Omega Owners Forum

Chat Area => General Car Chat => Topic started by: 3.0 power on 13 December 2010, 12:44:13

Title: which box?????
Post by: 3.0 power on 13 December 2010, 12:44:13

hi all i am not an omega owner but i am building a vauxhall chevette and will be using an omega box  ;D
just wondering which box will be the best for acceleration?????

thanks
mike

Title: Re: which box?????
Post by: vauxfan2k on 13 December 2010, 14:48:23

what engine are you using? going by your username id guess 3.0, so you will need a 3.0 box, otherwise the internals of any lower spec box wont last.

im afraid its not like the old cav days where you used a 16 box in your sri for acceleration, or a cdi box for top speed.

Title: Re: which box?????
Post by: Kevin Wood on 13 December 2010, 15:00:04

With a manual box it's not to critical. Both the R25 and R28 will handle the output of a 3.0, especially in a light car.

Gear ratios are here:

http://www.omegaowners.com/forum/YaBB.pl?num=1163895469/0#0

There appears to be a small difference in ratios between the 4 cylinder engines and V6s, so a little choice there assuming the 4 pot boxes will fit the V6.

Ultimately, the diff ratio will give you more control of the characteristics.

Looking at those ratios you will probably find first gear very short in a light car with V6 power, and quite a large step up to 2nd, so your choice will probably be between fitting a diff with a short ratio and forgetting 1st gear, effectively using it as a 4 speed box, or fitting a much taller ratio diff and having a useable 1st..4th gear with 5th being rather high - suitable only for relaxed motorway cruising.

Best course of action is the plug those ratios into a gearing calculator - something like this: http://www.ukmotorsport.com/misc/gears.html .. and see how they look.

Kevin

Title: Re: which box?????
Post by: 3.0 power on 13 December 2010, 16:45:10

sorry forgot to add i am using a saab b204 2.0 turbo. The name was created when i was building my 3.0 astra estate lol thanks for all replys :)

The engine will be between 260-300bhp which box will take this amount of power and torque???

Title: Re: which box?????
Post by: 3.0 power on 13 December 2010, 17:42:36

thanks looks like i want a mv6 box anyone got one :)

Title: Re: which box?????
Post by: r1 on 13 December 2010, 17:51:12

Quote

sorry forgot to add i am using a saab b204 2.0 turbo. The name was created when i was building my 3.0 astra estate lol thanks for all replys :)

The engine will be between 260-300bhp which box will take this amount of power and torque???

have you read performance classics [i think that is what its called] they fitted a saab engine with omega box[2.6] into a rwd escort.

Title: Re: which box?????
Post by: 2woody on 13 December 2010, 19:17:03

any Omega box will do, with a low-weight car, you'll simply not be able to put full torque through the box without spinning the wheels.

worst case for a gearbox is setting off from rest pulling a full trailer up a hill, not high-horsepower.