Chris Foster

From what I've read, the K20 is a pretty solid engine. The reason why I've chose to go with EP3 is the dash shifter and interior. And it seems like the last hatchy hatchback for the civics in the US.

My questions are:
Honestly, about how much would it cost to get 300-350hp (likely a turbo build)? A safe build. I mean a decent price. And a real honest price. Not the typical "just spend 50 bucks and throw a Lsx in it and go" like most of the comments that I'm reading online. Who here has done this and can say?
Is 300-350 DD'able - in a reliable fashion, with a k20? No CELs? Pass a Tx City inspection?
And to double confirm what I've read, a factory ep3 wheel is a 15 inch wheel, right?

I'm going to sell my G35 or trade it for an ep3 (whichever comes first). 18 inch tires are pricey for how slow it is. 18mpg hwy/city (premium) is just great! And customization to everything seems super drawn out and pricier than it should be (example 2 ohm audio system). Plus you feel the weight of the car in the wheel.

I mean, it's EP3 or yeah, get an s10 or something and LSx swap it. But it'll probably cost the same as a turbo EP3 for the initial EP3 price.
But will have bad MPG, higher tire prices, ultimately lower handling than ep3, no dash shifter lol, etc )

Any links to more reliable and decent (and recent) 300-350hp builds would be supertastic!
This will be my first custom turbo build, all my other turbo cars in my life either came with turbos or they were swaps.

Thanks!

extremeracer

You can check out some builds/threads on K20A.org which is a K series specific forum. I don't personally have K series experience but 300 - 350 whp is very do-able on a stock block K20 (provided you have a version with dual i-VTEC and performance minded cams as there are many variations of K series engines.)

A known requirement of a boosted stock block K series is upgraded valvesprings at a minimum - whether this applies for a power target of 350whp I'm not sure and the K series experts would need to advise.

Some basic parts needed:

- GT3071 or similar sized turbo (smaller turbos will work too but the K series heads breathe very well and need adequate turbine wheel flow to remain efficient at high rpm)
- Turbo hot parts kit
- 450 - 500 hp rated intercooler
- Walboro 255 fuel pump
- Bigger injectors ~750cc
- Boost reference FPR
- Hondata Flashpro or similar
- "Stage 2" clutch

Use this kit as guideline: UPP 02-05 Civic Si/EP3 Side Mount Turbo Kit | Under Pressure Performance - Turbo Systems

Chris Foster

Very very good info.
I didn't know about the valve springs thing. I guess they're prone to valve float?

And I never thought of looking at a complete turbo kit for all the necessary parts - duh! Makes sense.
Wonder if I could get away with a TD06. I won't make as much power as the GT3071, but I don't think I need that much? A 20g might spool faster too?

TheShodan

iTrader: (14)

TD06-25G, 20G? Those make a difference in terms of what power level you want to have efficiently. When you start getting into Mitsubishi turbochargers, you have to take into account your exhaust manifold and if it will properly fit with the correct flange. Most Mitsubishi turbine housings will not fit pre-fabricated exhaust manifolds for the K-series that are available. You're best to stick with the T3 turbine housing configurations.

As for valvetrain for the K-series, switching out is not nearly a necessity as it is with the B-series engines, so I don't think that will be an issue. But unless you have the resources to fabricate a majority of these parts, it's best to get the entire kit (except possibly the turbocharger) from the main U.S. companies that offer it. This ensures proper fitment for not only the turbocharger, but all of the supplemental components such as the intercooler, intercooler piping, couplers, clamps, and other essentials that you'll need.

As extremeracer stated, use his link as a guideline to what you need by way of components to complete a turbo system. These systems don't allow for mitsubishi-flanged turbo systems.

You also may want to see our FAQs highlighted in grey at the top, to know precisely what you're getting into when it comes to these systems. It's always a good start

Balor_Gr

Mate im in europe and there are a TON of turboed k20a2/z4 here.
Ill tell you this everyone here is rocking around 500hp on the stock internals.
Some folks with water/meth injection run more but they are the racer type that need to hide some hp

This engine has superb mid rpm power so you dont need to break the bank on expensive turbo.
Get a journal bearing s256 or a turbo from the shodan and call it a day.Trust me if you use small
turbo you WILL SPIN. Ep3 6gear trans haskinda short gearing for 1-2 and 3rd if i remember correct.
Id use a 450+hp turbo to save my tires.Unless were you live the asphalt is germany type.(I hope we had
asphalt like this here)