MOfroggy,
Excellent question! I actually started with the HPI Tarmac tires as it took a little while to get the AMS adapters. I also did quite a bit of testing and my impressions are as follow:
The handling was decent, but after just two tanks I started to see quite a bit of wear in the center of the tire which indicated the tires were balooing out some, not much but some, that forced me to have to mess with camber after every tank in order to make the tires last. I am used to doing the same for my other racing cars so not a big deal at first, but after just 6 tanks of gas I was running out of places to move the tire contact area.
I setup my cars to have quite a bit of forward bite with little bit of steering push which in turn forces my style of driving to be aggresive as I normally brake very late which means I kept on making the tires fold under the rims during heavy turning which caused a blow out in one of my rear tires in just 7 tanks of gas.
A set of tires lasting 7 tanks of gas in a heavy car like the buggy seemed reasonable and I was happy enough. I was getting ready to buy another set and continue testing, but then the AMS adapters became available and decided to just try the 1/5 scale touring car tires instead.
So in a single sentence 'YES, the HPI Tarmac tires will work', but you have to make some other changes to the setup, and have to deal with revisiting the camber and toe-in, toe-out in the tires quite often to make them last a few more tanks.
The changes needed are :
- 10,000/5,000 diff oil front/back (less forward bite, but easier on the tires)
- 55/45 shock oil front/back (To allow the chasis more roll to have more tire traction, but you have to be careful with an oversteer condition)
- use about 2 degrees of toe-out in front (to keep it tracking straight with tires that have less traction due to the small contact area on the tires)
- goto 29/31 and 25/25 if stock motor or 27/33 if using a motor bigger than a 26 (bigger radius tires)
- start with zero degrees of camber up front and 2 negative on back to see where your tire contact patch is and then change it as needed to avoid premature tire wear. (to correct for balloning effect)
As far as where you can get the 1/5 touring tires? You have several choices, but I like getting them from the Pro 5th scale site, they do not have as good customer support as Rob at RampageHopUps, but they seem to have the tires at a reasonable price (I imagine with the dollar being down this will change soon). You also have three good tire choices as PMT makes several kinds of tires for the 1/5 scale touring cars.
My recommendation depends on what you want to do:
All out racing: Eclipse
http://www.pro5thscale.com/inc/sdetail/244
Semi-Pro : Kronos
http://www.pro5thscale.com/inc/sdetail/243
New technology, cheaper, lighter and I hear better than the kronos : Icaro
http://www.pro5thscale.com/inc/sdetail/245
One note: the track where I practice has a smooth to semi smooth surface and it barely got to 125 degrees during the summer; that is how I got away with the 27/20 shore combo. Depending on you asphalt surface and temperature you might have to choose another shore. Sometimes when you choose the wrong shore you can half or double the life of the tire.
In thinking about it, you really can't go wrong with either the HPI or PMT tires , is just a matter of preference, whether is easier to get one tire or the other and setup know-how; you exchange cost and ease of use depending on your point of view. It just so happened that I had a few Kronos/Eclipse tires laying around the house and they seemed to fit my driving style.
DRT.