Anyone done this? how did it affect the car? I was chatting to a mate at a party over the weekend and he said it totaly transforms the car so i may give it a go as i have a banger mate with loads of old grannys sat about i can take the 3.9 out of then just get it shot peened and put it on my gripper

 

Makes a big difference mate! Car feels so much more alive right from when you pull away obviously revs build quicker so turbo comes on song sooner as well..
Downsides: worse economy (who cares!) and incorrect speedo (which is probably out anyway )
Do it!

 

i may give it a try just dont wont to lose to much top end!

 

I worked it out once.. I think you'll still do 170+ depending on your tyre size.. May be wrong though.
My biggest concern with it really is the fact that first and second become pretty useless with your foot down

 

My car was standard when i put it in and it seemed like i gained 100bhp.

Really liked it and i'm not taking it off

 

Ive got a 3.9 cwp to fit in mine, why can't you not use 1st and 2nd Is that down to wheelspin?

 

Yes mate.. Bad wheel spin

Need a modded beam

 

So why is it actually better then?

 

A couple of more questions - what size wheels have you got? And what was it like before with the 3.6 fitted?

I'm undecided wether I should swap it over or not because mine spins up already

 

It's hard to explain why it's better mate.. The acceleration mine had in third/fourth/fifth before it went pop was enough to give me wood. It just feels more alive than the 3.6!

Was running 235/40/17

 

Ps, my 3dr is fully stripped So won't help grip!

 

Cheers I might have to put my gripper diff in it anyway just to try it.

Last question - how much power you running (Ish if you don't know)

Cheers
Dan

 

Search dyalpina on you tube, then the black flagged video from Bedford

Thats a 380hp 3 door with a 3.9 diff, there are earlier videos on his page of when it had the stock ratio in there

 

Cheers I'll have a look

 

Made 471bhp with mapping unfinished and a poorly coil pack .. We finished the mapping on the road a few weeks later with a new coil pack and she was foooookin flying! (then it broke )

 

good while it lasted 471 is good going I'm not so worried now I thought you were going to say 350 or summit.

 

 

The less power you have, the more a shorter diff can benefit acceleration, obviously at the expense of any top end.

When you are making decent power, the last thing you want is short gearing unless it's for a very specific application or you have a sequential box.
You'll spend more time spinning the wheels and changing gear than actually moving forwards.

You just need to find a balance that suits your driving, your power delivery, and the usage the car will see. And of course what traction you have available.

 

as stevie said,
wheel spin in my car is terrible atm,
cant imagine what it would be like if it was lower geared even more,
imo it would be a great mod on a track car with big sticky tyres

 

mine has 500bhp and to be honest wheel spin isent that bad in the dry with warm r888s coil overs and my gripper diff i think i may give it a go for the summer if i dont like it then i can swap back as said my only worry is how much it will take my top end down!

 

That's very easy to calculate using any of the readily available gear ratio calculators online or by simple maths based on what you can currently achieve.

 

I did this, as it was the only new CWP i could get for my 2wd, and at 100 quid, it was cheap too!

I run 225 45 16 rear tyres which do increase the rolling circumference a little, but I had my speedo redone by speedy cables, so its spot on!

Upsides
It helps if you have a slightly laggy bottom end!
Boost comes in quicker!
The car goes through the gears like a motorbike!

Downsides
Traction is poorer as mentioned
Slightly less top end - but be honest - who uses that?!
Speedo needs recalibrating..

In Summary, one of the best mods I have done to my car! Get involved!

Weeksy

 

I have a smaller diff on my E36 and the acceleration is great. Top speed is now down to 135mph ish but I don't really take the car to that speed anyway

 

That's my point RAN.

It's a good swap, and it makes the car quicker for the sort of driving you do more of - exactly the same situ for me on mine dude

 

i dont think id do it if it took my top end to less than 170!

 

Rod wrote a post the other week about ratios and said on a 3.9 cwp with 18's it takes it back to near the std ratio.

 

Id never put 18s on mine they look like big foots

 

Monster truck style!

 

I'm running 225/45/17 on the back and the top end must be +- the same as a 3.6.

 

My E36 is a drifter so needs more poke lower down and it will never hit 170

It loves the traffic light grand prix and even gets sideways when changing into second from high revs

 

Sounds spot on RAN!

 

Lee TiB still managed 180 at brunters running a 3.9, the 3 door in the video I posted is running his old setup