1uzfe + w55 Diff ratio options??

[drifty325i]

Hey guys me again

Just tossing up with changing my diff ratio. My engines revving a little high on the motorway for my liking and does not really suit a v8 in my opinion (it is allot of fun though). Currently my setup is

Car is 1250kgs so its not that heavy

3.73 in 5th @110 its revving at 3100rpm

Now I have some different options availible and they give me this.

3.15 in 5th @110 its revving at 2650rpm

3.08 in 5th @110 its revving at 2550rpm

Where do you think it should be at? Performance is NO1 for me, its a road car but im not worried by using a little more fuel.

Any thoughts would be great!!!

 

[drifty325i]

By the way the engine makes max power at 5500rpm and its climbing all the way, 279hp at the wheels if it makes any difference.

Cheers
Riley

 

[Fasteddie]

...not a real difference between 3.15 and 3.08, right ?...would go with the 3.08 and take those extra rpm...I like cruising at high speed with low rpm....

Did go from a 4.083 to 3.267 in a Lexus GS300 a while back:

4.083 diff:
U/min 1000 2000 3000 4000 5000 6000 6500 6800 6900 7000 delta gearchange
1.Gear 10.3 20.5 30.8 41.1 51.4 61.6 66.8 69.8 70.9 71.9 3178 U/min
2.Gear 18.8 37.6 56.4 75.3 94.1 112.9 122.3 127.9 129.8 131.7 2428 U/min
3.Gear 28.8 57.6 86.4 115.2 144 172.8 187.2 195.9 198.7 201.6 2065 U/min
4.Gear 40.9 81.7 122.6 163.4 204.3 245.1 265.6 277.8 281.9 286 U/min

3.267 diff.
1.Gear 12.8 25.7 38.5 51.3 64.2 77 83.4 87.3 88.6 89.9 3178 U/min
2.Gear 23.5 47 70.5 94 117.6 141.1 152.8 159.9 162.2 164.6 2428 U/min
3.Gear 36 72 108 144 180 216 234 244.8 248.4 252 2065 U/min
4.Gear 51.1 102.1 153.2 204.2 255.3 306.4 331.9 347.2 352.3 357.4 U/min

Driving with the 3.267 diff was a lot of fun...but off course the car didn't have the power to pull beyond 5000rpm in 4. gear...this might be something you have to look at!

 

[drifty325i]

Cheers, thats handy

 

[justcallmefrank]

To be honest, I'd be inclined in getting a W58 to replace the W55. The ratios are more suited to the commonly available diff ratios.

 

[drifty325i]

To be honest, I'd be inclined in getting a W58 to replace the W55. The ratios are more suited to the commonly available diff ratios.

I will at some stage mate, no big $$$ at this stage

 

[65gtmustang]

Running 3.15 diff in my E36 coupe with w57 gearbox on 17"wheels it is doing 2400rpm at 100k and gives good fuel economy as well as plenty of acceleration

 

[drifty325i]

Running 3.15 diff in my E36 coupe with w57 gearbox on 17"wheels it is doing 2400rpm at 100k and gives good fuel economy as well as plenty of acceleration

Nice thats just the kind of info i need!! cheers. Do you think if you tracked it a bit you would change the ratio to a lower one for more accelration?

 

[65gtmustang]

If i was to track i would want to run a diff ratio around 3.5-3.7 dependant on the track

 

[drifty325i]

If i was to track i would want to run a diff ratio around 3.5-3.7 dependant on the track

Hmmm ive decided on a 3.25 that will give me around 2750rpm at 110, top speed of 246kph and should hopefully still get off its arse just as well

 

[drifty325i]

Just finished putting in the 3.25, Ive taken it for a good hard run and I love it!! still plenty of pickup, infact it feels better as i can hold the gear slightly longer, more comfortable on the highway

Cheers Guys

 

[65gtmustang]

awesome glad it worked out okay