Driving questions? Setup questions?

[arrutled]

I cannot believe I have not seen this thread before

Ok so here are some questions
1. What are your preference of tire sizes front to rear? I am planning to have 245/265. Thoughts on that setup? or aim for square setups?
2. How do you feel about progressive springs versus linear springs on coilovers? Examples) KW V2 versus KW street comfort
3. For autocross application, I added M3 wishbones and tension rods and afterward realized I could not speed up coming out of corners without doing donuts So I bought the M3 front sway and it feels much better on the street and will verify this weekend at autocross. If that is not enough to improve corner exit speed/stability What do you suggest next? Coilovers? springs? will M3 rear bits help? camber plates? better driver mod?
4. Also as far as springs go what is the rule of thumb for understeer/oversteer? stiffer front = understeer?
5. Another preference question....Whats more important between neutral balance versus corner exit speed? Can you have both? how?
6. Do you think you could add to the first post a summary of the current berk setup from sways/camber/spring rates/ride height/tires/wheels and opinions of how it reacts and what you/they plan to do next to improve?

[pkcormier]

aarutled,

Did you do anything special to your performance rotors before mounting and bedding in the pads? Did you clean them first with brake cleaner? Is that even necessary? I just bought a set for track events.

I had Stoptechs on my old car that required a meticulous cleaning process before use.

Thanks

[BrokenVert]

Do you mind answering a question about another type of car?

Im buying a 91 318is I plan on autoxing it until I have enough money to track it occasionally.

Ive been told to set it up for STX but im not sure what that entails.

Thanks!

[arrutled]

Originally Posted by pkcormier

aarutled,

Did you do anything special to your performance rotors before mounting and bedding in the pads? Did you clean them first with brake cleaner? Is that even necessary? I just bought a set for track events.

I had Stoptechs on my old car that required a meticulous cleaning process before use.

Thanks

I had a shop do it for 50 bucks, lol. I doubt they did anything meticulous for 50 bucks though. Sorry I can't be of further help. I can call the shop and see if they did anything special if you like?

[adrean8j]

You do not need to do anything special before installing them. Just make sure after they are installed you do the standard acceleration and moderate to hard braking to bed them in.

[axoid]

Here is a handling question.

I was autocrossing this weekend and I was experiencing an undesirable trait in the handling of the car. The weekend was cold (~45 degrees) and a little wet, I was getting the rear of the car to slide a bit due to the weather conditions and my driving style. I was finding that the car is a little unpredictable on how it recovers from a slide and often when the tires regained grip the rear of the car, for the lack of a better term, wobble. I was wondering if anyone else had experienced this and if this was due to the shocks, springs and/or sway bars. My initial thoughts are to look to the shock first and then the sway bars.

I’m new to BMWs and autocrossing independent rear end cars, but I’ve been autocrossing live axle pony cars for 9 years. The car is a completely stock 128i with sport package and 13k on it.

[arrutled]

probly a combination of soft springs,spaghetti for a rear sway, and poor subframe bushings.

[cpt97m3]

Originally Posted by arrutled

probly a combination of soft springs,spaghetti for a rear sway, and poor subframe bushings.

Yeah, I think there is a lot of soft bushings back there. I've noticed the same issue. You can add the M3 subframe bushings, and some of the M3 arms with stiffer bushings. I've heard people say that helps a lot.

[arrutled]

I plan on replacing the tension link and guide rods back there before the bushings because of the install cost of those.

[vitig]

[QUOTE = arrutled; 5922062] No puedo creer que no he visto este hilo antes de que

Ok así que aquí están algunas de las preguntas
1. ¿Cuáles son sus preferencias de los tamaños de llanta delantera a la trasera? Estoy planeando tener 245/265. Reflexiones sobre la que el programa de instalación? o finalidad para configuraciones cuadrado?
2. ¿Cómo te sientes acerca de muelles progresivos frente lineal resortes coilovers? Ejemplos) KW v2 frente a la comodidad de la calle KW
3. Para la aplicación de autocross, añadí espoletas M3 y tirantes y después comprendí que no podía acelerar saliendo de las esquinas sin hacer donuts Así que compré el dominio frente a M3 y se siente mucho mejor en la calle y comprobar este fin de semana en el autocross. Si eso no es suficiente para mejorar la velocidad de salida de las curvas / estabilidad ¿Qué sugiere usted después? Coilovers? manantiales? se M3 bits trasera ayuda? placas de la comba? mod mejor conductor?
4. También en lo que va muelles ¿cuál es la regla de oro para subviraje / sobreviraje? más rígida frente = subviraje?
5. Otra cuestión de preferencias .... ¿Cuál es más importante entre el balance neutro frente a la velocidad de salida esquina? ¿Es posible tener las dos cosas? ¿cómo?
6. ¿Crees que podría añadir a la primera entrada un resumen de la configuración actual de Berk balancea / comba / tasas de primavera / altura de marcha / llantas / ruedas y opiniones de cómo reacciona y qué / que piensan hacer ahora para mejorar? [ / QUOTE]


Berk please reply it.

[vitig]

J tyler help us.

[J Tyler]

Hey guys, my apologies. I have been very busy with school/work and have neglected this thread. Every time I go online I notice it and tell myself "I'll do it tonight when I get home..." Anyway, here goes:

Originally Posted by Terp1

I've read through all the threads on here and e90post about the M3 conversion kit. I am completely amazed by your level of expertise and appreciate all you've added. I'm definitely going to get the M3 conversion kit from Harold but have a question on the rest of the suspension. Would you suggest a Coilover setup or spring/strut setup? I was originally considering the TC Kline D/A setup but now I'm thing of the Koni/H&R Stage 1 kit from Harold, or KW v2. Also, do you think the camber plates and sway bars would work well with this setup? Sorry for so many questions. The car will be primarily for HPDE and Track Days. I may occassionally drive it around town during nice weather. Thanks for all your help.

I'm not sure what you mean by "coilover or spring/strut setup"? Do you mean a kit like the KW V-series vs the AST's with custom springs? Assuming that is what you mean, my $.02 is to buy whichever dampers are the best since that is really what you are paying for. Nice custom springs are cheap relative to the cost of the dampers, so whether you do KW or AST or Koni or whatever, I say go with the best damper that fits your budget. Just make sure you order springs from someone who knows your car so you don't get the wrong diameter/length spring!

In that regard, I am a big fan of the KW V-series. From my experience they are the best dampers in their price range -- their characteristics are 'proper', they don't overheat during hard on-track driving, and they have a good range of adjustment with well-placed adjustment 'clicks'. Also, KW uses a shaker rig to determine their spring and damper rates for the exact car -- something no other kit maker does as far as I know. The main downside (IMO) to the KW"s is that for these cars, they really need to be re-valved to provide enough damping force for track duty if you have sticky/wider tires. On the Berk car I ended up at or near full-stiff on on most channels, and we weren't even running R-comps. Also, if this car is going to be a track toy, you want something that is at least double-adjustable! For KW, that means the V3.

The one I cannot say anything about is the AST -- I haven't driven them yet. I've checked them out in person and they are made of very high-quality materials, and AST was formed by ex-Ohlins guys so I would assume they are at least "good".

I do like the Koni's on Harold's 335i, they had great characteristics and a (very) wide range of adjustment -- very similar feel to the KW's but with a wider range of damping force adjustment. I can easily recommend them. However, I have had one bad experience with Koni - a good friend of mine (Stuntman on here) put them on his E36 M3 and after about ~20k miles, they lost valving. That is roughly the typical lifespan of an OEM damper; usually the aftermarket stuff lasts longer. Of course, if that happens, all you have to do is get them revalved which is not a big deal.

If you are semi-serious about making the car well-balanced on the track, you'll have to do custom springs. Who knows what the 'kit' spring rates were calculated for. For example, when we had the kit KW V3's on the Berk 135i with non-staggered tires + camber plates, the car was wayyy too loose. That's because KW designed the spring rates for a stock staggered setup with no camber plates. Harold and/or I can help you with spring rates once you get your camber plates/alignment/sway bars/etc on

Originally Posted by NTTY

Hi Jeff, thanks for the advice I sent a mail to Autowerks. Their site speaks about an improved response and better control in corners, which is what I need
I see they have a M3 conversion kit including front and rear parts + anti-roll bars and sub-frame bushing kit. Do you think I should consider that? Do you know anyone who tested this M3 kit?

Thanks very much for your time!

If you want to really enjoy your car on the track and are willing to spend the money, HP Autowerks' M3 conversion kit is the way to go. I cannot decide for you if it is worth the money, but I can try to give you some feedback on it. The M3 control arms & bushings make the car more precise & stable -- you especially notice it under hard braking from high speeds. The Berk car will wander around a little bit, whereas the HPA car just plants itself and does not wander. The HPA car also gives you more of an 'instant' feedback as to what it is doing, whereas in the Berk car things are a bit more delayed (its hard to describe). As far as lap time goes, the main thing that really helps are the M3 front arms which get you to -3* camber. I would really like to do a back-to-back test of stock vs. HPA M3 conversion -- then I could really tell you!

Originally Posted by kc_skyrider

Hey J. Thanks again for the advice. Nice to see someone abusing bilsteins. I have PSS10's as well and agree they do drop the car low. I am heading to a weekend of drag/autocross at bitburg and wondered what settings you would use for either of these types of performance driving. I'll be running star specs in the rear so a little improved traction, don't know if I'll get my fronts in on time so understeer should be a limiting factor I just wondered what dampening setting you'd use in my shoes?

For drag racing I would make sure the rear dampers are not too stiff (set them near the softer end of the spectrum). You can leave the front alone for drag runs.

For Autocross, you want the bump set pretty stiff, usually a little bit stiffer than what the ideal for a real track would be -- this makes the car respond quicker to your steering inputs which is important in autocross. Use the front & rear rebound to tune the balance of the car: more front rebound = understeer on entry, more rear rebound = oversteer on entry.

Originally Posted by pkcormier

Jeff, I haven't installed the AST coilovers yet, but in preparation I could use your advice on ride height. Assuming I had an infinite range of height adjustment, what would you recommend? My uneducated guess would be slightly lower than stock, but not too much. Perhaps 15-20mm. I am not interested in how it looks. Just how it performs. I understand the physics of a lower center of gravity, but I don't want to go too low and adversely impact the suspension geometry.

Thanks.

You're right, there's simple physics (lower Cg is better) vs more complex stuff (lower the car too much and roll centers + roll moments get goofy). The rear end of these cars likes to be low because they gain negative camber as you go lower. The roll center & moment of the rear becomes less-than-ideal, but the gain in negative camber outweighs it in this case. I would look at where HP Autowerks & Berk have their cars now -- I really like the behavior of both cars and neither are so low that the geometry is terrible. I'm not sure exactly what their ride heights are though... I'm sure you can PM them to find out. If you go higher than what they are running, that's fine, but you won't be able to get the same negative camber in the rear.

Originally Posted by arrutled

I cannot believe I have not seen this thread before

Ok so here are some questions
1. What are your preference of tire sizes front to rear? I am planning to have 245/265. Thoughts on that setup? or aim for square setups?
2. How do you feel about progressive springs versus linear springs on coilovers? Examples) KW V2 versus KW street comfort
3. For autocross application, I added M3 wishbones and tension rods and afterward realized I could not speed up coming out of corners without doing donuts So I bought the M3 front sway and it feels much better on the street and will verify this weekend at autocross. If that is not enough to improve corner exit speed/stability What do you suggest next? Coilovers? springs? will M3 rear bits help? camber plates? better driver mod?
4. Also as far as springs go what is the rule of thumb for understeer/oversteer? stiffer front = understeer?
5. Another preference question....Whats more important between neutral balance versus corner exit speed? Can you have both? how?
6. Do you think you could add to the first post a summary of the current berk setup from sways/camber/spring rates/ride height/tires/wheels and opinions of how it reacts and what you/they plan to do next to improve?

1. As wide as you can get! 245/265 is fine, but if you are tracking your car a lot you can save money on tires if you go non-staggered. If you set your suspension up for staggered tires and then put non-staggered's on, you will add some oversteer (or less understeer).
2. Progressive springs are nonsense, get linears! - Progressives make it tricky to set up a car because they are acting at different rates during different parts of a corner. Also, dampers are always linear in action -- it makes no sense to have a linear damper mated to a progressive spring.
3. An LSD! And if that is not an option, you are going to have to go to great lengths to suppress that inside rear wheelspin. Coilovers would help because they would let you adjust the dampers and spring rates to try to give the rear more grip. M3 rear bits won't help.
4. Correct
5. It depends.... If you had a perfect figure-8 track with 2 tiny straights, perfect balance and maximum mid-corner speed would be the fastest setup. But, say you have a track with lots of low-speed corners leading onto long straightaways -- then corner exit speed is MUCH more important than mid-corner balance/speed. Generally, IMO, a light understeer is the best compromise between mid-corner speed and corner-exit speed. At most tracks. Think about it -- if the car is "perfectly neutral", then all 4 tires are at their limit in the middle of the corner; how can you put power down without exceeding the limit of the rear tires in that state? - You can't!
6. I haven't driven the Berk car recently, and they have made some changes that I recommended (springs and a few other things) so I can't say anything about how it is now. Last time I drove it, it had: 400lbF/800lbR springs, H&R front bar with stock rear bar, -2.5*F/-2.0*R camber, 255F/265R tires, HP Autowerks Quaife LSD. Overall it was too loose and needed more front spring, but it was getting close to "really good".

Originally Posted by BrokenVert

Do you mind answering a question about another type of car?

Im buying a 91 318is I plan on autoxing it until I have enough money to track it occasionally.

Ive been told to set it up for STX but im not sure what that entails.

Thanks!

I am clueless on SCCA stuff, sorry! I would try bimmerforums.com track section, lots of SCCA guys on there who will know whats up!

Originally Posted by adrean8j

You do not need to do anything special before installing them. Just make sure after they are installed you do the standard acceleration and moderate to hard braking to bed them in.

^This. Make sure you bed them in on track. Do not do it on the street, I guarantee you will beat up your rotors. They need to get HOT to bed in and this simply cannot be achieved on the street -- use them as lightly as possible until you get to the track, or just put them in at the track.

Originally Posted by axoid

Here is a handling question.

I was autocrossing this weekend and I was experiencing an undesirable trait in the handling of the car. The weekend was cold (~45 degrees) and a little wet, I was getting the rear of the car to slide a bit due to the weather conditions and my driving style. I was finding that the car is a little unpredictable on how it recovers from a slide and often when the tires regained grip the rear of the car, for the lack of a better term, wobble. I was wondering if anyone else had experienced this and if this was due to the shocks, springs and/or sway bars. My initial thoughts are to look to the shock first and then the sway bars.

I’m new to BMWs and autocrossing independent rear end cars, but I’ve been autocrossing live axle pony cars for 9 years. The car is a completely stock 128i with sport package and 13k on it.

The "wobble" is due to a combination of things: the open diff, the soft bushings in the rear end, to a small extent the soft stock dampers, and, I'm pretty sure, you not recovering from the slide smoothly

An LSD would tighten things up back there, as would stiffer bushings. If you ever put coilovers on your car, the stiffer dampers will help a little as well.

Originally Posted by vitig

J tyler help us.

Sorry again!!! Hope this helps guys, come back with more if I didn't answer well enough!


Happy & safe holidays,

Jeff

[adrean8j]

Originally Posted by J Tyler

^This. Make sure you bed them in on track. Do not do it on the street, I guarantee you will beat up your rotors. They need to get HOT to bed in and this simply cannot be achieved on the street -- use them as lightly as possible until you get to the track, or just put them in at the track.

Jeff,

The BMW OEM performance rotors do not need to be bedded in on track do they? (I understand the purpose of the thread of course..LOL) I mean if you installed them on your everyday driver should you wait until you have the opportunity for a track/autox day to do it? I am kinda confused....

[bradford]

Originally Posted by adrean8j

Jeff,

The BMW OEM performance rotors do not need to be bedded in on track do they?

You can bed in a pad/rotor combo anywhere you can perform a series of high speed braking exercises. Personally, I prefer a lightly travelled country road - the kind that surround more tracks here in the USA.

You want to do several successive threshold braking sessions from, say, 80 to 20, until the brakes are good and stinky/smoky. Accelerate to 80, full braking (w/o ABS) to 20, full throttle to 80, repeat until they reek.

Then drive the car without touching the brakes at all until they return to ambient temperature. This will get an even deposition of pad material on the rotors for optimum braking performance.

[adrean8j]

Originally Posted by bradford

You can bed in a pad/rotor combo anywhere you can perform a series of high speed braking exercises. Personally, I prefer a lightly travelled country road - the kind that surround more tracks here in the USA.

You want to do several successive threshold braking sessions from, say, 80 to 20, until the brakes are good and stinky/smoky. Accelerate to 80, full braking (w/o ABS) to 20, full throttle to 80, repeat until they reek.

Then drive the car without touching the brakes at all until they return to ambient temperature. This will get an even deposition of pad material on the rotors for optimum braking performance.

^^^Yeah I know about that..it is what I was referring to when I wrote what I wrote....In hindsight I just think JT was referring to bedding in track pads(?)...when he gets a chance I am sure he will clarify

[pavelitto]

Jeff,

hopefully you will be able to identify some issues for my 135i looking at the attached results of alignment check.
Does the car with those results have tendency to pull to the one side if steering wheel kept straight?
I have the feeling that it does but won't say which way not to bias the diagnosis

[arrutled]

I am gonna guess left because you have toe-out left and toe-in on the right! right?

[HP Autosport]

I am going to say the car will pull to the right. Your aligment is way off if this was the final print out.

I hope your alignment tech centers your wheel before the alignment and this is just a before aligment print out.

[pavelitto]

It is the pre adjustment chcek. I'm going to do the full alignemtn on Wednesday after changing one of the rims.
And yes the car is slightly pulling to the right when I keep the wheel straight ahead. Hopefully the the alignment will rectify the problem,
Waiting for Jeff to put in his two cents...

[J Tyler]

Originally Posted by pavelitto

It is the pre adjustment chcek. I'm going to do the full alignemtn on Wednesday after changing one of the rims.
And yes the car is slightly pulling to the right when I keep the wheel straight ahead. Hopefully the the alignment will rectify the problem,
Waiting for Jeff to put in his two cents...

You need more negative front camber!

$.02

[HP Autosport]

Originally Posted by pavelitto

It is the pre adjustment chcek. I'm going to do the full alignemtn on Wednesday after changing one of the rims.
And yes the car is slightly pulling to the right when I keep the wheel straight ahead. Hopefully the the alignment will rectify the problem,
Waiting for Jeff to put in his two cents...

Camber and toe are adjustable, so you should be able to everything within specs. However, your caster is a bit off, but not enough to cause the car to pull to one side or the other.

For more camber you will need the M3 lower wishbones or a set of camber plates.

[pavelitto]

Originally Posted by J Tyler

You need more negative front camber!

$.02

I wish but it is my daily driver and 700+ miles trips are not rare. The insides of tyres wouldn't last to long than...
The tech guy at wheel center actually showed my that the thread on the inside of rear tyres is gone- is it do do with the negative camber on the back? (within specs)
I will put new tyres in spring anyways becasue I already hit the marker (1.8mm i think
They did last 19k miles daily driver