Rb30dett

[KISIN]

In the making is my 26/30 and since i cant afford to go all out atm with big single + supporting mods, im just going to put it together stock...

My problem is will the stock GTR turbos be too responsive on a 3L block (car being rwd also) ? I was thinking of making adapter plates to fit T3 flange and use either rb20/25 stock turbos (x2)...

Anyone done this before...would the 25 turbz be too laggy (5k+rpm) ?

Please no smart ass comments ! Any info/advice is greatly appreciated .

[R31Nismoid]

Running any ceramic wheel'd turbo is a risk that i personally wouldnt take... especially if its a built bottom end. Its simply madness to do so as a failure will cost you a motor most likely.

Having said that, GTR turbos on a 3ltr would spool really early, but if thats what you must live with so be it.

I wouldnt run anymore than 10psi through them also if you MUST go down that path

[N1GTR]

+1

It will feel like a stock TT supra

[TTT]

how about 2 t25G from a CA18det?

they have steel wheels I believe.

they should be cheap as chips.

if you are making adapter plates, why not branch out to other turbos?

VF10 is the smallest turbo's used by EJ20's.

they came on Auto Legacy Turbo's.

on the 2L ej20, these were at fullboost (10 psi stock) by 2300rpm.

VF8 or VF12

these were on the AUS Liberty RS Turbo, slightly bigger than the VF10.

full boost on the EJ by 2800rpm

TD04

stock WRX turbo from 97 - 2003 or something like that.

similar spec to the VF8 and VF12 but newer.

possibly slightly quicker spool.

all of the above turbo's cost between $150 - $300 each.

next level up is TD05 which was on the early STI's and early WRX's.

these are more laggy but have good top end on the EJ's.

2 may be too laggy on a 3L.

some guy on Performance forums used 2 VF10's on a 1jz and was making over 250rwkw at a lowish boost.

with not much lag.

All of the turbo's above are good for about 16-17psi.

[KISIN]

  R31Nismoid said:

Running any ceramic wheel'd turbo is a risk that i personally wouldnt take... especially if its a built bottom end. Its simply madness to do so as a failure will cost you a motor most likely.

Having said that, GTR turbos on a 3ltr would spool really early, but if thats what you must live with so be it.

I wouldnt run anymore than 10psi through them also if you MUST go down that path

  GTST said:

how about 2 t25G from a CA18det?

they have steel wheels I believe.

they should be cheap as chips.

ok so far we have stock GTR turbs

or

2 x ca18 turbz (confirmation they are steel wheel?)

Nismoid: so you wouldnt recommend 2 x rb25 turbos running 8psi low, 12psi high boost (only sometimes - maybe 1-3hr a week) ? would they be too laggy?

[KISIN]

ps: the bottom end is not forged for the time being so failure wouldn't be TOO dramatic.

[N1GTR]

Thats a lot of fkn around to save some dollars.

Have a look at a 2nd hand set of N1's

[KISIN]

  N1GTR said:

Thats a lot of fkn around to save some dollars.

Have a look at a 2nd hand set of N1's

if i had that money, id rather buy a 3540 straight away.

[paulr33]

i dont see why you would set it up for "low" boost and then run "high" when you wanted

if you can't afford to safely run 12psi then why do it at all ? you should just run the highest safest setting all the time

but yeah ceramic wheelies on a new 3 litre sounds like a death sentance

if you insist on doing this and have no other choice run a low safe boost setting (always) and check the exhaust temps with a EGT, get them down nice and low, make sure the tuner knows to keep the EGT's really low at all costs

[KISIN]

  paulr33 said:

i dont see why you would set it up for "low" boost and then run "high" when you wanted

if you can't afford to safely run 12psi then why do it at all ? you should just run the highest safest setting all the time

but yeah ceramic wheelies on a new 3 litre sounds like a death sentance

if you insist on doing this and have no other choice run a low safe boost setting (always) and check the exhaust temps with a EGT, get them down nice and low, make sure the tuner knows to keep the EGT's really low at all costs

Hey mate thanks 4 reply/tips !

nah im not insiting on the set up at all, just want to see what you guys think would be the cheapest option without having insane wheel spin.

PS: like i said before its not a fresh 3L.

[WHITER33GTS-T]

Whats wrong with insane wheel spin???

I will be running twin T3/T4s on my 25/30 setup

[TTT]

2 rb25 turbo's will surely be too laggy.

they are responsive on a 2.5L, they feel OKish on a 2L.

2 of them on a 3L will be lazy as.

Have you had a look at HYPERGEAR stuff?

they seem to be cheapish.

by the time you bought unknown quality second hand turbo's, created 2 adapters, probably modified the intake piping and dump pipes, you might not be saving that much money for what might be a shit result.

can't you save for another month then do it right?

[BHDave]

If you can't afford to do it right then just leave it alone.

Don't tool around with interim turbos and stuff, just leave it and save up for the right turbo(s).

Also consider that even though an sr/ca turbo has the right flanges, the turbine housing is different so it isn't a bolt up option.

[paulr33]

i agree %100 with bhdave

[VB-]

if your handy with a welder, look at subaru turbos like GTST mentioned, they are small, and built to run fairly high boost so unlikely to fail with two of them on an RB30. i've seen a couple of these used on a soarer, cant remember numbers but it went alright apparently, and you could even keep these turbos for bigger power down the track

if maintaing stock GTR turbos, do as R31nismoid said, dont go over 10psi

[KISIN]

  VB- said:

if your handy with a welder, look at subaru turbos like GTST mentioned, they are small, and built to run fairly high boost so unlikely to fail with two of them on an RB30. i've seen a couple of these used on a soarer, cant remember numbers but it went alright apparently, and you could even keep these turbos for bigger power down the track

if maintaing stock GTR turbos, do as R31nismoid said, dont go over 10psi

Yeh the twin suby turbos got me really interested atm...ill do some more research on it and see what happens

Big thanks to GTST for bringing it up. To be honest, when i saw that you replied, i thought...here we go...smart ass central But turned out to be some VERY useful info, cheers ! haha.

[VB-]

yeah think its the first ever serious post i've seen from him, i was honestly impressed

[KISIN]

  VB- said:

yeah think its the first ever serious post i've seen from him, i was honestly impressed

Wonder what kind of lag (or lack of) would there be with twin TD04's...

Edited February 2, 2008 by KISIN

[Trust33]

wait a little longer and get what u want.

[discopotato03]

Bolt on style 2530 or Garrett marketed equal , surely these must come up 2nd hand from time to time .

Don't forget its a lot of work to R&R turbos in a GTR so ideally something practical first up I reckon .