What 2 change to lower the revs while cruising?

[finmac]

My x flow has fab acceleration but is a pain while crusing (revs at 4000 at 80 mph).

 

Standard 5 speedbox and 4.1 LSD axle.

 

What are the options to allow a more relaxed cruise?

[AMMO]

Rear axle. I have a 3.92 and I feel I could gear higher for cruising. Have just stuck some 205 tyres on the back so that will raise the gearing a bit. There is a 3.62 available but this may be too high.

 

Is your gearbox a stock type 9. If not 5th gera may have been changed for something lower. .82 is stock I think.

 

AMMO

[Asklepios]

Finmac,

You have a lower than standard Dif. The standard factory issue was 3.92:1 This will make your standard 1st gear almost unusably low geared. Most people swap to a higher 1 and second,even with standard dif.

Since you wish to change the gearing, it is either across the board ,at the dif, or by optimising ratios within the box.

Do a search of the archives, as there are several gearbox ratio calculators for you to play with.

 

BGH gearboxes seem about the best value for money, though Brian can be a bit grumpy!

[Lawrence_Z]

As suggested make use of a gear calc program

 

For cruising there are few ways to up your gearing

 

Change the diff to a lower number (I don't know the Ford live axle ratios)

Change top gear in the gearbox ( speak to BGH)

Change the rear tyre size to a higher profile (check what's available)

Change the rear wheel and tyres to a larger circumference combination

or a combination of any of the above.

 

16inch wheels on the back can increase gearing by up to 14% depending on you starting point this equates to about 500 revs

 

Lawrence

[Paul Richards]

De dion :-

3.92 diff is normal with 5 speed.

You can change to 3.62 which is normally used in conjunction with 6 speed. There are likely to be other diffs available, but I'm not familiar.

Live axle (Ford) :-

3.90 - most common - used on most Escorts and easy to pick up second hand.

3.88 - no distinguishable difference from above and just as common.

3.54 - Fitted to RS2000 Escorts and some Capris. Bit rarer, but often replaced for lower ratio by racers and therefore some second hand about.

Live Axle (Ital) :-

Sorry - no knowledge of these.