View Full Version : Twin scroll??? IHI

Sun 17th May 2009, 07:34 PM
Does anyone know if all RHB52EW ( Standard ea82t )turbo,s are twin scroll?
There are a few different spec available for this engine, I have learnt there was even a ball bearing spec RHF55 for the ea82t also...any further info on this would be helpful.

Sun 17th May 2009, 08:08 PM
I don't believe any EA82T turbo would be a twin scroll, for a start the EA82 heads dont allow for splitting the exhaust pulses because each head dumps both cylinders out of one port. I have also had both a VF2 and a VF4 which are both single scroll. Unless there is a different version of the engine i don't know of???

Sun 17th May 2009, 08:25 PM
EA82T and twinscroll ..... :D Ah Hahahahhah

Farmsci is right, the EA82T has siamesed exhaust ports making dividing of exhaust pulses for twin scroll operation impossible.

As for ball bearings, i highly doubt it.

As far as we know, there were only 3 variants of EA81/82T turbos, all based on the RHB5 cartridge)

VF2 = Non watercooled all markets
VF4 = Watercooled for Australian and Japanese markets ( rumored to be mated to the smaller diameter up-pipe for quicker spool)
VF7 = Watercooled for US and UK markets (in the UK they got 130 odd hp with this turbo and a different tune, they also had better fuel and no cat converter

Discospud was chasing up the differences between the VF4 and VF7 and i think it had something to do with the turbine wheel

Mon 18th May 2009, 01:45 PM
What discospud found (so far) was that all the EA82T engines used more or less the same turbo , I think the same cartridge is listed from VF2-VF7 .
The only significant difference was I think in the VF6 which had a slightly larger 15R instead of 12R sized turbine housing .
I have some pics on my PC (amongst about 3000 other turbo and related things) of a bare 15R EA82 turbine housing , it's useless because its cracked but at least you can see that its def EA82 up and down pipe flanges so engine specific .
I haven't gotten around to cross referencing the unit part numbers but I suspect the VF6 15R was the Rally spec turbo and being an OEM one that would make homologation sense .

I don't know of any factory twin scroll EA82T , it could be done by welding a port divider into the exhaust ports and making a divided four runner header but that's probably more trouble than its worth on an EA82 . IMO what chokes the EA82's is small inlet ports and tight bends in the exhaust ports .

As for twin scroll IHI turbos yes the VF36/37/38 (and I think some later ones) are as is the Mitsubishi TD04HLA-19T .

I decided not to go with Mitsy or IHI turbos because I think Garrett GT ball bearing turbos are better and rebuildable .
Really any non std turbo is going to need up/down pipe mods and often oil and water plumbing alterations .
Since I've been there with Garrett BB turbos grafted into non std apps I already have oil and water fittings so half the fiddly stuff is covered .
I also have the dump flange section off the GT2860RS which I think bolts to the GT2854R series turbine housing .

Anyhow from the Subaru range in the EA82T era the two turbos that are worth looking into are the VF10 and if you can get your hands on one a USDM VF11 , that VF11 is really like an EA82 turbo with a slightly larger trim EW series compressor and the same turbine but in an EJ flanged 15R turbine housing . Its comp housing is clocked slightly differently but could be got around .

A .

Mon 18th May 2009, 07:34 PM
IHI = Ishikawajima-Harima Heavy Industries.
Some ea82t info i found on the web......

Here is some good info revealed about our turbine from the casting numbers:
I don't know if the 2, K or OD mean anything but 52 means a 5200 wheel the 20 is the a/r and R5 is the material which is D5-niresist or high temp material for gasoline(not diesel). The 5200 wheel is 52mm (52.5mm to be exact per sixsick6) wide at the inducer tip. The inner diameter of the VJ11 turbine is 42.40mm (again from Sick: http://www.mx6.com/forums/showthread.php?t=124920&page=1 )

For IHI, the A/R(Pxx) is in mm2/mm. It can be converted and compared to other turbines, which are more typically in2/in. [example: Just divide it by 25.4 to get the "real" A/R, for example, if you have a p20 it's what Garrett would call a 0.78 A/R housing.]

More good info about IHI turbos and their names/spec #'s:

The VI-34 (Isuzu Impulse (Piazza) turbo) number is called a short spec. V=Vehicle I=Isuzu (don't know about our "J" or "F") 34=the first 2 numbers in the long spec. The long spec is actually the part number on the IHI bill of materials or the list of parts that make up the turbo right down to the snap rings, nuts and bolts. RHB5 is typically called the frame size. RH=Right Hand(the direction the wheel rotates) B=Generation( IHI is now on F in 2005) 5=size range(5 is approximately 80hp to 250hp) Within a frame size things like shaft diameter and bearings are common.

Compressors: EX. stock compressor - VJ11 (spec: BRL3911) 39=39mm inlet, 11=???, BRL=Back Rake large (BRLL - very large). Back rake is how much the exducer tips of the compressor lean back. The more back rake the wider the map and the less pressure ratio.

Turbine wheels: 5200II=52mm inducer tip width. II=revision 2. I think all RHB5 turbines are 60mm in major diameter and 52 or 54 at the minor outlet diameter. You can stick a 5200II turbine wheel in a P9,P12,P15,P20 or P25 A/R turbine housing. Each increase in A/R shift the turbine hook to the right a little on the compressor map. In engine terms the larger the a/r the more lag and more top end.

RHB5 is a IHI frame size that was used in many turbos:
The RHB52w is found in our Mx6/Probe's with the VJ11 from 89-91. The RHB52w was also used in the TBird from 87-88(VJ17)[some sources say VC32M -for manual trans and (VC32A) for auto], 85-90 Isuzu I-Mark (VI-55), 84-87 Isuzu Impulse(Piazza)(VI-34), 90-94 Subaru Legacy (VF-11) and all 1.8L T subarus from 86-91. The VJ20 is in the 1.8L Mazda GTX the 88-98 1.6L 323 had a VJ-14 and the 86-87 2.0L 626 had a VJ-5.

The RHB52 was used in the 84-86 turbo Escorts(VC-31), the 88-89 Chevy Spectrum (VI-55), 91-94 Ford Laser-Capri (VJ-14), 84-95 Mercury Lynx (VC-31), Ferrari 208, and Bugatti EB110(x4). Fiat used them and it's a popular turbo for motorcycles. It was also going to be used in a TT version of the DeLorean, but the company supplying the parts went out of business before they could build them.
The RHB51w is found in the 84-91 Maserati BiTurbo(VM-3 and VM-4)

Some known RHB52 part numbers:
subaru turbos:
VF8 - RHB52XW - 10000 3X P20NR BRXLL4625CFZ
VF10 - RHB52XW - 5200 2 P15NR BRXLL4225CFZ
VF11 - RHB52XW - 5200 2X P15NR BRLL4016EZ
VF12 - RHB52XW - 10000 3X P20NR BRXLL4726CFZ

Isuzu turbos:
VI34 - RHB52A-10000 3 P25NR BRL3911EZ
VI37 - RHB52W-10000 3 P25NR5 BRL3911EZ
VI23 - RHB52A-10000 3 P25NR BRL3911EZ

and the mazda turbos:
VJ11 - RHB52KW - 5200 2K P20NR5 BRL3911EZ
VJ14 - RHB52MW - 5200 2M P12NR5 BRKL3711EZ
VJ16 - RHB52MW - 5200 2M P15NR5 BRKL3911EZ
VJ17 - RHB52BW - 10000 3B P25NR5 BRL4016EZ
VJ20 - RHB52UW - 5200 2U P15NR5 BRUL3911EZ

Here's a TON more I found: www.turbomaster.info

RHB51 hold compressors up a BRL348
RHB52 holds all compressors up to the BRLL4625 (VF8 compressor).
A "W" on the end means it is a water-cooled center section.

Tue 19th May 2009, 07:41 PM

This is the page you want from turbomaster , it gives you the "long" names of most of the RHB5 family that Subaru people would be interested in .

In those long names it seems that those with 5200 in them use the same turbine as the EA82's VF2/4 etc . Note the VF6 has the 15R turbine housing .
The long names with 10000 seem to cover the larger trim versions inc VF8 and VF12 .

The easiest way to look at Sube ones is to think big and small trim turbines and big and slightly smaller major diameter compressors - in various trims .

Turb sm/big ....... Comp sm/big

EA82 = sm ...... sm
VF11 = sm ...... sm
VF10 = sm ...... big
VF8 = big ...... big
VF12 = big ...... big

Here's another link to Turbo Internationals IHI Index , it covers the 52 and a bit mm OD compressor wheels , E series , but not the larger 56mm ones from the VF10 8 and 12 .
For a heads up the EA82's comp wheel pt no is BR3911E and the slightly larger USDM VF11's is BR4016E , the trims are 54 and 56 though the OD is a whole 0.33 mm larger on the 4016 wheel .


A .