135i vs. the 1M on a road course - No widebody or tune needed!

[1spirit]

Can the 135i keep up with its sweetly ///M-tailored counterpart, the 1M, at a track like Laguna Seca? With some upgrades, it can...while remaining a comfortable daily commuter.

Our benchmark for comparison is the BMW 1M lap time of 1:43.31 at Laguna Seca established by MotorTrend's Pro Driver Randy Pobst. That's pretty quick - in the E92 M3, Randy managed only 0.35 seconds faster.

The 135i just needs a new suspension, camber plates, LSD, wheels/tires, and better brake pads+pistons. Adding power or installing wider fenders are not necessary to match the 1M!

Properly sized brakes are preferable however... Currently, the car needs to be braked earlier than necessary due to lots of brake fade and pedal softness/dropping - at least quarter of a second in some corners. A bigger brake kit is the next upgrade this car really needs! And of course, more seat time

There is another 2 good seconds to squeeze out in this current setup especially once the brakes are sorted.

My list of upgrades to match the 1M:
-Ohlins R&T with Swift springs
-Quaife ATB Limited Slip Differential
-All E92 M3 arms, bushings, front sway bar
-Vorshlag camber plates @ -2.4
-Apex EC-7 18" wheels, 8.5" front / 9.5" rear
-Hankook R-S4, 235 front / 255 rear
-PFC-08 brake pads
-Racing Brake stainless steel pistons
-Castro SRF brake fluid

I must note: As fast as the 135i can be, it will likely never be as fun to toss around like the 1M...

[Esteban]

As always, love your video and your driving skills. Since I will probably never track my 1er, I will continue to live vicariously through you. lol

[Ric in RVA]

That looks like a whole lot of fun! Wish I could drive Laguna Seca one day.

I see lots of under steer and dialing it back to save the front tires.

I don't think there was any opposite lock applied...the whole way around.

More front tire is going to be very helpful. Maybe a stiffer rear ARB.

Got to get that thing to rotate instead of push.

[1spirit]

Originally Posted by Esteban

As always, love your video and your driving skills. Since I will probably never track my 1er, I will continue to live vicariously through you. lol

Esteban, thank you very much! It brings me great pleasure to share these moments in the 1er and to reveal its possibilities, especially with other owners in this community. This car keeps surprising me and it has been a joy to own and drive both on the street and track. Long live the 1er!

[1spirit]

Originally Posted by Ric in RVA

That looks like a whole lot of fun! Wish I could drive Laguna Seca one day.

I see lots of under steer and dialing it back to save the front tires.

I don't think there was any opposite lock applied...the whole way around.

More front tire is going to be very helpful. Maybe a stiffer rear ARB.

Got to get that thing to rotate instead of push.

Yes, good observation! Constant push through the corners...

I've tried more tire up front (255), and although it reduced some of the understeer, I very much disliked the feel and responsiveness on the 8.5" wheel. Sloppy is one word to describe it.

I'll be happy to run more tire when I can fit a wider wheel up front. Plan is to eventually install the 1M front bumper/fenders to make that work!

I may consider the rear bar but only as a last option...

Totally agree it needs to rotate more!

[c1pher]

Cool, imagine what a basic tune will do.

[Ric in RVA]

Originally Posted by 1spirit

Yes, good observation! Constant push through the corners...

I've tried more tire up front (255), and although it reduced some of the understeer, I very much disliked the feel and responsiveness on the 8.5" wheel. Sloppy is one word to describe it.

I'll be happy to run more tire when I can fit a wider wheel up front. Plan is to eventually install the 1M front bumper/fenders to make that work!

I may consider the rear bar but only as a last option...

Totally agree it needs to rotate more!

Been thinking about that a while. Perhaps the early release of brakes is allowing weight off the front. Maybe try braking later, harder and trail braking into the corner to get it to rotate. Basically sticking the nose down with the brakes and leaving the rear light to allow rotation.

Bigger bars only lessen traction at that axle and I agree stay away as long as you can but you have to get balance and it will transform the car. Having to back off to dial out that understeer is no fun.

Maybe less toe in front and rear too.

[dbronnik]

Dumb comparison, Randy was running on stock MPSS tires..

[ilikebmxbikes]

You need the same driver, both cars, same day.

[WhatsADSM]

Originally Posted by 1spirit

Can the 135i keep up with its sweetly ///M-tailored counterpart, the 1M, at a track like Laguna Seca? With some upgrades, it can...while remaining a comfortable daily commuter.

Our benchmark for comparison is the BMW 1M lap time of 1:43.31 at Laguna Seca established by MotorTrend's Pro Driver Randy Pobst. That's pretty quick - in the E92 M3, Randy managed only 0.35 seconds faster.

The 135i just needs a new suspension, camber plates, LSD, wheels/tires, and better brake pads+pistons. Adding power or installing wider fenders are not necessary to match the 1M!

Properly sized brakes are preferable however... Currently, the car needs to be braked earlier than necessary due to lots of brake fade and pedal softness/dropping - at least quarter of a second in some corners. A bigger brake kit is the next upgrade this car really needs! And of course, more seat time

There is another 2 good seconds to squeeze out in this current setup especially once the brakes are sorted.

My list of upgrades to match the 1M:
-Ohlins R&T with Swift springs
-Quaife ATB Limited Slip Differential
-All E92 M3 arms, bushings, front sway bar
-Vorshlag camber plates @ -2.4
-Apex EC-7 18" wheels, 8.5" front / 9.5" rear
-Hankook R-S4, 235 front / 255 rear
-PFC-08 brake pads
-Racing Brake stainless steel pistons
-Castro SRF brake fluid

I must note: As fast as the 135i can be, it will likely never be as fun to toss around like the 1M...

Yea doesn't surprise me at all. The 135i has "great bones" doesn't take much to make it outperform its M counterparts. Of course they can upgrade as well, but the big advantage here is simply how cheap it is to get into a 135i.

As always I love the videos and good driving


About the brakes. Consider brake ducts and possibly an F30 335i front swap. Cheap and very effective.

[WhatsADSM]

Originally Posted by 1spirit

...

I must note: As fast as the 135i can be, it will likely never be as fun to toss around like the 1M...

Originally Posted by Ric in RVA

That looks like a whole lot of fun! Wish I could drive Laguna Seca one day.

I see lots of under steer and dialing it back to save the front tires.

I don't think there was any opposite lock applied...the whole way around.

More front tire is going to be very helpful. Maybe a stiffer rear ARB.

Got to get that thing to rotate instead of push.

Yea I think these two comments go hand in hand. There shouldn't be a reason that the 135i should be inherently any less fun to toss around than a 1M. Persistent understeer however will do that.

I echo the rear bar comment. For some reason that seems to be a mod few try around here. Another option is to re-adjust the sprint rates. Most of the kits are a bit to heavily sprung in the front versus rear. OP what are your current spring rates?

Originally Posted by dbronnik

Dumb comparison, Randy was running on stock MPSS tires..

He is also a professional driver
It's always weird to me that people think its surprising that a 135i with a few mods can perform the same or better than a 1M. Would it surprise people if a modified naturally aspirated FWD civic does so too??

[1spirit]

Originally Posted by MGM135is

Cool, imagine what a basic tune will do.

With a basic tune, I imagine the car will break 1:40 along with wider tires (without the use of R-compounds) and a front BBK.

[1spirit]

Originally Posted by Ric in RVA

Been thinking about that a while. Perhaps the early release of brakes is allowing weight off the front. Maybe try braking later, harder and trail braking into the corner to get it to rotate. Basically sticking the nose down with the brakes and leaving the rear light to allow rotation.

Bigger bars only lessen traction at that axle and I agree stay away as long as you can but you have to get balance and it will transform the car. Having to back off to dial out that understeer is no fun.

Maybe less toe in front and rear too.

Yes, aggressive trail-braking is a must to help rotate this car. If you closely watch right foot in the video, I tried that for as long as possible without scrubbing off too much speed in each corner. Maybe I could do more?

However, I experienced a ton of brake fade (and a deep drop in the pedal) so it was quite a challenge to brake later without going into the corner too hot and missing the apex.

Another important task is managing the brakes for consistency throughout the entire length of the session and to have them last the rest of the day! Hard to do that when going nuts on the brakes lol.

I can see the stiffer rear bar helping quite a bit for autocross, but not really for the track. Some even run without a rear bar for more rear stability in the higher speed corners. I believe Scott Cary raced the 135i successfully without one.

A larger wheel and more rubber up front may be all that it needs to dial out enough understeer. A 265 square setup on 9.5” wheels might be the recipe.

I already run very low toe-in both front and rear (0.06” or less).

[1spirit]

Originally Posted by dbronnik

Dumb comparison, Randy was running on stock MPSS tires..

The intent was to simply make an enjoyable video and give hope to other 135i owners who may wish they had a 1M. Sorry if you were expecting anything more! You’re right though…it’s not the best comparison by any means.

Regarding MPSS, don’t discount it…it’s a fast tire! Actually not much slower than the Hankook, if at all, at the right temperature. The main difference is the window of time for optimum grip at the track which is much shorter. Like 3-4 hard laps on MPSS as opposed to 10-12 consecutive hard laps with the R-S3 or R-S4 at a sub-2min track. The MPSS can’t handle the heat and wear out very quickly, but if you can get into rhythm quickly and produce a nice flying hot lap before that happens, the grip is very close to the Hankooks.

With that said, I’m sure Randy’s skill and experience more than makes up for any difference in performance that these two tires may have!

Comparing tire/wheel sizes:
The MPSS on the 1M were 245 / 265 on 9.0” / 10.0” wide wheels (diameter 19”).
The R-S4 on the 135i were 235 / 255 on 8.5” / 9.5” wide wheels (diameter 18”).

[1spirit]

Originally Posted by ilikebmxbikes

You need the same driver, both cars, same day.

For sure, I second that.

[1spirit]

Originally Posted by WhatsADSM

Yea doesn't surprise me at all. The 135i has "great bones" doesn't take much to make it outperform its M counterparts. Of course they can upgrade as well, but the big advantage here is simply how cheap it is to get into a 135i.

As always I love the videos and good driving

About the brakes. Consider brake ducts and possibly an F30 335i front swap. Cheap and very effective.

Under $15k for a used 135i plus around $10k for the mentioned upgrades…and you have a great dual-duty car that is still very comfortable for daily use and can drive for long periods on road trips with lots of cargo!

And if I had a 1M, I think I would keep it stock. I probably wouldn’t want to change its nature in any way! The handling seems perfect - both fast and loose. If I owned both cars, the 135i would become the faster car on the track for sure.

Thanks!

I have tried brake ducts, but it only allows me to run a little longer before the heavy brake fade settles in. It seems rotor size is too limited and too small to begin with. The brake ducts are also a pain to drive with on the street.

Originally Posted by WhatsADSM

Yea I think these two comments go hand in hand. There shouldn't be a reason that the 135i should be inherently any less fun to toss around than a 1M. Persistent understeer however will do that.

I echo the rear bar comment. For some reason that seems to be a mod few try around here. Another option is to re-adjust the sprint rates. Most of the kits are a bit to heavily sprung in the front versus rear. OP what are your current spring rates?

He is also a professional driver
It's always weird to me that people think its surprising that a 135i with a few mods can perform the same or better than a 1M. Would it surprise people if a modified naturally aspirated FWD civic does so too??

Current spring rates are 392lbs/in front and 672lbs/in rear.

There does seem to be a common misconception that a tune and/or wider fenders are necessary to keep up with the 1M at the track. I made the video to help dispel that.

If that said civic was still pretty comfortable to drive and you can fit 4 wheels & tires, 2 suitcases, 2 golf bags, a cooler, and a passenger…all inside the car? Yes, it would surprise me!

The 1er is special!

[dbronnik]

If you want 1M performance, do it properly with an M3 rear axle, differential, subframe, etc. You can build a legit 1m clone for much less than the cost of an original, especially if you skip the rear fenders (you can run 275 square without bothering with that).

I used to run a similar setup to you but with 275 square RE71s before I did the M3 subframe/diff swap and it's a night and day difference in feel/performance.

[1spirit]

Originally Posted by dbronnik

If you want 1M performance, do it properly with an M3 rear axle, differential, subframe, etc. You can build a legit 1m clone for much less than the cost of an original, especially if you skip the rear fenders (you can run 275 square without bothering with that).

I used to run a similar setup to you but with 275 square RE71s before I did the M3 subframe/diff swap and it's a night and day difference in feel/performance.

The idea is to pour the least amount of money possible into this car. Those parts you mention are all nice to have but they are not necessary to match the 1M performance. Really, all that the 135i needs now is better brakes. Once it has the wider wheels up front, it will surpass the 1M on the track. And this is before adding a tune.

I know a fast driver in a 135i who upgraded to the M3 subframe/diff but unfortunately it didn't translate to any improvement on the track. The Quaife/Torsen is better than one may think. Plus no maintenance!

Personally, I'd rather save the money and spend as much as I can on driver improvement (coaching/education) and more seat time.

[WhatsADSM]

Originally Posted by 1spirit

I have tried brake ducts, but it only allows me to run a little longer before the heavy brake fade settles in. It seems rotor size is too limited and too small to begin with. The brake ducts are also a pain to drive with on the street.
.

Few things:
1) Just making sure you have coded out the DSC nannies.
2) With the right brake duct setup you can run them 24/7 on the street with no issues lock to lock
3) The F30 335i setup I mentioned does come with different disks. I used the 340mm setup which is only 2mm larger diameter but like 4mm thicker! Dramatic difference in thermal capacity. Thickness is paramount in brake thermal performance. Additionally the setup is plug and play, and the calipers can be found dirt cheap used. (IIRC I paid like $240 for a set of grey ones from a junkyard. Came from a 2015 car with like 10k miles on it and even included a set of stock pads I use on the street). Once I get around to selling my stock 135i brakes I think I'll make money on the deal!

... and yes you are correct the civic would suck to live with on the street likely

[dbronnik]

Originally Posted by 1spirit

The idea is to pour the least amount of money possible into this car. Those parts you mention are all nice to have but they are not necessary to match the 1M performance. Really, all that the 135i needs now is better brakes. Once it has the wider wheels up front, it will surpass the 1M on the track. And this is before adding a tune.

I know a fast driver in a 135i who upgraded to the M3 subframe/diff but unfortunately it didn't translate to any improvement on the track. The Quaife/Torsen is better than one may think. Plus no maintenance!

Personally, I'd rather save the money and spend as much as I can on driver improvement (coaching/education) and more seat time.

It's a lot less expensive than you think. The whole front end conversion can be had <3k (very easy to DIY) and all the parts for the functional swap can be had for 3-4k off a wrecked M3 (not very easy to DIY). Sure it's still more money but it's a hell of a lot more car too.

As far as the saving money for driver mod is concerned, you're right. But you're far better off buying a cheaper car (miata, e30, brz, etc) and investing in safety equipment than tracking the 135i Lockton track insurance will be cheaper too.

[ilikebmxbikes]

Originally Posted by 1spirit

Personally, I'd rather save the money and spend as much as I can on driver improvement (coaching/education) and more seat time.

I credit your driver mod as the largest factor in your comparison. It would be awesome to see you drive both a 1m and a 135i and get your impressions on both.

[MightyMouseTech]

To help with understeer, would be running a lot more that -2.4 in the front. Closer to 3.5-4.0 would be better IMHO.

Very enjoyable thread BTW.