First off let me state that this is only a list of recommended upgrades. This is not law. Many things can be done in different orders, I do not know everything so if I do happen to leave something out or something is out of place please give me the heads up so I can make changes. Second the 420a was not meant to be a “go fast” motor, but it can be. Everyone who drives a 4g63, us 420a guys get the point, we should all sell our cars and buy GST’s and GSX’s because we are wasting money.

*Stages with the star should be completely finished because some parts need supporting mod’s.

[Anything] boxed off is optional, but recommended

+ are notes

(Reason for or describing product)



Stage one
-Cat back exhaust (Something 2.5 or bigger to increase air flow.)

-Plug wires(Improves spark, most old motors need plug wires replaced anyway.)

-Ignition coil (This stage is inexpensive and it’s something you will need in the long run.)

-Plugs (Bkr7e-11 gaped out to 20-35, DO NOT install yet, it’s a cold plug and will make your car run crappy when n/a)+ Believe it or not the plugs are made for an Audi.

-Straight pipe [optional] (The stock cat can be gutted to get the same effect but either straight pipe or gutted stocker you will not pass inspection.)



Stage two
-Turbo kit

+ This is actually tricky. Thanks to Chris (gsgoingfast) and his “how to build a turbo kit for under 1g” lots of people are making their own kits. Also Conceptillusions released their kits this year, and Hahn sells their manifold, turbo, oil line kits, ect. Separate now. As of today your options for a turbo kit follows,
Stage one kits- Conceptillusions 1400, Hahn 2g, Star 2g, Chris style 1g, or a Hahn custom kit 1200-2g.

Stage 2 kits- Conceptillusions 2200, Hahn 3400, Star 2900, Chris style 1g, or Hahn custom 1200-3g.



Stage 3
*… the expensive stage!

-Built Head (New valves, seals, springs, retainers, rockers, [*cams, adj. cam gears, ignition retard, starter amp.].)

-Head port (Conceptillusions offers 3 types of port jobs. 1 being mild and requires little supporting mod’s. 3 being an extreme port and requiring a bigger throttle body, intake manifold either after market or ported, and a ported exhaust manifold.)+while it’s their get them to check the head for heat warp.

-[60mm TB, ported intake manifold or a obx/venom] (Only necessary if you go with a stage 3 port job, but useful non the less if you do get them with a 1 or 2 port job.)

-Built bottom end (8:6:1 forged compression pistons, forged rods, mopar bearings, milling oil pump.)+ Make sure to get block honed by a machine shop, [Blue printing the block is usually cheap and cost effective, total seal piston rings go for 120 bucks but not necessary]

-Replace all studs head, intake/exhaust manifold with APR studs. Replace all gaskets with mls gaskets. +Never reuse gaskets, why go this far and cheap out on a 15$ gasket.

-[Crank scraper and baffles/trap doors.] (The 420a oil pan can cause the lower bearing under cyl. 1 to spin when making hard right turns, 200 bucks for nearly nothing seems like a lot but it’s a cheap insurance for the expensive motor you just put in your car.)

+Please let someone who is a trained professional assemble the motor. Improper instillation of the cyl. head can cause it to warp, and improper timing adj. can push a valve into the shiny new pistons you paid so much for, and also ruin the 400 port job.

Now that the motor is built you can turn up the boost, but you have to watch your fuel. Everything listed so far is good for 10psi. I assume if your still reading you want to go past 10psi. Stage four is for the person who wants to go above 10 but wants to stay under 15psi. Stage 5 will list some things that are in stage 4 because some people what to go higher and instead of confusing everyone I will just list it 2 times.



Stage 4
+ This step helps the tuning process for the do it you self person that wants to stay above 10psi but under 15psi. If you are a sick and twisted individual, and want more boost than 15psi skip stage four and go directly to stage 5.

-Gauges (wideband kit, oil pressure, pyrometer, fuel pressure)

-Safc (**** has an excellent write up on install and tuning your car with this unit, great reading!!)

-Vortech sfmu (Replaces the cartech or obx one that comes with sooo many turbo kits, reason for switching, rock solid fuel pressure under WOT and you can use it to adjust the static fuel pressure.)

-Injectors (For sizes refer to Corbins site, again only if you wish to stay under 15psi.)+Safc is needed to control bigger injectors, many kits like Hahn and Star come with injectors big enough to run this stage.

-MBC or electronic boost controller. (Self explanatory)



Stage 5
– In this stage, like stage 2, things are not so cut and dry and there are a lot of routs to take to achieve high hp.

Bigger turbo (This is all up to personal preference. At this point a Super20G for the Hahn manifold would probably be the best way to go. Another possibility would be getting an evoIII16g w/an external waste gate setup on the Star manifold. There are about a million different combos the best thing to do is read about what other people have and what they like about it. Rule of thumb bigger the turbo, more lag, more hp, external waste gate needed).

Now for the fuel

255lph fuel pump (The pump that comes with most turbo kits max out at this stage.)

-Setup one- SAFC, Crane ignition system (By far cheapest way to go but the SAFC is limited, and you need to get someone who knows their crap to tune it. Its deff. not the safest way to go.)

-Setup two- Hahn Portfuler, Crane ignition system (This is probably the best way to go. After 15psi all you need is a dyno tune to work out the trimming.)

-Setup three- Custom 8inject setup, Crane ignition system (This is a knock off of the Hahn system but is a lot cheaper if you make it your self.)

-Setup four- AEM Standalone plug and play (Expensive route, deff. need a pro to tune it, or you need to know your crap, but can be the very best.)

-Setup five- Accel DFI 3BAR (Same thing as the AEM just a different company, very good.)

-Setup six- Megasquirt (Very cheap, this is the ultimate do it your self unit. Started off as type of a piggy back but can be used as a standalone with a few mods. If you want to save money and have brains to work this thing it’s the only way to go.)

-Stiff Suspension(Wheels like to hop especially on fwd cars, a stiff suspension will keep you wheels on the ground, again something that’s up to personal preference. I recommend Tokico Premium HP)



Stage 6
+This is not a stage but merely a list of things that will break and need to be replaced, but these can be done at any time during the time line.
-Clutch (Spec stage 4 or 5, depending on you torque numbers. [Billet pressure plate and an Aluminum Flywheel].)

-The 98 neon r/t tranny (Strongest transmission availed for the 420a. While you’re in there get a phantom LSD put in. Helps the traction problem) +The gear ratios are different for the r/t tranny, but the final drive is the same. What’s this mean? Faster tranny, no change in spedo readout!!

-Solid motor mounts (HP is lost when the motor rocks back and forth while shifting)

- Axles (Replace them when they break, Conceptillusions and exileracing both sell Fidanza Axles, and your tranny will explode before these snap.)

There’s A lot more that can be done to the car to make it perform better like tires, nitrous, oil cooler, radiator, egr block kit, water sprayer, methanol sprayer, weight reduction, brake kits, ect.

A big thanks to slow420a for this write up! - Patrick<script

 

-[Crank scraper and baffles/trap doors.] (The 420a oil pan can cause the lower bearing under cyl. 1 to spin when making hard right turns, 200 bucks for nearly nothing seems like a lot but it’s a cheap insurance for the expensive motor you just put in your car.)


where do I get this