420A 99 Eclipse 420a engine build

[artemGS99]

Hey guys recently bought a 99 Eclipse and got the engine out and gonna get new gaskets etc. I’m looking to build it to around 300hp many people have said that these engines are slow and hard to push power and a money pit. I’m just wondering the best way to push for around that power. Was thinking about putting an Evo head but probs not.

Thanks guys any help would help✌

 

[jesse12345]

There are a few ways you can go, but if your looking to make power your only options are Wiseco pistons and Eagle rods.

To tune your best option is Megasquirt. If you want just a little more power that actually feels decent, you can do upgraded stock pistons and an FMU.

Your also going to want a wideband, and boost gauge so you know what's going on. I'd also run head studs, I was using stock bolts but I didn't want to chance it. This is all just a few things you can do the information is out there.

You also cannot Evo swap any head onto the 420a. The Evo is Mitsubishi and the 420a is Chrysler. Good luck with whatever you decide.

 

[steve]

I'm not aware of anyone reaching 300HP on a 420A without turbocharging it and that brings in a lot of supporting mods and expense.

There are many threads here for both NA and Turbo builds with the 420A. Reading them should give you a better idea of what your next set of questions might be.

 

[jesse12345]

I should have been more specific everything I noted was with a turbo. So my apologies.

 

[steve]

Did you see that there is a whole forum dedicated to turbocharging the 420A?

420A Turbo Conversion

Turbo kits, swaps, etc - specific to 2G N/T DSMs.

www.dsmtuners.com

 

[BLACK'98DSM]

Damn near everything you need to know is already on this forum. I myself have given input on probably hundreds of threads pertaining to 420A builds. And many others have for well over a decade before I started. I recommend you dig deep in this website/forum. You can click links for hours and everything is there. This is more of a history book or enthusiasts dream resource rather than a website.

300whp is not attainable naturally aspirated without nitrous (or hasn't yet been achieved and probably won't as the enthusiasts dry up). Easiest way to get there is with a turbo build. Some have reached 700whp with enough boost and a serious tune. In the realm of N/A, 200whp is achievable but requires hefty modification and tuning.

Decide how streetable you want the car to be and how much you want to spend, then pave your path from there. In the meantime do some reading. It's all here if you can sit down for a while and find it.