Cutting to the chase, any advice on the following would be appreciated (M20 stroker turbo, maybe e85), see further below for background/context:
As the title states, I am planning to build an M20 stroker setup for my VGT turbo car, to replace the currently running "2.7i" I built in 2015 with the following:
Starts making boost (slowly!) starting around 2000rpm, 10psi after a few seconds at 3000rpm, full boost pretty quickly at 4000rpm. I think this is not bad for the altitude and 60mm turbo. Primary goal for the car is to make really good power numbers for a given boost level, secondary goal is to retain good boost response at low-mid RPM via the VGT.
I think I have achieved both goals given that I'm using eta pistons with the 885 head. I don't think this is doing me any favors with low-rpm boost response, especially since I'm at altitude. I also did not get any machining done on the block, and suspect I don't have the best ring seal. Last compression test was fairly low, even given the altitude factor. So, I want to put together a new short block to improve the low-end, and digger's build thread and the great info posted over the years by ForcedFirebird have me inspired to do maybe 84mm crank, new pistons, and maybe new rods. In addition to the eta short block that's in the car, I have a spare b25 bottom end in my garage too.
- Which version of 84mm crank to look for (given I'm in the US, although I suspect this may lead to eBay so possibly worldwide sourcing)? Or go with a different stroke, such as keep the eta crank or go bigger?
- Which pistons? IE 2.9L Mahle cast pistons, JE, CP-Carillo?
- What compression ratio? Open to running e85, although that may bump the power enough to need bigger injectors and pump (currently running Deatschwerks 700cc injectors and 340lph pump).
- Any insights/feedback on vendors and their lead times, especially experience with custom pistons, would be appreciated.
As the title states, I am planning to build an M20 stroker setup for my VGT turbo car, to replace the currently running "2.7i" I built in 2015 with the following:
- eta bottom end (block, crank, rods, pistons) with 885 head
- IE HD rockers and springs
- Enem Z45 turbo cam (280/280 with 112 lobe separation).
- HE351VE VGT turbo, 60mm/60mm, supposedly 26cm^2 with vanes fully open
- 2.93 LSD and Getrag 260
Starts making boost (slowly!) starting around 2000rpm, 10psi after a few seconds at 3000rpm, full boost pretty quickly at 4000rpm. I think this is not bad for the altitude and 60mm turbo. Primary goal for the car is to make really good power numbers for a given boost level, secondary goal is to retain good boost response at low-mid RPM via the VGT.
I think I have achieved both goals given that I'm using eta pistons with the 885 head. I don't think this is doing me any favors with low-rpm boost response, especially since I'm at altitude. I also did not get any machining done on the block, and suspect I don't have the best ring seal. Last compression test was fairly low, even given the altitude factor. So, I want to put together a new short block to improve the low-end, and digger's build thread and the great info posted over the years by ForcedFirebird have me inspired to do maybe 84mm crank, new pistons, and maybe new rods. In addition to the eta short block that's in the car, I have a spare b25 bottom end in my garage too.
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