Shouldn't be an issue of AVGas hurting your car any worse than full blown leaded racing fuel. Both will attack a cat and/or O2 sensors. In prod, you have to live with that because that's the rule, stupid as it is.
I find it hard to believe that it is against the law to use AVGas in an offroad vehicle. Many of the big time Formula car engine builders recommend using AVgas to their customers (Ivey, Elite, Quicksilver come to mind). These are extremly reputable builders, well known nation wide. I find it hard to believe they would suggest something illegel to their customers. Multi-time national champ Dave Weitzenhof indicated (on the FC website) he uses AVgas during the normal season for cost reasons, but switches to the 'brew of the month' for the runoffs where the additional 1/2 HP or so becomes important.
I would say it is fair to state that some airports might have restrictions on who they sell to, and in some cases, drivers have come up with clever, legal solutions. As an example, the airport might require a tail number, any number, just to allow them to sell the gas, especially if it is some type of automated billing. They don't care what the number is but need a number before they can press the 'accept' button i.e. the computer needs to see all the data fields filled out. I've heard that one solution is to enter a tail number of 'N00000'. In other cases, the simple solution is to say your using the gas in an ultra-light, which doesn't require FAA approval or have an ID number but does require AVgas to run properly. There are quite a few airports in the rural areas that are unattended, pay-at-the-pump.
I do agree that it is illegal to use AVgas in a street car, because it bypasses the tax laws, and it damages the emissions equipment.
Not all AVgas will pass the SCCA fuel test, but I think LL100 does (this is what the DW and other formula drivers use). You would be wise to spend $5 and have a sample tested before using, or go to a known source that other racers are using who have had the fuel tested. Keep in mind that just because it passed the test today doesn't mean it will pass the test tomorrow. This is true for any fuel. Mistakes are made. The gas supplier can screw up and mix unleaded into the leaded tank causing it to fail (as happened at IRP in the past causing several national drivers who used 'track' fuel to get bounced!!)
Regarding the engine and suspension rules, in IT you are limited to how much you can physically remove from the head, i.e. 0.025" max, not to excede 0.5 compression point. In LP, you have no restriction on head milling, other than total CR which will be listed as a spec item in the PCS and will chnage from car to car. I think spridgets are allowed 11:1 CR but don't quote me. You can run ANY piston with any dish/dome configuration in prod. Other than the milling, the head rules are pretty much the same as IT i.e 1" port matching only, no porting or polishing.
I'm not sure about the valve rules. I am currently running stock. It has been implied that they must have the exact factory valve grind, but this has been debated on the prod web-site. I am running stock. DO NOT ASSUME FACTORY STOCK VALVES MEET THE PCS LIMIT FOR MAX DIAMETER! That's how one HP winner got bounced two years ago. One valve was 0.001 too big or something minor, but the driver admitted, he didn't check. Check them and have them machined down to the legal limit if required.
I don't know what the pushrod rules are because I don't have them so I tend to skip over that section of the PCS.
You can change the cam, max lift is spec item in PCS, duration is free. You can add an adjustable cam gear and timing is free.
In LP you must run stock rods but you can polish/lighten/nitride to your hearts content. You can regrind the crank to a maximum undergrind limit of 0.040"???? (I know there is a limit but off the top of my head I don't know what it is.) You can polish/lighten/knife-edge to your hearts content. Flywheels and clutches are free. Dry sumps prohibited unless factory stock.
The suspension rules are being strongly debated on the prod website. Suffice it to say the current rules only allow control arms to be reinforced or modified, but you must retain factory ball joints and tie rods. The Heim joint issue is being debated. Shock rules are similar to IT, but I think RR shocks are permitted. In the case of a spridget, your screwed because you have to retain the lever arm design, but you can upgrade to something bigger like MGB shocks. Dust off your 70's competition guide to relearn the forgotten art of tuning Armstrong shocks
The other big difference between LP Prod and IT is that you do need to pay attention to specific items listed on your vehicle spec line in the PCS. There are general rules for everybody and then specific adders/limits for each car. IT doesn't have that.
I'm still learning myself and am slowly working on changing the car from an 'IT car with slicks' to an actual production car. The nice thing is, you don't have to do it all at once. I'm doing it in stages on a tight budget, and I'm having a ball!
[This message has been edited by Greg Gauper (edited March 04, 2004).]
[This message has been edited by Greg Gauper (edited March 04, 2004).]
