Intermittent fuel starvation

1987 944S LS1 track car.

I have been suffering what appears to be intermittent fuel starvation at the track. I have replaced fuel pump, fuel filters, fuel regulator, and fuel pump relay, but the problem continues. Problem seems to occur only at the track when temperatures are relatively high. Never had a problem driving to/from the track, when temperatures are more moderate. I am now suspecting vapor lock.

My latest trial solution has been to install hood louvers to try to lower peak under hood temperature, and to wrap the LS1 filter/regulator unit under the hood with insulation. I will see what happens when I head to the track again next week.

My questions:
Has anyone else had similar problems?
Has anyone installed hood louvers and found them effective to lower under hood temperatures?
Any other suggestions?

Thanks, John

I never had this issue with mine. My fuel filter / pressure regulator is mounted in the back at the 944's stock filter location. It's a dead head system with a factory fuel rail, is yours? What did you do with your fuel tank vent system? If you just cap it, this generates a vacuum in the tank as you use fuel which can cause fuel starvation or even collapse the tank. I left the stock charcoal canister and purge valve, tied it all into the intake as close to factory as possible.

And yes, I vented my hood to help draw air through the radiators. Not sure if it helped under hood temps but it certainly helped water/oil temps. Key here is to locate the louvers forward of the shock towers to access the low pressure area above.

Rich

My car severely overheated during a competition, the swap radiator just isn't good enough without major hood venting and some proper Spal fans. Cost me a $6000 motor to find that out.

For the fuel issue: Is your fuel pump pushing enough GPM for the increased consumption by the LS? Is your regulator set at 45psi? Are your injectors big enough and not clogged? Are you using a proper recirculating regulator setup to keep the gas flowing and cool? Fuel issues absolutely suck, as there are dozens of potential causes. Also, the 944S fuel tank has a plastic "swirl tank" inside of it. That tank is not well secured, and could have broken or come loose over the years. I had to painstakingly make repairs to mine during my swap process, it was an absolute nightmare.