Hey all. Firstly thank you for all your help answering my questions to help me make up my mind on what I want to build.

Ive now decided and well underway. im doing a Westfield cosworth.

I have taken a sierra glsi as a donor and got myself a 4x4 yb cossy lump and gearbox to throw in the mix. Your probably thinking 4x4? Why? Ok so hear are MY reasons why.

1. The 205 block is stronger
2. The head has less water jackets. Ie less likely to blow head gaskets mid/high boost levels
3. 4x4 exhaust manifold will be a lot easier to fit in the car
4. I can make up a hybrid gearbox using my donor + 4x4 and is a lot cheaper than trying to find a t5 at a sensible price

I understand that I need to change the sump and a few other little things to make it fit.

However I do have some grey areas which I could do with some help on.

1. I'll be using the hybrid box using the gears from the 4x4 for the ratios but I have a 7.5" lobro 3.14 open diff. How do you think this will perform?
2. Is there a difference in 4x4 and 2wd cosworth management? if so how will I over come this?
3. Is there a difference in 4x4 and 2wd inlet manifolds? Will I have to change to a 2wd plenum?
4. Will a starter motor out of a dohc sierra fit a cossy 4x4 gearbox and flywheel?

all constructive thoughts welcome. Thanks Chris.

Speak to HICOST He has been there and bought the tshirt


[Edited on 23-8-11 by mangogrooveworkshop]

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Originally posted by DixieTheKid

I have taken a sierra glsi as a donor and got myself a 4x4 yb cossy lump and gearbox to throw in the mix. Your probably thinking 4x4? Why? Ok so hear are MY reasons why.

1. The 205 block is stronger
2. The head has less water jackets. Ie less likely to blow head gaskets mid/high boost levels
3. 4x4 exhaust manifold will be a lot easier to fit in the car
4. I can make up a hybrid gearbox using my donor + 4x4 and is a lot cheaper than trying to find a t5 at a sensible price

However I do have some grey areas which I could do with some help on.

1. I'll be using the hybrid box using the gears from the 4x4 for the ratios but I have a 7.5" lobro 3.14 open diff. How do you think this will perform?
2. Is there a difference in 4x4 and 2wd cosworth management? if so how will I over come this?
3. Is there a difference in 4x4 and 2wd inlet manifolds? Will I have to change to a 2wd plenum?
4. Will a starter motor out of a dohc sierra fit a cossy 4x4 gearbox and flywheel?

all constructive thoughts welcome. Thanks Chris.

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Hi, I can answer 2 for you.
yes there are differences firstly the 2wd uses the most basic ecu the l6 the4wd one is the l8 which has twice the memory and can be fitted with a pectel board if you want to go sequential there is also a difference in the wiring between the two this is in the way the throttle position sensor is wired its just a case off two wires swapping in the plug.
want you want is a 2wd loom with a 4wd ecu and if you use a 4wd tps you wont have to change the wiring. using the 2wd loom makes wiring really simple its only 4 0r 5 wires to get the engine running but make sure you get it right or you could blow the ecu

let me know if you need to know how to wire up a 2wd loom and ill have a look at my escort wiring (its been ages since i built it)
do you need a 2wd sump? i have a spare with a pick up/spray bar if you want it make me a sensible offer.
Ray

[Edited on 23/8/11 by RAYLEE29]

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All 4x4 Sierra/Escort Cosworth had 200 blocks, earlier cars had 205 blocks.

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do you need a 2wd sump? i have a spare with a pick up/spray bar if you want it make me a sensible offer.

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you can use either but if you have a 4wd use that as above
Ray

gotch ya!

Thanks for the info Mike & Ray

You will need 4x4 front hubs
The 3.14 diff will give a theoretical top speed in excess of 170 mph and reduce acceleration even with 13" wheels and 60 profile tyres the 3.62 will be fine
You can sell the 3.14 for a lot and buy a 3.62 LSD for half that.

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Originally posted by snapper
You will need 4x4 front hubs

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Originally posted by DixieTheKid1. I'll be using the hybrid box using the gears from the 4x4 for the ratios but I have a 7.5" lobro 3.14 open diff. How do you think this will perform?

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Originally posted by DixieTheKid
3. Is there a difference in 4x4 and 2wd inlet manifolds? Will I have to change to a 2wd plenum?

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as quadra says the T5 box will be a stronger and easier option, not sure how that affects the ratio's your after though...

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cossie 4x4 boxes and 3.14 diffs (even if it is a 7.5" ) are both worth a wee bit too
and there will be a cost in converting the MT75 to 2wd....

I've not been keeping myself upto date though so as for how much I'd have a look around the usial places and see what other ones are selling for....


If ratio's are a massive problem then you could do what I did and get a HD type 9 from the likes of BGH, there top spec ones can handle ~280bhp / 250ft.lbs - so not as strong as a T5 but alot more choice in the ratios

I like this gear cal: http://locost7.info/gearcalc.php
but I don't pay too much attention to the top speeds, but more to the rev's in each gear at each speed - that way you'll get an idea of what it'll be like in real world driving (or compare it to your power/torque curves if your going to be on the track more than the road)

eg. for mine it tells me that I'd be doing 163mph in 5th at 7500rpm (assuming I had the power )
but in the real world were power is limited the engine would be doing 3214rpm to sit at 70mph in 5th - which is only a little worse than my tin-top, so it 'should' cruse down the motorway quite nicely (I had been considering ratios that would make that more like 4000rpm)
and at the same time I should be able get to 50mph+ in 1st gear (maybe even 60mph if the valves will take it )

[Edited on 24/8/2011 by mcerd1]

[Edited on 24/8/2011 by mcerd1]

Would like to add that if you change between a 2wd and 4wd inlet plenum the mounting points for the fuel rail are different and so are the fuel regulator mountings.