Do you know what box prodrive used in their rally cars in the early years ?

 

This is an interesting read, considering i'm aiming for 400BHP/lb and still have the standard 5spd box on my94 WRX.

 

That won't work. Early (pre-97) 752 boxes are on danger money at 300lb/ft upwards. I've killed quite a few at 330hp, though that did involve motorsport.

Observe: http://www.youtube.com/watch?v=pBgWavmRJyg

 

Ooops! was that yours?

 

One of the company cars.

 

all gearboxes listed here.... hope it helps...

RalliSpec Ltd. -- Subaru Gearbox Chart
Model Range Trans. Code 1st 2nd 3rd 4th 5th 6th Rev. T.R. F.D. Center Diff. Type Front Diff. Type Notes Application Notes
6MT Transmission --
JDM Impreza WRX STi MY01-02 TY856WB1AA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) Open
(also Prodrive Style & STi Limited MY02)
JDM Impreza WRX STi & STi RA MY01-02 TY856WB1CA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) A.P. Suretrac RA STi w/ 17 in. wheel
(also Prodrive Style & STi Limited MY02)
JDM Impreza WRX STi RA MY01 TY856WB1BA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (45:55) A.P. Suretrac RA STi w/ 16 in. wheel
JDM Impreza WRX STi RA Spec C MY02 TY856WB2GA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) A.P. Suretrac w/ external transmission cooler w/ 17 in. wheel
(also S202)
JDM Impreza WRX STi RA Spec C MY02 TY856WB2DA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (45:55) A.P. Suretrac w/ external transmission cooler w/ 16 in. wheel
JDM Impreza WRX STi MY03 TY856WB3AA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) Open
JDM Impreza WRX STi MY03 TY856WB3KA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD system
JDM Impreza WRX STi Spec C MY03 TY856WB3JA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD on 17 in. wheel only
JDM Impreza WRX STi MY04 TY856WB4AA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) Open
JDM Impreza WRX STi MY04 + V-Limited MY04 TY856WB4KA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD system
JDM Impreza WRX STi Spec C MY04 TY856WB4JA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD on 17 in. wheel only
JDM Impreza WRX STI MY05 TY856WB6CA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) Open
JDM Impreza WRX STi MY05 TY856WB6KA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD system
JDM Impreza WRX STi Spec C MY05 TY856WB6JA 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 DCCD (35:65) Helical LSD automatic DCCD on 17 in. wheel only
JDM Legacy S401 ?? 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) A.P. Suretrac
US Impreza WRX STi MY04 TY856WH3MA 3.636 2.375 1.761 1.346 0.971 0.756 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD system
US Impreza WRX STi MY04 late TY856WH4MA 3.636 2.375 1.761 1.346 0.971 0.756 3.545 1.000 3.900 DCCD (35:65) A.P. Suretrac automatic DCCD system
US Impreza WRX STi MY05 TY856WW6MA 3.636 2.375 1.761 1.346 0.971 0.756 3.545 1.000 3.900 DCCD (35:65) Helical LSD automatic DCCD system / front axle design change
UK/Europe/NZ Impreza WRX STi MY02-04 TY856WN*** 3.636 2.375 1.761 1.346 0.971 0.756 3.545 1.100 3.900 Viscous (4kgf) A.P. Suretrac
Aus. Impreza WRX STi MY02-04 ?? 3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.000 3.900 Viscous (4kgf) A.P. Suretrac
5MT Transmission (Pull Clutch)
JDM Legacy RS & GT (turbo) MY93 TY752VB2DA 4.111
JDM Legacy RS & GT (turbo) MY94-95 TY752VBAAA 4.111
JDM Legacy RS & GT (turbo) MY96 TY752VBBAA 4.111
JDM Legacy RS & GT (turbo) MY97-98 TY752VBCBA 4.111
JDM Legacy GT B-Spec MY97-98 TY752VBCAA 4.444
(also GT B-Spec Limited)
JDM Legacy RSK & GT-B MY99-00 TY754VBAAA 4.444
JDM Legacy RSK MY00 TY754VBACA 4.444 Viscous (4kgf) Helical LSD w/ LSD option
JDM Legacy RSK & GT-B MY01 TY754VBBBA Viscous (4kgf) Open
JDM Legacy RSK & GT-B MY01 TY754VBBCA Viscous (4kgf) Helical LSD w/ LSD option
JDM Forester Turbo MY98 TY753VB1AA 4.444 Viscous (4kgf) Open
JDM Forester Turbo MY99-00 TY755VB1AA 4.444 Viscous (4kgf) Open
JDM Forester Turbo MY01-02 TY755VB2AA 4.444 Viscous (4kgf) Open
JDM Impreza WRX MY93 TY752VB3AA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111 Viscous (4kgf) Open
JDM Impreza WRX RA MY93 TY752VB3BA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 4.111 Viscous (4kgf) Open
JDM Impreza WRX, WRX SA, WRX STi MY94 TY752VB3CA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111 Viscous (4kgf) Open Double-cone 2nd synchro added (all turbo Impreza)
JDM Impreza WRX RA MY94 TY752VB3DA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 4.111 Viscous (4kgf) Open Double-cone 2nd synchro added (all turbo Impreza)
JDM Impreza WRX & WRX STi MY95 TY752VB3FA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111 Viscous (4kgf) Open
JDM Impreza WRX RA MY95 TY752VB3EA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 3.900 Viscous (4kgf) Open
JDM Impreza WRX STi RA MY95 TY752VB3EA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 3.900 DCCD (35:65) Open DCCD fitted off production line
JDM Impreza WRX & WRX STi Ver.II MY96 TY752VB4AA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111 Viscous (4kgf) Open
(also STi 555 & WRX V-Limited Ver.II MY96)
JDM Impreza WRX RA MY96 TY752VB4BA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 3.900 Viscous (4kgf) Open Double-cone 3rd synchro added (RA only)
JDM Impreza WRX STi RA Ver.II MY96 TY752VB4CA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 3.900 DCCD (35:65) Open Double-cone 3rd synchro added (RA only)
(also STi RA 555 & RA V-Limited Ver.II MY96)
JDM Impreza WRX & WRX STi Ver.III/IV MY97-98 TY752VBCAA 3.166 1.882 1.296 0.972 0.738 3.416 1.000 4.444 Viscous (4kgf) Open Double-cone 3rd synchro added (all turbo Impreza)
(also STi V-Limited Ver.III MY97)
JDM Impreza WRX RA MY97-98 TY752VB5BA 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 Viscous (4kgf) Open Widened 1st,2nd,3rd gears (EJ20K models only)
(also WRX R V-Limited MY98)
JDM Impreza WRX STi R & RA Ver.III/IV MY97-98 TY752VB5CA 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 DCCD (35:65) Open Widened 1st,2nd,3rd gears (EJ20K models only)
(also STi Type R V-Limited Ver.IV MY98)
JDM Impreza WRX 5-Door MY97-98 TY752VBCBA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111 Viscous (4kgf) Open Double-cone 3rd synchro added (all turbo Impreza)
JDM Impreza WRX STi RA V-Limited Ver.IV MY98 TY752VB6EA 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 DCCD (35:65) Helical LSD
JDM Impreza 22B TY752VB6SZ 3.083 2.062 1.545 1.151 0.825 3.416 1.000 4.444 DCCD (35:65) Open Specially treated gear components
JDM Impreza WRX 5-Door MY99-00 TY754VB1AA 3.454 2.062 1.448 1.088 0.825 3.333 1.000 4.111 Viscous (4kgf) Open Bellhousing attachment changed from 4 to 8 points (all models)
JDM Impreza WRX RA & RA Ltd. MY99-00 TY754VB1BA 3.083 2.062 1.545 1.151 0.825 3.333 1.000 4.444 Viscous (4kgf) Open Bellhousing attachment changed from 4 to 8 points (all models)
JDM Impreza WRX & WRX STi Ver.V/VI MY99-00 TY754VBAAA 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open Bellhousing attachment changed from 4 to 8 points (all models)
JDM Impreza WRX STi R & RA Ver. V/VI MY99-00 TY754VB1CA 3.083 2.062 1.545 1.151 0.825 3.333 1.000 4.444 DCCD (35:65) Open Helical FLSD avail. 12/99 on regular STi RA (optional?)
(also STi RA Limited Ver. V/VI MY99-00)
JDM Impreza WRX STi RA Ltd. Ver. V/VI MY99-00 TY754VB1EA 3.083 2.062 1.545 1.151 0.825 3.333 1.000 4.444 DCCD (35:65) Helical LSD
(also S201)
JDM Impreza WRX NB, NBR, 20K MY01-02 TY754VBBAA 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open
JDM Impreza WRX MY03 TY754VB4AA 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open Reverse engagement & 3rd/4th synchro revised (see US info)
JDM Legacy 2.0GT MY04 (also US Legacy 2.5GT) TY757VBAAB 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.111 Viscous (4kgf) Open
JDM Legacy 2.0GT spec B MY04 TY757VBABB 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open
JDM Legacy 2.0GT MY05 TY757VBBAB 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.111 Viscous (4kgf) Open dual cone 1st synchro
JDM Legacy 2.0GT spec B MY05 TY757VBBBB 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open dual cone 1st synchro
US Impreza WRX MY02 TY754VN2AA 3.454 1.947 1.366 0.972 0.738 3.333 1.100 3.900 Viscous (4kgf) Open Rev. pop-out addressed 10/01 (main shaft, rev. idler, rev. hub)
US Impreza WRX MY03 TY754VN2BA 3.454 1.947 1.366 0.972 0.738 3.333 1.100 3.900 Viscous (4kgf) Open 1st, 2nd, 3rd gears widened to RA width
US Impreza WRX MY04 TY754VV4AA 3.454 1.947 1.366 0.972 0.738 3.333 1.100 3.900 Viscous (4kgf) Open 3rd synchro stop changed (3/4 gear, synchro assy)
US Impreza WRX late MY04 TY754VV5AA 3.454 1.947 1.366 0.972 0.738 3.333 1.100 3.900 Viscous (4kgf) Open 1st synchro changed to dual cone type?
US Impreza WRX MY05 TY754VZ6AA 3.454 1.947 1.366 0.972 0.738 3.333 1.100 3.900 Viscous (4kgf) Open
US Forester XT MY04 TY755VH4AA 3.454 1.947 1.366 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open Gears as per WRX revisions
US Forester XT MY05 TY755VW5AA 3.454 1.947 1.366 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open
US Baja Turbo MY04 TY754VHEAA 3.454 1.947 1.366 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open Gears as per WRX revisions
US Legacy Turbo GT MY05 TY757VBAAB 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.111 Viscous (4kgf) Open
US Legacy Turbo Outback MY05 TY757VWAAB
UK/Europe Impreza Turbo 2000 / GT MY94-95 TY752VN3BA 3.454 1.947 1.366 0.972 0.738 3.416 1.000 4.111 Viscous (4kgf) Open
(also Series McRae MY95)
Aus. Impreza WRX MY94 ?? 3.454 1.947 1.366 0.972 0.738 3.416 ?? 3.900 Viscous (4kgf) Open
UK/Europe Impreza Turbo 2000 / GT MY96 TY752VN4BA 3.454 1.947 1.366 0.972 0.738 3.416 1.000 4.111 Viscous (4kgf) Open
UK/Europe Impreza Turbo 2000 / GT MY97 TY752VN5BA
UK/Europe Impreza Turbo 2000 / GT MY98 TY752VN6AA
UK/Europe Impreza Turbo 2000 / GT MY99 TY754VN1AA
UK Prodrive P1 MY99 ?? 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444 Viscous (4kgf) Open
5MT Transmission (Push Clutch)
US Impreza (AWD) MY93 TY752VX3AA 1.000 4.111 Viscous (4kgf) Open
US Impreza (AWD) MY94 TY752VX3CA 1.000 4.111 Viscous (4kgf) Open
US Impreza (AWD) MY95 TY752VT3AA 1.000 3.900 Viscous (4kgf) Open
US Impreza EJ18E (AWD) MY96 TY752VT4AA 1.000 3.900 Viscous (4kgf) Open
US Impreza EJ22E (AWD) MY96 TY752VABBA 1.000 3.900 Viscous (4kgf) Open
US Impreza EJ18E (AWD) MY97 TY752VT5AA 1.000 3.900 Viscous (4kgf) Open
US Impreza EJ22 (AWD) MY97-98 TY752VA5AA 3.545 1.947 1.366 0.972 0.780 3.416 1.000 3.900 Viscous (4kgf) Open
US Impreza 2.5RS MY98 TY752V2DAA 3.545 2.111 1.448 1.088 0.780 3.416 1.000 4.111 Viscous (4kgf) Open
US Impreza EJ22 MY99-01 TY754VA1AA 1.000 3.900 Viscous (4kgf) Open
US Impreza 2.5RS MY99-01 TY754VCAAB 1.000 4.111 Viscous (4kgf) Open
US Impreza RS MY02-03 TY754VFBBA 1.000 4.111 Viscous (4kgf) Open
US Impreza TS MY02-03 TY754VC2AA 1.000 3.900 Viscous (4kgf) Open
US Impreza Outback MY02-03 TY754VC2BA 1.000 3.900 Viscous (4kgf) Open
US Impreza RS MY04 TY754VC4CA 1.000 4.111 Viscous (4kgf) Open
US Impreza TS MY04 TY754VC4AA 1.000 3.900 Viscous (4kgf) Open
US Impreza Outback MY04 TY754VC4BA 1.000 3.900 Viscous (4kgf) Open
US Forester MY97-98 TY753VJ1AA 1.000 4.111 Viscous (4kgf) Open
US Forester MY99 TY755VC1AA 1.000 4.111 Viscous (4kgf) Open
US Forester MY00-01 TY755VC1BA 1.000 4.111 Viscous (4kgf) Open
US Forester MY02 TY755VC2AA 1.000 4.111 Viscous (4kgf) Open
US Forester MY03 TY755VC3AA 1.000 4.111 Viscous (4kgf) Open
US Forester (non-turbo) MY04 TY755VC4AA 1.000 4.111 Viscous (4kgf) Open
US Legacy Outback MY94 TY752VAAAA 1.000 4.111 Viscous (4kgf) Open
US Legacy MY94 TY752VAABA 1.000 3.900 Viscous (4kgf) Open
US Legacy MY95-96 TY752VABAA 1.000 3.900 Viscous (4kgf) Open
US Legacy Outback MY95-96 TY752VABBA 1.000 4.111 Viscous (4kgf) Open
US Legacy GT MY97 TY752VACBA 1.000 4.111 Viscous (4kgf) Open
US Legacy Outback MY97 TY752VACCA 1.000 4.111 Viscous (4kgf) Open
US Legacy MY97-98 TY752VACAA 3.545 2.111 1.448 1.088 0.780 3.416 1.000 3.900 Viscous (4kgf) Open
US Legacy GT MY98 TY752V2DAA 3.545 2.111 1.448 1.088 0.780 3.416 1.000 4.111 Viscous (4kgf) Open
US Legacy Outback MY98 TY752V2DCA 3.545 2.111 1.448 1.088 0.871 3.416 1.000 4.111 Viscous (4kgf) Open
US Legacy MY99 TY754VAAAA 1.000 3.900 Viscous (4kgf) Open
US Legacy GT MY99 TY754VCAAB 1.000 4.111 Viscous (4kgf) Open
US Legacy Outback MY99 TY754VCACB 1.000 4.111 Viscous (4kgf) Open
US Legacy L & Brighton MY00 TY754VCAAA 1.000 3.900 Viscous (4kgf) Open
US Legacy Outback MY00 TY754VCACA 1.000 4.111 Viscous (4kgf) Open
US Legacy GT MY00 TY754VCADA 1.000 4.111 Viscous (4kgf) Open
US Legacy L & Brighton MY01 TY754VCBAA 1.000 3.900 Viscous (4kgf) Open
US Legacy GT MY01-02 TY754VCBDA 1.000 4.111 Viscous (4kgf) Open
US Legacy Outback MY01-02 TY754VCBCA 1.000 3.900 Viscous (4kgf) Open
US Legacy L MY03-04 TY754VCDAA 1.000 4.111 Viscous (4kgf) Open
US Legacy GT MY03-04 TY754VCDDA 1.000 4.111 Viscous (4kgf) Open

 

I don't know if Paul B still posts on here, but he would be the one to ask about the relative merits of different gearboxes, he's been inside enough of them.

 

Craigo, that list is one of the "internet rumour" sources I use Most of it seems to be spot on although there are one or two entries that I take with a pinch of salt.

Most interesting is the introduction of the widened 1st, 2nd and 3rd gears in 1997 on some models. I'm not sure what widened means here - teeth, cogs, etc - and I'm doubtful that anyone knows for sure whether the 22B gearbox goes through any special process.

A different gearset is important. We know that you can take a weedy MY94 TY752 box and make it strong with a PPG or scoobyclinic gearset. If the gearsets did change when that transmission chart says it did, it could be a pointer to where the stronger gearboxes are.

I've amassed quite a bit of evidence to confirm the STi gearboxes in 99/00 seem to run good power. As joz points out, these gearboxes were also fitted to WRX saloons so I would assume these are identical. The gearset also claims to be in the 97/98 WRX type RA, STi type R and STi type RA, but only these cars. The boxes are also fitted to some legacies (not surprising, given that the legacy twin turbos are torquier than the imprezas). So there is potential sources of low cost strong 5 speed boxes there.

However, I'm not convinced that the upgraded gearset is necessarily fitted to other models - UK models, WRX wagons, etc. I'm also not convinced that newage lower spec models have them either - I've heard of newage WRXs break gearboxes at low-ish power output. (Of course, these may be UK cars, whereas classic WRXs are all JDM).

Disclaimer as ever: this is all speculation at the moment. I'd like to gather evidence supporting some of these hypotheses, and all experiences are welcome!

All MY92-MY96 gearboxes tend to be weak and break even when the engine is pretty standard and mapped out to 330 ish.

MY97-MY98 WRX, STi and UK gearboxes possibly similar to the above, but need more evidence to verify this.
MY97-MY98 Legacy GT-B, RS-B, shares gearbox with WRX/STi as above
MY97-MY98 WRX type RA, STi type R, STi type RA possibly stronger, but not enough info at this time. Watching Shaks for evidence (although that is one torquey motor!)

MY99-MY00 WRX saloon, STi, STi type R, STi type RA, P1, Legacy GT-B, RS-B, good evidence of many cars running 400+ bhp without too many problems
MY99-MY00 WRX wagon, UK turbo 2000, unknown at this time, possibly weaker?

If anyone has any stories, evidence or info to support / add to this list, please do. One anecdote may not be representative; strong boxes can break and weak ones can survive depending on driving style, abuse, luck, many other factors. The more data points the better!

 

I'm within those ranges! (Well, 0.8lb ft 'under' on the torque and 4.3bhp 'over' on the power LOL! )

Should be 'fine' then .................................. *immediately breaks 'box*

 

So this would be an ideal solution for me then. Any idea which gearbox codes these are and would they be a direct bolt-on affair?

 

just spunk £2.5K on a jap 6speed and be done with it. you will certainly be future proofed

 

+1 why scrimp on the gearbox, seems pointless to me. Nothing more rewarding than rapeing a 6speed through the gears with 320+ bhp on tap in a classic

 

TY754VBAAA is the one fitted to the most cars. It is not DCCD but is the easiest to fit. NOTE YOU WILL NEED THE MATCHING REAR DIFF AS WELL. Your diffs have different final drives and you will kill the box if you just swap the gearbox. This gearbox was fitted to the 99/00 STi and WRX, P1, legacy GT-B and RS-B. Should be able to find one second hand for around £400-500. If you can when buying, check to see if 4th gear synchro is sound.

Next up is the TY754VB1CA from an STi type R or type RA. This has the DCCD. This is more complex to fit - again you'll need the rear diff, but you'll need to check driveshafts etc. which were different on the DCCD cars, as well as wiring in the DCCD controller, pot and lights. You can juggle diffs to simplify installation but it is extra complication. You'd be looking at around £700-£800 for the 'box. The extra hassle is only worth it if you really want the DCCD. Again watch for 4th gear synchro issues.

To those who ask why not spend £2.5k on a JDM six speed, obviously because if your budget is around £4k-£5k then you've just pi$$ed over half your budget on the gearbox. Which means, after brakes and suspension mods, you're stuck with near standard power output.

A 400bhp 5 speed equipped classic will urinate all over a 300bhp 6 speed classic from a great height, and that might be all you are left with depending on budget. Unless you're spending £10k+ (in which case you're probably aiming for 500bhp) then a six speed is not a sensible way to spend your budget.

 

LOL, Murphy's law strikes again...

You can be our test pilot joz. All we need you to do is keep turning up the boost until your gearbox breaks and then report back to us

 

Makes for some very interesting reading this thread as I am about to change out a box in my Classic sti wagon for a 01 legacy box and diff, some came with optional helical front diff

I'm running a forged 2.5 with a VF48

 

Ah, now that does change the equation a little bit. The 2.5 litre engine produces more torque and puts more stress on the gearbox. You need to factor that in when assessing the power potential of the gearbox.

As mentioned earlier, Shaks-STi is running a setup similar to yours (forged 2.5, different turbo perhaps?) and his appears to be holding up so far at 380lb-ft. You might be a bit of a guinea pig here in some ways! I'd definitely be interested in seeing how it progresses if you do get one.

 

no **** sherlock what's the gearbox got to do with a 100 bhp discrepancy

Which ever way you cut it 300+ bhp scoobs munch 5spd gearboxes, and you'd be a fool to think otherwise

 

It's the torque not the hp

TX.

 

Completely agree but if your car is running 300 and doesnt have near as damn it similar torque...you did it wrong 300ftlbs or 300bhp, i've seen more dead 5 speeds at this level than I care to mention...

Budget doesn't really come into it for me. 6Speed is awesome which is why I have them in both my classics and of course standard fit in my Spec D. Pays your money etc...

 

i for one would love to know more about what prodrive did to rally boxes....

 

I explained it quite clearly in the last comment, but just for you, I'll explain it for you again. It really is quite elementary, Dr Watson

People have a limited budget. Depending on what your budget is, the money you spent on the gearbox can be spent on "other things", e.g. power.

Whether the six speed makes sense depends on your budget. If you're spending £10k+ and targeting 500 or more bhp a £2.5k six speed makes complete sense. If your budget and target is less than that, then you are probably spending unwisely.

My goal here is to figure out how to get the quickest car for a given budget, seeking value for money. Unfortunately most people seem to want to just insist that the only way to tune classic imprezas is to gold plate every mod they make, then moan about how expensive it is to tune classic imprezas. Oh well, that's scoobynet for you.

 

Damn, nearly missed this bit.

Not all 5 speeds are the same. Have you not followed anything that we've been discussing in this thread? It depends on the gearset. Some 5 speeds fail with mild mods, some will run 400/400 all day long.

 

Lol I do love a condescending retort Holmes

If you think the average recon 5 speed will do all that (regardless of the codes) it's a gamble to say the least. All 5 speeds are indeed not the same but they are all inherently weaker than the 6 speed and I don't budget to fail.

I'm not really interested in budget building, and I'd never moan about the cost of doing things right first time I've never been a fan of 'getting away with' things. I would much rather over engineer with room to progress than underspec and end up with an incrementally expensive gearbox timebomb.

If people are happy to hit and miss 5 speed purchases and end up paying near as damn it 6 Speed money (albeit spread over a few years of fails), then good luck to them . Personally the thought of 400bhp/ftlbs on a 5 speed of undermined age or condition booting up and down the road or track at silly speeds doesn't appeal. Like I say pays your money...

Would be interesting to hear real world price comparisons and condition expectations of these stronger 5 speeds ?

I bought a complete 2003 6 speed conversion for £1450 and a complete car mint 30k '95 WRX with a six speed already fitted for £1900. I don't subscribe to the 5 speed argument at all, but respect your point none the less.

 

Damn, nearly missed this bit.

Scoobyclinic's kits requires a donor 754 casing, I don't know if this is true of all PPG's but certainly the Helical gearset offered by Scoobyclinic required a 754 casing and not a 752. So in essence you're not really making a 752 box stronger but putting better engineered corresponding ratios and maybe a more sympathetic 5th gear into a more suitable casing.

 

with all due respect,for some people to even own more than one car is near on impossible,let alone 2 or 3 six speed boxes.

 

While I accept most of your points, I don't understand this one. Everyone has a budget, and the aim is to use that budget most efficiently. Even prodrive has a budget. In fact, if prodrive weren't seeking the best value for money from their components, they wouldn't be winning any rallies. If money really wasn't an option, you'd be installing this sort of stuff in your car. (Hopefully that answers craigo's question as well) But you're not, so money clearly is an option.

Yes, there is a balance between reliability and cost. But loads of people are running 400bhp on the right 5 speed gearboxes without any problems at all.

It's not just me saying this, either. Here's harvey on the P1 forums saying the same thing.

Unfortunately people propagate the myth that because some 5 speed gearboxes are weak, they all are. I think it does the community a useful service to better understand which gearboxes are weak, which are stronger, and why.

 

i think even the earlier ty752 dccd type r box has strengthened 1st and 2nd.heard of many early type r and the later type r running alot of torque through them.many of the uk 752 and 754 have gone pop around the 300 mark.

 

PPG gearsets can be fitted into a TY752. They are typically 450bhp capable.

As yet I am unconvinced by the claims about the casing. There are at least two TY752 gearboxes from the factory that seem quite strong. Although I'm still trying to gather evidence on these, I'm not making any strong claims about these yet.

My hunch is that it is the gearset that counts. It's still a hunch which I'm trying to confirm. Just waiting for joz to break his box for us. It won't answer the question, but I'm sure we'll all see the funny side

 

lol

Funny you should mention that...

As I'm still oohing and aahing whether or not to move to Twin Scroll and stick on a TS SC42 Billet... Or even a TS SC46!!!

 

well stop oohing and aahing!