GARETH T

i agree mike,,, at the end of the day theres a PCP we cannot go over because of a petrol

pee vee

as an off-shoot from this,
what exactly would be needed to convert a standard 4x4
cosworth running gear to the 3.9 set up that Gareth and Porkie
are talking about?
Rear diff, but what effect does this have on Transfer box/front diff?

sounds exactly the sorta thing i would like TBH
quick off the line and thru the gears,
but not too bothered about going anything abouve 120
at all really.

sounds good especially if you dont need a crazy 600 bhp to get
the cars accelerate quickly.

thanks!!

GARETH T

Bosch-Man
yes mate not far off

Anonymous

Porkie what are you on about If i put Spikeys diff in what else do i have to do apart from strengthen the front case?

Gareth why does everyone go on about proving times etc I doin this for MYSELF not any of YOU I just love my car.

Mike Rainbird

iTrader: (3)

I'm a realist and am just telling you how it is .

I refuse to post any further on this thread, as I don't want to be associated with someone that can't grasp basic principles .

You have my opinion (which is concurred with by EVERY other single person that has posted ). I'll now leave you to dream of your fantasy world where MT75s are made of titanium etc .

I would also point out that the Grp A rally cars achieve their power and torque on Ł20 a gallon rocket fuel . Would be lucky to see 280bhp on Optimax - BYE!

ian sibbert

All you need is a new gear set in the transfer box...new shortened chain and a 3.9:1 rear diff....

pee vee

thanks mate.
would gearbox man be the guy to help me out on this?
thanks

sorry for topic hi-jack Bosch man!

Anonymous

OOOOOOOOOOOOH HANDBAGS Mike go have a wank over Mark Sheads picture and release that attitude

Disabled Account

Phil, notice how on a thread titled: "engine specs - help please" how most of us are more concerned about your drivetrain (gearbox & diffs)........Many of us have had to learn the hard/expensive way......

markk

iTrader: (2)

'Amen to that '

having experiance of high comp rally engines and big horsepower road engines , i would say it all depends on your use, and seeing as its phil were talking about here the whole car is 'lifed' from day one.

for a decent roadgoing quick car i would build somewhere in between a rally motor and a big horse power motor, a 400/400 conversion is a mega decent quick car with the correct gearing, too much emphasis imo is spent in the engine spec first.

decide the primary use, decide the top speed required for the use, gear to suit, i can then guarantee if its not for top speed use then the correctly geared car on a std motor would be a quick car.

but to me - road cars - pah - not interested

Mr C

iTrader: (2)

Nicely said,
Another quality thread, Ive leant a bit through this, lots of advice and I will be following some of it to suit, even if others wont. Thanks

Anonymous

"and seeing as its phil were talking about here the whole car is 'lifed' from day one."


Does make me smile all the insults i get,i get a warm feelin knowing nobody has any faith which means i have nothing to live up to

Mr C i only do informative threads...you see the secret is argue and dissagree and this gets more knowledge coming out...i aint just King of the net for my dog fucking on web cam malarky..ROFL

Mark Shead

Phil

A couple of changes to you engine spec and a nice GT30 turbo you could pull 450hp/450ftlb with the responce of a T34

Mark

Porkie

iTrader: (1)

yes, and then get a bigtooth Quaife or a Fixit, thickwalled front diff case, sort the 3.9 final drive and you should have a SILLY fast, reliable, usable, supercar eating cossie.

Listen to everyone on here Phil and you will get a car you like. You have experienced Rally people like Sibster and Mark and others who have huge experience of fast road cars.

You don't need to make the expensive and time consuming mistakes we have.


P.S 190mph should still be possible on 3.9 diffs. I hope to prove that next time I go to Brunters

You don't need to make the expensive and time consuming mistakes we have.

RichardPON

Phil,

Just look how fast Martin's Escort was with the right box/ratios/diffs etc with a simple stage 3 engine in it.

I've got the video somewhere - plenty fast enough for a road car even at that spec..........

Porkie

iTrader: (1)

Martin took someone quite experienced out in that and they said wow you can really feel the 500bhp+ its just mental power...

Then he pointed out the shonky standard engine on greens

Fiecos Dan

Porkie

iTrader: (1)

and look out how fast the car above is! dannys fiesta has an 'adequate' engine but his gearbox makes it one of the FASTEST cars you will ever see

RichardPON

Why are we bothering? Phil will end up with a medium power engine with the right box and diffs, and then claim it was all his idea

Porkie

iTrader: (1)

No he won't! he is a talker, not a doer!

I await the bite

Anonymous

Phil, Mark Shead gets you torque not a restrictor .

NUTS RuS

iTrader: (35)

But rally cars have to run a restrictor - and as Phil says he wants a full rally type spec then he'll have to follow the rules or be banned

Disabled Account

But Tony, maybe we could all chip together and buy him a very "special" turbo:

http://freespace.virgin.net/shalco.com/tte_ban.htm

"It's the most ingenious thing I have seen in 30 years of motorsport." admitted FIA President Max Mosley after an extraordinary meeting of the FIA's World Council convened following technical reports on Toyota from the Catalunya Rally.

markk

iTrader: (2)

we may even see phil on a 'stage' .................................................. ..........




i'll leave that one for you guys

capri-rs

btw off topic. how much will a 3.9 diff+gears and chain cost?

Geir

PAUL S

iTrader: (8)

An alternative to changing the step offs in the box is to use the front 3.9 diff from a 2 litre DOHC 4x4

As long as you match the diffs front and rear you dont need to touch the box

People say its not a strong front diff but then again neither is the 3.6 cosworth version

capri-rs

too bad they dont grow on trees in norway
isn´t possible to put a 3.9 ratio with and atb in a cosworth diff housing?

Geir

PAUL S

iTrader: (8)

plenty of them for sale for pennies on uk ebay - just find a seller who will ship abroad - they are only light

Andreas

Wont the 5th gear rev much higher than before ie making highway drive a pain in the arse reving what? 4000rpm?

Martin-Hadland

iTrader: (2)

the 3.9 front diff is known for being very weak hence the use of the standard ratio front diff and step off gears

PAUL S

iTrader: (8)

yes I agree for high power/heavy footed applications, but for people using standard 4x4 boxes they are a cheap and readily available alternative - I know of quite a few people running both front and rear sets of 3.9 diffs from the 2 litre dohc in 4x4 cosworths with moderate power increases who have had no problem with them, and if they do go they are easy and cheap to replace.

edited

meant to also say a lot of the problems are caused when people do not use the 2 proper extra mounting brackets that only came with the cosworth front diff when they use the 3.9 front diff which then allows the casing to flex and crack

Big Andy W

Bugger just answered my question, i've a pair of mint 3.9's from an 2.0 xr4x4

Big Andy W

but i also have a 8mm diff strenghtening plate to fit would this help the 3.9 front diff from exploding???

PAUL S

iTrader: (8)

I dont have any experience of these sorry -but if it was that simple then I doubt the thick wall casings would have been produced, I have a feeling they might just be a gimmick, as its the case that cracks I believe rather than the cover flexing which causes problems

Big Andy W

That is the idea of the plate, it stops the case from flexing! as far as i'm led to believe anyway!

Hooligan

Right, I had a Nissan Sunny GTI-R for about a month some 2 years ago...
It was supposed to be a group N rallycar but I guess with a proper group A shell, big AP brakes, Proflex group A suspension and a very illegal engine it was what we call a mini-group A car...
The engine was a full group a engine with silly cams, God knows what compression and a restrictor on the turbo.
It would FUCK OFF at an alarming rate untill you hit 5-5500 rpm and it's like hitting a brick wall The way it catapults out of corners from on 2000 rpm defies belief but you are forever changing gears...I used to love hammering it around town wich is fun as you have loads and loads of corners and jumps (some people refer to them as speedbumps) but it's thirst, constant need for fettling (the cams or followers needed some specific maintenance, can't remember) and the lack of top end killed it for me. On the motorway you'd be in top and topspeed in a second and next thing you know is you're droning away whilst every mondeo passes you...
Oh, and it broke several gearboxes and diffs, had a whole case full of them in the garage wich were destroyed by the previous owner!

So I would advise against it and recommend a nice 400-400 engine with shorter final drive for more resonsive feel (less laggy) and proper accelleration!

Oh dear...a sensible response to a post by Phil from me...what is the world coming to???

Anonymous

Pon...i dont know why YOU are bothering being Mikes lover...you got a lousy choice of partner,you think you gonna get respect from my block?


Porkie...i wont bite i a changed man/dog/whatever....i wont prove it...but maybe i may sell the F-Car after Martin pops the new records off MAD and i may prove DIY is a pain in the PRO butt....but maybe i a dreamer...Say what you like haters i living MY dream

Fiecos Dan

and still on 3.6 final.

Martin-Hadland

iTrader: (2)

first you say that you agree that its not suitable for high power cars and then you mention that you know a few people with moderate power increases using them... were we talking about moderate power increases? nope.

pee vee

lol.
so what are these DOHC diffs good for then? Power wise.

would the rear one be any good if it was coupled with the
transfer box mods?

martin-reyland aimed at you mainly lol