[peelerec]

I am going to share my thoughts on the handling performance of my G20 M340i at Streets of Willow.

https://www.willowspringsraceway.com...illow-springs/

1st time at The Streets January 2022:
-100% stock
-2 week old car still in break in period
-225/19 square pirelli pzero run flats

Feedback: As I was driving conservatively due to still within the break in period, I was initially impressed with the grip and driving dynamics the M340. Keep in mind I had just traded in my G20 330i.

After three sessions of driving extremely slow and just learning how the car responds to tight corners, I was quite pleased with all aspects of the M340 stock. Traction control was turned on 100% during the day.

I wouldn’t really consider this a “track day” as I really was only there to drive my car and just take it around some turns for some fun spirited driving and not deviate from break in recommendations.

My only serious concern was that I was having brake fade by lap 4 of each session even though I was driving conservatively. This shocked me to say the least. I did not feel confident in pushing the car any harder for this sole reason.

2nd track day at The Streets August 2022:
Car setup:
-Dinan Intake + Strut Bars
-AA Catted DP
-MPE
-Dinan Monoballs
-Dinan Springs
-19” 791M wheels w/ 245/35/19 PS4S square
-Hawk HPS 5.0 pads and Motul fluid

Feedback: The car had huge amounts of grip with the PS4S. Again, I was really conservative in simply trying to have a fun time, learn the lines. The only gripe I had was the car definitely felt heavy and sluggish due to the various grades of the track and slight elevation. I feel the car really needs to be much stiffer and lighter in order to push for the fastest lap time. Albeit, this was not my goal in just learning my car and how it responded to the intricate short road course of The Streets.

3rd track day at The Streets December 2022:
Car setup:
-Dinan Intake + Strut Bars
-AA Catted DP
-MPE
-Dinan Monoballs
-Dinan Springs
-19” 791M wheels w/ 245/35/19 Pirelli PZero Run Flats square
-Hawk HPS 5.0 pads and Motul fluid

Feedback: I was invited last minute to a private event and was extremely cheap so I said why not, well knowing I had my “winter tires/road trip” tires installed.

Again, my approach was to be conservative and have fun since I knew the Pzero’s ….. for the lack of a better word, SUCK compared to the PS4S. The Pzero were absolutely fine for a road trip run flat. However, my fun, conservative sessions were cut extremely short since the Pzero could not maintain grip with traction on, dynamic traction, dsc off. Totally uninspiring and practically had me driving like a grandma all laps. 10/10 don’t recommend with this tire, lol.

[jmg]

I’ve been to Streets many times. No surprise the PZeros were not great. They aren’t track tires!

MPS4S are decent, especially the BMW * Spec, but they will chunck if you push too hard with too much heat.

I would look into RT660, or RE71R for more grip.

Pads are a must, and 4 laps is about right for factory M pads. Get some Castrol SRF fluid too.

Did you record any lap times?

[peelerec]

Originally Posted by jmg

I’ve been to Streets many times. No surprise the PZeros were not great. They aren’t track tires!

MPS4S are decent, especially the BMW * Spec, but they will chunck if you push too hard with too much heat.

I would look into RT660, or RE71R for more grip.

Pads are a must, and 4 laps is about right for factory M pads. Get some Castrol SRF fluid too.

Did you record any lap times?

I’m considering RT660 and/or Cup 2. I have a couple RX-7 buddies who swear by the RT660. I may try both on my next set of tires once these PS4S are finished.

Yes, pads are absolutely a must. I should’ve mentioned that. I’m on hawk HPS 5.0 and Motul fluid.

No lap times as I really am just patiently learning the vehicle and how to drive properly on a road course. To be frank, at my slow learning curve, I would probably have negative results with timing. The plan is to add one of those neat Garmin Catalyst Driving Recorders eventually.

[jmg]

Originally Posted by peelerec

I’m considering RT660 and/or Cup 2. I have a couple RX-7 buddies who swear by the RT660. I may try both on my next set of tires once these PS4S are finished.

Yes, pads are absolutely a must. I should’ve mentioned that. I’m on hawk HPS 5.0 and Motul fluid.

No lap times as I really am just patiently learning the vehicle and how to drive properly on a road course. To be frank, at my slow learning curve, I would probably have negative results with timing. The plan is to add one of those neat Garmin Catalyst Driving Recorders eventually.

I have a Catalyst and it’s a pretty great tool for fast and simple for post-session data analysis. I also use an app called Race Chrono paired with a witeless OBD reader for a little more metrics.

Cup2’s are great, they are just super $$ and won’t last more than a few track days. I’m running that currently.

[peelerec]

Originally Posted by jmg

I have a Catalyst and it’s a pretty great tool for fast and simple for post-session data analysis. I also use an app called Race Chrono paired with a witeless OBD reader for a little more metrics.

Cup2’s are great, they are just super $$ and won’t last more than a few track days. I’m running that currently.

Good to know on the app paired with catalyst, thanks!

[thnsteven]

Originally Posted by jmg

I’ve been to Streets many times. No surprise the PZeros were not great. They aren’t track tires!

MPS4S are decent, especially the BMW * Spec, but they will chunck if you push too hard with too much heat.

I would look into RT660, or RE71R for more grip.

Pads are a must, and 4 laps is about right for factory M pads. Get some Castrol SRF fluid too.

Did you record any lap times?

Can you put Castrol SFR into m340i? The factory one is using low viscosity while Castrol SFR probably has normal viscosity.

[jmg]

Originally Posted by thnsteven

Can you put Castrol SFR into m340i? The factory one is using low viscosity while Castrol SFR probably has normal viscosity.

Yes, viscosity decreases as heat increase. So in track conditions, factory brake fluid will actually start to boil and vapor lock, which decreases its effectiveness to apply hydraulic pressure to the pads and can lead to increased braking distance or failure.

On the street, where brakes do not reach higher temps, higher viscosity fluids like Castrol SRF will result in a slightly slower brake response. However, your brake system will be fine. Using a higher viscosity brake fluid won't damage it, it only changes how fast the fluid can transfer hydraulic pressure.

Pair race fluid with track pads and you have a noticeable drop in response and effectiveness with cold brakes.

It's definitely a trade-off, but personally, I'd rather not have potential brake failure at high speeds on the track.

[thnsteven]

Originally Posted by jmg

Yes, viscosity decreases as heat increase. So in track conditions, factory brake fluid will actually start to boil and vapor lock, which decreases its effectiveness to apply hydraulic pressure to the pads and can lead to increased braking distance or failure.

On the street, where brakes do not reach higher temps, higher viscosity fluids like Castrol SRF will result in a slightly slower brake response. However, your brake system will be fine. Using a higher viscosity brake fluid won't damage it, it only changes how fast the fluid can transfer hydraulic pressure.

Pair race fluid with track pads and you have a noticeable drop in response and effectiveness with cold brakes.

It's definitely a trade-off, but personally, I'd rather not have potential brake failure at high speeds on the track.

Got it. Thanks mate.
So basically low viscosity for street use and normal viscosity for track use

[Dan B]

Originally Posted by thnsteven

Got it. Thanks mate.
So basically low viscosity for street use and normal viscosity for track use

Important note, DOT 4 and 5.1 are glycol and DOT 5.0 is silicone.

If you change from the stock fluid to a silicone based like the DOT 5 Castrol SRF, you will need to flush the system very thoroughly with the Castrol to remove all traces of the stock glycol based fluid.

[thnsteven]

Originally Posted by Dan B

Important note, DOT 4 and 5.1 are glycol and DOT 5.0 is silicone.

If you change from the stock fluid to a silicone based like the DOT 5 Castrol SRF, you will need to flush the system very thoroughly with the Castrol to remove all traces of the stock glycol based fluid.

Noted, thanks mate

[Z K]

Originally Posted by Dan B

Important note, DOT 4 and 5.1 are glycol and DOT 5.0 is silicone.

If you change from the stock fluid to a silicone based like the DOT 5 Castrol SRF, you will need to flush the system very thoroughly with the Castrol to remove all traces of the stock glycol based fluid.

Castrol SRF is DOT 4 and compatible with all DOT3/4/5.1 fluids.

[Dan B]

Originally Posted by Z K

Castrol SRF is DOT 4 and compatible with all DOT3/4/5.1 fluids.

Thanks for the correction, it is DOT4.

It can be mixed but the performance will be reduced to the current fluid rating. It is recommended to flush the system.

[Antares713]

This whole break-in period. Has there been any actual concrete studies done to verify a break-in period even exists? I think people just like using the term in general within a conversation.
Reminds me of the word Goretex. Its fun just to say and people want to use it whenever they can.

[Dan B]

Originally Posted by Antares713

This whole break-in period. Has there been any actual concrete studies done to verify a break-in period even exists? I think people just like using the term in general within a conversation.
Reminds me of the word Goretex. Its fun just to say and people want to use it whenever they can.

Are you talking brake pads or engines?

Yes to both.

[peelerec]

Originally Posted by Dan B

Are you talking brake pads or engines?

Yes to both.

I think that post was either spam or responding to the incorrect thread.