P1 gearbox - a good idea?
 

I have been offered a P1 gearbox, by a good friend, which is no longer suitable for his power requirements, for £450. It comes with history, and I have been in his car when it has been used, so I know that it can select all five gears!

Is it worth me considering this? Some of you will know that I am putting 330 lb ft through a fast road clutch into my standard gearbox, and therefore wondered whether this was a sensible upgrade, bearing in mind I don't want a six speed. I am not planning any significant power upgrades either.

Thanks in advance for your thoughts.

:SMBLU:

Is there any real difference between this and what you have at the moment

Don't know enough about it James.

Might also need a 180 diff cos I have a 160.

I also have a cabbage fixer unit and a bolt-on splarth runt so you can see that I know what I am talking about.....................

:SMBLU:

Keith the 180 diff comes with a sweed adapter plate and a gibble flange.
I hope that helps :-)

You could just buy it as an investment,

The P1s are so common on here now you'll be able to make a tidy profit.:five:

That has put my mind at rest Martyn!! :ok:

Can I try your gearbox?

:SMBLU:

will be no stronger than what you have

Buy it anyway. It must be worth it just for the GIBBLE FLANGE! :lol:

presuming you have a 99/00 car then as CJ states its basically the same box just differing ratios to a std UK car........it also uses a 4.44 final drive so you would need a matching back diff however these are R160 as std on the P1 not R180 as mentioned........

Thank you for your help, and thanks CJ too. It was all about wanting the close ratios really in gears 1-4 with a "UK fifth".

I understand the P1 box is good for about 360 lb ft and no more, but would be less of a strain on a P1 box than what I am putting through my MY00 standard UK box.

So maybe I don't need a new diff?

Big temptation for sure, and very rare in this country!!!!:mrgreen:

:SMBLU:

CJ, P1 'box is essentially the same as an sti5 'box so is stronger than Keiths' current UK spec 5 speed.

Alyn, it's my 'box that Keith is referring too, I had to swap diffs when I uprated my MY00 and was under the impression it was an R180...perhaps that is a mistake on my part and it is a R160 as I swapped it some time ago but the upgrade definitely required a diff swap...unless I was misled by the company that carried it out?

It is the same bell housing as v5\6 cars but as stated above the internals are essentially the same as those in an sti5 which have proven to be far stronger than standard MY00 UK internals...be grateful if you could clarify. :ok:

Ian

I had always believed that the STi5/5 STI/P1 box was/is stronger than the UK version and was good for 370-400 ?

I think they are the excepted figures but I wanted to err on the side of caution...and have you seen Keiths' driving :-o:-P

Would also say that those figures are conservative, especially when you look at the P1's running higher figures. Guess it's a capable box but depends greatly on how much abuse is thrown at them.

Would require speedo recalibration with the change though....

Worth the purchase price even for just a spare / exact replacement IMO

As long as you change the rear diff no calibration required :)

the rear diff would need to be changed because of the 4.44 FD ratio in the P1 biox but it is std size (R160) same as a UK car................

have never found any difference strangth wise between the STi's/UK boxes as they are basically the same unit, however i have a number of customers running nearer 450lbs/ft through them so they dont simply implode

i find boxes generally are very subjective depending on how they are used/abused rather than power level, with aggressive down shifting being the main issue

Thanks for clearing the diff issue Alyn: my fault for confusing size with final drive ratio I think.

Got to say your comments re the sti vs UK/wrx internals are confusing though...I thought it was generally accepted that the sti v5/6 were the strongest classic variants available...anecdotal evidence (as you suggest), also seems to support that opinion?

the customers running near 450 are using 99/00 UK boxes due to the more suitable longer ratios..................

Martyn at enginetuner was doing 10.6's on the quarter with over 500bhp on a uk 5 speed

Well that all flies in the face of everything I've read\experienced...but always happy to learn so posted some questions...

http://bbs.scoobynet.com/899524-10-s...it-take-2.html

and here

http://bbs.22b.com/cgi-bin/ultimateb...&f=36&t=000927

Are we getting confused with the earlier boxes as I beleive the UK 97/98 boxes are weaker then the 99/00 ones

All V5 onwards had the wider channels for oil and didnt suffer from over heating as much

Why people always want to put PPG's in later boxes

the bell housing were different on the 752 'boxs... 754 'boxs are much bigger, all the variants discussed above are v5\6 so all the later 754 bell housing :)

http://spda-online.ca/modules/tinyco...ite/tc_28.html

Paul Blamire (Paul is Zen Perfomrance for those who don't know), has replied to my thread on 22b;

"Definitely stronger."

"Slightly wider teeth on some gears and totally different profile on 2nd to 4th with fewer teeth of larger size. "

I rest my case m'lud :yeah:

Are the P1 gears the same as a STi tho or did prodrive change when they got rid of the dccd

All the P1's ive driven have felt longer geared than STi5's ive driven

UK Prodrive P1 MY99 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444

JDM Impreza WRX & WRX STi Ver.V/VI MY99-00 3.166 1.882 1.296 0.972 0.738 3.333 1.000 4.444


from the transmission chart linked above...I was alwasy under the impression 5th was taller in the P1 but perhaps not?

4th and 5th are longer from what ive always been told and when driving a P1 to a STi5, 4th always feels a lot longer

So who knows lol

LOL, I am equally confused, all I can confirm is my wagon felt much nicer to drive with the P1 'box...I didn't have any issue with motorway cruising and crucially I didn't break it :D

oh and with the diff swap I didn't need my speedo recalibrating :)

If i had the money and space to store i would have it Keith, hardly come up forsale and its always good to have spares... I have a broken scoob in my garage as spares :)

I will have my P1 box and matching rear diff up for sale in the new year as I have my 6 speed ready to go in but have other things to do first. Both items are perfect.