[khcoaching]

A bit of a cross post, but I thought it might be good info for people in the track section -

After finally dealing with the blown motor, new motor and some tuning issues, back on track with it!

Here is the original blown motor thread -

https://www.2addicts.com/forums/show....php?t=1781019

Update from running it on the track -

Drivetrain - No other changes from post engine work other than it has the stock tune in it with the rear O2 coded out. Runs good and pulls clean with none of the top end missing issues I had. While it would be nice to have more power, for what I am using the car for, it's great. I did 1x15 session with me driving and then 3x1 hour student sessions and it ran flawless.

Suspension - Since the camber plates and and alignment, I added a 18x8 square setup with 245/35/18 Michelin 4S.....

So.....I drove this directly after driving my 1LE and it initially felt slow and soft. (HA! Of course) I drove it a few laps with my wife and rushed my entries and of course, forgot to lower the tire pressure and remove crap from the trunk, so it was probably 200lbs more than the previous run. Still went quicker than the pre-engine failure in near 40 degree higher temps.

At this point, it is a very fun and capable car and with cleaner driving and proper tire pressure, easily capable of running under 2min at The Ridge, which is very respectable given the very stock nature of the car.

Red is PRE- engine and stock staggered setup
Blue is POST - engine and square setup

Ken

[msendit]

Looking at the slope of the WOT sections, new engine seems to be a fair bit down on power, no?

Without more data, hard to say if it's just pulling throttle because of the higher temps. But still a bit surprising given extra bolt-ons and custom tune.

[khcoaching]

Originally Posted by msendit

Looking at the slope of the WOT sections, new engine seems to be a fair bit down on power, no?

Without more data, hard to say if it's just pulling throttle because of the higher temps. But still a bit surprising given extra bolt-ons and custom tune.

It was quite surprising that it was that much slower, the tune was reset back to stock, but I did expect the same or slightly better speed. I think the combinations of the extra weight and higher temps is the issue. I'll try its again in a few weeks with my Solo DL looking at temps. The flip side is, it runs amazing.

Ken

[jas00x]

I just got my camber plates last week and plan on installing this weekend. I've got a 2014 228i (M-performance). Excited to see how much difference the front camber makes. Right now, I'm just killing the outer shoulders of the front tires! I'm also thinking about doing the square wheel/tire setup as well. Trying to decide on 17" vs 18" wheels. Is the 245 on an 8" wheel pretty much as big as we can go with stock suspension and camber plates?

[dradernh]

Originally Posted by jas00x

Is the 245 on an 8" wheel pretty much as big as we can go with stock suspension and camber plates?

I can't speak to your fitting a particular tire into your car's wheel wells, but there are some rules of thumb with regard to matching wheel and tire widths.

Below are data for Michelin's PS 4S in 245/35-18 and 255/35-18. In there, you can see that the tire industry has specified a width range for the wheels that a tire can safely be mounted on. However, enthusiast owners regularly make exceptions for any number of reasons; autocrossers in particular do some very creative things with wide tires on narrow wheels, but I don't think those cars are generally driven on the street nor is that approach commonly used in circuit track setups.

What you can see in the data is that a 245 tire is intended to fit on a wheel that's 8-9½" wide, and a 255 tire is supposed to go on a wheel that's 8½-10" wide.

While you can choose to operate outside those parameters, there's a rule of thumb for matching wheel and tire widths for track driving: the tire's tread width should be +/- 1" of the wheel's width; and, when you have a choice, choose a wheel wider than the tire's tread width. For example, if you're going with a PS 4S in 245/35-18 and a tread width of 8.4", go with a wheel that's 8½" or 9" wide. Same with the 255/35-18 and its 8.8" tread width: choose a wheel that's 9" or 9½" wide.

I'm running the 255/35-18 PS 4S with a 9" wheel in front and a 9½" wheel in the rear. That's specific to my setup, though; it won't necessarily fit on your car. FWIW, it's easy to buy wheels and tires that won't fit; ask me how I know.

What difference do tires with tread widths narrower than wheel widths make? That stretches the tire tread to be somewhat wider and flatter than it would be on a narrower wheel. That puts more rubber on the road and makes the car more responsive to your driving inputs. When combined with the negative camber offered by camber plates in front and our cars' available camber adjustment in the rear, basic problems like rolling-over onto the sidewalls and using-up your outside tires' shoulders in front go away.

I'm running camber of -2.6° F and -2.2° R, and on the street I've found the life of my original Michelin Pilot Super Sport tires to be much better than I expected. They've got ~9K on them and still have tread depths of 6-6.5/32nds. I think they've got another ~5-7K more life in them. That's not too bad considering the incredible improvement in handling offered by the negative camber.

[jas00x]

Originally Posted by dradernh

I'm running the 255/35-18 PS 4S with a 9" wheel in front and a 9½" wheel in the rear. That's specific to my setup, though; it won't necessarily fit on your car. FWIW, it's easy to buy wheels and tires that won't fit; ask me how I know.

I'm running camber of -2.6° F and -2.2° R, and on the street I've found the life of my original Michelin Pilot Super Sport tires to be much better than I expected. They've got ~9K on them and still have tread depths of 6-6.5/32nds. I think they've got another ~5-7K more life in them. That's not too bad considering the incredible improvement in handling offered by the negative camber.

Yeah, I've been a long time autocrosser and a long time believer in "wider is better" for tires. My last production-based car was an NC miata setup for STR class. I ran 17x9's with 255 tires. Same deal with the camber- I usually ran 2.7 degrees and tire wear was fine. It seems funny to try to run the much heavier BMW on smaller width wheels and tires

What other mods- besides the camber plates- on your car did you do to get the 255/9" combo to fit up front?
All the stuff I've read about fitment on the 228 is that fender/rub sort of limits how big you can go with the front wheel/tire. typically the inner depth is limited by the shocks. I'm sure I'll learn more this weekend when I install the camber plates.

[dradernh]

Originally Posted by jas00x

Yeah, I've been a long time autocrosser and a long time believer in "wider is better" for tires. My last production-based car was an NC miata setup for STR class. I ran 17x9's with 255 tires. Same deal with the camber- I usually ran 2.7 degrees and tire wear was fine. It seems funny to try to run the much heavier BMW on smaller width wheels and tires

What other mods- besides the camber plates- on your car did you do to get the 255/9" combo to fit up front?
All the stuff I've read about fitment on the 228 is that fender/rub sort of limits how big you can go with the front wheel/tire. typically the inner depth is limited by the shocks. I'm sure I'll learn more this weekend when I install the camber plates.

My build is described here: https://www.2addicts.com/forums/show....php?t=1532418. There you'll see that I'm running Konis up front; which, according to a vendor here, leave more room on the inside than most other coilovers. Along with the negative camber, the fenders are pulled; however, I can't tell that they're pulled by looking at the car, so I suspect that was a relatively minor adjustment. This photo gives one view of the car post-fender pull:

https://www.2addicts.com/forums/show...2&postcount=18.

On the track, I ran Toyo R888Rs in 255/40-17 on 9"-wide wheels in front and it worked. Those tires have a section width of 10.2" and a Rack-measured tread width of 9.2". However, when I finally got around to leaning hard on the car in my last event before retiring from track driving, I took a decent divot out of each front strut and created some rubbing on the front fender liners (strut photo below). Both TC Kline (who built the car) and the race shop I use in Cincinnati said the struts continue to be good to go.

The race shop owner further said: "You know, when wheels get hot enough (and I have no doubt that mine did (see my other posts on brake component temps)), your wheels change shape." I don't know if I replied with this or not, but my first thought was "Who knew!"



None of that rubbing was noticeable from inside the car (i.e., I heard and felt nothing while running the car). Both shops said if I was going to continue running the car, 3mm spacers and a further, minor fender pull and/or a fender liner delete would have stopped rubbing inside and outside.

Same-o, same-o, right – if you're at all trying to maximize performance in some part of the car, there's not necessarily a one-size-fits-all way to reach that goal. If a problem crops up, you bear down and solve it, knowing that with a car driven on the street you have fewer options. IOW, bring patience, plastic, and an upbeat attitude and you will always be prepared for what a modified car throws at you!

Because they measure tread widths, I look at the Rack's data for that as well as section widths to see both how wide the rubber is that (roughly) meets the road and how likely the tire is to not rub on the inside or outside.

As far as what's wide-enough for our cars' stock weight and power, I think a tire in the range of an 8-10" tread-width will work for most drivers. I also think the 7.9" tread width of the OEM Michelin Pilot Super Sport front tires is the bare minimum of what our cars need to show what they can do. A wider front tire is always going to be an advantage when turning-in, reducing speed, or coming to a stop rapidly.

As always, the driver mod comes first if going faster is an owner's goal. This can't be emphasized enough.

[AmuroRay]

Originally Posted by dradernh

My build is described here: https://www.2addicts.com/forums/show....php?t=1532418. There you'll see that I'm running Konis up front; which, according to a vendor here, leave more room on the inside than most other coilovers. Along with the negative camber, the fenders are pulled; however, I can't tell that they're pulled by looking at the car, so I suspect that was a relatively minor adjustment. This photo gives one view of the car post-fender pull:

https://www.2addicts.com/forums/show...2&postcount=18.

On the track, I ran Toyo R888Rs in 255/40-17 on 9"-wide wheels in front and it worked. Those tires have a section width of 10.2" and a Rack-measured tread width of 9.2". However, when I finally got around to leaning hard on the car in my last event before retiring from track driving, I took a decent divot out of each front strut and created some rubbing on the front fender liners (strut photo below). Both TC Kline (who built the car) and the race shop I use in Cincinnati said the struts continue to be good to go.

The race shop owner further said: "You know, when wheels get hot enough (and I have no doubt that mine did (see my other posts on brake component temps)), your wheels change shape." I don't know if I replied with this or not, but my first thought was "Who knew!"



None of that rubbing was noticeable from inside the car (i.e., I heard and felt nothing while running the car). Both shops said if I was going to continue running the car, 3mm spacers and a further, minor fender pull and/or a fender liner delete would have stopped rubbing inside and outside.

Same-o, same-o, right – if you're at all trying to maximize performance in some part of the car, there's not necessarily a one-size-fits-all way to reach that goal. If a problem crops up, you bear down and solve it, knowing that with a car driven on the street you have fewer options. IOW, bring patience, plastic, and an upbeat attitude and you will always be prepared for what a modified car throws at you!

Because they measure tread widths, I look at the Rack's data for that as well as section widths to see both how wide the rubber is that (roughly) meets the road and how likely the tire is to not rub on the inside or outside.

As far as what's wide-enough for our cars' stock weight and power, I think a tire in the range of an 8-10" tread-width will work for most drivers. I also think the 7.9" tread width of the OEM Michelin Pilot Super Sport front tires is the bare minimum of what our cars need to show what they can do. A wider front tire is always going to be an advantage when turning-in, reducing speed, or coming to a stop rapidly.

As always, the driver mod comes first if going faster is an owner's goal. This can't be emphasized enough.

Why did you quit tracking?

[dradernh]

Originally Posted by AmuroRay

Why did you quit tracking?

I'm 72, and it wasn't exciting enough anymore to continue with it. I'd gone from ~25 events a year ten years ago down to 3 per year in 2018 & 2019. 2020 was going to be my last year, but the pandemic put paid to that.

I started out racing motorcycles back in the late 60s, and I've gotten my money's worth, so to speak.

[AmuroRay]

Originally Posted by dradernh

I'm 72, and it wasn't exciting enough anymore to continue with it. I'd gone from ~25 events a year ten years ago down to 3 per year in 2018 & 2019. 2020 was going to be my last year, but the pandemic put paid to that.

I started out racing motorcycles back in the late 60s, and I've gotten my money's worth, so to speak.

I bet you got some cool stories to tell! Seems like the tracks are losing a great guy, because I’ve gained quite a bit from reading a few of your posts on here.

Sorry to thread jack OP - but I always enjoy reading track stories the most. I loved the really detailed geeky analysis, the cliff hangers, track drama and of course the builds. Keep them coming guys.