mender

You could mount a GoPro inside your fender and see exactly what the tire and rim combo is doing out on the track. If you really want to get crazy you could mount a GoPro inside the tire:

Leakdown and watch for bubbles in the rad to locate the bad hole.

Which one/part number?

Not sure if this will help: https://grassrootsmotorsports.com/articles/engineer-weighs-corvette-leaf-springs-deep-talk-se/

Looks like that's an update of the system used in this book: https://www.ebay.com/itm/223777330559

I haven't run into this issue of high pressure/not opening; sounds interesting. I used a 55 spi Corvette filter/regulator (WIX 33737?) on the Fiero and selected injectors to get the recommended 80-85% duty cycle, so haven't ventured into that pressure range. Any particular injectors that have that issue?

Yes. You may find that the engine likes slightly over 13:1 AFR.

The fuel injection doesn't know what changes you made to the engine, all it does is read the various sensors and command a pulse width based on the programmed fuel map. If a change you made improves the air flow through the engine (eg, better exhaust scavenging), the MAF should read that improvement and adjust the AFR accordingly. The compression ratio change will affect thermal efficiency and improve the engine's output and fuel usage but won't change the commanded AFR.

Looks like there may be provisions but you should contact U.S Customs directly: https://www.cbp.gov/trade/basic-import-export/importing-car Cars Imported for Other PurposesNonresidents may import an automobile or motorcycle and its usual equipment free of duty for a temporary stay to take part in races or other specific purposes. However, prior written approval from the EPA is required and such approval is granted only to those racing vehicles that EPA deems not capable of safe or practical use on streets and highways. If the contests are for other than money purposes, the vehicle may be admitted for 90 days without formal entry or bond if the CBP officer is satisfied as to the importer's identify and good faith. The vehicle becomes subject to forfeiture if it is not exported or if a bond is not given within 90 days of its importation. Prior written approval must be obtained from DOT. A vehicle may be temporarily imported for testing, demonstration, or racing purposes. A vehicle may be permanently imported for show or display. Written approval from DOT is required and should be obtained before the vehicle is exported from the foreign country to the U.S. Information on how to import a vehicle under show or display is available at DOT's NHTSA Vehicle Importation Regulations website. A vehicle permanently imported for show and display must comply with all U.S. emission requirements as well, and in general must be imported through an EPA-authorized ICI for modification and testing. EPA will not allow the vehicle to be released to its owner until ICI work is complete. Exceptions The following vehicles need not conform to emission or safety requirements but may NOT be sold in the U.S. and may require EPA and DOT declarations: Those imported by nonresidents for personal use not exceeding one year. The vehicle must be exported at the end of that year - there are no exceptions or extensions. Those belonging to members of foreign armed forces, foreign diplomatic personnel, or other individuals who come within the class of persons for whom free entry has been authorized by the Department of State in accordance with international law. Those temporarily imported for testing, demonstration, or competition, provided they are not licensed for use, or driven on public roads. These vehicles may be operated on public roads or highways provided the operations are an integral part of the test. Parties responsible for such vehicles must submit proper documents - forms EPA 3520-1 and DOT HS-7 - to CBP at the time entry is made. Also, applicable written approvals from these agencies must be obtained in advance and presented to CBP along with these forms. Remember, the cost to return vehicles that have been refused prior approval can be very high and must be borne by the vehicle owner(s). This site might be more informative: https://www.a1autotransport.com/importing-a-race-car-into-the-us/

http://i89.photobucket.com/albums/k224/johnny_3301/IMG_1792_zps596ee481.jpg I remember reading an article about the rapid change in tire width and rim width in the early sixties. IIRC, the tire engineers thought that the tire should be wider than the rim and the rim engineers thought the rim should be wider than the tire. Testing went back and forth with a wider tire then a wider rim, and in the space of about six months the combo went from pretty narrow rims and tires to about double the width, with grip increasing every time. That apparently flew in the face of accepted physics which basically said that the available friction was dependent on the normal force and not the contact area. As they say, the theory says it should work in practice, but if it doesn't, it's time for a new theory.

I ran the 225s on 9" rims.

For the engine nerds out there, more food for thought:

DI engines adapt well to boost...

https://www.jstor.org/stable/44730726 Just the compression ratio change is worth about 3%: https://www.musclecardiy.com/cylinder-heads/maximizing-cylinder-head-compression-ratios-power-part-12/ Also, more oxygen gets through the same intake tract because there's no fuel being induced with the air.

Third place finished 10 laps down last year... I think it's a good package, I'll be watching!