My two cents...
Quote:
Originally Posted by travisjb
interesting... so berk used a hybrid setup? please point us to the link if you find it... i'll look as well... thanks
|
Yes we used a hybrid setup. The air/water cooler was used in addition to the stock oil cooler but we also blocked the airflow to the stock cooler as we didn't think it would need it. An adequate water cooling system is absolutely necessary to make an air/water cooler work, there's just no way around it. NA with a big radiator and proper shrouding I think it would be no problem. Adding an SC to the mix...not sure...
Quote:
Originally Posted by travisjb
Would like your guys input on tire selection... I will be running a 275/35/18 square setup, which will help keep my costs down and also gives me the 0.4 bonus points above (versus running 315s in the back and adding 135 pounds of ballast)... Given I have to use a DOT approved tire, I think I have three choices in this size
1. Ventus Z214 with "very soft" c91 tread... $267 per tire on tire rack
2. Hoosier A6... $315 on tire rack
3. BFG R1... $319 on tire rack
Do you guys have opinions on these three?
|
The C91s will last you all of 3 laps before they start blistering, the A6s will last you 4-5 laps. The C51 compound Hankook is much much better for longer runs. The Berk 135i is pretty much exactly the target weight/power you're shooting for. The C51s are what we run in the MotoIQ Pacific Tuner Car Championships, 275s all around, and they are excellent. The longest we've ever run on one set was a few qualifying laps, a 30 minute race, another few qualifying laps, a 15 minute race, and about 3 hours of track time giving people ride-a-longs at MFest. They still had life left in them but they were replaced with a new set for the next race. The BFG R1s will last you a good bit too but they are MUCH slower than the Hoosier R6 or Hankook C51. If you had a big time attack race that you really wanted to do well in and you have two sets of wheels I would suggest one set with C51s for practice then a set of C91s for a flying lap.
Quote:
Originally Posted by travisjb
Yet another question then done for tonight haha
What fasteners do you guys recommend for the bottom of the car? I'm tearing through bolt heads on my splitter, as they contact the tarmac at 100mph, and imagine same will happen on undertray depending upon how aggressive I get with it
|
Countersunk flat head screws. No matter how much they scrape you can always get a flat head screwdriver in there.
Quote:
Originally Posted by jnaut
As for the oil cooler situation, Travis I would only run oil to water...multiple reason's.
1.Water is more efficent than air in transferring heat. True, unless that water is also hot. Cooling 230 degree oil with 210 degree water may not be as effective as cooling 230 degree oil with 80 degree air. Granted, since water is much more effective the temperature difference can be smaller for the same effect, but there's a point where it is less effective. Again, you MUST have an adequate water cooling system for it to work.
2.The whole system will weight less than any oil to air system, that gives you equal cooling. Not sure if you have weighed both systems but the air/oil cooling system vs. the water/oil cooling system we used on the car I race weighed about the same. Totally different cars though.
3.You have more options in location, leaving the front open for intercooler/radiator. Agreed. Plus you can put the weight in a more ideal place.
4. With mulitple large oil to air, I have a feeling that you are taxing the factory oil pump. I would rather have the pressure/volume to the engine.Being the most oil to water are about a 1/3 in overall size to the comparable oil to air, less stress on oil pump. Agreed.
The situation with the 135i is not comparable for obvious reasons, installer/chassis/equipment plus BMW cooling system is horrendous. If there's one car that I would say is worse than the BMW cooling system its the 370Z.
|
Good luck Travis! Thanks for being a pioneer for all of us!