thing .

Cheers A .

[sweetr33]

nah they didnt advertise it at all, i had to ask if they did it, so opted to do it, coz on my rb25, im not going to outflow the comp wheel in a hurry haha so thought wat the hell.......cheers

[T04GTR]

they sound awsome!! i actually got the wanker bug and almost got my t04z converted to a surge cover just for the whissle