[320touring]

Hi,

My iS project is currently fitted with a 5 speed Manual Gearbox

5th is 1:1 ratio, and Final Diff ratio is 3.45.

this translates as 3289rpm at 70mph-a speed of 21.27mph/1000rpm

The car has
max HP 138bhp at 6000rpm

max torque 129ft/lb at 4500rpm.

I've been looking at ways to re-time the Cams to give better low down torque, as the car is mainly used on motorways, running approximately 70mph

I dont need it to rev to 6500 for power, as its not a fast car, and doesnt get driven as such.

I've been hunting round my Unit and the web, and have some interesting options available to me to raise the gearing, as follows:

Parts I can use (all of them are "direct bolt on replacements")

e30 318i gearbox- gives 0.8 5th

e36 325 diff- 3.15 ratio final drive.

e36 328i diff- 2.93 final drive.

Info listed as
5th Gear Final Drive MPH/1000rpm RPM@70MPH %change from stock (reduction in revs)

Stock 1:1 3.45 21.27 3289


1 1:1 3.15 23.3 3003 8.7%


2 1:1 2.93 25.05 2793 15%


3 1:0.8 3.45 26.60 2631 20%


4 1:0.8 3.15 29.13 2403 27%


5 1:0.8 2.93 31.32 2235 32%


So which option would you choose and why? I'm thinking the last 2 may be too long for the engine to be able to turn them efficiently...

If any mod knows how to get the table to appear more clearly- cna you please let me know or fix it?

Thanks