rear diff beam difference?

[midnight]

basically ive got the poly bushed rear beam off my old e30 which was a 320i, and wanna put it on my 325se, just wondered if the diff mounting mite be a different size etc?

[maxfield]

Nope, it's exactly the same.

[Chris-W]

Same part

[Ant]

Polybushed main subframe mounts may last forever, but you'll have LESS grip afterwards Kevin !!

That is one place I will not fit Polybushes.

[JungleGus]

Interesting you say that, mind sharing why?

[midnight]

well since i have the spare beam with the polys on it, i was gonna paint it while it was off, but ill save the beam thats on it anyway, if it does become an issue, i just wanna stiffen everything up really

[12345kevin]

From experience I would say its an advantage for Trackdays and fast roads as it stiffens the whole back end up, however because there is no "give" in the rear beam you appear to loose out on traction for the traffic light grand prix !

[midnight]

nothing wrong with a bit of tire smoke off the line, its my magic trick, big cloud of tire smoke and then gone......

[jaistanley]

The rubber bushes in the standard beam are designed as a dynamic part of the suspension system. Like Ant these are the only bushes in an E30 I definately wouldn't poly bush. I can live with the compromised road noise etc of the rest of the bushes, but the rear beam bushes do indeed reduce the grip, even more so in wet conditions. It's not just from a standstill either, there is less absolute grip in corners too. Handling and grip are different things remember, the car feels more 'electric' with the poly beam bushes fitted which might suit track cars I spose, but I'd say for the decrease in roadholding it isn't even worth it then (unless you are going all out and building a fully adjustable rose jointed car).

I actually fitted poly beam bushes before doing a vehicle dynamics module and have experience of both real world and theory..

Just my two pence..

[midnight]

well i had the beam on my old e30 and seemed to be alrite, stiffened up the back, i find the back end to be a bit skitish on standard bushes, so i prefered the polys, but i suppose everyone has there own opinions on different products, otherwise everyones cars would be pretty much the same, i wanna poly the whole car and also get some aftermarket anti roll bars to, i want the car rigid as f**k