Don't forget to keep in mind PPIHC often requires a bit different approach to things than normal road racing. Part of the reason I'm after wider tires is so that I can put more grooves in them (i.e. biting edges for the dirt sections, much like siped tires in the snow), but still be left with the lateral grip of say a 245ish tire on pavement.

I'm fully aware of the weight penalties of increased rotational weight, but picking the right tread compound takes precedent over the lightest parts on The Hill. I'm sure a BFG R1 or Kumho V700 was lighter than the yokohama rally tires I ran last year up there, but with the proper compound and tread design, we put 40 seconds on the nearest competitor over 12.4 miles (top guys from PPO and Time Attack AWD), and our car didn't have the best power/weight by a long shot.

Dave

 

more power only helps you in one direction of acceleration.

less weight helps you in EVERY direction of acceleration.

To me... the Evo takes to power mods very well. Get the low hanging fruit... TBE, Intake, Retune.

TAKE THE WEIGHT OUT!

 

I dont have access to the BFG R1 over here but the V700 rates quite a way down our list of preferred tyres. Is that what you are considering running?

 

One of the subies ran the V700s last year. He was a second or two quicker than us on the tarmac stretches, but we made up lots of time in the dirt.

The biggest problem I have with using proper rally tires (BFG or Pirelli) on the car is that most rally cars are making ~300hp/400tq, and the widest ones I can find are only 225s. Based on my experiences last year, a 205 barely cut it at 300hp/300tq, so with our new engine setup, a 225 has even less "contact patch/hp" than the old setup.

I'm curious to see what the Ford Fiestas will be running, as those guys are at ~800hp. All I know is that they'll be on BFG/Michelins.

Dave

 

True, but on topic as you take the weight out, it's that much less mass to move around on x contact patch. Personally if you have the practice time, I'd bring both and see what the logs tell you. I'd almost lean more towards the rally tire because you'd require more mech. grip in the dirt, especially with increased power, that the road tire simply cannot provide. Is it also steeper in the dirt sections?

 

Unfortunately, as many have alluded to, the weight reduction path is a much more expensive one. Since I'm not a lottery winner, I went with a combination of some weight reduction (hood, trunk, driveshaft) and an FP HTA35R. My reasons for choosing these parts were that I'd be able to run these parts at other hillclimbs and rallies. Carbon doors are a no-no at rally events, so it would've been an expensive purchase for one race per year.

On the tire testing, we typically only get 3ish passes at each section of the road, so I picked two tires to try, and I'll have to leave it at that for this year. The way I typically approach the runs is to ramp up speed throughout the morning, so it'd be hard for me to make good back to back to back comparisons.

FWIW, one tire was on the recommendation of engineers from BFG who have been involved with PPIHC for years, and their suggestion was to continue running a tire that they've seen success with when the road was all dirt. The other tire I settled on came as a recommendation from Paul Dallenbach, a multi-time PPIHC winner, based on his results at one of the private testing days up on the hill this spring.

I do have to say, the car looks flat-out mean with the big meats on it! Also, for reference, stock Evo VIII rims with 255 width Star Specs weigh more than the NT0-3s with the 275 BFGs. I forgot to grab a BFG rally tire on Compomotive 15x7 rim for comparison.

Dave

 

Nods, roll the dice and see what ya get . With all your inf. spare time you still owe us pics of the pump relocation, and exterior shots with fat tires and new wings

 

Maybe I'll try to get Allison to help out with some of the documentation shots while I'm working tonight.

Dave

 

when you replace the doors with seibon's, you can use the stock windows, motors, etc?