rb25 hx40 vs. hx52

[93slicktoptt]

Im almost done with my forged engine build and im unsure of which turbo i should get. Im somewhere between a hx40 pro with a 19 exhaust, and a hx52 .not sure which will work best for me .I still have stock cams in , prolly gonna need to upgrade to get me where i want to be. Im shooting for 500-600 at the wheels. Someone with some info on which turbo i should get let me know . Thanks

[julio]

Are you talking about pump gas or the occasional race fuel? An HX40 can get you 500-600whp with cams on high boost. HX52 is capable of 700whp+ on race w/cams.

[93slicktoptt]

thats pretty much what i thought . pump with occasional race gas. i guess the hx40 will be good enough for me then. thanks man .

[Blown240sx]

we are running a HX50 on my friends and it spools ok for the size of the turbo but the efficiency range is higher than you can run on pump gas. We ran 22 PSI and it didnt make much more than the GT3076R we had on it at the same psi.

[93slicktoptt]

ok, just curious ,what kinda power was he makin at 22 psi

[Blown240sx]

410-420 whp

This was on a completely stock motor with bolt ons.

[julio]

Hmm, for some reason I haven't seen any decent numbers with hx50's. Although, recently there have been some dynos posted of a 575whp HX40 (T3 hotside) dsm on 25psi, a 700whp HX52 honda on 35psi (mustang dyno), and a 473whp HX40 R33 GTST (stock cams) on 21psi.

[Blown240sx]

Like I said this is on a completely stock RB25 (block, rotating assembly, and head/cams)

Mods
740cc injectors
SARD FPR
Greddy Intake
Q45 TB
HX50 with T6 hotside @ 22 psi
Power FC
GT Spec Exhaust
Cutsom J pipe/down pipe
FMIC

[93slicktoptt]

Like I said this is on a completely stock RB25 (block, rotating assembly, and head/cams)

Mods
740cc injectors
SARD FPR
Greddy Intake
Q45 TB
HX50 with T6 hotside @ 22 psi
Power FC
GT Spec Exhaust
Cutsom J pipe/down pipe
FMIC

thats not bad power for that setup. u think that turbo might be hurting more than helping tho? with a stock engine and a big exhaust housing that prolly spools pretty late huh.

[93slicktoptt]

Hmm, for some reason I haven't seen any decent numbers with hx50's. Although, recently there have been some dynos posted of a 575whp HX40 (T3 hotside) dsm on 25psi, a 700whp HX52 honda on 35psi (mustang dyno), and a 473whp HX40 R33 GTST (stock cams) on 21psi.

s*** ,i hope my rb will make 575 on 25 pounds. damm dsm's

[Blown240sx]

Like I said this is on a completely stock RB25 (block, rotating assembly, and head/cams)

Mods
740cc injectors
SARD FPR
Greddy Intake
Q45 TB
HX50 with T6 hotside @ 22 psi
Power FC
GT Spec Exhaust
Cutsom J pipe/down pipe
FMIC

thats not bad power for that setup. u think that turbo might be hurting more than helping tho? with a stock engine and a big exhaust housing that prolly spools pretty late huh.

I agree. The original plan was to build the motor and swap in a RB26 head. He and his wife have a kid now so it went to back burner. The original setup with the GT3076R was great. Made 363 whp on 16 psi and made full boost @ 4000 rpms.

The HX50 spools full boost around 5500 but will stay spooled between shifts.

[julio]

s*** ,i hope my rb will make 575 on 25 pounds. damm dsm's

Ha, your telling me! I'm shooting for 500whp at 20-22psi and 600ish on race once I get some cams. Those damn dsm's run crazy boost on pump too.

BTW, that dsm made 573fwhp on 27psi, not 25psi...E85 too, so that explains a bit. His car is down for an awd drivetrain swap, not surprised! Says he spins the front tires until about 110mph or so lol.

[WhatsADSM]

s*** ,i hope my rb will make 575 on 25 pounds. damm dsm's

Ha, your telling me! I'm shooting for 500whp at 20-22psi and 600ish on race once I get some cams. Those damn dsm's run crazy boost on pump too.

BTW, that dsm made 573fwhp on 27psi, not 25psi...E85 too, so that explains a bit. His car is down for an awd drivetrain swap, not surprised! Says he spins the front tires until about 110mph or so lol.

RBs aren't so bad. I made 501whp on 17psi and 594whp on 24psi, with a little 62mm turbo and almost a completely stock longblock (even stock cams)... And I know of others that have made even more at moderate boost levels. RB26 head does help that a bit though.

To the OP. I agree go with the HX40. Sure it might be down a bit in terms of peak power and maximum potential. However you will be giving up a lot of powerband for it. So unless you really plan to push it into the 600whp range you are better off with the "smaller" HX40 turbo.