My wheel fell off on a trackday

At 137 km/h coming into a long right turn, my inner rear wheel fell off. A loud clonk and I could see how the inner rear wheel was bypassing me! I slowed down slowly standing on three wheels and could keep the car on track the whole time. A guy ran out on the track to help me, and we could easily push the car out from the track by lifting at one corner while pushing.

The loose wheel had hit the rear wing rivets loose. Other than that, no damages at all! No scrape marks, nothing. I put the other set of wheels on and continued driving the rest of the day as nothing happened.

But how could this happen?

The wheels have been used three seasons. Magnesium centres are known for the need to be inspected every season - but this is aluminium and they're supposed to hold together. Then I noticed that the rear centres had larger bolt holes than the fronts!

I've emailed the manufacturer and got the following replies:

Cracks forming on the other rear

I have spoken to two other owners  with the very same design billets,  I think I only made 5-6 sets like your before changing to the later profile as  the power and weight of customer cars was  going up so I thought to beef them up a little, The two I have spoken to  have no problems and have used them now for three seasons hill climbing here in the uk. I do not have an answer for you why  there has been a failure, but I can Only assume fatigue, The later billets you have are now used on lots of similar cars to your including some saloon circuit  cars around the 850kg mark with no problems reported 
I am of course more than happy to send out replacement centres .

And later:

I see the  old wheel bolt holes are larger, this is because when I originally worked with Meteor  we were going tom use floating taper washer that needed a bigger hole, using these washer didn't work out so I changed the hole to smaller dia, the set you have were simply a set form stock that were used up.

I see the damaged inner rim. No problem for me to send a replacement under the circumstances.

After investigating the new design I'm confident they're much stronger than the one that broke, and I feel assured they'll hold. If you have similar wheels, I suggest you check them and see if you have the larger or smaller holes, and replace them if you do. If you have the new style centres I wouldn't worry.

I must say I got an immediate and professional response from the manufacturer, and they did everything they could have done in this situation. However, I don't think I should have gotten the weaker style centres in the first place.

New style centre from the inside.
 Note that this picture doesn't show that the centres are also thicker than before.

Old centre, with big bolt holes.

Gearbox disaster

My gearbox failed with a bang on on the King of Mantorp TA-event. Totally unexpected on the day's last cooldown lap. Looking at the log file I didn't even have 50% throttle when it happened.

The good news was it was easy to see where the problem was. The bad news was I it looked rather serious. When opening the top lid everything looked normal which at least gave me some hope.

We don't have a company named Road'n'Race Transmissions here, so it took some effort to find somebody that was even interested to look at the gearbox. As it turned out, the man I eventually found knew a lot about type-9 gearboxes and I must say gave me very good confidence it could be fixed, and with an helpful attitude.

Bertil Carlsson in Vejbystrand, described what have happened as a locking nut had shaken loose, causing the big end nut unscrew itself through the casing. Something that he'd never seen before.

The case was welded, the nut was replaced, and while he was at it he replaced the sync-ring between gear 5 and 6 which was very worn. Everything prompt and for a very reasonable price. (I'm not sure what could have caused the worn sync-ring. The only thing I can think of is that I had a cracked clutch plate a long time ago that made gear changes difficult at high rpm.)

That said - someone (not me and not Bertil) did really mess up the order of the bolt from Caterham, and therefore this little disaster took a big part of the summer. I'm a bit disappointed about this but I guess I should be happy it turned out as good as it did, and that I didn't have to buy a brand new Sadev sequential gearbox with paddles.... ...because I couldn't afford it.

All right - time to put the engine back in and see what's left of the summer!

TimeAttack - "King of Mantorp"

Valtonen Motorsport RX-8

Normally I don't like to compete but somehow I participated a Time Attack competition this weekend. Seven type cars are not allowed in their series, but this time they had a "no limits" class. Some of the competitors car's was completely insane, as the tube frame, all carbon RX8 to the right, accompanied by a complete race team.

Photo: Felix Eriksson

I managed to get the 4:th place. I'm really satisfied with that. Not so much for the final time (1.23,4), but that I kept my head together and managed to get a good run in the super final which was one lap only!

In fact, the qualifying lap and final lap was one second faster than all my practice laps during the whole day!


The official noise check reported 97.5 dbA drive-by which they said they allow today but not tomorrow. I'm getting there...

Everything else worked very good, except....

Gearbox problems!

Just when the day ended something happen with my gearbox on the cool-down lap. I works but makes some chirp noises and the gears are hard to engage. .... .... ghh

Update: I got a couple of seconds of fame in this movie:

Finally some driving!!

A "test drive a Radical SR3" event at Mantorp. I was also invited but drove my own car.

The engine runs great! The car handles great! Even the weather was great! My driving - not so great, but who cares? Well not that bad, today's best was 1:22.3. Compared with my all time best 1:21.8 it is all right considering I had no "rabbit" in front of me and I was feeling a bit rusty. The Radicals didn't stand a chance with those inexperienced drivers.

But of course...

Fuel surge and alternator problems!!

This spring when my engine broke, it was because of the small wire from the alternator went loose and it stopped charging the battery. The fuel pump couldn't keep up with the lower voltage and the engine run lean. Things got hot inside the cylinders and the engine got damaged.

Today the alternator broke completely.

The same symptoms - no power on the long straight. But this time I knew, and backed off the throttle immediately. Also the no-charge light on the dash was lit this time.

I also experienced fuel surge in the long right hander "Parisern" when the fuel level was below half. I always had that problem, even with the stock CSR200 engine. Today it annoyed me more than ever before.

I need a more robust fuel system! I can't risk loosing my engine because the alternator fails, or if a connector jumps loose.

Anyway I got five or so laps on film. Here are a couple of them. I'm not very satisfied with my driving here, as soon as I try to push hard I get sloppy and miss the apexes.

Brise starter

This is the second time my starter solenoid has broken. It is a mechanical failure where the plastic actuator arm inside the coil has broken off. The starter motor has also been very sluggish lately and not always been able to crank the engine when the engine has been hot!? If it is the solenoid that has been causing that too, I don't know. I do know it's not the battery, because I've replaced that one too. And it is not the wiring either.

I've been forced to ask a random person for help at a parking lot many times. So I just want it fixed and have installed a new Brise starter because "they're the best" according to a reseller.

And the difference is??

I don't know. I just hope it works better than the old one. The casing looks very similar for sure. It appears to turns the engine with much more determination than the old one. I read somewhere the gearing is different and that is probably why it copes better with high compression engines like mine.

Engine damage

Bad start this year. 

The fuel surge on last trackday caused more damage than I initially thought.

Damaged spark plugs. These are from cylinder #2, #3 and #4

A compression gave the figures 14.5, 12.5, 12.0, 13.5 bar and they're supposed to be within 10%. Some oil in the bad cylinders increased the compression quite a lot. According to Google that puts the suspicion to damaged piston rings. I also see a little bit of smoke from the breather.

I had to take the engine apart.

The pistons are damaged, and so is the block. I put the block into the trunk of the daily driver and asked around among professionals and the verdict is that three pistons are gone, the block can be saved but it would be easier and cheaper to simply buy a new one. Fortunately the head and the rods are not damaged at all.

Damaged block and #3 piston

Damaged piston

I found a good document about piston damage.

Except that, all bearings and everything else looks as new.

The people I've asked about the engine agrees with my theory of what happened - the alternator stopped charging, and when the battery discharged during the day the fuel pump could not keep up on the long Mantorp straight and the engine run lean.

Mantorp first time 2013

This years first trackday was a warm day with blue skies on Mantorp and a huge mix of different types of cars.

Things didn't go that well. It started with me being a bit late.

Then there was a Porsche that spilled oil on a long section of the track. (Those German cars....)
Then someone else went off and one corner was covered with gravel and the track was closed again.
When I finally got the tires warm there was too much traffic and no clear laps.

Engine problems

Lost top end power and the top speed on the straight was a bit too low. It got worse and worse, so I stopped driving and went home instead, worried that there was something very wrong with the engine.

When I got home I did some troubleshooting and found out the alternator warning light connector was broken, and that prevented the battery being charged. (Stupid design!) My speculation is that the battery's voltage went down during the day and caused the fuel pump not being able to keep up the pressure when the fuel demand was peaking, making the engine run lean. Running an engine like this lean is not good at all and could cause fatal pre-ignition.

I need some way to prevent this from happening again.

I would like to be able to log the fuel pressure, and have some warning system for a fuel or oil pressure drop.

Here is a video I found describing how voltage affects the fuel pump flow:
http://www.youtube.com/watch?v=RjykWzDr1Kk

Noise check

A couple of months ago I bought a cheap noise meter from Hong Kong, and today I asked someone to measure the drive-by noise of my car.

The guy told me it made 106.4 dbA!

In many race circuits in this country have from this season a drive-by noise limit of 95dbA.

I started measuring the other cars, and no-one, except a stock Corvette, was below that limit.

Then I moved a little, and all readings changed. Then the wind changed, and the readings changed as well. Then I realized I could not get the same reading twice for the same car.

It seems like measuring noise at a race track is not an exact science.

I refuse to think my car makes as much noise as 106db, but I'm not surprised I have to do something about it if I'd like to drive on other circuits. I just don't know what yet.

What about all the work done this winter?

All good!

The roll cage... stayed in place. 

The suspension bushes hold together. The car felt nice and precise.

The exhaust manifold was not leaking!

The silencer mounts did not break.

No oil spew from the catch tank.

Engine did not leak oil from the front cover

Overall the car feels wonderful. Too bad I was worrying about the engine instead of enjoying myself.

I did not have the aeroscreen mounted as I didn't think it would do much difference. At the end of the straight the force against the helmet was overwhelming. I must put the aeroscreen back on.

Mantorp wear and tear

An humid day at Mantorp with rain in the morning and dry after lunch. One of those days when nothing felt good. I pushed harder and harder but the lap times stayed high and today's best time was 1:23.0. A Camaro cup team confirmed that the track was slower than usual because of slippery rubber from drift cars the days before. Still I didn't feel like I drove as good as I could have.

A couple of other things didn't go very well either.

Cracked wing with zip tie

First my right front wing went loose and cracked. Back in the pit I drilled a small hole and put it back with a zip tie. The next lap the left wing went loose...

The oil catch tank got full and spew oil in the engine bay. I don't know how that is possible but that is what happened.

The exhaust manifold sealant didn't hold and the leak is back. Another winter project.

The orange colour is where the pad material ends.

Rear brake pads worn out completely. I have ordered a new rear set of Pagid RS4-2 (1158 for my calipers). When the front pads wear out I'll try a different brand and see how they compare. I'm also considering installing a pressure reducer valve to rears and use the same compound on both ends. (Right now I use Pagid RS14 on the fronts and RS4-2 on the rears)

The A frame bushings are worn. At least I think so. When I brake I can see the wings move much more than they did before. I'm thinking of replacing them with Powerflex bushings during the winter, but they sure are expensive!?

One more trackday before the winter, this time at Gelleråsen. Lets hope it doesn't rain.

Inertial switch

Who said highway driving isn't exciting?

Fortunately it was only the inertial switch that cut off the fuel pump. Never happened before and took a while to figure out standing roadside with oncoming darkness and decreasing battery power.

A press on the top and I was back on the road.

Inertial switch

Flat tyre

The missing screw found... DOH!