Help With Rb20Det Response

[Ke55pig]

Hey recently got my car tuned with the new rb25 hi flow and have found the turbo not to be hitting fullboost till 4500 would like to be able to bring this down as much as possible.

Have been told a steel intake pipe should help with response ?? what about the rubber aftermarket ones ?

At the moment just looking for response. Tuner thinks will make 210 on 18 psi with injectors and afm but really looking for respose bring boost on earlier

greedy fmic

turbotec boost controoler

nisstune

full straight through 3" dump to 3.5" back

.8 plugs

yellow jackets

rb25 hypergear hi flow

186 at 16-15 psi very laggy

cheers

The above intake could be corect i can close the rubber stock pipe with reasonable eas with 2 finger so chance it could be closing a bit ??

Edited February 14, 2011 by Ke55pig

[Truffles]

Have you thought about aftermarket cam gears? Especially the exhaust gear. They have good results on RB20's. Can provide higher top-end and should bring on full boost 400-500 rpm earlier.

[Ke55pig]

i have but have heard both good and bad stories i gues worst case is no gain at all .Looking for thing to regain response because im not to sure but i thing 450 full boost is pretty dam laggy even on a 20

[zebra]

Rb20 will be laggy and shit down low no matter what you do, if you want more bottom end go RB25

edit - plus you are using a journal bearing High flow turbo...so that by nature will be laggy

[Ke55pig]

I understand im not going to get nothing awesome but a mate got a 25/40 and get full boost at 4000 rpm on a 20 something musnt be right with my setup.

Also maybe thinking about e85 have heard of it bringing boost on earlier

Edited February 14, 2011 by Ke55pig

[zebra]

Well I doubt that because they wont make 20psi under 4000revs on a 25, even a 25/30 would struggle.

E85 will hurt boost response in 99% of cases

if you only want 210rwkws when ditch the high flow and use a standard RB25 Neo (OP6) turbo. or find a RB specific HKS GT2530

[JKR-32]

I understand im not going to get nothing awesome but a mate got a 35/40 and get full boost at 4000 rpm on a 20 something musnt be right with my setup.

Also maybe thinking about e85 have heard of it bringing boost on earlier

3540 on full boost by 4000 on an rb20? No freaking way, not even with a .63 rear housing. With a .63 rear housing you're lucky to get hit full boost on a rb25 that early dude. Unless he has some top secret goodies and some jungle juice fuel he's using.....

edit: beat me to it zebra

Edited February 14, 2011 by JKR-32

[Ke55pig]

sorry typo 25/30 he said about 4000 is about full boost

[Ke55pig]

Well I doubt that because they wont make 20psi under 4000revs on a 25, even a 25/30 would struggle.

E85 will hurt boost response in 99% of cases

if you only want 210rwkws when ditch the high flow and use a standard RB25 Neo (OP6) turbo. or find a RB specific HKS GT2530

Im not ditching it i only bought it awhile ago im looking to make around 230-240 But at the moment would like to get some better response

As stock 20s with 25 turb keep up till top of 3rd kinda sad wen i spend decent money on a turbo and heap of boost.

[Dobz]

That is as good as response will get for the turbo you're running so either sell it and buy something more suited to rb20 like an hks25/30 or get used to lag.

[SECURITY]

i see your problem.... you're missing around 1000cc of engine capacity.

[kwickr33]

Get a 3inch hard intake pipe as hypergear mentioned. The turbo can't build up boost if it can't suck in air.

Get an high pressure actuator. That will make lot of differences as stock actuator lets loose at 2psi and fully opens by 7, while high pressure actautor don't starts to open till about 15.

[Legionnaire]

What's the size of your current turbo? I mean wheel sizes as well as ex. housing A/R size. 

Since it's a RB25 highflow, I assume it has like 400-450hp worth of compressor flow and appropriate turbine to support that flow, so must be 2871 52 or 56 trim-sized. Now some easy calcs, just to verify. 450hp turbo on a 2 litre equals to 225hp/litre and should have similar response to a RB25 with a turbo, that provides 225*2.5 = 562.5 hp. This power fits right between GT30R and GT35R turbos, and RB25 spools GT30 at ~3500-4000 and GT35 at 4000-4500, depending on rear housing, so your response sounds right. Even SR20's spool 2871 at  around 4000 rpm (again, depending on compressor trim and housing A/R), and having bigger capacity cylinders they tend to spool turbos better than RB20's.

I'd change your current turbo to a Disco Potato or a 2860R and used it in a RB25 21U housing for more response or in a OP6 housing for slightly more power.

But that's just my opinion.

[badhairdave]

It's been asked but you haven't answered. Which highflow did you get? Hypergear does quite a few different ones so if you have one of the bigger 280+ capable ones you aren't going to significantly improve your response.

I had one of the original GCG stage 2 highflows on my rb20, same same. lazy coming onto boost and you had to keep the revs up so you didn't drop off boost.

With an rb20 you just have to accept that nothing will happen below 4k. Been there, done that, got an rb25.

[joeyjoejoejuniorshabadoo]

exactly. it's an RB20, just learn to keep the revs up and smash the tits off it.

[GTScotT]

Seeing as you havent done injectors or any engine hardware yet, I would say drop an RB25 in with your RB20 cams and forget about the VCT.

Simply bolt all your peripherals to an RB25 long motor and intake manifold and get it retuned. The difference should be everything your looking for plus more, much more torque, better response and about 220rwkw on the stock injectors I believe.

I just dont see a problem with your dyno sheet to be honest. If you were in NSW I would sell you my old RB25 for cheap, too bad it looks like your in SA.

GL

[Ke55pig]

i got told it can flow 250 max on a rb 20 and 270 max on 25 no quite sure on the sizes ?

[BLITZ-26]

seen more 20s with more mods and still the same, its never going to be responsive dont waste your money and time doing what other people have already tried and had no sucess best thing the cheapest is already mentioned here, pull out the RB20 and slot a RB25 into it you wont regret it!

[bubba]

i see your problem.... you're missing around 1000cc of engine capacity.

+11ty

Best thing I did to my 32gtst was drop a 3L in

[honan]

exactly. it's an RB20, just learn to keep the revs up and smash the tits off it.

best thing for it!!