98 Eclipse GST

[mcornelison]

This is the Build Thread for 98 Eclipse GST. Reply below.

 

[mcornelison]

OK... my online upgrade and build starts....

I have made sure the basic and regular maintenance is done.

I am going to follow the upgrade path that was posted in is forum.

https://www.dsmtuners.com/threads/1998-eclipse-gsx-upgrade-path-question.338260/

I am new to this group and I apologize if I use the incorrect term. Please be kind and nudge me in the right direction

As of Feb 23, 2024
What I have done to date
- oil, belts, and fluids
- Strut Bar Front - Front Strut Tower Brace
- Strut Bar Rear - Rear Strut Tower Brace
- HD Radio - KDC-BT382U (yea not that fancy)
- Speakers Front
- Speakers Rear
- M52 Black Aluminum rims (I am not going for the low-ride look)
- POTENZA RE950 wheels
- Tinted windows
- Rear Tail Lights
- Center Tail light panel upgrade (customized)
- Performance Spark Plugs
- Performance Spark plug wiring

What I want do
- cold air intake
- breaks
- BOV
- Boost Controler
- fuel pump
- clutch
- turbo
- intercooler
- oil catch can
- computer controller

 

[mcornelison]

Doing a clutch upgrade next week. upgrading to a LUK clutch. While the trans is dropped, is there anything I should do as long as I am in there?

 

[mcornelison]

LUK clutch install. (LuK RepSet Pro: the repair set for hydraulic clutches. (schaeffler.us))
While in there replace rear main gaskets, clutch master and slave, and new starter.

Also last week I finished my stereo upgrade. Here is my part list:
Pioneer DMH-W2770NEX - head unit
JL Audio C1-650x - 4 x 4" JL speakers for front and rear
Rockford Fosgate P300-10T - base / subwoofer
Boyo VTL17LTJ - backup camera
RetroSound PA-03 Power Antenna (black)

sounds and runs great! Now onto more performance wants.

 

[mcornelison]

This weekend I did a long-awaited easy bolt on. I added my cold air intake. I am sure this is rather beginner this to do. but I have to start somewhere.

parts:
Injen Technology IS1890P Polished Short Ram Intake System

It looks great.

 

[mcornelison]

This week I am installing Megan Racing EZ II Coilovers (https://shop.redline360.com/product...ers-mitsubishi-eclipse-95-99-mr-cdk-me95-ezii).
This was a simple and straightforward job. Just a little penetrating oil and all the nuts came off easily. I will need to set the ride height, but they are installed.

Because these went in so quickly, I moved to install the front coilovers. I moved the jacks to the front and started the process. Everything was going smoothly until I reached the small control arm that connected to the knuckle to the sway bar. OH my! I spent an hour just getting the bolt to turn. Heat, penetrating oil, and repeat. Then to realize that it was just spinning and I needed a small hext wrench in the center to hold that still. Well.... after another hour or two, I gave up.

Once I can get them off, I have ordered new replacement control arms. For a small piece of metal, they are not cheap, and as of today, Mitsubishi doesn't make them anymore. The old OEM part number is MB892981 and the new part number is 4056A026. I have included a diagram if anyone is interested.

Any tricks to getting a tool in there and getting it to come off without cutting it or breaking the hex wrench?

 

[mcornelison]

Engine Bay Fuel System Upgrade: AN6 Lines, PTFE/E85 Compatibility, and FPR Install
After two weeks of wrench time, I’ve completed a full upgrade of my engine bay fuel system—swapping in AN6 PTFE lines rated for E85 and installing a new vacuum-referenced fuel pressure regulator (FPR). Here’s the parts list that made it happen:

Parts Used:

• EVIL ENERGY 6AN EFI Bypass Return Fuel Pressure Regulator
  Link
• EVIL ENERGY 6AN 3/8" PTFE LS Swap EFI Fuel Line Kit
  Link
• Extreme PSI 6AN Fuel Rail Fitting
• Extreme PSI Fuel Pressure Regulator Firewall Install Kit

The Process:
I started by watching a few tutorials on cutting and assembling PTFE/AN6 lines. After a couple of trial-and-error fittings, I got the hang of it.

Roadblock #1:
The fuel filter outlet required an AN8 to AN6 male adapter with a sender port. Took two days to get the right fitting, but once it arrived, it mated perfectly with the fuel rail adapter.


Fuel rail fittings installed.
Next issue: I needed an AN6 to hardline adapter. I initially ordered a 5/16" version—too large. Reordered a 1/4" AN6-to-hardline adapter (another two-day delay). But the return line had a factory flare, which prevented the fitting from seating properly. I had to order a mini tube cutter and a compact 90° AN6 fitting to make it work—again, all PTFE-compatible.

Hardline Modification:
Using the tube cutter, I carefully removed the flare from the return hardline. This allowed the 1/4" AN6 adapter to seat and tighten correctly. Pro tip: cut the flare off first—saves a lot of hassle.

To access the return line fitting, I removed the timing belt cover—gave me the clearance I needed to route the 90° AN6 fitting cleanly.

Fuel Pressure Regulator Install:
With all lines routed, I mounted the FPR—finding a suitable location on the firewall wasn’t easy, but the install kit helped. All AN6 lines were connected: feed, return, and vacuum reference.

System Test:
Turned the key to AUX—no leaks. Fired up the engine—it started, then immediately died. I suspected fuel starvation. I recorded the FPR gauge during startup and confirmed: zero backpressure.

Quick Google confirmed it—rotated the FPR adjustment screw clockwise to increase pressure. The car fired up and held idle. I dialed in the pressure to 42–45 PSI, per spec, while monitoring for leaks.

Final Touches:
Re-secured all hoses, wiring, and bolts. The engine bay is now fully E85-ready. Rear pump and fuel line upgrades are next on the list.