Discopotato On An Rb20

[Josh]

I just did a quick search, but didn't see anything relevant - How do you guys reckon a Discopotato(GT2860R i think) would go on an RB20? too laggy?

Just considering some new turbo options for the 20 and a few mates suggested this..

EDIT* This is for a heavily drift orientated setup by the way..

Edited April 18, 2006 by Josh

[CATKICKER]

I am looking into turbos myself and from what I have picked up it would be a bit too laggy! Big power top end though!!

[Josh]

on SR's the disco is not too laggy, doesn't have huge top end power, but is pretty grunty down lower...

what would make it work differently on an RB20? Im no expert but would it have something to do with the different exhaust pulses(and volume of gas in each pulse) of the SR and RB's?(Considering they are the same displacement, just 2 more cylinders..)

[CATKICKER]

hmmm, I thought it was quite a big turbo... Might have to do a little more research before I give an opinion All the best with it Josh and wouldn't mind hearing how you go once you have replaced the turbo!

[silver gts-t]

shouldnt be to laggy at all..

on a rb20 you would get about 220rwkw with it

but with it you will also need a new dump pipe, water and oil lines, and t28- t3 adapter flange + labour

in the end better off getting a GCG highflow for the same power and less hassel straight bolt on

[Josh]

Mmm, not gunna worry about a highflow.. I do realise I will need the flange adapter, oil + water lines, but just considering something different..

However talking to a fella I know, he reckons it should go alright, but will be fairly laggy. Won't go as well as it does on an SR due to RB not having the dynamic torque that the SR's have..

[StockyMcStock]

Won't go as well as it does on an SR due to RB not having the dynamic torque that the SR's have..

explain that one to me?

[Josh]

because of the stroke of the SR it has the torque already there before boost comes in.. helping a lot, the RB just doesnt have the stroke..

[grim32]

I really dont think it will be that laggy, but my idea and your idea of lag may be two different things.

ps. i have a 3071 and thats not laggy to me.

[Josh]

true, plus boost is just a clutch kick away

[N I B]

I have some Dyno runs on an RB20 with a 2871RS(Disco's bigger Bro)

Ill see if i can get hold of the rego number to recall them for you but it was quite good from memory.

[StockyMcStock]

because of the stroke of the SR it has the torque already there before boost comes in.. helping a lot, the RB just doesnt have the stroke..

i am of the opinion that the presence of two more cylinders will more than make up for it.

[Josh]

Maybe, I guess the only way I will find out for sure is to actually do it myself.. or if someone who has done can come forward..

[discopotato03]

The Discopotato GT28RS AKA GT2860RS is really a slight compressor variation on the HKS GT2530 but its housings suit 4 pot 1800-2000cc better . It tends to like being used in .86AR (GT28) exhaust housing and the TO4B compressor cover is fitted because it can turn some big revs and pump a lot of air for a 60mm compressor . I do remember someone fitting it in this form to an RB20 and found it laggy - sort of the all in with a bang at 4000rpm . If you were lucky and had the HKS T3 flanged 2530 exhaust housing (.64AR) it would no doubt pull the bottom end up but then its not operating as its designer intended so no promises .

I don't have time to get into an SR20/RB20 debate but it is obvious that the RB20 was designed to rev where the SR20 was not . The whole 4 cyl/6cyl thing is going to revolve around individual cylinder capacity and breathing so they really are worlds apart . For convienence sake I reckon DP for SR20 and either Hi Flow or model specific 2530 for RB20 . Because I'm obstinate I would build (get built) a variation of the real GT3071R with the slightly smaller 52T compressor so that it would not have high boost anywhere but a broad power range to roam around in . It would have to hang off the HKS manifold and be externally gated so not cheap easy or convienent .

Cheers A .

[MerlinTheHapyPig]

discopotato (GT28RS) is less laggy than GT2871R

here are the specs for people who are intersted

GT28RS

HP 350

Compressor 60mm A/R .60 Trim 62

Turbine 53.85 AR .86 Trim 76

GT2871R

HP 400

Compressor 71mm A/R .60 Trim 56

Turbine 53.85mm AR .64 Trim 76

(2 versions of gt2871r one has .64 A/R on turbine, one has .86 A/R on turbine, all other specs are the same)

[Josh]

Another thing we were possibly thinking about was getting an RB25 rear housing machined to fit the disco.. that way its a straight bolt to manifold jobby not to mention retaining the same dump..

all in by 4000 doesn't seem too bad either..