the weather is looking up for the upcoming HPDE

a cool day will keep Mini very happy

 

mini is a camera hog



The new-to-me front racking brake pads are Hawk with HT-14 compound. I have no prior experience with high performance brake pads biased to track use. I was pleasantly surprised they provide similar bite like the stock pads when cold. I was expecting them to be very hard and lack bite when cold, hence dangerous for road use. I eagerly want to find out how they are like on road, and on track.

HT-14 is the red curve in the graph while the OEM (stock) is the light grey


I waited for the traffic to get light to go for a more thorough test drive, and to begin bedding them into the uneven worn surfaces of the rotors.



On safe stretches of road I heated up the brakes by applying throttle and brake - such a unnatural thing to do. I also repeated some modestly hard braking. Unlike the stock pads, these pads respond with increased bite as the temperature rises.




On the return trip I did a few more aggressive braking and the brakes bit well. There was only a hint of noise. Arriving home I grabbed the IR thermometer and checked the temperature. The rotors was around 260 F. Based on this I had experienced the entry grip temperature range of these pads. Naturally this trip only give me a taste of how the brakes feel at the low side of the grip/temperature envelope. I am eager to experience them on the track.

 

Always cool reading your updates. You are very thorough!

 

Thanks. I learnt long ago mistakes are expensive so I try. Often the difference in the initial investment is just a bit more due diligence and willingness to ask questions.

 

It was only after I was committed to my modest $35 investment on the set of HT-14 Hawk pads that I found this PDF. It has a nice summary of their offerings of different brake pad compounds.



Visually the HT-14 pads look strikingly similar to the OEM pads but with more metal particles. I infer it is old school pad composition.



I've learnt a lot recently from being observant at the track of what seasoned drivers do. The biggest bang for the buck for brakes is to invest in a good set of pads and use with your stock calipers and rotors, and a set of SS lines. For me I am still using the stock bungee cord rubber lines.

 

I went to the HPDE day at PIR. My friend and I both wanted to have one more track day to wrap up the season. It is a day designed to maximum the time on the track. Each run group gets 120 minutes of driving, which is a lot.

this panoramic was taken when I arrived at 7:00 AM so not all the cars has arrived



my NAM buddy's red Mini and the yellow Lotus we befriended



this is a monster Mini with a lot of RMW rare go fast parts - the owner said it produces just south of 400 HP










the front of the monster Mini that I got to ride in for a few laps





we also have good chats with these folks - an AMG Mercedes Biturbo and a Carrera S with PDK both ran in our group


this Lotus must be the fastest in our run group that day


I have been seeing a lot of BRZ and its rebadged siblings at the track this year






I have seen this same GT4 Clubsport at PIR many times now





I generally travel light to the track


Nissan GTR


Carrera 4S


as always there are many Vettes


we finished at about 5pm

 

I wanted one more track day to wrap up the season because I felt that I had not a chance for some clean laps to establish my best lap time for the season. Up until before the last track day, I only had one session in which I have an instructor riding with me.

In the last track day in early September my instructor friend rode with me for two sessions. I then rode with him for a few laps. I wanted to have the last session for the day to put what he told me to practice. Unfortunately the track in the last session was doused with motor oil at turn 10 through 12.

This past Saturday I signed up with one last HPDE day, which promised to have a lot of time on the track. This would be my 5th full track day in my life all counted. We got 120 minutes for each run group, which is a lot of intensive driving. I had my best time ever in which I improved my time by an average of 3.5 seconds. It is immense by most measures.

here is my best lap in early September 1:40.60

here is my best lap this past Saturday 1:38.17

here is a longer video with laps that bracketing the fastest lap (lap 15)

After my instructor friend gave me the coaching I only have a vague notion to reach ~1:38 but I have very little idea how hard the climb it would be. I just didn't know. To close out the season with 1:38.17 is my wildest dream come true. I was the fastest Mini in our run group where there were three R53s.

 

Driving on the track tax the car much more than one would ever driving on public road, as I found out from personal experience. It is extremely important to perform detail pre and post track day mechanical inspections. The heat, mechanical stresses, shocks, and vibration put the parts to their extreme limits. The most dangerous is fasteners loosen from shocks and vibration. There are many things I took for granted until I discover their vulnerabilities when pushed to the limits.

I always check the torque of the wheel lugs before and after a track event. They have been fine until after this most recent track event. I wanted to check them at the track but I didn't bring the torque wrench with me. In my post-track day inspection, I was very surprised to find a few of the front wheel lugs has lost their torque. I had brake much later and harder at the end of the straights from speed in excess of 100 MPG down to circa 40s.

The other thing that I discovered is how hot the floor of the boot is after a track session. I found out the high density Styrofoam tool kit container in the batter box has melted from the heat of the floor. The metal floorpan about the muffler is so hot that it burns the hand.

the small tool kit tucked next to the batter in the battery box


the styrofoam container was melted by the heat from the muffler and tailpipe under the boot floor





MINI engineers has placed heat shields to protect the boot floor as well as the battery box


the last 1.5 foot of the tailpipes are the only spot that are not protected by heat shield


Also in the last track day the muffler pipe joint worked loose leading to sagging tail pipe which rested on the battery heat shield. I realigned the muffler/tailpipes and tighten the muffler pipe clamp before the track day. Less than half way through the the event the joint is loose again, and I wonder if the U-shape steel clamp had grew red hot and stretched, or just the two nuts has worked loose. It is impossible to tell after the fact. This time I added two nuts to act as lock nuts.

I added two nuts to lock the two nuts.


here shows heat shields by the muffler



this shield for the battery box looks to be more of a splash gaurd rather than a heat shield, and I think it traps heat and leads to hotter battery box


I was worrying the heat might melt the plastic bumper cover





I noticed a few drop of liquid on the driveway. It turned out is engine oil. I was alarmed. My immediately thought is may be the compression fitting for the mechanical oil pressure gauge had worked loose from extreme vibration and rocking of the engine.

a few drops of engine oil


I notice that the connector for the factory oil pressure switch is charred - obviously from the radiant heat emitted by the exhaust feeder pipes. I have no doubt after mostly sustained wide open throttle driving on the track the header pipes must be glowing red hot.

the charred connector for the factory oil pressure switch


I believe the reason the connector is charred is due to my installation of a oil pressure gauge pickup fitting. In order to add the oil pressure gauge pickup I had to install a T-adapter fitting, which pushed the oil pressure switch and its connector farther away from the engine by about 1.5 inch. Just this subtle change of the location vastly increases the exposure to the irradiated heat from the feeder pipes.

The other thing that alarmed me is the cause of the engine oil leak. It is not from the compression fitting for the oil pressure gauge. It is from the pipe thread of the T-adapter that screws onto the oil filter housing. Because of the tight confine of the location, the T-adapter must be installed with the extra tap facing 11 o'clock I did not tighten the adapter as tight as I would like for the fear of breaking the aluminum oil filter housing. I relied on the teflon tape to take up the looseness of the threads.

The heat and vibration stress from the track as well as the engine oil acting as excellent lubricant on the teflon and metal mating surfaces caused the fitting to become so loose that I could turn it with my fingers. My initial thought that may be the teflon tape has been dissolved by the engine oil turned out not to be the case.

the teflon tape held up just fine to the engine oil and heat


with the advise of my ME friend I drove to Napa Autoparts to buy a $15 tube of special automotive thread sealant; it turned out I do not like the product over generic household teflon tape


here is a better view of the charred connector of the oil pressure switch


The problem with the T-adapter is, to install it with adequate torque I will have to tighten it one half turn in order to orientate the compressing fitting for the oil pressure gauge at 11 o'clock. I am very wary in doing so I might fracture the aluminum oil filter housing.

alarmed by the charred connector I removed the T-adapter and put the oil pressure switch back into the factory configuration


I covered up the for-now defunct oil pressure pickup compressing fitting and zip-tied it securely until I can decide what to do.


The next thing is to inspect all the tyres and rotate them. I always read the tyre wear after a track event.

left front (left) and left rear (right) side by side so I can see the outer shoulder wear


the center thread of these tyres took a beating and a slant is worn on it, while the outer shoulder wear is not excessive





here is a better view of the slanted center thread; these tyres only had 2 1/2 track days




the right rear (left) and the right front (right)


On thing that I like in reading the tyres is the right side tyres wears are very close to the left side counterparts. Portland International Raceway is a clockwise track so the left side tyres should wear significantly more than the right side.

I performed a X-pattern rotation on the tyres to even out the wears. These tyres are asymmetrical but bidirectional.

Mini's rear suspension has the colours of German flag - black, red, yellow


The next task of business is to inspect all the brakes.

the front racing brake pads has lost about 1/4 of the friction material in just one track event


the pads for both rear brakes are considerably worn from having to keep up with the front brakes, and that I braked harder and later during this track day





Mini consumed about 1 3/4 tank of petrol for about 145 miles of intensive driving



I topped up with Costco cheap (price wise) fuel so I can more accurately calculate the MPG at the track. My rough calculation of the fuel that I put in in three occasions worked out to about 20.5 gallons consumed based on 161 miles results in 7.85 MPG on the track!



I should add that as soon as I saw the few drops of oil left on the driveway I look under the engine too and confirmed some wetness. I immediately check the oil level, and it was only down 1/4 quart if at all on the dipstick. So Mini is absolutely fine.

As I wrote above that I was reluctant to tighten the T-adapter fitting for the oil pressure gauge pickup for the fear of breaking the aluminium alloy oil filter housing. I went and look for a good closeup photo of it for a better look how strong it is. I found one from back in May when I did the drivetrain modifications.

the threaded boss of the oil pressure switch seems to be strong enough to take a half more turn without causing any harm; it is a $375 part if I break it plus the PITA factor

 

A Miniac who also has tracks her R53, took these video at the chicane. There are three R53s in the same run group. We all friends now - or I should say frenemies. We were braking from over 100 MPH down to about 45 at the chicane (turn 1 and 2) and accelerate through turn 3 to about low 80s by turn 4.

 

I had never been black flagged up until this past Saturday. That day I got my first - not one, but 2 in the same day. The pepper white street car named Desire was the black sheep amongst the herd of Mini's.

here is a video when Mini went offroading into the pasture; it is Desire's first spinning out

 

Now that the rainy season has started, I have time to begin think of a few enhancements that I may make to the Mini. Some of these are from my experience of driving the Mini on the track hard that I discovered something that I would not have otherwise.

First is the brakes and suspensions. I am extremely pleased with the modest investment in the suspension modifications. These upgrades not just made the car better on the track, but also improves handling and even ride comfort on the roads. I cannot say enough good things how spot on is the design of the Swift Spec-R Sport Springs. The modest drop in ride height is just right given that our cars have to content with all sorts of challenges on public roads, and driveways.

• Swift Spec-R Sport springs
• Koni Yellow dampers
• IE fixed camber plates
• Alta 22mm rear sway bar
• Hotchkis rear lower adjustable control arms

For the rear lower control arms, I have left it at the same lengths as the factory fixed arm. My hunch and how the car drives tell me the modest drops in front and back ride height the alignment should not be too far off. I performed a rudimentary poor man’s alignment check and the front and back wheel cambers are very close.

In the two most recent track days, I have been braking later and harder at the end of the straights, and from higher top speed than any previous experience. In the last track day I use a set of Hawk HT-14 front racing pads. Because of all these the ABS activated a lot. I also experience rather strong front end shake braking so hard. I initially thought this was mostly due to pad lining transfer to the front rotors when I abused the stock pads. However with the Hawk pads which all but cleaned up any trace of the lining deposit on the rotors, I know the cause is something else.

I suspect the cause of this front end shake is due to two causes. The first is the factory rubber bushing for the front control arm. While there is no perceivable steering or handling shortcoming, I think under extreme hard braking the flexible bushings leads to temporary change in front wheel toe – resulting in excessive toe out. The shakes is probably the result of a sequence of toe change oscillations. While at the track I wanted to check the wheel lug torques for I was concern they may have worked loose. I didn’t because I didn’t bring the torque wrench with me and my friend who has one had converted to hex head lugs so I couldn’t use his.

When I performed the post track day inspection, I would found 2 of each front wheels lugs had loosen slightly – may be by 10 footpound max. This has never happen before.

In addition to the control arm bushing, I suspect the other contributor to the front end shake under heavy braking is the strut tower flex. I have no strut tower brace and I have been wanting to take a wait and see before investing in one. Over the off season I plan to install a set of Powerflex bushings for the front control arms. As for the strut tower brace, I would like to have some basic idea on the extend of the movement but that will require first invest in a brace to instrument up some sort of measurement.

I should mention I find the Mini’s electro-hydraulic assisted steering excellent on roads and especially on tracks. In turns at the edge of tire adhesion there is no shortage of steering feedback and the weight (torque feedback) is just right for me. I do not feel there is any need to increase the caster to get more steering torque.

I set the Alta 22mm rear sway bar at the softest setting. The car has very little tendency to push though at time there is a hint. For wet road safety I have so far want to leave it at this setting especially to get over this coming wet seasons. Next season I would likely to experiment with the more aggressive settings (medium and stiffest) to get a bit more rotation tendency.

In advance of next season I plan to:

• Replace the front control arm bushings with Powerflex
• A good strut tower brace
• Wilwood 11.75 inch front big brake kit
• Steel braised brake lines for front and back calipers
• More aggressive brake pads for the rear stock calipers
• Milltek cat back exhaust

I have a set of JCW 380cc injectors that I am waiting to try out. However I want to install a wideband A/F gauge before I do that so I can find out the difference between the stock 330cc versus the bigger injector.

I have so far not mention the Exedy single mass flywheel and clutch kit that I install. For about the same price as the very popular Valeo I am very happy to have taken the road less travelled, while I have never driven with Valeo. The Exedy flywheel is a few pound lighter, and about 1/3 lighter than the stock dual mass flywheel/clutch all counted. The difference in the throttle responsiveness is very pronounce. The Mini engine now feels like a race engine as the RPM spools up so much faster, which is very important when you have to heel and toe from 113 MPH down 2 or 3 gears as fast as the brakes and tires can decelerate the car.

One reason that I chose Exedy over Valeo is I was hoping for a heavier clutch pedal. It turns out the Exedy is very close to the stock Luke clutch. Despite the pedal being lighter than I’d like there is no shortage of clutch grip. In retrospect now knowing the rather light duty of the MINI’s plastic release bearing I can understand why, stock, Valeo and Exedy all have light pedal. The only aftermarket clutch/flywheel kit that I know that has a strong release bearing to go with the race performance clutch is OS Gekin. The Exedy clutch engages noticeably more crisply than the OE Luke clutch which feels vague. It is too bad the Exedy single mass flywheel and clutch kit is not more recognized due to some incorrect information (unintentionally) disseminated here on NAM. Before I settled on the Exedy kit, I was looking at $1000 clutch kits and I am very glad of my final choice.

What I especially like about the Exedy clutch kit is the feedback of the drivetrain vibrations as well as the pleasant kind of sound. The Mini just feel more communicative to me. There is ever slight increase in vibration on the steering wheel but far from triggering rattles of the interior. Turning on the AC in the hottest summer day does not induce unpleasant vibrations. It just adds the right amount of rawness to the Mini which it deserves. Together with the excellent suspension and brakes, and the modest increase of engine output all comes together as a very balanced whole, on roads and on tracks. I now seldom drive with the car audio on as the Mini is such a treat to drive.



you can find much lower price than the list price shown on Exedy's direct sale site

 

Pads for the wilwood are much cheaper too, I just installed the 11.75 4 piston kit last night, test driving tonight

Abs is more a function of tire grip, I can abs on street pads or race pads the JCW fronts have plenty of torque but I overheated mine and went through pads every 2 events

 

One best thing about the Wilwood 11.75 kit is easy pad change. I withhold installing mine because of mechanical interference with my soggy PNW rainy wheels, and I didn't want my not so worn rotors and pads go to waste.

I trigger ABS on street if I drive spiritedly even with stock brakes. Pretty hard to tax these brakes and tires except my wallet:



I am madly in love with my slow Mini. I love the allure of driving a slow car fast.

 

Milltek cat back muffler is coming, before the winter comes. The soggy season has started here right on time on the first day of autumn.

There is nothing that I do not like about the factory cat back with the one-ball modification. If I were to pick one thing I dislike the most about the Mini design, the soda can tail pipe tips win hands down. I have always like the Milltek exhaust but taking off a perfectly good muffler is such a waste. I am however at the quandary of if I want to put nice parts into the Mini it make more sense to do it when the car is in its prime. The sportier tone of the exhaust would give the Mini a bit more character especially on the track.

The 10% off promotion sealed the deal and I ordered the non-resonated version. I think it is a better choice not to have a big lump of red hot cylinder under the gear shift mechanism.

Such a shame that I put so much work into the one-ball exhaust.

non-resonated Milltek


weather outlook is great when the shipment arrives


All I can wish for is a trouble free installation and fitment. With aftermarket exhaust system you just never know. There is nothing more annoying than exhaust parts rubbing against or hitting any part of the car.

 

I tested the wilwoods last night, they feel like stock so that's a big+ because I like how the jcw fronts work. Pad changes are incredibly easy no more excuses street driving race pads

 

I gather you got the plain vanilla black caliper kit too? Driving race pads on street can be dicy especially when winter is coming, and easy pad change is one major benefit.

 

Yeah plain kit no dust boots to melt

 

Mine has no drill, no slot. Just the way I like it. I am cheap and contrarian.

 

drilled are a big no no they crack between them. I have slotted, I thought the solid did not have as many cooling vanes or as much mass

 

I think you are right about solid vs slotted, which I later would read about in fine print. Product positioning at work. I got mine at a price that I could not pass off. If I am on a tight budget, stock brake with race pads would go a long ways. It is a slippery slope.

 

my jcw fronts with g-lock r12's only last 2 weekends, and it's 200$ per set. I cant keep spending 50 $ per day on brake pads.

The wilwoods cost just a tad over half, and they are vented better with the 2 piece design so I should get a lot better pad life and it cut the cost in half even if the wear is still bad.

I got mine at a big discount

 

^

 

I just had a cold sweat moment thinking my mind is on the way out. Which Wilwood BBK do I have, and 11.25 inch seemed foreign to the feeble storage bank?

I was quite sure I maximize the space capacity of the 16" SSR type-C wheels. I had to refer to my record of the order. I have the plain Jane 4-piston with 12.19" rotors.

perfect fit with the SSR


not so fit with the x-lite


The racier looking kit with drilled and slotted is identical to my cheapskate version except the color of the caliper and the drilled and slotted. No difference in the rotor blanks and the brake pads that are kitted. The MSRP difference is $200.




BP-10 pads should be good for street too

 

It took a bit of time to find the compatible pads for my BBK. This is just a list of Wilwood pads. There must be other options from other pad manufacturers such as Hawk.

BP-10 ships with the BBK

 

I normally do not like excessively loud exhaust. That was the reason I first did the one-ball mod, and I do like it. It is very liveable for road use, and no drone at freeway speeds. Having discovered during HPDE how hot the metal floor inside the boot is with stock exhaust, one-ball included I decided to give Milltek a try. Here is what the one ball sound just driving around the blocks at low speed.

there is nothing to see in the video; it is just a mean to host the audio file

this video has some working through the gears and a spirited acceleration

I took this video to compare against the Milltek.