Quote:
Originally Posted by FunnyGopher
There's a post on here from Delicious somewhere explaining that they opt for customers to use a stock compression or 12:1 compression built block when going FI, because there was no need to lower compression. I have a buddy locally who just built his block through CSG via Bluemoon Performance, and they opted for a 12:1 compression. Both of these companies are regarded as companies that know their stuff, and both chose to use stock-ish compression.
Just sharing some knowledge about what those companies prefer, not trying to tell you you're wrong. Many different ways to make power.
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^this. It was the dyno for TJ Hunt's car w/ Edelbrock super charger for the delicious tuning one. Long story short, the car made roughly 400 whp but had they had to dial back the power due to the amount of linear boost coming out of the super charger. IIRC eventually TJ Hunt changed over to a turbo kit instead for more power while keeping that same CR.
Quote:
Originally Posted by 86TOYO2k17
When these cars first came out, it was commonly thought that even 10:1 compression was high compression, and people thought with 12.5:1 that no way this can handle any boost, then people tried it and thought, OK it can handle it but 7psi is the limit, and then they kept testing it and pushing it and its been shown that even 12-13psi is pretty reliable on a stock engine. Many tuners in recent years now have changed their thoughts on needing to lower the CR stating its not really necessary, and often times not recommended.
New tuning methods, the cars ability to monitor so many parameters and give instant feedback, being able to adjust and tune so many parameters, and having both PI and DI, has allowed tuners to safely push these cars closer to the edge, as well as push the edge further out, allowing for safe reliable power with out needing to drop the CR.
400whp on E85 is easy to get with stock CR, I would possibly consider 12:1 for a slight added margin of safety and being able to push the car more in the future if desired. but much lower doesn't seem necessary or worth it on these cars, unless your shooting for some crazy numbers.
Hearing from people who dropped CR stating its worth it or recommended doesn't really say much. I would much prefer hearing from people with built engines and kept stock CR and what their tuner said was the limiting factor for reliable power.
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I agree with this. Not much people ran the 12.5:1 CR on built motors for our platform but it has been proven that it does work. I would like to see more builds with the standard CR. Pretty sure everyone has seen how TJ Hunt drives his BRZ. He has not blown his motor yet from what I can recall but had snapped a lot of belts off of the supercharger.
Another view on this are the stock motors built by Honda (I know different engine). I have seen even the type-r engines (both B and K series) push around 350-400 whp on stock blocks w/ boost (these are already running 11:1 or 11.5:1 CR iirc from factory) and still driving fine.