Radford43

I am hoping to start to build a 20b powered autograss car in the coming year I am looking for as much help as possible I have a few questions if anyone could help me with. The car will run for about 50 hours a year and will be run at about 10,000rpm looking for around 400whp, I will run a standalone ECU. It will be placed over-slung in a classic mini-pickup inline mounted to a VW transporter gearbox with a Hewland gear kit in it. I will be doing all the work myself with the exception of the tuning, as I can make the manifolds and wire the car myself. I will run the engine pretty much standard with a better manifold and exhaust and a retune. If people are interested I would happily vlog the build or just make a build thread of the stages.

1) What size turbo is the smallest single turbo I can run for about 400hp that will not restrict the engine to much on standard ports or a very slight street port?
2) What engine mods would you suggest for the longevity of an engine?
3) What standalone ECU would you recommend with support?
4) What coils would people recommend?

Thanks, Will
Located: England

reddozen

20b was not designed to run over 8-8.5k RPM, and over reving them is why most of the eshafts are out alignment (including mine).

For 10k RPM, you will need a perfectly straight shaft (good luck). Lightened, balanced, and clearenced rotors. Also, a dry sump set up would be recommended (OE units are pretty rare at this point, and expensive) with a direct bearing oil feed tapped into the irons.

You're probably taking about a $15-20k in just the short block work. A 13b REW can easily meet your power goals at a fraction of the cost with larger part availability. Welcome to spend all the money you'd like, but people typically use a 20b or 26b to get higher HP NA setups or "more reliable" 600HP+ builds.

Radford43

Thanks for the reply not sure you've seen autograss racing before we race on a dirt oval track that's about 100mm long so we need as much torque as we can get and as it will be rear engine I need the weight so I can get the grip off of the line so a 20b is a better alternative as the 13b just isn't heavy enough. I will leave the engine internals standard and I am going to keep it very mild as it needs to be reliable and very toque with a useable rev range so I can have a better chance at gearing it right which is the biggest challenge.

But thanks for letting me know about the rpm I thought they would be able to handle it.
Will