Follow my attempts at racing the V8 powered Harper Type 6 prototype down in Cape Town, South Africa.

Thursday 2 May 2013

A cat in a bag

The cat is out of the bag. It's an odd saying really, and always confused me as a youth until I put it to the test with our trusty, and mostly laid back, family cat. Actually getting the cat into the bag is not a problem as they are naturally curious creatures. They are also fantastically suspicious, especially around the motives of a ten year old with a sack. The furious feline exited the "bag" as a hissing bundle of fur and claws leaving me somewhat bloodied and in no doubt that the cat had left the bag, and would not be entertaining any future bag activities.

I suppose that's more what it's about. Once the cat is out, it's not going back. As it is with certain changes that are going to be taking place with my Type 6 over the course of this season.

A photo appeared on Facebook a little while back depicting some engine parts, one of which was the unmistakable shape of a large turbocharger. Craig then ran a little post on the Harper Sports Cars web site around some upgrades heading the Type 6 way. 

Go faster goodies slowly coming together
The activity drew a couple of comments, but nothing too compelling. However, during the race meeting this past weekend I was accosted by quite a number of drivers around the plans for my Type 6. More specifically they were all Class C drivers and wanted to know what power and torque figures we had in mind. Competition is a good thing, and it's always good to know as much about the competition as one can. While I appreciated the fact that they thought I might be able to compete in their class at some point, I was under no illusions that trying to harness the Type 6 when it sported twice the power output would be a job my limited skill might not accomplish all that well.

Still, you can't get better by staying the same and I tend to throw more power at the going faster problem. Probably not the best way to solve the issue, but it does make for some fun times.

However, I am not oblivious to the fact that making a car go faster has a number of side effects, the greatest of which is that, well, you end up going faster. This is all good and well, but it means at some point you have to slow down again. Upgrading the acceleration parts of a race car without looking into the deceleration parts can turn out to be a mistake you only get the chance to make once. So long before any of the go faster goodies come near the car, we are doing some more mundane upgrades. These include larger 17" rims that can take wider semi-slick tyres, but more critically can house much bigger 300mm disks for massive added breaking force. We are also looking at redesigning the pedal arrangement to a top mount direct push system for a more "connected" feel. 

At this point I would like to introduce you to a new word in the english language. It's a word most sporting folk will be familiar with, but seems particularly relevant in the world of motor racing. The word is "cashcade" and describes the knock on effect of making a small change to an otherwise perfectly fine race car. Thus, to get the new 17" rims to fit means we have to swap from four bolt hubs to five bolt hubs since you don't get 17" rims in 4x100 bolt pattern. Thankfully Toyota have an off the shelf five bolt hub. Then once the hubs are replaced, the rear shocks need to move inward a bit to clear the inside of the rim. The front end does not escape either, since the, now larger, front wheel not only fouls the body work, but also come in contact with the headlights.

A box of Toyota five bolt hubs for the three Type 6's


"Spats" adding to the new brutish look of the Type 6's
Then, finally, the callipers also need to change from the rather lumpy RunX units to the similar sized, but lower profile, Corolla RXi units.  A cashcade of truly epic proportions!


New vs Old disks, quite an increase

New front brakes fitted

New rear brakes fitted

Eventually all the changes will stop, at which point, hopefully, so will the car. The final addendum to the Type 6 prior to us doubling the horses is to increase the downforce. This will allow us to make more effective use of the bigger brakes and tyres. A rear wing and front splitter is on the cards at some point. Of course, by this point the entire season might be over, or the little bits of paper fuelling the cashcade may be depleted. Time will tell which comes first.

Then, just to add to the whole effect, we are fitting a new clutch. There is a good reason for this however. A while ago my third gear synchro decided it had had enough of this track racing nonsense and went from synchromesh to just mesh. Luckily I use a standard off the shelf Audi gearbox and quickly sourced a new used one off Gumtree. However, once we came to fit the box, we discovered the source of my persistent pull off shudder. The clutch plate was basically spring-less and about to become spline-less as well. With three days 'til race day there was no time to faff about getting it rebuilt so a standard off the shelf Audi unit was quickly dropped in. The clutch felt fantastic and the race meeting went off without a hitch, although in hindsight, I might have felt a bit of slippage near the end of the second race. The following weekend was a open track day and we decided to make a bit of a day out of it. I was planning to take the kiddies for a joyride and Leigh was going to venture out in the car for only the second time. We were all poised for some fast fun when, coming down the back straight as I shifted into fifth, there was a muted bang at the rear and the car lost all forward urge. Thankfully I had enough momentum to coast around and into the pits. This put a rather immediate stop to our days planned activities and the car was duly dispatch to the doctor for analysis. 

The results, I suppose, were somewhat expected given the ask we had placed on the little off the shelf clutch plate.


Manufacturers specs somewhat exceeded
I had always been a little concerned about my clutch and, frankly, am quite surprised it has lasted a whole season. However, there was absolutely no chance the current setup would manage with any increase in power. Something better will be needed. 

After some ernest searching, conventional wisdom was that we needed to fit a more racing biased unit instead of the standard road unit we had. A little later we had procured an ex Nascar twin plate Quartermaster clutch from the fine folk at G&A Promotions. 

Then the cashcade effect once again set in and we finally ended up with a whole new flywheel and clutch assembly. 


New twin plate vs old single
On the upside, the whole assembly has gone from a somewhat hefty 15kg, down to a flyweight 7kg. This should really help the engine spin up!

By the time everything is back together again I'll pretty much have a totally different car and should, once again, be following my trend from last year by pitching up on race day with a whole bunch of new bits. Qualifying will be more fun than usual I suspect.

So what about the actual race day just gone past, you might ask? Well it turned out to be a great day of racing. The weather was fine and slightly overcast making for a cool day. I had a great battle with some Class D guys, notably Hennie in his 'vette, while sadly the other Hennie shortened the front of his Lotus 7 by slamming it into the back of Martin's 7. The two had been furiously dicing and exited Turn 4 literally nose to tail. Unfortunately, as Hennie pulled out to pass Martin, Martin missed a gear. With Hennie accelerating to pass, and Martin not accelerating any more, the two came in contact, forcing both to retire for the day. 

In race two I once again showed my lack of race craft while trying to overtake the Corvette, finally getting the job done after far too many laps. I then, surprisingly, managed to catch a Porsche GT3RS and, even more surprisingly, managed to pass him in Turn 1 while we were tangled up with the three leading Class A cars.

The day ended with a Class D win for me, and a rather nagging feeling that I should be leaving well enough alone. Ant had just fitted an aftermarket ECU to his car and had tuned things up to a nice 200kw. It did not last long, with him melting his pistons not far into the race. 

Maybe that large turbo is not such a good idea after all. But then, I fear the lure of 400kw might turn out to be just too strong to resist.

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You can catch some of the action, and watch my misguided attempts to pass Hennie, in the footage from race 2 here. Keep an eye out for the corner action around lap 6 when myself and the GT3 are both passed by three class A cars between the entry and exit of Turn 1.