OK, let me start at the beginning: On the one hand I have had a Slot.it McLaren M8D for quite some time now. In typical Slot.it fashion this is a pretty car that runs well. Not a bad thing for a slot car....
On the other hand: a couple of guys in our group have some of the older HSRR McLaren M8D's. Very pretty cars but not great runners. But I have always looked at how pretty they are and wondered...
And then a few weeks ago Electric Dreams advertised what was essentially a two for one deal on the HSRR McLarens. Two HSRR McLarens for $50? This was too much for me to resist: I caved and ordered the cars. And once they arrived the question arose: how to prepare them? This is a bit of the story on what then transpired. I will briefly review the three cars in terms of:
* Mechanicals
* Appearance
* Performance
1.1 Slot.it McLaren #48
A Slot.it McLaren is likely a known quantity to most of you out there. Typical Slot.it chassis, sidewinder pod (as all the Slot.it Classics have), 21k motor etc etc. These cars do not need to have much done to them so that is what I have done: not much.
The one mechanical change was largely cosmetically inspired: I really do not like the small wheels and tyres on the Slot.it Classics (well, most of their cars actually). I understand the reasons for it and I am mostly sympathetic to the reasons but it still does not look great to me. So I replaced the rear wheels with CB Design 15 x 11 insert wheels and glued and trued some PG urethanes to suit.
For the rest: put on softer NSR braid (I find the stock Slot.it braid to "springy"), added 7g of lead in the pod, loosened the pod a touch, taped the pod, added body float.
And that's it.
1.2 HSRR McLaren #5
I decided that I would keep this one as close to stock as possible. I was not greatly concerned with out and out performance: I just wanted to make it run decently and look good. So I did 3 things:
* I wanted to glue and true urethanes on the car. However: the back axle with the press-on aluminum wheels did not fit in my truer. So I replaced the rear end with a Slot.it axle, bushings, spur gear and CB Design 15 x 12 insert wheels.
* Because the stock HSRR McLaren sits very high, I tried to mitigate it ever so slightly. To this end I reamed out the rear bushing holders and glued the bushings in place just a touch higher, dropping the chassis by a minuscule amount. In retrospect this ended up being such a trivial amount that it really did not achieve much of anything.
* Added about 10g of thin lead sheet under the chassis as there was a LOT of clearance!
That's it: no body float (not practical), no changes to the guide or steering (looks cool!), no chassis changes.
1.3 HSRR McLaren #7
OK, this is where I went to town! I decided I wanted to take a bit of effort on this one to see if I could make it competitive performance-wise with the Slot.it. So I did the following:
* Chassis: I decided right off the bat that I was going to replace the chassis. And this is quite a big step for me: I do not lightly go this route! So I considered a number of options. Option 1 was seeing if one of the spare NSR chassis I had would fit (or at least be relatively fit-able). I had spare Porsche 917, Ford GT Mk IV and Mosler chassis from when I replaced these with hard white chassis. Unfortunately none were a decent fit.
Second alternative was to go to a Slot.it HRS chassis. I was loathe to go this route because I would have had to buy more bits than I wanted and I thought fitting it might be more of a challenge.
Last and finally preferred option was to see if a stock current model Slot.it chassis would be a reasonable fit. So I held the body against a number of my Slot.it cars and decided the Matra chassis seems to offer the best possibility of a fit. The main reason for this was that I had to get the rear axle to guide distance right as there is very limited space for the guide in the McLaren.
So I ordred a bare Matra chassis and once it arrived I started the transformation.
* Pod: Decided on a Slot.it SICH03 pod that I had. Part of the reason was that this is probably the pod with the greatest offset (1.3mm according to Maurizio) and I needed a big offset due to the lack of space in the back of the HRSS body. I had a spare Slot.it orange endbell motor so that went into the pod.
* Wheels and tyres: I decided I wanted FAT tyres on this one! I mean, that was what CanAm was all about: horsepower and fat tyres!! So I ended up using CB Design 15 x 13 Racing wheels on the rear. Also used Vanquish-size NSR Ultragrips as these are a good fit with the wide wheels. Used matching 15 x 8 CB Design Racing wheels on the front, paired with Slot.it Zero Grips.
* I decided to cut the body parts off the HSRR chassis and glued them to the body.
* Trimmed the Matra chassis to fit inside the exaggerated recessed front wheel wells on the HSRR body.
* While the Matra chassis was perfect for the rear axle to guide distance, the front axle was too far forward. So I had to cut off the stock front axle mounts and replaced it with a spare HRS front axle carrier that I had and glued it in place. Note that narrowing down the chassis to fit inside the front wheel wells and removing the stock axle holders weakened the chassis to such an extent that I decided to epoxy in some thin brass square tubing reinforcement at the same time that I epoxied in the front axle carrier.
* Used a Slot.it universal screw in guide with NSR soft braid.
* Body mounting: because I wanted to use the outsize rear tyres and because Slot.it chassis and sidewinder pods have more space on the one side than the other, I ended up offsetting the rear body mounting post to center the wheels and tyres under the body. And it JUST fits! Fortunately the CB Design Racing wheels have recessed hubs otherwise I would not have been able to make it!
At the front I crafted mounting holes in the chassis to match the existing HSRR mounting positions: worked out great!
* Chassis clearance: there is very little space inside the HRSS body for the mechanicals. I removed the small piece of plastic that holds the intake stacks from the interior assembly, trimmed it and raised it up: this was essential to get the motor in a decent position. I also ground away the bottom of the interior (including the driver's butt and bottom of his legs...) to clear the pod. This surgery is all but invisible: just about impossible to tell the modified interior from the stock one. The bottom of the (visible) left seat was replaced with a piece of card stock painted matte black: looks great.
* I cut the rear engine/gearbox/exhaust/suspension detail from the HRSS chassis and glued it in place on the body.
The rest was just basic finishing and tuning: gluing and truing the tyres, profiling the front tyres, adjusting the front ride height, pod float, 7g of lead in the pod, pod float, taping the pod, body float, lubrication etc.
Make no mistake: the Slot.it car looks great. But the HSRR body in my eyes look just that little bit better. While I am not sure which one is historically more correct, I prefer the slightly darker, richer shade of orange in the HSRR car. The HSRR body is also slightly larger than the Slot.it (particularly wider and longer): I have not measured it but I would suspect the HSRR car is quite a bit over scale. However, in spite of the larger size, the HSRR car has less internal space due to a deeper interior and a flatter rear deck: this is one area where I think Slot.it probably adjusted the dimensions to facilitate accommodating the motor in the rear sidewinder pod.
Out of the box the HSRR cars sit way too high, particularly at the rear. There is a sizable gap between the rear tyres and the top of the wheel well: it really does not look very good.
Some pictures:
Firslty the three cars side by side. To be noted is the smaller size of the Slot.it (#48) compared to the other two, the colour difference (although photographs do not do the difference justice) and the height of the HSRR cars:
Note that the #48 is the lowest of the three, the #7 is a bit higher and the almost stock #5 is higher still. The height difference is more clear in this comparative #48 vs. #7 pictures:
While the #5 sits very high (note gap in rear wheel well): boy, does it look good with the steering etc.!
From the rear: while much, much better than the stock relatively skinny tyred car, the Slot.it still can do with more tyre....
The #5 HSRR looks similar but way too high and a hair prettier I think:
Now THIS looks like the business!! The lowered #7 with fat tyres:
Aahh, now we are getting to the meat and potatoes! And for some perspective: I consider lap times on Luf's Targa in the following categories:
>8 seconds: Not particularly quick. I am not happy if I have a car in this area.
>=7.5 but <8: This would be decent runners. Nice to race. Got to be a relatively well prepared car to meet this
>=7 but <7.5: This is quick. Not everybody in our group gets to these kinds of lap times, particularly not towards the lower end.
>=6.5 but <7: Very fast. I think there are 3 of us in our group that do lap times in this area. Would typically be NSR Mosler type cars but a quick driver with a good Slot.it can make it as well.
<6.5: Obscenely fast. I have two cars that have gone this fast. I do not think anybody else has come particularly close to this.
So to start: the benchmark:
4.1 Slot.it McLaren #48
I still find the Slot.it McLaren to be somewhat twitchy. It feels on the edge all the time. My better Slot.it Classics, the newer anglewinder cars and Group C's feel more competent. Basically all my NSR's feel more comfortable.
Best lap time: 6.949 seconds
OK, so in spite of my reservations this is not a slow car. I just find it more challenging than some others: I need to do some more work on it.
3.2 HSRR McLaren #5
OK, so I did not have great expectations of this one. It is a relatively high car with the guide set further back than I think is suitable for good performance.
So I ran it and it was.... nice. Relatively smooth, relatively quiet and quite well behaved. It clearly was never going to be a rocket ship but it was.... nice. And I like nice. A good looking car that I got for $25 and spent another $15 or so on and that runs nicely? I am comfortable with that.
Best lap: 7.541 seconds
This is on the better side of what I was expecting and just about as good as I could probably have hoped for. I consider this a total success: I am a happy camper.
3.3 HSRR McLaren #7
What to expect from this one....
OK, I did a fair bit of work on it. Essentially all Slot.it running gear so it cannot be bad, could it? OK, so it is not engineered all together like a Slot.it. And it does sit higher than the Slot.it McLaren. But it has FAT TYRES ((I like that...). And it has Ultragrips (which I have never really had success with but they are supposed tot be good!).
So what should I expect? Pluses and minuses, so call it similar lap times to the Slot.it? Not a bad target I thought.
Started driving it... and it felt GOOD! Like REALLY good! I love it! Rock solid, planted, quick.
Best lap time: 6.614 seconds!!! EDIT: I inadvertently added a 3 in the number!!!!! Now fixed
Love it!! I am hugely happy with this car. Expectations exceeded.
Alwyn
