[Jamesons Viggen]

Originally Posted by ToyotaBMW

I had H&R and Koni Yellow full adjustables and have rode in various friends cars who had the H&R with Bilsteins. I then went to Eibach Pro-line with the Koni and then finally the PSS9's and let me just say while the former where good the coilovers are superior. It is money well spent and it won't be 3k you can get the PSS9/10's for around $2000-2500.
IMO you can have all the power but if you can't put it to the ground properly what is the point especially on a track. Of course it is your decision but just letting you know that you are missing something. I do understand what you are saying just that I think if you tried the coilovers you will understand what I am saying.

James summer is here and have fun on the track with your cars.

I rode in my exact car with some good coilovers and while it was better, it wasn't better ENOUGH lol.

My money is better spent right now getting rid of dry-rotted T1Rs up front and bubbled 265mm Star Specs in the back and go to 295mm Pilot SS'.

Every aspect of the car is another project. Maybe when the car is 99% done will I re-do things like coilovers. It came with the H&R/Bils, I saw no point in ditching them if they work this well when I have so many other "projects". Right now the stock center section is getting custom fabbed pipe and cats at MaxPSI freeing up 20+whp. Then it's the interior where I am wrapping plastic parts in Alcantara myself

Point again, car is approaching 20 years old and everywhere I look is a $$$$ project as it is a show car, street monster, summer toy, and occasional track day autoX car. So if the suspension that came on it works well enough-it stays

[S4NoMore]

Originally Posted by ToyotaBMW

When are you going to get the idea around your head that it has nothing to do with coilovers and spring rate and your harsh ride? Look if you lower your car 1" with coilovers and you lower your car 1" with springs/shocks what makes you think that the coilover will have a higher spring rate than the 1" drop from the shock/spring combo?

It's not a matter of what I think, it's what is known. Look up the spring rates of a few systems if you don't believe me.

Originally Posted by ToyotaBMW

Head over to the M3 or racing boards and those guys will agree because the ones who have tried various TOP Quality setups done properly will know what I am talking about.

You're right, definitely handling will suffer if the shocks aren't close enough to their design range. I think it's worth noting that this is the F30 board, not the M3 board and not really a racing community. Consider your audience.

Originally Posted by ToyotaBMW

If you are hitting the bump stop with your coilover than you either haven't set it up properly or you have a cheap coilovers. The coilover allows for maximum suspension travel due to the design which is explained in the video.

True. But it's also possible in certain cases with the majority of coilover designs to hit the bump stops if the spring perch is run at or near the bottom of its adjustable range. Cheap or not, the spring must be at a level of stiffness to resist the force of potholes or dips in the highway to prevent bottoming out the shocks. It's really just a physics problem.

Look at the Bilstein PSS coilovers for F30:



As you raise and lower the spring perch, you are not able to compensate by adjusting the shock stroke.

As an aside, this system is only $1k. Really not a terribly expensive option...

Originally Posted by ToyotaBMW

What coilover are you using for your E30?

Not to go too off topic, I am running Ground Control's custom specified conversion. I spoke with experts at GC and researched the vast E30 community to understand that with the height I want, I need a certain spring rate... and it's a high spring rate.
Eibach winds the coils for GC and Koni makes the damper that is valved for the high rate and shortened to accommodate a significant drop (the E30 is very high stock, so the lowering amount is in a different league compared with the F30 Sport). The front strut housings are actually modified (shortened) for this smaller strut. GC is the benchmark for E30s, short of the $3000 KW options.
The ride is excellent in terms of handling - grip, balance, feedback. In my opinion however, I have sacrificed some ride quality - the ability to soak up any and all road imperfections in a luxurious manner - for a tight ride without much gap between tire and fenders. If I soften the spring rate, I run the risk of bottoming out over dips etc. unless I raise my ride height. Get it?

I'm a mechanical engineer and I have some experience in suspension design. I'm not talking out of my ass, I'm trying to explain that coilovers do have their downside and are not a no-brainer, even if you want to spend alot of cash and despite the generic internet ramblings of "coilovers-or-bust."

[Jamesons Viggen]

Originally Posted by S4NoMore

I'm a mechanical engineer and I have some experience in suspension design. I'm not talking out of my ass, I'm trying to explain that coilovers do have their downside and are not a no-brainer, even if you want to spend alot of cash and despite the generic internet ramblings of "coilovers-or-bust."

Woot-woot

That is why I interjected in this thread in the first place.

[MDIVISION]

I would stay away from the Super Sports but you will be fine with Sport Springs. For a DD

[ToyotaBMW]

Originally Posted by S4NoMore

It's not a matter of what I think, it's what is known. Look up the spring rates of a few systems if you don't believe me.



You're right, definitely handling will suffer if the shocks aren't close enough to their design range. I think it's worth noting that this is the F30 board, not the M3 board and not really a racing community. Consider your audience.



True. But it's also possible in certain cases with the majority of coilover designs to hit the bump stops if the spring perch is run at or near the bottom of its adjustable range. Cheap or not, the spring must be at a level of stiffness to resist the force of potholes or dips in the highway to prevent bottoming out the shocks. It's really just a physics problem.

Look at the Bilstein PSS coilovers for F30:



As you raise and lower the spring perch, you are not able to compensate by adjusting the shock stroke.

As an aside, this system is only $1k. Really not a terribly expensive option...



Not to go too off topic, I am running Ground Control's custom specified conversion. I spoke with experts at GC and researched the vast E30 community to understand that with the height I want, I need a certain spring rate... and it's a high spring rate.
Eibach winds the coils for GC and Koni makes the damper that is valved for the high rate and shortened to accommodate a significant drop (the E30 is very high stock, so the lowering amount is in a different league compared with the F30 Sport). The front strut housings are actually modified (shortened) for this smaller strut. GC is the benchmark for E30s, short of the $3000 KW options.
The ride is excellent in terms of handling - grip, balance, feedback. In my opinion however, I have sacrificed some ride quality - the ability to soak up any and all road imperfections in a luxurious manner - for a tight ride without much gap between tire and fenders. If I soften the spring rate, I run the risk of bottoming out over dips etc. unless I raise my ride height. Get it?

I'm a mechanical engineer and I have some experience in suspension design. I'm not talking out of my ass, I'm trying to explain that coilovers do have their downside and are not a no-brainer, even if you want to spend alot of cash and despite the generic internet ramblings of "coilovers-or-bust."

Like I said you should know what you are talking about before posting. You have picked the cheap coilovers for the F30 the PSS. I said PSS9/10. They are the TOP QUALITY coilovers that are fully adjustable. They are $2000.

http://www.turnermotorsport.com/BMW-...coilovers.aspx

The ground control IMO doesn't make high quality products IMO that is why you feel the way you do about coilovers. Not sure what you are talking about but if you are talking about these that you have for you E30 than I understand completely what you have. Get back to me if you ever put KW V3's. If you are an engineer than I hope you didn't purchase the following coilover items for your E30.

http://www.ground-control-store.com/...gory.php/CA=98

Also if you are an engineer instead of telling me how you think that coilovers are inferior you still haven't answered my question in how you keep saying that the coilover spring is stiffer on a 1" drop compared to a 1"drop on shock spring?

[S4NoMore]

Originally Posted by ToyotaBMW

I said PSS9/10. They are the TOP QUALITY coilovers that are fully adjustable. They are $2000.

They only give you more damping adjustment, compression as well as rebound. I'm sure they are great but look at the PSS10 picture, there is not shock travel adjustment.

Originally Posted by ToyotaBMW

you still haven't answered my question in how you keep saying that the coilover spring is stiffer on a 1" drop compared to a 1"drop on shock spring?

The GC link you posted is not the entirety of their kit, no. See here.

If by "shock spring" you mean "sport spring," then yes I have answered your question at great length. The coilover spring rate is higher. No matter what settings are chosen, the spring rate is a constant.

[dannywooly77]

Drop it for an xDrive that look particularly high mine isn't no where near that ride height!