Having a 2.5 forged engine fitted to my p1 and was wondering what power figures i can run, or what people have run through it?

Cheers tempo

 

I was running 400/400 plus on a standard V4 Type R gearbox for a long time.

 

Nice one. Thats what i wanted to hear.

 

Don't get too excited by this, 'many' more have failed at wayyy less than 400/400.

Basically it's the luck of the draw, some get away with it and others don't.

 

300/280, mines just ripped out 3rd gear.

 

A 2.5 will chew up your TY754 and spit it out in little pieces, you could go for a 6 speed, that will set you back 2k+, or a PPG on your 5 speed, that will set you back 5.5k+

Tony

 

i've gone through a ty754 vn1aa and vn4aa and im running a standard UK Turbo 2000, the vn1aa lasted a few years though the vn4aa lasted 2 weeks. Just the luck of the draw I guess.

 

i have heard the v4 r/ra box is quite strong in comparison, hope so cos i will be running 380ish soon.

 

Its stronger, but its not that much stronger, 320lbs is tops, then just count the days before your going to replace the box

Tony

 

Mine went bang with below 300, 3rd went and it was like a hand grenade going off.

 

Right ok looks like i may have to bite the bullet and get an uprated box. Not sure on whether to get 6 speed or scooby clinics 5 speed though

 

i through the ty 754 was a s.trong box the one to have, not like the 752

 

none of the 5 speeds are mega strong. mine blew at 280ftlb


where you got that figure from tony? my ppg was only slighty more than half of 5.5k :S

 

The gearsets on their own are just under 2800 quid, then add the cost of a rebuild, its pushes the 5k mark and as PPG boxes are very rare (and not as strong) as 6 speed boxes, its a new cost rather than a 2nd hand one.

Tony

 

im running 340/340 with a p1 box, all seems fine
but wouldnt do any power runs with it.

 

whats the crack with ppg boxes, never seem to hear anything about them exept them going BANG?

 

i saw a scooby quaife gearbox once for sale, i know quaife have a good rep for other cars , surprised i dont see more in scoobies.

 

yer, me too. great rep and the "only" choice on other makes, dont hear much about them with scoobs.

 

The 6 speeds are more widely available and cheaper.

Tony

 

im running 360/360 on a uk 1997 5 speed for well over a year now and it is my daily drive to.

 

Not quite true, the version 5 STi 5 speed puts up with quite a bit of abuse. Been running mine at levels up to 560bhp and 520lbft for 2 complete seasons of the Prostreet drag series and quite a bit of running around customer demos etc. It popped 4th on a dyno day last year but cost no more than £250 to put right and has been perfect again since. I am sure someone will put me right, but to my knowledge it holds the record for the fastest 1/4 mile on a stock 5 speed box. Code on the box is TY754VBAAA for those who want to look for one.

Over the same period one of my fellow competitors has broken his PPG box 3 times costing him in excess of £1000 in repairs at the same BHP and Torque levels. Unless you happen to stumble upon a 6 speed going cheap, chuck in an STi 5 speed and the matching diff and repair it if it brakes, it'll be cheaper in the long run.

Martyn

 

can you honestly say that all TY754VBAAA will take that? if they survive its pure luck, you can always find more examples of them failing than surviving and i think that says it all realy.

if your lucky you'll get away with it, but its more likley it will go.

 

Ive heard of many an STI TY754 popping its clogs well below that sort of torque
Maybe more regular oil changes and a better oil helps? but still not going to run that sort of power through one and hope it lasts

Tony

 

Obviously not all of them will take it, some will have had a worse life than others with ham fisted owners poor servicing and poor changes. My own experiences with these boxes have been very good and it is certainly a cheaper option. If you can change the box yourself, you could fit 10 s/h gearboxes for the price of one PPG. It's also be worth noting that cryo treating the box before you fit it may be a worthwhile option, heard of Pulsar owners having good success with it extending the life of their boxes.

Martyn

 

In fairness I think Martyn accepts the TY754 is an expendible item at his power levels.
Also please remember some people are mechanically sympathetic while others are just animals.
The TY752 box M/Y93-98 is not as strong as the tuned engine ability and many fail quite easily it would appear. The casing on the 752 is not as strong as the 754 and it may flex.
The 754 is a clear upgrade on the 752 and has a stronger casing. I ran one in my STi 6 Wagon which won one of the early Scooby Shootouts. Subsequently that 2 litre car on race fuel was rolling roaded at 585 bhp and 464 lbs ft. A number of very successful track days showing Porsche, Ferrari, Lamborghini etc what a fast car goes like. I then put that same box in my STi 3 Wagon. 422 bhp, 399 lbs ft. 2 litre, standard pistons, every day road car. All that has failed gearbox wise was a very noisey centre viscuous diff, replaced with secondhand twice and still going strong. It will fail but in the meantime..... Manner of driving is probably very important but as many know I am not a slow driver.
The six speed STi and Forrester boxes are much stronger again and you have to be unlucky, or an animal to break one of these with 500 bhp plus.

PPG and others. Well use a 754 casing for starters to have a half decent chance.

 

i understand what cryoing box's is, i don't know how successfull it is.

 

i have this box fitted to my uk classic (TY754VBAAA) but im getting a wrining sound
need to find a place who can tell me why, could just be the fact its fitted to an early classic.

im at 340/340, but havnt pushed it yet
once i get the funds, im after a stonger box

 

A UK Classic has 3.9 front diff and 3.545 rear diff with a 1.1:1 drop gear.
The bad news is that the TY754VBAAA is a Jap box with 4.44 front and rear diff with 1.0:1 drop gear. Unfortunately unless your rear diff has already been replaced you have 4.44 front, 1.0:1 drop and 3.545 rear. This is a bad thing and apart from the noise the car will not handle well.
Drain the oil out the rear diff, remove the back cover and count the pinion teeth and crown wheel teeth. Sometimes these are hard stamped but with some tippex to mark the starting point you can count the teeth and work out the ratio yourself. As an example a 4.44 is 40 crown wheel and 9 pinion.
If you look on your VIN plate you will see the correct part number for the box required on your car.
Unfortunately if you have been running different ratios front and rear chances are the centre viscuous is now goosed and that is what is making the noise.
Do not take this as read until after you have identified what rear diff is there already because it may well have been changed when the gearbox was changed. If not unfortunately a numpty has been on the case. Come back if you need any more help.

 

i fitted a 4.4 plated diff, the box came from a p1
it made this sound when i first got it, so got another diff from grade a
i was always told, one of the ways to tell if its a 4.4, is the matching shaft ends that enter the diff. i changed the box/diff/prop & linkage form a p1

only does it when coasting, and get a sound as if you traveling in heavey wind

 

to Harvey and Martyn, can i ask what gearbox oil you run / ran in these boxes that have lasted at your power levels? Cheers