Driving questions? Setup questions?

[kc_skyrider]

Open track days? The owner of my shop just bought a acre of flawless concrete and he wants to start drifting his STI (one to many Ken Block videos) after I get a feel for it on this controlled surface I doubt I'll ever drift on a track around here. After all Nurenburgring is for cornering not sliding Thanks for the advice.

[J Tyler]

Originally Posted by kc_skyrider

After all Nurenburgring is for cornering not sliding

[NTTY]

Hi Jeff,

Thanks for this thread! Here are some questions for you

I have a 135i on which I already installed the Quaife LSD. Rest of the car is stock on a chassis perspective. I'm not suffering any particular understeer at the moment, even if the improved grip provided by the Quaife has stressed it a bit. So the chassis appears to me kind of neutral at the moment.

Note that this is my day to day car and I don't plan to go on track regularly. It may happen, though, but it would only be for fun, not to do the best lap time.
I live in Switzerland, it rains often and I drive around 6 weeks a year on snow.

Next week, my mechanic will install a Bilstein PSS set on the car (I'm not happy at all with the rebond on the stock supensions). I will ask him to lower the car around 1". I don't really want to go for more as I'd like to keep the car practical to use.

Here are my questions:
- Considering this (especially the lowering), do you think I'll need camber plates to get the original front camber setup, or is it possible to adjust it accordingly without? Again, I will not run -2° as I use the car everyday, so just wondering how far it is possible to adjust front camber without going for Camber plates. If they are really needed, I need to order them and make them installed at the same time, it would save labor.
- To make the front a bit more reactive, do you recommend toe modification or anything else?
- Generally, and again considering what I plan to do with my car, what would be your recommendation for my wheels alignment?
- Any other thoughs are more than welcome!

Thank you very much in advance for your time

PS: the video above has been ma referenced one over years. I learned how I could drive my 911 just looking at it hundred times. It's not really efficient to be fast, but at least it shows how that particular chassis reacts and it gave me some clues to be faster with mine when I used to go on tracks.

[CDR_UK]

^^^ difficult to only lower 1" at the front with PSS10 (despite the manufacturer claims). I took the min drop possible, and it's about ~35mm...

[Frog-San]

^^^ Same setting, 25mm on the front for me, that's about 1 inch

(seems too low for winter driving, space between tires/fenders)

[NTTY]

Hi guys,

Thank you for these comments. I'll let you know exactly how much the car is lowered.
I went for the PSS (B14) not the PSS10 (B16) ;-)

Cheers.

[pkcormier]

Jeff, it's me again. Need another round of advice. I am going to buy coilovers. 95% sure I'm going with AST 5100's. I need help with spring rates. To recap, below are my current suspension mods and setup:

1) Vorshlag camber plates
2) M3 control arms
--I can get -3.2 to -3.6 neg camber. More obviously when the car is lowered on coilovers
3) UUC 2-position front sway - 27mm. Currently set at soft setting.
4) 255 toyo r888 tires - square setup

This setup still has a little understeer, but it is pretty neutral. Certainly not tail happy.

I am hovering around 450f and 600r. What do you think?

Philip

[Tom_135]

Jeff,
First off thanks for the replies, it allows us to all to keep our day jobs.

I have a relatively new stock 135i and I have done a few months of autocross. I love this car on and off the track but I think everyone here agrees its a few ticks away from perfect.

Ive been sifting through the forums and hoped you could provide some answers; I apologize if these are somewhat redundant.

My goals in order of precedence:
-Reduce the understeer - for track and daily use, and to be able to participate in some drifting events. Dont want it out of control flailing all over the place.
-Reduce the body roll
-Looking to increase track abilities but maintain some practicality. To put numbers on it, maybe a 35% increase in track abilities.
-Stay within a $2000 budget (realize this might be unrealistic)

Other considerations:
-Dont want to lower the car, but if I have to I dont want it lower than .75" to 1.0"
-Id like mods that I can do myself, relatively mech guy, dont have a degree mech engineering

The plan I was thinking:
-Buy KW coilovers, I was thinking the V1s due to balance of value and daily driving. I know yall all recommend V2 or V3s. For my objectives what do you recommend?

-New tires as soon as these RFTs are done. Want tires that again will give some track increase but wont last a few months on daily driving. I have no idea what to go with here, have heard everything under the sun.

-Maybe a front sway bar - looking for a suggestion on brand.

-Unrelated but, also going to throw a SSK on there, I had a UUC in a 335i and I think Im going to try a B&M.

Thats all I was thinking. Thanks for any insight,
Tom

[J Tyler]

Originally Posted by pkcormier

Jeff, it's me again. Need another round of advice. I am going to buy coilovers. 95% sure I'm going with AST 5100's. I need help with spring rates. To recap, below are my current suspension mods and setup:

1) Vorshlag camber plates
2) M3 control arms
--I can get -3.2 to -3.6 neg camber. More obviously when the car is lowered on coilovers
3) UUC 2-position front sway - 27mm. Currently set at soft setting.
4) 255 toyo r888 tires - square setup

This setup still has a little understeer, but it is pretty neutral. Certainly not tail happy.

I am hovering around 450f and 600r. What do you think?

Philip

Hey Philip,

Sounds like you have an awesome setup! This will be a very fast car. I'm sure you will love it when it is all done.

Ok, as for spring rates... Considering your setup is very similar to what Berk Technology (135i) and HP Autowerks (335i) are running, I would recommend going with 450lb/in F and 800lb/in R. This puts your wheel rates at 415lb/in F and 253lb/in R. Berk and HP are at 400F/800R springs, and the cars are a little too loose. They both need a bit more front spring rate. That is why I suggest 450F; both Berk and HP Autowerks are going to try 450F next to help with the oversteer. 400F/800R results in a very neutral car: perfect for drifting, but to go fast it needs a little more front spring.

Also, I sure would think the ideal setting for that front bar would be the 'stiff' setting. Strut-type front suspensions usually like a lot of bar.

I'd like to see some pictures of your ride height after you get the coilovers on

[J Tyler]

Originally Posted by NTTY

Hi Jeff,

Thanks for this thread! Here are some questions for you

I have a 135i on which I already installed the Quaife LSD. Rest of the car is stock on a chassis perspective. I'm not suffering any particular understeer at the moment, even if the improved grip provided by the Quaife has stressed it a bit. So the chassis appears to me kind of neutral at the moment.

Note that this is my day to day car and I don't plan to go on track regularly. It may happen, though, but it would only be for fun, not to do the best lap time.
I live in Switzerland, it rains often and I drive around 6 weeks a year on snow.

Next week, my mechanic will install a Bilstein PSS set on the car (I'm not happy at all with the rebond on the stock supensions). I will ask him to lower the car around 1". I don't really want to go for more as I'd like to keep the car practical to use.

Here are my questions:
- Considering this (especially the lowering), do you think I'll need camber plates to get the original front camber setup, or is it possible to adjust it accordingly without? Again, I will not run -2° as I use the car everyday, so just wondering how far it is possible to adjust front camber without going for Camber plates. If they are really needed, I need to order them and make them installed at the same time, it would save labor.
- To make the front a bit more reactive, do you recommend toe modification or anything else?
- Generally, and again considering what I plan to do with my car, what would be your recommendation for my wheels alignment?
- Any other thoughs are more than welcome!

Thank you very much in advance for your time

PS: the video above has been ma referenced one over years. I learned how I could drive my 911 just looking at it hundred times. It's not really efficient to be fast, but at least it shows how that particular chassis reacts and it gave me some clues to be faster with mine when I used to go on tracks.

- You can run -2* as a daily and you will be OK on tire wear! But, you will need camber plates to get to -2*. I'll be honest, I don't know how much camber you can get without camber plates, as I have no experience with that setup.
- For front toe on a street car, I recommend just a tiny bit of toe-out (also, this is what the factory recommends). Like, 1/16" total (so, 1/32" on each side). I also suggest setting it to the max caster you can get. This really helps with overall steering feel, gives it a nice "on-center" feel. Also helps with U-turns on the street.
- My other advice: Under compression, the rear toes out. So, I suggest running more rear toe-in to compensate. But, since yours is mainly a street car, I'd keep it down to about 1/8" total rear toe in (1/16" each side)


Hope that helps! Sorry for taking so long to reply...

[J Tyler]

Originally Posted by Tom_135

Jeff,
First off thanks for the replies, it allows us to all to keep our day jobs.

I have a relatively new stock 135i and I have done a few months of autocross. I love this car on and off the track but I think everyone here agrees its a few ticks away from perfect.

Ive been sifting through the forums and hoped you could provide some answers; I apologize if these are somewhat redundant.

My goals in order of precedence:
-Reduce the understeer - for track and daily use, and to be able to participate in some drifting events. Dont want it out of control flailing all over the place.
-Reduce the body roll
-Looking to increase track abilities but maintain some practicality. To put numbers on it, maybe a 35% increase in track abilities.
-Stay within a $2000 budget (realize this might be unrealistic)

Other considerations:
-Dont want to lower the car, but if I have to I dont want it lower than .75" to 1.0"
-Id like mods that I can do myself, relatively mech guy, dont have a degree mech engineering

The plan I was thinking:
-Buy KW coilovers, I was thinking the V1s due to balance of value and daily driving. I know yall all recommend V2 or V3s. For my objectives what do you recommend?

-New tires as soon as these RFTs are done. Want tires that again will give some track increase but wont last a few months on daily driving. I have no idea what to go with here, have heard everything under the sun.

-Maybe a front sway bar - looking for a suggestion on brand.

-Unrelated but, also going to throw a SSK on there, I had a UUC in a 335i and I think Im going to try a B&M.

Thats all I was thinking. Thanks for any insight,
Tom

Hey Tom,

I am just going to pick apart your questions one-by-one. Here goes:

My goals in order of precedence:
-Reduce the understeer - for track and daily use, and to be able to participate in some drifting events. Dont want it out of control flailing all over the place.
-Reduce the body roll
-Looking to increase track abilities but maintain some practicality. To put numbers on it, maybe a 35% increase in track abilities.
-Stay within a $2000 budget (realize this might be unrealistic)

I'd say: KW V2's + camber plates. Bye-bye understeer and body roll, and you will still have a good-quality ride on the street (not too stiff). Plus, you can adjust the damper stiffness individually for track days and street driving. If you are really tight on budget, the V1 is OK. It's just nice to be able to stiffen up the dampers for track driving.

The V2's are rebound adjustable, which is nice because rebound has more of an affect on the balance of the car than compression does. Most other single-adjustable coilover kits are compression-adjustable, which is silly IMO.

Other considerations:
-Dont want to lower the car, but if I have to I dont want it lower than .75" to 1.0"
-Id like mods that I can do myself, relatively mech guy, dont have a degree mech engineering

Check and check

-New tires as soon as these RFTs are done. Want tires that again will give some track increase but wont last a few months on daily driving. I have no idea what to go with here, have heard everything under the sun.

Dunlop Direzza Star Spec Z1, hands-down. They hold up incredibly well to track abuse, and last way longer than all the other high-performance street tires. By far my favorite street tire, and I've tried just about everything. My #2 choice would be Michelin Pilot Sport PS2's, but they just don't hold up on the track. The only time they are better than the Dunlops is in very cold weather, and in heavy rain. Those Dunlops are by far my fav's.... and Berk is sponsored by them too

-Maybe a front sway bar - looking for a suggestion on brand.

No clue. I wish our H&R bar was a little stiffer, but it paired nicely with the KW V3 kit spring rates when we had them (those are the same as the V2 rates). What I can say confidently is: keep the rear sway bar stock. A stiffer front bar will help, but is not a huge deal. You would simply notice a small increase in front roll resistance and understeer. Not nearly as important as camber plates, IMO.

-Unrelated but, also going to throw a SSK on there, I had a UUC in a 335i and I think Im going to try a B&M.

Haha, I will get flamed for this but here goes: I don't like SSK's. They mess with the factory-designed directional lever loads, relative gate placement, and overall precision/feel of the lever. Not a fan. Watch my videos, I have no problem shifting the factory lever quickly and efficiently, without having to worry about whether or not I'm hitting the gates properly. This is a bit subjective, though.


Ok Tom, good luck, hope that helps. Keep us all updated with what you do

[Tom_135]

Jeff, thanks again for the timely response:

Im pretty much going to take all of your recommendations by the letter.

I think I hear you when you say if I get the KW V2 and the camber plates, AND tires, I dont need to mess with the sway bar. Minimal cost/benefit ration. I think I wont buy the bar.


For the camber plates - any brand recommendations and a good place to buy them online? I googled it and cant find much.


Hear you about the SSK but I dont know how much effect a new kit will have on the drivetrain/tranny over the long run. The way these cars are made, Id say minimal. I dont have too many issues with my stock one, but the throws are longer and looser than they need to be. I put a UUC on my 335i and it completed the feel - such a well engineered power train with a poor mechanical feel on the shifter.

Any thoughts on cold air intakes - I love these things on NA cars for the sound, feel, and minimal perf gains.
Thanks,
Tom

[NTTY]

Originally Posted by J Tyler

- You can run -2* as a daily and you will be OK on tire wear! But, you will need camber plates to get to -2*. I'll be honest, I don't know how much camber you can get without camber plates, as I have no experience with that setup.
- For front toe on a street car, I recommend just a tiny bit of toe-out (also, this is what the factory recommends). Like, 1/16" total (so, 1/32" on each side). I also suggest setting it to the max caster you can get. This really helps with overall steering feel, gives it a nice "on-center" feel. Also helps with U-turns on the street.
- My other advice: Under compression, the rear toes out. So, I suggest running more rear toe-in to compensate. But, since yours is mainly a street car, I'd keep it down to about 1/8" total rear toe in (1/16" each side)


Hope that helps! Sorry for taking so long to reply...

Hi Jeff, no problem, thanks for your time

The Bilstein have been installed on the car. I don't exactly know the lowering, but it seems to be a bit more than what I expected. Anyway, my mechanic made an basic alignment and asked me to run with the car for something like 1500 miles, because the car is expected to lower again more. I already did 400 miles and front has lost again 1/4". He'll then make an final alignment, end of september, just before my first track day with the car.

At the moment, because of the lowering, front has around -1° of camber and rear has much more. Front toe has been corrected, as you suggest, to the original factory values. Again, because on the lowering, rear has more toe in, but this has not been modified, since the car seems to be well balanced with that setup, and it saves labor (anyway the car will lower again and everything will have to be reviewed).

-2° on front seems huge to me, especially if you stay with factory toe out. It will certainly reduce understeer, but it will reduce a lot tires life, no?

Thank you for the suggestion on caster, will try that

BTW, bilstein PSS make a huge difference to the standard suspensions. I am very happy with them.

Camber plates do not seem to be homologated in switzerland for street use, but I'm waiting confirmation. I saw some using M3 lower arms, do they allow more camber even if we don't go for camber plates? Are we speaking of the E90/E92 M3 arms?

Cheers.

[HP Autosport]

Originally Posted by Tom_135

For the camber plates - any brand recommendations and a good place to buy them online? I googled it and cant find much.

Vorshlag makes a set of nice camber plates for your application.

[J Tyler]

Originally Posted by Tom_135

Any thoughts on cold air intakes - I love these things on NA cars for the sound, feel, and minimal perf gains.
Thanks,
Tom

Yes - most of them are actually "hot air intakes". Get one with a shroud that intakes air from the front of the car!

If it were my car, I'd probably just drop in a K&N filter. The stock airbox is very well engineered and takes into account the proper shape/volume for frequency resonance and airflow direction into the manifold. The stock intake point at the front of the car is also ideally placed and designed for the right air pressure & flow around that particular point.

[J Tyler]

Originally Posted by NTTY

Hi Jeff, no problem, thanks for your time

The Bilstein have been installed on the car. I don't exactly know the lowering, but it seems to be a bit more than what I expected. Anyway, my mechanic made an basic alignment and asked me to run with the car for something like 1500 miles, because the car is expected to lower again more. I already did 400 miles and front has lost again 1/4". He'll then make an final alignment, end of september, just before my first track day with the car.

At the moment, because of the lowering, front has around -1° of camber and rear has much more. Front toe has been corrected, as you suggest, to the original factory values. Again, because on the lowering, rear has more toe in, but this has not been modified, since the car seems to be well balanced with that setup, and it saves labor (anyway the car will lower again and everything will have to be reviewed).

-2° on front seems huge to me, especially if you stay with factory toe out. It will certainly reduce understeer, but it will reduce a lot tires life, no?

Thank you for the suggestion on caster, will try that

BTW, bilstein PSS make a huge difference to the standard suspensions. I am very happy with them.

Camber plates do not seem to be homologated in switzerland for street use, but I'm waiting confirmation. I saw some using M3 lower arms, do they allow more camber even if we don't go for camber plates? Are we speaking of the E90/E92 M3 arms?

Cheers.

Your mechanic is correct about the new springs settling --- good man.

-2* is fine for street use with occasional 'spirited' driving. Maybe I drive more spirited than others, but from my experience -2 is fine on tire wear for the street.

Yes, the E90/92 M arms allow for a bit more camber. Talk to Harold @ HP Autowerks, he sells them and knows all about them. IIRC, they add about .5* of negative camber, but double-check that with Harold.


Good luck man, keep us updated

[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.

[pkcormier]

Thanks Jeff. I'll post when I have everything assembled.

Originally Posted by J Tyler

Hey Philip,

Sounds like you have an awesome setup! This will be a very fast car. I'm sure you will love it when it is all done.

Ok, as for spring rates... Considering your setup is very similar to what Berk Technology (135i) and HP Autowerks (335i) are running, I would recommend going with 450lb/in F and 800lb/in R. This puts your wheel rates at 415lb/in F and 253lb/in R. Berk and HP are at 400F/800R springs, and the cars are a little too loose. They both need a bit more front spring rate. That is why I suggest 450F; both Berk and HP Autowerks are going to try 450F next to help with the oversteer. 400F/800R results in a very neutral car: perfect for drifting, but to go fast it needs a little more front spring.

Also, I sure would think the ideal setting for that front bar would be the 'stiff' setting. Strut-type front suspensions usually like a lot of bar.

I'd like to see some pictures of your ride height after you get the coilovers on

[NTTY]

Originally Posted by J Tyler

Your mechanic is correct about the new springs settling --- good man.

-2* is fine for street use with occasional 'spirited' driving. Maybe I drive more spirited than others, but from my experience -2 is fine on tire wear for the street.

Yes, the E90/92 M arms allow for a bit more camber. Talk to Harold @ HP Autowerks, he sells them and knows all about them. IIRC, they add about .5* of negative camber, but double-check that with Harold.


Good luck man, keep us updated

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!

[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?

[HP Autosport]

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!

Jeff drove our 335i with the full M3 kit on it.

[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.

Originally Posted by J Tyler

Hey Philip,

Sounds like you have an awesome setup! This will be a very fast car. I'm sure you will love it when it is all done.

Ok, as for spring rates... Considering your setup is very similar to what Berk Technology (135i) and HP Autowerks (335i) are running, I would recommend going with 450lb/in F and 800lb/in R. This puts your wheel rates at 415lb/in F and 253lb/in R. Berk and HP are at 400F/800R springs, and the cars are a little too loose. They both need a bit more front spring rate. That is why I suggest 450F; both Berk and HP Autowerks are going to try 450F next to help with the oversteer. 400F/800R results in a very neutral car: perfect for drifting, but to go fast it needs a little more front spring.

Also, I sure would think the ideal setting for that front bar would be the 'stiff' setting. Strut-type front suspensions usually like a lot of bar.

I'd like to see some pictures of your ride height after you get the coilovers on