Speedhunters Article

Check out the article on our car here on Speedhunters.

We were approached by a guy who wanted to write an article on our car, as Speedhunters were doing a segment on bike powerd cars. There are some pretty interesting other write ups on there which are worth a look.

Events of the last year

Further more to my year long catch up, we have done more than a few events. I will have to look through the log book to remember them all. They have mostly been tarmac, but we have done 3 gravel events also. It is a rocket ship on tarmac, it has always handled well but the extra power and having a gear for all occasions makes it fly. It is not great on gravel as it struggles for rear end grip, still needs a lot of development here.

Here are the events and placings we have achieved over the last year or so. We mostly dual drive the car so there are usually 2 placings.

Waiti Rd (Tarmac, TVCC) 25/08/13. 3rd (Mike) and 4th (Kevin) overall. First event, a few teething issues. Car would not idle and clutch was difficult to modulate. Very wet road, .  Results

Kemps Rd (Tarmac, MG Car Club) 17/11/13. 1st (K) and 2nd (M) overall.  Car ran well. Kev’s favourite road. I pushed too hard and went slower. Almost came unstuck and ran off the road and through a big hole. Bending the left rear spring. Results. Videos can be seen at the bottom of the videos page.

Bright Rd (Tarmac, PCC Speed Weekend) 23/11/13. 2nd (K) overall. Kev on his own this time and with a great performance at one our car clubs oldest hillclimbs. Results.

Murray Rd (Gravel, PCC Speed Weekend) 24/11/13. 17th (K) overall, 3rd in class. Car struggles on gravel, a real handful to drive. Results

Golden Cross (Tarmac TVCC 2014 National Hillclimb Champs) 18/01/14. 8th (M) and 12th(K) overall, 1st and 2nd 2WD in the series. Great result with 45 cars in the event. New road for both of us, so still a bit more time in it for next year.

Pukewera Rd (Gravel TVCC 2014 National Hillclimb Champs) 19/01/14. 24th (M) and 25th (K) overall, 5th and 6th in class. Again the car is struggling on gravel, feels very nervous and does not inspire confidence on a slippery surface.

Lead Foot Hillclimb (Tarmac, TVCC) 1/2/14. 5th (K) and 7th (M) overall. Rod Millens driveway he holds the Lead Foot Festival at. This was a closed club event, not the actual festival. I crashed into a tree on my first run knocking the confidence a bit. Kev went fasted 2WD.

Pukekohe Raceway Bent Sprints, Round 1 (Tarmac, PCC) 5/2/14. 2nd (M), 3rd (Paul) and 4th (K) overall. My brother to triple drive the car for the first time in years, and he beat Kevin.

Pukekohe Raceway Bent Sprints, Round 2 (Tarmac, PCC) 5/3/14. 2nd (M) and 5th (K) overall. Another 2nd place for me means I won the series.

Autocross, Ardmore Aerodrome (Tarmac SACC) 5/7/14 DNF. Broken axle on the first run.

TVCC Te Tuhi Rd (Tarmac TVCC) 20/ 20/07/14 3rd (K) overall.

Taupo Classic Car club 2WD  Rally 80km 10/08/14  12th (K) overall. Always a great event to get some kms under rthe belt and have a few battles with other cars on a track. Really is a horsepower game on a curcuit, which we are lacking.

Rallysprint Pukekohe Race Track (SACC 30/08/14) 8th (K) overall. Absolutly pooring down with rain for half the day. Made for some pretty reserved driving as it was like driving on ice. The course went around the race track but included some additional chicaines which were to our advantage in the wet conditions as the 4WDs could not turn in.

Quine Rd (Tarmac TVCC) 21/09/14 Cant find the results but I think 4th (K) and 20th or so (M) overall. Another wet day and a big moment in one of my firt runs put the shits up me and made for  some slow times. Kevin on the other hand relished the conditions and mixed it up with the front runners.

Doctors Hill Rd (Tarmac Northland Car Club)  25/09/14 6th (K) and 7th (M) overall. Both of us beat the class hill record. Dry condition and only .01 sec between us.

Kemp Rd Hillclimb (Tarmac MGCC) 19/10/14 1st (K) and 3rd (M) overall. A good day for Kevin as for the first time ever beat 2nd placed Allen Fretwell. One of the quickest drivers around, although he is driving a 500hp? Legacy which helps.

Kemp Rd Hillclimb Championship (Tarmac PCC) 19/11/14 2nd (K) and 3rd (M) overall. At Kemps Rd twice in 2 months. This time the national hillclimb series. An awesome battle between the two of us, with 5 of our runs within .03sec of each other.

Murray Rd (Gravel PCC) 20/11/14 3rd (K) and 5th (M) in class. There is a real trend developing of Kevin beating me every time. A mixed bag of weather made for an interesting day. The car really struggles for grip. Although we checked our tyres and they were almost 10 years old, they do not age well.

Ngongotaha Hill Climb (Tarmac RCC) 1/2/15 4th (M) and 5th (K) overall. Finally I beat Kevin after a very long time, and it wet conditions. First time up this hill so there is a lot to learn. The weatehr was terrible and low cloud made visibility very difficult at times.

Bent Sprints (Tarmac PCC) 4/2/15 1st (M) and 2nd (K) overall.  Some fun on a Wednesday night, same format as last year. Weather was wet which made for some big slides. Some nice tight chicaines which gives us a good advantage over the larger more powerful cars.

Hillclimb Champs Kurarau Rd (Gravel Taumarunui) 14/2/15 1st (M) and 2nd (K) in class, 2nd and 3rd 2WD. Finally the car worked on gravel, made a few small changes and used new tyres. So much fun to drive, it had grip so gave confidence to throw it into the corners. I was leading the 2WD for the first 3 runs, but could not hold on to it as my rear tyres were gone. Try as I might the time did not improve.

Hillclimb Champs Saddle Rd (Tarmac Taumarunui) 15/2/15 4th (M) and 8th (K) overall. Back on our preffered surface and trying to charge for a top overall position. Unfortunatly there was a lot of gravel pulled onto the road making it super slippery and taking away our corner speed advantage. In fact my fastest run was my practise driving the course for the very first time.

Bent Sprints (Tarmac PCC) 4/3/15 1st (M) and 2nd (K) overall.  Second and final round of the Wednesday night sprints. Dry conditions meant we lost our advatage over some of the more powerful cars and it was a lot closer but for the second year in a row I won the series.

Anyway, that is it. A year or so of events summed up. I will try and keep this more up to date in the future.

We’re still here! Better late than never

Hi,

It has been a very long time between posts, a year or so in fact.
Finding time to race is hard enough, so finding time to update this is even harder. Anyway, all is going well with the car. It has run faultlessly, with very little need for attention of any sort.
OK there have been a couple of things. But generally it is awesome, it never misses a beat, we are still dual driving it and have even triple driven it with my brother, so at an event it does not get a rest we just continue to beat the little thing up, and it comes back for more.
So the little issues have been:

The first clutch plate was wearing badly and therefore wearing groves into the inner hub of the clutch. We theorised that it was not getting enough oil as there are no oil holes servicing that plate. So we made some, and it has been fine every since.

Also, I crashed it into a tree. It could have been a lot worse as I went in backwards. Just tagged the corner of the bumper, so the hatch survived unscathed. But it wrecked the bumper and bumper iron, squashed the floor and the force transferred down the side of the car pinching the door. Now usually you would cut out the corner and replace it but because it is a starlet, and that is where all of them rust out, and this car is mint, there was no cut and paste. 36 hours of pulling and massaging it back into shape by a panel beater made for a very expensive lesson about how not to keep your foot down when things get out of control.

The next weakest link down the chain broke, the axle. So a quick replacement and after one event this is what the “new” axle looked like.

Very close to another breakage, turns out we had the “small” axle version. 23 (small) vs 24 (large) spline and 1.3mm in diameter can make all the difference. We upgraded to the larger size axles, and all has been going well with plenty of tyre hazing starts on tarmac. But this is an area we will probably improve in the future.

Apart from that, a bit of general maintenance, lots of oil changes. We did pull the engine out once to check the gearbox for wear, again all is holding up well.

I will let you know how the events are going in the next post.

Drive line issues resolved

It has been a long time since I updated this. Life got busy and the car had to take a back seat for a while.

After the last post we revisited all the areas giving us problems.

Firstly the clutch, we thought the push rod was bottoming out. An easy fix, but a quick investigation found the free play length was fine and that couldn’t be the cause of the slip. So we puled the clutch apart, sure enough the plates were blue, a couple were a bit warped so we swapped them out. After some careful checking and theorising we discovered that because our clutch pedal stroke was too long, it could push the pressure plate right off the end of the inner hub. Once released it can get hung up on the inner hub causing it to slip.  So the solution is to reduce the amount of movement the pedal stroke gives the clutch slave cylinder. Either by restricting the pedal stroke, reducing the size of the master cylinder or moving the master cylinder pivot point up the clutch pedal. We went for the last option and now the pedal has the full stroke. It makes driving it a whole lot easier too.

The next problem was the drive shaft vibration. We previously checked and recheck everything for balance so knew that was not the issue. The issue is the reversing gear box. With our front drive shaft coming in a such an angle the single bearing in the gear box housing can not support the lateral force. In fact you can grab it with your hand and move it sideways. So the solution was to remake the gear box ends and shafts with double bearings and flanges instead of splines. The drive shafts also had to be remade as the lengths have changed. This took a couple of versions and until last week to get right but it is back in the car are the vibration has gone.

Now those issues have been resolved we can focus on tuning the car. The ECU software and log box we are using are awesome. We are running lambda sensor so can look at the mixtures at all pionts of the rev range. The software has an auto tune function which evens out the rich and lean parts of the map which you rewrite the ECU. Do this procedure a few times and the software will tune the engine for you.

We are racing the car this weekend at Kemps Rd (tarmac) on the Awhitu peninsula. Then again next weekend at 2 events, Bright Rd (tarmac) in Waiuku and Murrays Rd  in Tuakau (gravel), all going well.

Old spline shaft and gear box with new flanged shafts

 

First Event

We did our first event in the car a couple of weeks ago but have not had time to update this site.

We saw that the Possum Bourne Memorial Rally was coming up in a couple of weeks (it was run in the weekend) so we decided we need to do a shakedown as we wanted to enter the rally and it just so happens that Thames Valley Car Club were having a hill climb a few weekends before so we would have time to sort any issues.

It was a bit of a rush to get the car ready for the event, but we got it ready enough to race. We only drove it down the road at 6pm the night before the event. In fact dad did not drive it at all until the event. On that drive down the road, the engine threw an error. The idle speed control had a fault which meant it was difficult to get it to idle and wanted to stall, but was not a major as it was fine once you were moving, and holy sh*t does it move. The first time I put the foot to the floor it was more than impressed, this thing is quick. I can’t imagine this in a bike, those guys are crazy. But once I hit 130kph the vibration kicked in and I knew it would be a problem. Also it is deafening loud and can be heard a couple of kms away, so test runs around home might be a bad idea.

Once we got back to the house I saw that the wheel had hit the brand new and freshly painted flares and smashed the fibreglass, not a huge amount of damage but not a great start. So we quickly lengthened the diff arms to clear the guards and it was on the trailer.

The event was a 60 second tarmac hill climb. It was raining and the road looked slippery. The first couple of runs were just getting used to driving it. It is no longer like driving a car it is a serious machine, it makes a huge amount of noise, both the engine screaming and gearbox dogs banging away make for quite an experience. You think you need to change gear then realise it’s only doing 8500rpm and has another 2000rpm to go.

On the way down for the 3rd run I noticed the clutch slip, but once I got to the start it was fine so ran again. This time with a bit more focus on the road I was able to feel out the car a bit more and the handling is still a precise as it ever was. Although I did notice the 50mm wider track and ran up a kerb which I was planning on going around. On the way down for the forth run the clutch slipped again, but this time it was for good. Game over.

So with the rally only a couple of weeks away we decided to not enter as there is too much vibration from the drive shaft. After a couple of previous attempts to get rid of the vibration not working we have decided to remake the reverse box shaft and eliminate the spline. Also the front of the box has been remade to take a double bearing. The angle of the front drive shaft seems to be flexing it causing the shaft to orbit and vibrate.

We think the clutch slip is caused by the clutch push rod being too long. We originally customised it to fit with a small amount of free play, but it needs to be shorter. Once the clutch plates bed in the that small amount of free play is taken up and then the pressure plate will be held off and it will slip.

So a couple of things to sort but it is all part of the development. This car should be great fun once we get these issues sorted. The next event is another tarmac hill climb on the 28th of October at Quine Rd in Tahuna.

 

The last 10 percent

How does the saying go, the last 10% takes 90% of the time. Well there is some truth in that statement.

Since the last post we have had it drivable, but that was short lived. Straight away we notice that the clutch pedal stroke is way to short as is the throttle. A couple of laps of the driveway and it was back on the hoist.

The clutch is a design fault of ours, as we assumed a couple of things in positioning the master cylinder. So the fix was to move the push rod further up the clutch pedal. It pushes at a bit of an angle but should be fine. The pedal stroke is much better, about 2/3 to the floor to disengage.

The throttle we knew would have to be changed as soon as we hooked it up. The bike engine throttle cable only moves about 25mm and it is wide open, meaning the pedal would only go half way to the floor. The solution was to move the pedal pivot point up, but how much? Some careful measurements, a bit of CAD and smouldering some brain dust trying to think make to high school maths class, which I failed, we decided on it needed to move 90mm up. A bit of a grind and weld later and it is perfect, a full pedal stroke.

While it was drivable we tested the balance of the drive line, it did not pass. On the hoist we put it in 6th gear and took the revs up, there was a huge vibration and at 8000rpm. A spanner on the floor was going to jump out the door. With almost 4000rpm left in the rev range this was not acceptable. So out came the drive shafts and gearbox. The drive shaft had been made and balanced by drive shaft professionals but it would seem their tolerances are not low enough, so a bit more machining was required there. The reversing box flanges had run out as well. The machining of the gearbox and the flanges is perfect, but when you put them together, the tolerance in the spline is enough to make it out of balance. So the fix was to take the shaft out of the reversing box, attach the flange and the machine it as one piece to balance it. It worked and once back together the vibration is hugely reduced, and we can live with what vibration is still there.

A bit of a rethink on the reversing was needed also. In an earlier post you will see we had a cable on the gear lever which we would pull to go in reverse. In reality it did not give us enough feel of the engagement, so you could not really tell if it was in gear. So we decided to put the lever trough the floor.

Also amongst all this we have had a few pesky wiring issues, and then the communication box between the ECU and laptop died. So back to Aussie it went for a replacement. We started to think our ECU might have some issues but we got another ECU to compare with and all seems well so one less thing to worry about. In hindsight we would not have had our wiring loom modified by someone else as they cut out and added bits which only they know about. After weeks of studying the wiring diagram it would have been easy enough to do the mods ourselves.

Pivot point moved up, and mounted from the original position

Reversing lever, needs to be lengthened. The spring is temporary also.

The extractors are getting a bit of colour in them. Also a cardboard heat shield template otherwise the tower will get cooked.

It Lives!

We had a small battle with an electrical issue. For some reason the software we were using to turn off the tip over sensor was not working correctly. Once we changed the software, away it went.

Parts Arrived

The parts from the USA have finally got here. The oil and water systems are now complete. The fuel is hooked up and the gear lever is now connected.

We are now getting very very close to this thing running, it cranks over and has oil pressure but we have a few problems to sort with the wiring. We have been able to use its self diagnosis codes to sort out what is wrong. You can get the ECU to diagnose what is causing an error and it displays it as a code on the dash. It would seem that we have cut out something it needs. We had the wiring sorted by Mike Downs in the USA but we decided to hook it into the car ignition, it seems we have not got it quite right.

We have also decided to pull out of our target event. Time has caught up with us, and the delays mean it will not be ready to race by then. At a push we could have just got there but we really want to test it thoroughly before hand and don’t want to risk anything, so we will be on the sidelines again.

The radiator modified with additional hoses and fan mounted.

The last dash fittings needed installed and the oil system is complete.

Oil cooler in place.

Tiny Shorai dry cell battery for some weight savings.

Drive shaft built and balanced with siding joint.

Gear lever installed, a few pulls on this thing and you realise how awesome driving this car is going to be.

Heater box mounted.

Trouble shooting engine problems is not like it used to be.

Exhaust built

The exhaust design has been in the works for a while. It is commonly acknowledged that 4-2-1 is the way to go with the exhaust on these engines. The length of the pipes is still up for debate, but we have decided on a design and set out to get all pipe lengths as close to equal as possible, the exact length is something we will be keeping under wraps.

We got a selection of stainless bends and collectors with the original shipment from the USA as they are crazy prices over here. We decided to uses the rest of the existing car exhaust but found a lot of it was rotten, the av gas we used to run dissolves the steel exhaust so a few bits need to be cut out of that too.

So here it is after many many hours of construction. It fits beautifully and all pipes are within 2mm of our desired length. I didn’t take any pics before we installed it, sorry.

 

Getting there but more delays

It has been a while since I updated this, I got a bit busy with other things.

So since the last post the oil rings turned up and the engine build was completed with no problems this time. The engine is now bolted in place for the final time, hopefully.

We have had some parts coming from the USA, but they have been lost in the post somewhere. Thankfully they have been found again but means they are going to be 4 weeks late. The parts includes oil system fitting and water hoses, without them we can’t go much further on the engine but we can carry on with a few other things.

We moved on to building the drive shafts but found there to be a less than desirable amount of run out at the rear of the reversing box. Initially we thought that the flanges we made were not quite right, but after a lot of check we found that it was in fact the tail shaft of the reversing box which was out by 0.009 inch. Acceptable is around 0.002 inch so this imbalance will cause a serious vibration and potential failure. We got in touch with the manufacturer in the USA and although that have not had this problem before they are sending us out a replacement shaft. Taking a part this reversing box gave us a chance to see its construction, it is a very simple yet brilliant design that we will never be able to break. It basically has a big spline that locks the front and rear turbo 400 shafts together so no backlash and will take many 100’s of HP.