Vg30 Rb20det is it worth it

[EVL032]

i got the Rb20det with T28 just wondering if the Vg30 is a good upgrade for the $500 mark or is the T28 better over all????

wat r the pros and cons???

i dont want an aftermarket turbo cant afford one so wat is the best standard turbo to bolt to my rb20det

any help appreciated!!!!!!

thanx

[discopotato03]

I'll assume you mean the Ceramic Turbined BB turbos . The VG30 version was designed to run an engine half as big again so response may be a bit lacking on an RB20 . However some use the RB25 BB turbo which uses a slightly larger compressor and cover . If you have access to the bits the RB25 type exhaust housing on the VG30 turbo should have reasonable mid range .

When you look inside the turbine housings of the RB20/25/VG30 BB turbos the difference is staggering , with the smaller RB20 Version I'm amazed they go at all . The VG30 version is huge in comparison so the middle RB25 version would be a good start .

Depending on which standard RB20 turbo you have you could always put the mid sized (RB25) turbine housing on the std turbo to reduce the restriction on the exhaust side . This would flow a little better and maybe give a bit more power per pound of boost than the std turbo .

Cheers A .

[EVL032]

so would the r33 be a better turbo than the rb20 turbo???

[discopotato03]

Better as in can it make more power - yes . I would be wary of going up too far in size as I believe its very easy to loose the bottom end torque with RB20's .

As I said I would change your RB20's exhaust housing for the mid or RB25 sized one . These housings are not difficult to find because plenty of people find out the hard way what happens when they ask too much of the std turbo on an R33 .

When you go up in compressor size you give the same sized turbine more work to do which adds to lag . Slightly free flowing the exhaust side (turbo) and maybe a fiddle with the cam timing should help .

[EVL032]

thanks for ur advice mate.

so wat u r sayin is that i keep my turbo on there now but replace the backing with a r33 housing so i can just use a blown 33 turbo yeh if i only need the housing???

[Cubes]

I've had the VG30 BB Ceramic turbo on my Rb20DET quite some time ago.

I wasn't impressed. The lack of mid range was really dissapointing.

It felt like it hardly boosted in first gear, making one slow off the line r32

I put the RB20DET 16V turbo back on and was much more happy with that running 1bar.

I went for a spin in a R32 with a rb25 turbo bolted on.

The RB25 turbo is the pick of the bunch.

Discopotato..

The rb25 has a larger exhaust a/r than the rb20?

When I compared, the exhaust a/r looked the same however the rb25's compressor cover was larger.

[discopotato03]

Yeah , all the RB25 housings I looked at have a larger passage internally . I once had all three side by side and they had different numbers cast into them . The VG30 version has a tad smaller comp wheel so spool should be a little better . The turbines all look the same so one up on the exhaust housing plus the next size up comp wheel (VG30) seems logical . The cheapest option would be just to change the turbine housing for the mid sized one and if its not enough then try the VG30 core and comp cover .

Like some others here I'm more interested in average power than all up the top end , so absolute maximums are an afterthought .

Too many people kill the bottom end power of engines like RB20's and it doesn't have to be that way .

[EVL032]

ur help is appreciated every1

[mr_rbman]

is it true that your better off getting the series 2 RB25 Turbo over the series 1? if so y is this so?

[Nismo_R31]

GARRETT RB20/25 SERIES

Even though many tuners refer to the RB20 and VG30 (single) turbochargers as being a T3, this is not the case. Being a Nissan-branded item and having only Nissan identification markings on them (no AR markings etc.) can make identification difficult. All of the ball-bearing turbos have a telltale 'fatter' centre core section, as well as a bolt through the centre housing, which looks as though it has an effect on the thrust bearing pre-load. Overall, these turbos are very good performers.

Car of Origin:

Nissan Skyline R31 GTS

Engine: RB20DET NICS (ribbed rocker cover)

Flange: Four bolt T3 style

Max. Power Rating: 140kW

Max. Boost: 1.2bar (17.4psi)

Cover Size: AR not identified

Comments: A poor-performing turbocharger that was only used on a handful of engines by Nisan before being replaced with the newer technology ball-bearing units. Top-end power is far from good, and the actual response (boost-response time) is also quite poor. It's one to steer away from.

Cost: Dirt-cheap, as they are not in any demand. They have been seen to be as low as $100.

Rating: One out of five

Car of Origin: Nissan Skyline R32 GTS-t

Engine: RB20DET ECCS (silver rocker cover)

Flange: Four bolt T3 style

Max. Power Rating: 160kW

Max. Boost: 1.2bar (17.4psi)

Cover Size: AR not identified

Comments: A big step in the right direction from both Nissan and Garrett. A truely nice turbocharger, complete with modern aerodynamics and ball bearing construction. It's a perfect choice to get the best from an internally stock, standard injector/management set-up. On a CA18 with a custom manifold, they are really good things.

Cost: Reasonable, with some examples floating around the importers for as little as $400. You have to be quick thoughm as they tend to sell fairly quickly.

Rating: Four out of five.

Car of Origin: Nissan Skyline R33 GT25-T

Engine: RB25DET

Flange: Four bolt T3 style

Max. Power Rating: Approximately 185kW

Max. Boost: 1.2bar (17.4psi)

Cover Size: AR not identified

Comments: The big daddy of the range makes the RB25 turbocharger good for almost any mild six-cylinder application. Sparkling boost response in the low-rpm range and a reasonably hard-hitting top end make this the most common upgrade found on the RB20DET. It's highly recommended.

Cost: Being very difficult to get hold of makes them highly variable in price. Sometimes about $700, sometimes more.

Rating: Five out of five.

Car of Origin: Nissan Gloria, 300ZX

Engine: VG30DET

Flange: Four-bolt T3 style

Max. Power Rating: 190kW

Max. Boost: 1.2bar (17.4psi)

Cover Size: AR not identified

Comments: Apparently, these are slightly larger in exhaust housing size than the RB25, but have a fractionally smaller and different trim compressor. Information on these is sketchy, but due to their almost unknown application they are easier to find than the RB25 roller. A good choice, particularly if you put the RB25 compressor and cover straight on. In excess of 200kW have been produced with this combination.

Cost: Fractionally cheaper than the RB25 turbo and not as hard to get. They have been advertised at $650.

Rating: Four out of five

[lows_13]

Its amazing how many people don't like the VG30's on the RB20's.

I'm going to look at one this weekend and it has a VG30 on it, front mount, boost controller etc. So i'll post up after i've taken it for a drive to let you know.

[Lithium]

Yeah , all the RB25 housings I looked at have a larger passage internally . I once had all three side by side and they had different numbers cast into them . The VG30 version has a tad smaller comp wheel so spool should be a little better . The turbines all look the same so one up on the exhaust housing plus the next size up comp wheel (VG30) seems logical . The cheapest option would be just to change the turbine housing for the mid sized one and if its not enough then try the VG30 core and comp cover .

Like some others here I'm more interested in average power than all up the top end , so absolute maximums are an afterthought .

Too many people kill the bottom end power of engines like RB20's and it doesn't have to be that way .

I have an RB25DET which I blew the standard turbo on and spent a lot of time messing around trying to work out what I wanted to do. I ended up buying a VG30DET turbo to get my car going on the road while I upgrade all the other bits and pieces (ECU, Front mount etc) in preparation for a larger turbo.

Your comment on replacing the turbine housing intrigues me - the VG30DET turbo has a noticeably larger turbine housing than the R33 turbo, but a slightly smaller comp wheel? I know the on road impression for one of these on an RB20 is bad, but on an RB25DET it should still spool quite well, aye? Would the smaller compressor wheel be a problem - or would I have all the power of the stock turbo, possibly plus a little more?

Additionally, to my understanding - all the turbos from this era for turbo Nissans (R32 GTSt, R32 GTR, VG30DET(T). R33 GTS25t) run the same spec T25G-type turbine wheel? Does this mean that if I got my hands on another R33 GTS25t turbo, I could possibly swap the VG30DET turbo turbine housing onto the RB25DET turbo and made one with the best of everything???