[rolltidef32]

Originally Posted by goj

I think I might know what you're talking about. And I doubt it's the tires. If you are gassing it through a corner at decent speed you you could be feeling the stability and traction aids at work braking the inside wheel. In all honesty it feels weird but maybe that's all your feeling.

And if you are doing hard launches in general any tire could rip loose with a torquey engine.

You make an excellent point here. Most drivers don't know what traction control feels like and it does feel weird when it engages.

It's not the tires loss of grip, but the system slowing the spin of the wheels.

[Vitoco]

Now those are proper responses, trying to actually figure out WHY he complains on the grip and not just pulling the troll card out immediately.

[jakou]

Thank you guys for the positive input. I get your point regarding traction control. But when traction control engages it usually mean there's excessive wheel spin that's causing the car to be "destabilized", am I right? So we're back to square one: why the excessive wheel spin (lack of grip) in the 1st place while at rather low speeds and light pressure on the gas pedal?
May be after all this is the normal way the 320i handles (i.e. a certain wheel spin is unavoidable at low speeds), although I also drive a 2016 mini cooper with michelin primacy 3 tires where I also experience a certain wheel spin (all torquey engines do eventually) but it is much lesser than the 320i and is quite normal to me.

[IndotagSwizz]

My mssp on my 320 are almost done and they still grip very well even when wet. This has to be a driver issue. Maybe you aren't used to the throttle, I can dart out of a light with almost not spin so I don't understand what your issue might be

[Daftasabrush]

They could be fake tyres

[a18012]

Got the same problem as the OP. Originally thought it was the rft, but switching to MPSS didn't seem to help.

Started thinking maybe it was dhp suspension, because I test drove a f30 without dhp and grip was great. Installed the Dinan shockware but didn't seem to help.

Weird thing is the MPSS never chirp/sqeal, they just lose traction really quickly. Anybody else get their MPSS to chirp/sqeal, wondering if we have a bad set?

[ghalacli]

Originally Posted by Daftasabrush

They could be fake tyres

This is what I think.

[Dmitry83]

Hi, jakou,

I have the same setup, but my 320i has 328i ECU program, which means around 259hp and 360Nm torque.
Pressure was 2,2/2,4 bar front/rear.
Remarkable is I've started with stock Pirelli Runflats already having reprogrammed the car. And the difference is more than significant.
The thing is that the turbo-engine provides a lot of torque in the low revs/speed, so you have a wheel spin easily.
But. There is a important balance Michlin PSS has between longitudinal grip, steering reaction, feedback, braking performance and heating resistance.
You can definitely get more acceleration grip with Goodyear Eagle F1 Assymetric 2 or Dunlop Sport Maxx. But the steering will be dull and slow- too soft rubber compound of the protector layer, the highway speed stability is worst- the car is floating under high speed steering and breaking.

So your issue with the low-speed acceleration wheelspin is not a fault of PSS- the relatively hard protector and sidewall gives you much much more on the cost of this feature.

PS
Do keep in mind the stock rear dampers are not the best (fronts are simply too soft)- having switched to Koni Sport the acceleration grip had improved VERY significantly. I'm also able now to decrease tire pressure to 2,1/2,3 without losing grip.

[MarkM5]

Seems like a lot of over thinking. Op have you turned off your traction control. Just because it engages doesn't mean the tire is worthless. Most likely it's a combination of having an open diff, the settings the computer has for a 320 and driving style. Feel confident to say that if you turn off traction control you won't over drive the tires. However the car being an open diff means it can snap back on you so be careful ( everytime you see a video of a car trying to slide and it catches traction and hits every thing in sight, this is a result of an open diff).

If you really want to learn the limit of your car and tires go to a track and take a high performance driving class. They can teach and show you more in 5 min than can be discussed here in 10 pages.

[shivaswrath]

Originally Posted by Polo08816

+1.

Just came back from a HPDE @ NJ Motorsports Park and I will say they have plenty of grip for a novice to intermediate run group even with a 2014 335i M Sport RWD.

I don't see how they wouldn't have enough grip for a 320i on acceleration...

Exactly, I track with these at Lime Rock and have never had an issue. And my 335i is putting down at least 400 (mods below).

[a18012]

Lots of good input here, thanks everybody!

I test drove a non-DHP 435 with factory good year run flats at the dealership and the acceleration grip was far superior to my car (435 with DHP and MPSS tires), so have convinced myself there is a problem. I swapped out for a new set of wider rear MPSS (265 wide) but didn't help, so I think the tires are OK.

Cornering grip seems pretty good, only a problem when I get on the throttle. Starting to think maybe the suspension bushings might be loose, but not sure how to check.

Does anybody's MPSS chirp/squeal when they accelerate hard (mine don't). Any other thoughts from the experts here?

[XRAVE]

Originally Posted by a18012

Lots of good input here, thanks everybody!

I test drove a non-DHP 435 with factory good year run flats at the dealership and the acceleration grip was far superior to my car (435 with DHP and MPSS tires), so have convinced myself there is a problem. I swapped out for a new set of wider rear MPSS (265 wide) but didn't help, so I think the tires are OK.

Cornering grip seems pretty good, only a problem when I get on the throttle. Starting to think maybe the suspension bushings might be loose, but not sure how to check.

Does anybody's MPSS chirp/squeal when they accelerate hard (mine don't). Any other thoughts from the experts here?

I have MPSS and are stickier than anything I've tried. After parking my car, you can see tons of dirt/rocks sticking to the tire. Look at run flats and nothing will stick to them.

One of the reasons you could have "felt" more acceleration with the run flats is because they aren't as sticky and will break traction easier. This gives the allusion of being faster. You'll also notice your car seems faster in the winter due to less traction and colder intake temps.

I see your in Austin Texas, on top of heat soak due to 100+ degrees, your MPSS are sticker than ever. It's extremely difficult to get these tires loose in the summer without popping the clutch or whipping the car around a corner. Another note is that adding wider tires reduces your power out put. Wider doesn't always equal better traction but what it does equal is more unsprung weight and more distance from the hub. This efficiency reduces your torque.

Also make sure your running the correct PSI. Dealers always forget to lower PSI which comes at like 45-50 from factory. The tracking handling 18" wheels with MPSS should be around 33 for all 4

[Dmitry83]

Originally Posted by a18012

Lots of good input here, thanks everybody!

I test drove a non-DHP 435 with factory good year run flats at the dealership and the acceleration grip was far superior to my car (435 with DHP and MPSS tires), so have convinced myself there is a problem. I swapped out for a new set of wider rear MPSS (265 wide) but didn't help, so I think the tires are OK.

Cornering grip seems pretty good, only a problem when I get on the throttle. Starting to think maybe the suspension bushings might be loose, but not sure how to check.

Does anybody's MPSS chirp/squeal when they accelerate hard (mine don't). Any other thoughts from the experts here?

The dampers are too soft- I had the same feeling before replaced them with Koni Sport.

[a18012]

Yeah, I'm thinking next step might be a suspension mod, I'm not too happy with the float in the backend anyway.

I'm a bit uneducated on this topic though. I was thinking of going with the Dinan springs, but worried I might be scraping my driveway with a 1" drop.

Do you think stiffer springs would help with the traction, or should I be looking at new shocks instead? Would koni sport work with DHP?

[Carlos@TAG]

Originally Posted by a18012

Yeah, I'm thinking next step might be a suspension mod, I'm not too happy with the float in the backend anyway.

I'm a bit uneducated on this topic though. I was thinking of going with the Dinan springs, but worried I might be scraping my driveway with a 1" drop.

Do you think stiffer springs would help with the traction, or should I be looking at new shocks instead? Would koni sport work with DHP?

Lowering springs are good if your main goal is to drop the car for aesthetic reasons, if you're after improved handling and feel then you will want to go to firmer springs & dampers in a matched package. The best bang for your buck IMO is the Bilstein B14 setup, ride and handling is improved over stock at a very attractive price.

PM me for more info & pricing.

[Polo08816]

Originally Posted by Neema@TAG

Lowering springs are good if your main goal is to drop the car for aesthetic reasons, if you're after improved handling and feel then you will want to go to firmer springs & dampers in a matched package. The best bang for your buck IMO is the Bilstein B14 setup, ride and handling is improved over stock at a very attractive price.

PM me for more info & pricing.

The Bilstein B14 setup might not be a bad combo, but the labor to replace shocks is pretty time consuming. If someone was going to do that, then they might as well do springs at the same time.

In that case, I'd recommend the BMW M Performance Suspension kit for a RWD vehicle.

[Carlos@TAG]

Originally Posted by Polo08816

The Bilstein B14 setup might not be a bad combo, but the labor to replace shocks is pretty time consuming. If someone was going to do that, then they might as well do springs at the same time.

In that case, I'd recommend the BMW M Performance Suspension kit for a RWD vehicle.

Just to be clear the Bilstein B14 is a full height-adjustable coilover system, new struts/shocks with matched springs and threaded perches for ride height adjustment, so you'd be doing it all at once you're right, labor to replace suspension components and properly align the vehicle is a big part of any suspension job so it's smart to research your options and try to get it right in one shot.

[a18012]

I looked into the koni sports and M performance suspension, but neither are compatible with DHP cars. Springs might be my only option i guess?

[Wires]

Did you do some sort of drop suspension to that car and mess up the camber? Either that or your are running the incorrect tire pressure.

[TANG2864]

I would say maybe the new rubber (or if u got new wheels) messed the camber up and ur not running the full potential of the tire. Or your lead foot should just simmer down. 😂 I know when I put m4 wheels on my 435, grip should be phenomenal with 275's in the back, but because only half my rear tire was on the floor, the traction wasn't fully there. Try getting an alignment

[a18012]

Makes sense. Thinking I will get the Dinan springs and then an alignment. Will report back if it helps. Dealer quoted something like $200 just for an alignment! Anyone know if I can get it done at Sears or something? Thanks all for the input.

[MickAv8r]

Originally Posted by a18012

Weird thing is the MPSS never chirp/sqeal, they just lose traction really quickly. Anybody else get their MPSS to chirp/sqeal, wondering if we have a bad set?

Yes, MPSS will squeal but you really gotta push them, they only start to make noise as you approach the limit but they will definitely make noise. I'll try to post a video later.