HI wondering if anyone can help with this. on the us 2.5 block are the standard pistons and rods capable of 440/bhp/400tq regian or would i need cp pistons rods and gasket, also the head i will be using are v3 sti rebuilt, i have read that usuing these heads its not safe to run higher than a 7k rev limit? what would have to be done to safly run a 8k rev limit, and finaly the uk six speed box versise the jdm is there much diferenecs in the ratios?

Thanks for any help
Neil

 

Neil, over the last 3 months all your questions have been answered!
2.5 engine, find MarkA in the Group Buy section on these engines. he knows a lot!
My Sti v3 engine runs reliably to 8200 so I think the heads are ok, not sure about the 2.5!
6 speeders do come in all shapes and sizes, UK and JDM are different. Try looking back on Snet 'Drivetrain' about 3 months or so for this subject, there was some really good info on the subject.

good luck,
911

 

Thanks m8 im going to look now....

 

Us 2.5 block - no idea - only time will tell. Think John Banks had the best figures so far - 450bhp, 400lbsft i think but he is looking at upgrading

Sti heads can run to 8000rpm. Its the stock 2.5 that apparently should only run to 7250rpm

Yep there is quite a difference in Jap and UK ratios in 6speed. THink David Wallis has a n excel sheet showing ratios

MarkA speaks to CP direct i believe, so just email them and they will answerthe qs same as mark (will save mark emailing them and then emailing you, you can just go direct)

 

Mine seems to be OK and it has been worked hard.

The rev limiter is from 7500-7700 but I don't visit there often as there is little benefit apart from flexibility.

 

You keep nudging that limit up dont you John . You have different heads though ?

6 speed gearbox, do NOT go with the JDM box for the 2.5 engine unless your reving to 8000rpm. Personal experience, UK one is much better.

 

http://www.wallis2000.co.uk/uploads/ratios.xls

David

 

Scooby Woo - I would say the engine as a whole is capable if limited to 7k, but if you want a bullet proof engine change the pistons and rods. CP pistons are not very expensive and a lot lighter than the standard ones. If you change them both then you can rev to 8k.

As John says I don't know if you need to rev the nuts off the engine, it's more about the torque characteristics of this engine.

Steve - "Do not go with the JDM box", why ? are you refering to a road car ?

Mark A

 

I am refering to my car, which is primarily a road car, but also with a bit of fun in mind.

The 6 speed JDM is just too in your face re revs and gear changes. 5th gear on a UK 6 speed is nearly the same as 6th on a JDM one. It was great for quick top speed, but that wasnt very high.

At the last Elvington, i hit limiter in 6th way before the 1.25 mile mark, had a bit of det and lifted off, and went through the line at about 6000 rpm, with a recorded speed of 133mph. It hit 160mph at just over 7000rpm very quickly.

It would, however be fairly good for track days.

The torque of the 2.5 just pulls it through the JDM gears too quickly for my liking.

Go look at the Cletus video here http://www.scoobyduck.mine.nu/module...download&cid=3 and watch how quick the gears go.

 

steven,

do you therefore think UK 5 speed gearing which spreads 195 mph over 5 gears would be better on a 2.5 with 500lbft,

because I am contemplating going for a 6 speed.

 

I will have another 6 speed on Monday. From an STi 8 Type UK, 3500 miles only

 

Does he miss a gear, red light and arm waving ?

Mark

 

thats p20spds film, i downloaded it as well

whos cletus?

 

Cletus is something someone called me on 22b, due to the tone of the comment in the video.

That video is me, yes, and i did miss the 4th to 5th change. Should give you an idea of how rapidly you go through the gears.

Adam, i actualy like the UK 6 Speed, 5th and 6th are great for the 2.5, and i am only putting about 1.2bar through it atm. If you get chance on Saturday, you can have a quick drive and see what it feels like.

Everyday driving i am prefering the 6 speed, as the closeness of the lower gears, offers a better choice of gear for the corners over the 5 speed. Drag stuff, the 5 speed would be better IMO, as you can achieve 130in 4th whereas you would need to be in 5th on a UK6MT and JDM6MT. I am not saying i can achieve 130 over a 1/4, just showing the scope of the gears.

 

Slack jawed yokel

F

 

 

Agree with P20's thoughts on gearing and the 2.5.

 

Running a JDM 6 speed on mine. I had a choice of Uks or jap. Went for the Jap instead as it had dccd to.

Happy with the 6speed at the moment. Real beauty to drive and is feeling rapid now, and i havent got a lot of boost yet

 

Oh well if I don't like it I can always swap it over

Mark

 

ok so looks lke everyone is stll testng the water on this and having fun doing it!!, is there a five speed box or gear set similar to that of a type r ratos that can live with the torque of the 2.5 with the 8k rev limit in mnd? or has the six speed jdm got similar ratios to the short type r gearing

Neil

Mark A Dont suppose you have any 2.5 blocks still laying round m8?

 

Funny you should mention that, I'll have some more soon.

 

Plenty of 5 speeds, all depends how big your pocket is

 

Frank, the JDM will be too short ratioed for you 2.5 and YOUR turo

Mine felt superb whilst running in, and ideal. The minute the boost went up above 0.5bar, it was clearly too short for my liking.

 

may take you up on that drive, steven. Normally not keen on driving other people's cars.

thing is the engine is making upwards of 450lbft from 3000 rpm until about 6000, I thought with 5 further stretched gears it would make for a more relaxed drive which could ride the torque.

I have a feeling the PAR synchro will be able to hold it together.

 

The PAR syncro should hold it together, it has on Trouts.

I really do think the 6 speed is great for every day stuff, as the close ratios low down, 1 2 and 3, aid for easier driving IMO whilst around town and tight b roads.

I think stretched 1st and 2nd, would be a ball ache IMO, just my view. More awkward to launch smoothly, etc.

Remind me when you get there, or if you can get to my house before hand, then you can take it for a drive.

Steven

 

well i spoke to to quafe today they do the gear set for £2300 plus fitting but can only say it will cope with upto 350bhp!!!, and wouldnt confirm any maxmum tq figures, i geuss i was hopping to get this sorted for £3000 on a five speed? hewland are another but the final gear ratios are maxing out at 130mph so i hear and then this means messing with the diffs, which i would like to avoid for the time being

Neil

 

ROTFLMAO

Think i need to jump in a scoob at the next meet with a UK gearbox

 

[QUOTE=P20SPD]The PAR syncro should hold it together, it has on Trouts.

Who does the PAR syncro m8?

 

Speak to Paul Blamire (Pavlo) about the PPG gear sets, he replaced his broken PAR gears with them.

 

Thanks andy