[Slidewayz-Jones]

Originally Posted by oldman

I was on the fuel debate for a long time. I finally went to a fully upgrade DI, able to run E85.

Within reason 93, E85 and Meth will all put out the around the same HP at stoi, the slight advantage of the alcohol is there is just more liquid being injected leading to more expansion gasses. E85 has a higher max rich mixture than fuel, meaning there is more liquid to not only expand, it also means a lot more cooling of the piston during the compression cycle where the phase change takes place. It is the phase change that absorbs heat.

Now meth has such a high rich max power A/F ratio, you can literally pour it into an engine and continue to make power. Also very insensitive to cylinder variance and atomization compared to gas. A perfect choice IMO for PD. That said for a centri, I would still go to 8 points on a high ram as the stock manifold is not made to flow liquid. Call it OCD. The second issue is what if something goes wrong with the secondary injection, it can be as simple as running out of fluid.

Given the added complexity of meth injection, it was just easier to go with a DI system. The cheapest upgrades are in order: Lt4 injectors, cam lobe, LT4 HPFP, LPE HPFP, lt 4 based 30% injectors FIC GDI, "52%" more KDI injectors. Not including labor. It would be interesting to see what a LPE HPFP, and KDI injectors would support on E85 with the stock fuel lobe, this would be the max "bolt on" that can be done for $1600 and $4250.

I just wish more options were available for fuel on these damn cars haha