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420a turbo build / What do I need? -- WRITTEN BY PWEE05

I want to start by saying building an engine is almost like ordering a hamburger. Everyone likes something different and your build should reflect that. If you do decide to build you have complete freedom to build EXACTLY what YOU want.
(excluding California R.I.P.)

The 420a (A588) engine is a Chrysler made engine. Good news: Chrysler has been turbo charging cars for over 20 years. Unbelievably started from the K-car platform, don’t laugh, and there is a video floating around of a Dodge Caravan AWD destroying a Camaro SS at the track running a 12.96! Definitely one of the funniest, and most shocking things I’ve ever seen (Soccer Mom meets V8 racer AND WINS!!!). So don’t worry we can make your 420 scream. Bad news: besides oil leaks, you have to spend some money.

The eclipse 420a is very similar and is in some dodge models of the same years with only slight differences. The head is reversed (compared to neons), but building internally will be the same and you can even search for neon, avenger, or sebring parts if you can’t find any for an n/t eclipse. Never hurts to cheat, but make sure they are correct before purchasing.

There is a long list of what you will need for more power but don’t fear, you can turbo a stock 420 car, do so cautiously (I will get into that later). If you look at the below pictures you can clearly see a difference between the connecting rods. The picture to the left is a piston and rod assembly for a stock 420 engine. The other is an aftermarket Eagle made rod which can support over 300hp. The stock rods, obviously, can not take much of a beating and must be replaced if you want higher hp numbers.
[attachment=3966:stock_pi..._and_rod.jpg] [attachment=3967:h_beam_rods.jpg] [attachment=3968:piston.jpg] [attachment=3969:high_comp_piston.jpg]

If you take a look at the first piston picture you can see that it has a “dish” in it. This is to reduce compression. The second is a high compression piston for a different engine that is only here to give a comparison. The stock 420 engine has a compression ratio of 9.6:1. A stock turbo car will be somewhere around 8.3/8.5:1 compression. Under boost periods cylinder pressures will increase because you are forcing air and fuel into the cylinder, thus the need for pistons providing a lower beginning compression ratio. Stronger metal composition doesn’t hurt either.

With turbo applications you do not necessarily need an intercooler if you are scrounging for money. HOWEVER, without an intercooler you MUST keep the mixture rich and low boost to keep from predetonation. THIS WILL DESTROY YOUR ENGINE!!!!!! It's a hard thing to avoid without an intercooler so lets just say, you need one.

Another thing that some shops do with turbo builds is allow a little bit more space between the piston and the cylinder wall than is normal. This will let the piston safely expand under boost periods, caused by increased heat. I am mentioning this because sometimes you can hear the piston “slap” against the cylinder walls and it may be interpreted as something else.

On to a list of things you should do to build your 420 for pressure. This does not include machining of the block/head and/or labor:
Stronger connecting rods------------------------Air fuel controller (AFC) or some other type of tuning device
Stronger pistons and rings-----------------------Larger fuel injectors
Metal head gasket---------------------------------Larger fuel pump
ARP head studs can’t hurt------------------------High flow exhaust
- (for a lower hp build you can use bolts)-------Fuel management unit (FMU) a 1:1 fuel pressure regulator is best(AFPR)
Turbo charger--------------------------------------Turbo manifold to fit your turbo
Oil lines---------------------------------------------Coolant lines depending on your turbo
Down pipe or O2 housing-------------------------Wastegate if not internal
Blow off valve (BOV)------------------------------Boost gauge
Boost controller------------------------------------MAP sensor check valve (missing link)
(if higher boost is desired)
new rod and main bearings
Upgraded ignition system-------------------------Vacuum line
Light weight crank pulley-------------------------Copper 110 exhaust gaskets
new oil pump--------------------------------------new O2 sensors
turbo timer ----------------------------------------new water pump
timing belt, pulleys, tensioner--------------------new seals
Intercooler-----------------------------------------Charge pipes

To give a comparison this is what I have in my engine.
JE 8.6:1 pistons and rings-------------------Eagle Rods
Clevitte main and rod bearings-------------ARP main studs
ARP head bolts-------------------------------Felpro head gasket and seals
Melling oil pump------------------------------Stage V port and polish
crane stainless valve springs----------------Crane titanium retainers
Accel 30lb/hour fuel injectors----------------Prothane engine and trans mount bushings
Walbro 255lph fuel pump---------------------FMU
Apexi AFCII-----------------------------------Screaming deamin coil pack
Crane firewire spark plug wires------------Ac delco double platinum spark plugs
ported stock intake manifold------------------------Treadstone cast turbo manifold
Knock off BOV----------------------------------XO2 22x12x3 bar and plate intercooler
Missing link MAP-----------------------------AEM UEGO wideband
Crane camshafts - Intake Duration [email protected] Lift .374 inch, Exhaust Duration [email protected] Lift .374 inch
Removed air conditioning & power steering (by choice, not necessary)
Garrett t3 super 60 (35lb/min) turbo (fast spooler)
My own welded and fabbed charge pipes using stainless exhaust pipe
And of course I replaced all of the preventive things I mentioned earlier.

I built this way because I like the sound of a very rough, loping idle and using the very efficient eclipse suspension for tearing up turns. I wanted a turbo that would spool quickly out of turns and power to fly away down straight aways. I will, for now, not be going over 250whp.

Now, I promised you I would get into turbo charging a stock 420. This is treading thin ice but you can do it. Low pressures and low volume turbos are key. You still need to upgrade your fuel and exhaust system:
Fuel pump-----------------------------Injectors
Missing link----------------------------High flow exhaust
BOV------------------------------------Wastegate if not internal
O2 housing and/or downpipe---------Boost controller
Charge pipe----------------------------Oil and possibly coolant lines

The turbo can be 14b, t25, SMALL 16g, gt 28 will work fine but please keep the boost under 8psi. You can’t get over 225whp (guesstimate) for very long on a stock engine without a big BOOM. This gets back to the weak rods and compression set up for an engine supposed to only see natural aspiration.

Always watch your exhaust gas temps (EGT’s) and if you have the luxury of a 4-lead O2 sensor keep an eye on that too. If it reads below .92 volts you are getting too lean. A dyno and an AEM UEGO Wideband O2 is the best way to tune, but you can do it with a long stretch of highway, a heavy foot and voltmeter. WATCH FOR COPS!!!

If you are wondering about costs, this could take all day because of the variety of places offering parts and services. Let’s just say that the total amount I have in the engine and turbo set up I could buy a small island. (around $5k but you can get away with around $2500.00 if you stay stock) If you ask me, “was worth it?” I would tell you definitely.

To touch briefly on bolt-ons, if you buy out the entire stock of all bolt-ons available for this engine you will only increase to “a noticeable difference.” It is a good place to start learning though.

The sky is the limit but make sure you know what you are doing, and if you don’t just ask for help like I did. Slowboy racing put my bottom end together, ported and polished my head and has taught me so much, but I still don’t know everything. Everyone has to start somewhere and if I missed something please don’t hesitate to correct.

--The above article was written by pwee05

Originally posted by 95-2fast4u-GS+Jun 8 2006, 12:22 AM--><div class='quotetop'>QUOTE (95-2fast4u-GS @ Jun 8 2006, 12:22 AM)</div>
ok almighty god of 420a knowledge and wisdom... here i am worshiping your altar and paying homage wondering a few things of my own.* SO i got this stock 420a with some megan headers and no name CAI and some iridium plugs.* Other than that, WAAAAAAAAY to slow for a guy like me.* I want to turbo the life out of it.* However i was reading stuff on here and found out i can get 200hp from n/a?* such as the tune of a stroker and piston heads?* I wondering, seeing as the throttle respnse for n/a is much better, how much power COULD i squeeze out n/a?* I know all about bigger TBs and Intake mani's but i really am curious how much i could get.* cause im looking for like 350 hopefuly even 400 broad chested stallions out of this thing.* my backup plan is to hand it to my shop and say have fun, this plan includes a turbo and lots of financing.* SO to the point, i wanna know if its possible to pull 300 or so horses out of n/a and if i could do 400 with a big **** turbo and say less than ten g's or there-abouts.** I do know that i would have to do pistons head cams crank clutches axles and the like, but i think if you could help by giving some insight, it would settle much easier in my tummy.* gracias amigo.[/b]
@Jun 8 2006, 11:45 AM
definately funny* :clap:

I'm sure there are people out there that have more knowledge than I do but I'll take the worship* :laughing:

anyway, to your question.* 200bhp is probably the limit when staying N/A.* unless you can figure out a way to get the compression above 12.5 : 1 inject with methanol and make that **** squeal.* It is possible with a 2.4L to get above 200bhp n/a but there just isnt't enough displacement in a little 2.0L to do it.* even after bore and stroke.* I could be wrong though.* I just haven't heard of anyone putting enough money into an n/a car to get the horse power that high.

turbo, on the other hand, is a much easier way to increase compression by ramming air and fuel down the cylinders throat.* you could have a nasty turbo car for $10k.* if you can do some of the work yourself you can get the cost under that because labor is expensive.* I have about 8k in mine but did all the work except putting the bottom end in the block and machining.* The only problem I have now is worrying about when I will have to pick up my trans with a bucket piece by piece.*

Scroll the whole way down to the bottom.* There is a dyno slip to prove that the 96 eagle talon shown with the 420a engine makes 460whp on c14 and 340whp on 93 pump gas.** so it can be done, it's just a matter of how crazy are you willing to go. :thumbsup:
Originally posted by 95-2fast4u-GS@Jun 9 2006, 12:04 AM
BRAVO!!* ...go on take the money and run...* I mean the worship.* Thanks a ton for the info.* I was really just curious.* I had totalled up a ROUGH estimate of all that I wanted and guestimated install costs based on the inverse ratio of work to guy by dividing the recpirical of the attendants height by the approximate weight of the turbo and multiplying the difference by the sum of four circles ...and previous work ive had done by this place.* and it came out to around 8700 bucks.* this excludes ANY work other than making this thing a flowing field of green for the which the stallions to graze upon.* so as long as im near the mark i guess the apple is pretty much split, and there is a gash in littel tommys head on which the apple sat.* But a couple staples and some super glue, he'll be fine they assured me.* Again thank you for your help, im now about to call an artist i know to begin drwaings cause im not that good and because this place is showing an interest in sponsoring me.* so i could get labor for free!* thanks again pwee.* ill look forward to showing off pictures of my steroidal stallion in the future!* until next time....

"..rule number 1 no excuses play like a champion!.."** -Vince Vaughn* (Jeremy Ryan; wedding crashers)
Originally posted by cnitcf@Jul 4 2006, 06:55 PM
2.4L engine modifications:
Originally posted by 98GSXEclipse+Jul 12 2006, 03:42 PM--><div class='quotetop'>QUOTE (98GSXEclipse @ Jul 12 2006, 03:42 PM)</div>
Does anyone know the stock injector size for the 420a?[/b]
Originally posted by [email protected] 12 2006, 03:57 PM
19lb/hr(200cc).** they are just little things, the reason why they need to be upgraded if a turbo system is put on.

Formula for Injector Sizing

* * * lbs/hr = ((BSFC / #Cyls) X HP / Injector Duty Cycle%
* * * Brake Specific Fuel Consumption is normally (lb/HP X hr)
* * ** ** .42 BSFC - Race Engine
* * * * * .47 BSFC - Hi Performance Engine
* * * * * .52 BSFC - Stock or with Light Modifications Engine
* * * * * .57 BSFC - Supercharged / Turbo Charged Engine
@Jul 14 2006, 12:39 PM
Hahn kit

there really is no such thing as a "stage one" turbo.* what you mean is a low volume turbo.* Think of it as a garden hose and a fire hose both set at 15psi of pressure.* how much water do you get from a garden hose at 15 psi and how much you get from a firehose.* both have the same pressure but the volume of water that comes out is much different.* if you want to stay stock use a small 16g, t25, or 14b turbo.* don't go nuts and put a t04 turbo on because it sounds cool and has been used in movies.* this will destroy your engine in a blaze of glory if it ever spools
Originally posted by pwee05+Sep 9 2006, 06:16 PM--><div class='quotetop'>QUOTE (pwee05 @ Sep 9 2006, 06:16 PM)</div>
don't oversize the valves just get stock replacements if you plan on replacing them.* if you have the machine work done right to the head you won't need to replace the valves, only springs and retainers.* I would go stainless springs and titanium retainers[/b]
@Oct 12 2006, 08:07 AM
this should help get you started:

Info about Eclipses/Talons:
(this is to get you familiar with the trim levels and what engine/drivetrain they have):

the basic thing you should understand is that First Generation (1G) NonTurbo (NT) Eclipses have the Mitsu 4G63, 2G NT Eclipses have the Chrysler 420A, and all of the 1G and 2G Eclipses have the Mitsu 4G63T. All trim levels have FWD, except the GSX, which is AWD (or the TSi AWD for Talons).

And some info about turbos:

1,435 Posts
heres a write up for a 420a build.its from another mitsu forum. by slow420a

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.

11 Posts[/IMG]

This is what I had to start with. The run of the mill 420a Motor with a mildly blown head gasket.

I had many parts powder coated and to date I actually need to recoat one ( I didnt judge hood clearance and scraped the Tial wastegate) This is mosly what I am relying on to clean up the Engine bay to show acceplable street class.

For every smartie out there who thinks that powdercoat wont work on a turbo I have been running the turbo for three months with no problems.

Funny enough the hardest part of the Turbo install I did was getting the Exhuast manifold off. Every bolt was already stripped by previous owner or shop and made it a **** of a time to get the heat shield off! I actually had to chisel them off and it took all night

Here is the manifold unbolted finally, Oh and the manifold uses a couple different sizes of studs, dont ask I was scratching my head too.

Here is the turbo manifold lined up on the block, this is the old stainless exhaust gasket. It was very rusted and no I wont use this one agian.

Here is the Turbo bolted up and I painted the Manifold and turbo High temp semigloss black. This is temporary because the gloss will not stay through the heat. I will need to have this manifold coated with powdercoat later. I was already a week behind and my GF was mad the car was still in the garage so the Coating of the manifold will be a different day.

Here is a Day shot of the fresh T3/T4 Turbonetics turbo. The VROG FMU from Hahn was installed at a place down the street. I didtn have line wrenches and I was tired from being up all night from all the other work. While I was there I had them install the oil line supply for the turbo too.

The car says I eat HOndas ! no really when I was takin him apart I swear there was a 1.8 l tranny in the back of the intake ......JK

This is the larg version of me working in the rain, If I could stand jessi wanted me working on it :(

Here is the used intercooler I installed. I got this with the BOV and piping on ebay. It is dented but holds boost and is fint until I can afford the 600 dollar Spearco intercooler I want for the car.

Yes I know its a little crooked , I took the picture just to see what it would look like but you gotta loosen the mounting screws to get the IC piping to spread far enough apart to get the couplers on! Everything was bent very tight.

This was the single bent pipe that I used to run down to the cool side of the intercooler. I didnt want any couplers on this portion since the engine rocks back and forth. So insteead the pip will flex slightly and only two coupler flex. I have been boosting since Dec 2007 like this and I have not had a problem yet.

This was the hardest connection to make. It looks easy but the coupler is weak and doesnt have alot of strength for tension. I had to rap it with electrical tape and seal it with silocon on the inside. I didnt have time to wait on a coupler I was in somone elses garage. However on a lighter point this fix also seems to have worked very well and is still holding up even today ( yeah I should get a new coupler)

This is what the pipes connecting the intercooler looked like at first. They werent perfectly lined up with the IC. However this was how it had to be because the pipe had to make such a tight curve. I wish I still had my welder and I would just make all new piping myself.

Later that day I still could not get the pipes to hold in what I believe would be permenant. I beet my head agianst the wall for another 6 hours until I realized that Radiator hose is rated at 45 Psi and thats alot more that the boost I would run. My solution ended up being to make a coupler that was 2 inches longer and signifigantly beefier to handle the torque from the engine tuggin on it.

This is the end result of cutting a new section of hose for a coupler to tame the difficult high tension piping. I painted the piping black just becuase It looked wierd to have some chromed piping and some stainless steel that not polished beside each other. this realy cleaned it up.

I put a Small Red Tial Spring in which regulated the boost to 5 psi. That is until I purchase injectors and a calibration unit for the FMU.

I agian banged my head agianst the wall because no matter what I did I couldnt get all four mounting holes on each side of the tial to line up. At best I could get 3. What happened is that the Tial wastegate flange was welded outside the car, before it cooled the guy sprayed it with water.... ANYTIME you spray somthing with water that was jsut molten will warp slightly so when I unbolted the parts and tried to put them back together they didnt fit. However I leaned the fuel out a bit and let the car idle, the manifold got hot enough that the metal ( metal has memory) moved back to the way it was before it was sprayed with water and I screwed the one bolt in. I also too the time to tighten the other studs while it was warm.

This is the FMU idle screw, the darn shop that installed the FMU had the dile pressure set at 4 psi, what morons! no wonder it ran like ****

I used this supplied guage and threaded it to the FMU to moniter fuel pressure when tuning.

I adjusted the fuel till it was 55 psi, stock pressure
The momen of truth I started the car and had somone follow me around the block. The car overheated. For some reason the stock clamp wasnt making a seal, so I put a Worm gear clamp above it on the hose, added more water and tried agian and it drove fine. the car felt like a different machine all together. It probably has arounf 200 whp right now and I will bump the Boost as soon as I get the new injectors and intake in!

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