Tyre help please (or LSD?)

[Andy70]

I just had more upgrades to my 335i also had turbos rebuild and is so much more responsive as a result ( they must have been shagged), however as a result of the restored turbos,uprated intercooler, charge pipe, ported throttle body and now intake pipes the car struggles for grip even before the JB4 box gives me max power available. so, would a very decent pair of tyres on the rear make enough difference? I only have a pair of 130 quid (each) Avon's on the back which were just ok before or do I need an LSD to plant the power down? if so there are more than 1 option for these is the Quaife the only realistic option or are the 600 quid alternatives as good? Also do I need a specialist engineer to fit them? I live in Bristol if anybody knows of a garage that could help. I don't want to get into too much of a debate as to how great an LSD would be as I am aware of the handling benefits, at the moment I just want to put my power down properly. Thanks

Andy

[Aluminati]

Birds in this case could be your friend, not the custard makers.

[Till135]

When I got my D4 BiTurbo, I was convinced I needed an LSD. You could spin up the rears almost anywhere anytime. I possibly maybe even did a 180 ........ not on public roads obviously! No impact thankfully. Eventually I got new rears. Michelin Pilot PS4s. Transformed the grip even now in the winter. Haven’t gone down the LSD route as I don’t want to drive sideways and I tend not to keep my cars for long. What you might find though is that the PS4s are extremely difficult to find in some sizes. I had to give up on the fronts having waited 3 months! Fronts are now the Super Sports which seem very good but maybe slightly noisier.

[Huskyman]

I would try a car with an LSD fitted first before making the decision, I’ve owned cars with this type of diff fitted and it can make a huge difference. If the grip is still st then try some different tyres. Have a chat with Birds and see what they say.

[naturalaspiration]

You are struggling with the grip in a straight line acceleration or only when exiting the corner (and applying throttle early)?

[Andy70]

Thanks Huskyman, I get your point but I have had 2 M3's and at the time never realised they had an LSD, ( sorry back in those days I was ignorant to that knowledge) I tend not to rag my car around bends to the point where I need M3 handling but till135 sounds a bit more sensible to my needs, that's reassuring, thanks. However I do see the benefits of an LSD but like i said in my threat the other day about my turbo rebuilds, I think my missus would wince a bit if I wanted to spend money of those at the mo, especially as I just spent a grand on turbo rebuilds and intake pipes ( but I will get one eventually I hope), but just to plant my power down at the moment, that is reassuring that a decent set of tyres my suffice. Just out of curiosity, what are the costs of fitting an LSD? I get the impression its quite a specialist job, or can any mechanic do it? oh and who are Birds? I think I recall reading a thread about them on here the other day, but cant think which one it was

[Andy70]

naturalaspiration said:

You are struggling with the grip in a straight line acceleration or only when exiting the corner (and applying throttle early)?

In a straight line and in the dry. I tend to go careful around corners or you crash and loose your no claims discount :-)

[Huskyman]

Andy70 said:

Thanks Huskyman, I get your point but I have had 2 M3's and at the time never realised they had an LSD, ( sorry back in those days I was ignorant to that knowledge) I tend not to rag my car around bends to the point where I need M3 handling but till135 sounds a bit more sensible to my needs, that's reassuring, thanks. However I do see the benefits of an LSD but like i said in my threat the other day about my turbo rebuilds, I think my missus would wince a bit if I wanted to spend money of those at the mo, especially as I just spent a grand on turbo rebuilds and intake pipes ( but I will get one eventually I hope), but just to plant my power down at the moment, that is reassuring that a decent set of tyres my suffice. Just out of curiosity, what are the costs of fitting an LSD? I get the impression its quite a specialist job, or can any mechanic do it? oh and who are Birds? I think I recall reading a thread about them on here the other day, but cant think which one it was

kitsand
Birds have the exclusive rights to supply the Quaife diff for the BMW range. It is quite a specialist job and I believe birds do a fitting service, have a look on www.birdsauto.com
They do understand about setting up a car, I had one of their B3 suspension kits and it was superb.

[Andy70]

Huskyman said:

kitsand
Birds have the exclusive rights to supply the Quaife diff for the BMW range. It is quite a specialist job and I believe birds do a fitting service, have a look on www.birdsauto.com
They do understand about setting up a car, I had one of their B3 suspension kits and it was superb.

Oh right I see, thanks for that. I'll have a look. But you can buy a Quaife diff off ebay for just over a grand, where would you get that fitted if you live miles from Birds? (or is a grand expensive?)

[Huskyman]

Andy70 said:

Huskyman said:

Birds have the exclusive rights to supply the Quaife diff for the BMW range. It is quite a specialist job and I believe birds do a fitting service, have a look on www.birdsauto.com
They do understand about setting up a car, I had one of their B3 suspension kits and it was superb.

Oh right I see, thanks for that. I'll have a look. But you can buy a Quaife diff off ebay for just over a grand, where would you get that fitted if you live miles from Birds? (or is a grand expensive?)

It’s £919 from birds, just try and find a decent BMW specialist. A gearbox centre should be able to do the work for you, but I tend to work off recommendations before taking my car to anyone.

[liner33]

There is a guy based in liverpool who advertises on ebay and does a supply and fit service for quaife on BMs. I've heard very good things about him and plan to get my 235i up there in the spring .

I fitted a quaife to my 370 to replace the viscous diff and it was awesome a well worthwhile mod.

[aeropilot]

Andy70 said:

Huskyman said:

kitsand
Birds have the exclusive rights to supply the Quaife diff for the BMW range. It is quite a specialist job and I believe birds do a fitting service, have a look on www.birdsauto.com
They do understand about setting up a car, I had one of their B3 suspension kits and it was superb.

Oh right I see, thanks for that. I'll have a look. But you can buy a Quaife diff off ebay for just over a grand, where would you get that fitted if you live miles from Birds? (or is a grand expensive?)

The fitting issue is the CWP in the *35i diff is welded, so you need to make sure that whoever is doing it, has access to a decent enough engineering shop (or they're own facilities) to be able to split the CWP and then re-weld to the Quaife unit etc. Its not just a bolt-in/out job with the unit, that's why the fitted price from Birds is nearly 2k.

[Andy70]

Interesting points, I want a diff now, but that will have to wait I think after just spending a grand on hoses and turbos, I think I may as well buy some new wheels to go with my new tyres as mine have the odd crack in them so seems silly putting tyres on them, so that's another grand. I seen an ad for refurbed BMW wheels for 500 quid, so I may get some. As long as I have some reassurance that a decent set of tyres will provide good grip for now, they will have to do for the time being. Cheers

[RobM77]

I had a Birds suspension kit on my last car, an E90 3 series, and I agree with the above poster - it was absolutely fantastic. That, along with decent tyres, will make a fairly big difference. Onto the LSD though.. I've driven a number of 1 and 3 series cars without LSDs, plus M3s with them and I've got a quaife LSD in my racing MGB; based on that experience, from what you describe I think the Quaife would solve your problems overnight. Not cheap though! Generally the rule is to sort out the tyres and suspension on a car first, as you've discovered.

[Andy70]

RobM77 said:

I had a Birds suspension kit on my last car, an E90 3 series, and I agree with the above poster - it was absolutely fantastic. That, along with decent tyres, will make a fairly big difference. Onto the LSD though.. I've driven a number of 1 and 3 series cars without LSDs, plus M3s with them and I've got a quaife LSD in my racing MGB; based on that experience, from what you describe I think the Quaife would solve your problems overnight. Not cheap though! Generally the rule is to sort out the tyres and suspension on a car first, as you've discovered.

Lovely Rob, thanks

[RobM77]

Andy70 said:

RobM77 said:

I had a Birds suspension kit on my last car, an E90 3 series, and I agree with the above poster - it was absolutely fantastic. That, along with decent tyres, will make a fairly big difference. Onto the LSD though.. I've driven a number of 1 and 3 series cars without LSDs, plus M3s with them and I've got a quaife LSD in my racing MGB; based on that experience, from what you describe I think the Quaife would solve your problems overnight. Not cheap though! Generally the rule is to sort out the tyres and suspension on a car first, as you've discovered.

Lovely Rob, thanks

The other quick fix is to do what I do on a wet day if I want to drive fast: just turn the DSC off, or switch to 'Sport Plus' mode. I find the TC element of DSC just too nagging, and too slow to give me back control once it kicks in. Don't blame me if you have a heavy right foot and crash though

ETA: Birds have a 335i demo car with the LSD fitted, or at least they did have.

Edited by RobM77 on Friday 22 November 10:16

[naturalaspiration]

Andy70 said:

naturalaspiration said:

You are struggling with the grip in a straight line acceleration or only when exiting the corner (and applying throttle early)?

In a straight line and in the dry. I tend to go careful around corners or you crash and loose your no claims discount :-)

If both wheels are spinnimg at the same time then I would think that fitting an LSD will not help much. Stickier tickier tyres and gentle right foot might help. :-)

[RobM77]

naturalaspiration said:

Andy70 said:

naturalaspiration said:

You are struggling with the grip in a straight line acceleration or only when exiting the corner (and applying throttle early)?

In a straight line and in the dry. I tend to go careful around corners or you crash and loose your no claims discount :-)

If both wheels are spinnimg at the same time then I would think that fitting an LSD will not help much. Stickier tickier tyres and gentle right foot might help. :-)

It's a classic issue for all BMWs in recent years to suffer from traction problems at middling speeds (30-40mph). In my experience it's usually only one wheel. To my uneducated arse it feels like a combination of the lack of LSD, the lack of compliance from thin sidewalled RFTs, and the fact the suspension isn't optimised for our rough roads. I get it in my current car in the wet when crossing repair seams in the road. As above, I just turn off the DSC if I want to drive fast in the wet and use my right foot to modulate things. Unlike the computers, if I get a bit of slip I don't throw a wobbly and kill all power for a second or two.

[aeropilot]

naturalaspiration said:

Andy70 said:

naturalaspiration said:

You are struggling with the grip in a straight line acceleration or only when exiting the corner (and applying throttle early)?

In a straight line and in the dry. I tend to go careful around corners or you crash and loose your no claims discount :-)

If both wheels are spinnimg at the same time then I would think that fitting an LSD will not help much.

If he hasn't got a LSD, then both wheels are unlikely to be spinning at the same time

Given the OP's posts, in that his preference is only for going silly fast in a straight line only, your suggestion of being a 'bit light in the loafers' is the best suggestion for his issue.

[Andy70]

aeropilot said:

If he hasn't got a LSD, then both wheels are unlikely to be spinning at the same time

Given the OP's posts, in that his preference is only for going silly fast in a straight line only, your suggestion of being a 'bit light in the loafers' is the best suggestion for his issue.

I'll try changing the tyres and see what happens, wheels too ought to be changed as well as I been told they have a couple of small cracks on them, no point in putting new tyres on wheels knowing they aren't in the best of health. Bit of a gutter as Avons aren't old and they were just ok most of the time. I would like an LSD but that will have to wait now I know decent tyres should at least help