Building 420A

[eclipsetuner86]

I have a 1996 Eclipse GS with the 420A. It has 137000 miles on it i was contemplating on boosting it, but i was wondering if the 420A is a good motor to boost or if i should swap to the 4G63? And if i stick with the 420A what internals should be used?

 

[dsmpat95]

Keep the 420a.

 

[kris_stewart10]

why do you say keep the 420a i would swap to the 4g63

i love my 4g63

do the swap

 

[BoredDSM]

why do you say keep the 420a i would swap to the 4g63

i love my 4g63

do the swap

It would not be cost effective to swap a 4g63 into a gs or gt. If you plan to build the motor it will be fine.

 

[red97tib]

Ok, first things first, welcome to Tuners. As for keep or go to the 4G63, that is more a personal opinion. You can't simply swap motors in these cars, the transmission is on the completely wrong side. You would be better off selling the N/T and buying a turbo if you decide to stick with the 4G63. Now the 420A many people will tell you it's a worthless and not worth boosting. This isn't true as many people have successfully boosted the car with little problems. Just take a look around the site here and you will see some amazing results when people push thier cars. Again, welcome to Tuners and to the addiction.

 

[262crewtsi]

keep the 420a and boost it hell of a lot cheaper then swapping a 4g63 i have a friend who boosted his 420a and it hauls balls just do your reasearch and dont buy cheap parts

 

[99RedGs]

I would upgrade/replace:

Pistons
Rods
Main Bearings
Oil Pump (Melling possibly high flow)
Rod Bearings
Head studs
Main studs

Whatever your final goals end up being will determine your fuel needs.

Im sure you know what you would want for each of those, but when I spend the money to build a motor I like to over build so I don't need to worry about more issues. The stock head has been proven to over 500 hp so A stock rebuild would be sufficient, but depending on your goals in the end you may choose a different route. By replacing the Rods/Pistons you are pretty much removing the weak link in the 420a in terms of boost. It is a strong engine and can take pretty much whatever you can throw at it (Power Wise). I guess the other weak link would be our choice of tuning OPTIONS, but we have MS and that is good.

Here is a list I am in the progress of filling out to give you an idea on the average prices you will spend. (Atleast what I have been finding):

Block:
• Wiseco Pistons + Rings (8.8.1 .020): 429.99
• Eagle Rods: 309.99
• Clevite 77 Main bearings: 57.99
• Melling High Volume Oil Pump: 129.99
• Clevite Rod Bearings: 39.99
• ARP Head studs: 109.99
• ARP Main studs: 152.99
• Gasket kit: 45.99
Total: $1277

Head:
• SBI PT Cruiser Style Lifter Set: 159.99
• SBI PT Cruiser Style Rocker Arm Set: 159.99
• SBI Valve Guide Set: 59.99
• Felpro Top End Gasket Kit: 119.99
• Crower Valve Spring & Retainer Kit: 269.99
• Cams
Total: $770 (Not including Cams)

Misc:
• Bore cylinders
• Hot tank
• Decking
• Balance rotating assembly

Total:$250

Turbo set-up:
• Turbo Manifold
• Oil feed and return lines
• Wastegate
• Intercooler
• Blow Off Valve
• Couplers and Clamps
• Intercooler Piping
• 3" Down pipe
• Turbo

Transmission:
• Clutch ( TZ or OFE Series South Bend Clutch) (South Bend Clutch - DXD High Performance Clutches)
• LSD

Fuel and Tuning:
• Hahn Portfueler or PNP Ms (if it ever comes out)
• Harblo 255l Fuel pump
• Wideband O2
• Injectors (size depends on goal and setup)

Gauges:
• Boost
• Oil Pressure
• AFR


Again, This list is just a list in progress. I have only specifically listed a few items with their prices, while others are generic parts without prices that I will need, but have not yet determined which way I want to go. (disclaimer before I have people telling me to be more specific) Hope this gives you a better idea.

Oh yeah, and add about $200-300 to whatever total you end up with because I can gaurantee you will have forgotten about misc bolts, fittings, couplers, etc... the small stuff.
Online


Good luck on your build.

 

[rstare]

RedGs do you just have that list saved and give it to everyone who askes about boosting the 420a? Lol
To the OP, many 4g63 guys will tell you just to sell the 420a and get a 4g63. I would suggest listening to the people who actually have facts and more things to say then just sell it.
Now, the 420a is a totally different car from the 4g63 and honestly it will take more work to get the 420a to the same level as the 4g63. The 420a's 9.6:1 compression ratio limits boost right off the bat, the stock ecu isnt meant to see boost (and if it does, it will cut fuel). Most people rebuild the engine and lower the compression ratio to 8.8:1 with forged internals.
Stock internals is what makes the 420a seem weaker, as it can only handle around 15/16psi. But once you rebuild you are only limited by the same things that every other factory turbo'd car is: fuel setup (being the main one), a way to pull timing, ect.
This is the tip of the iceberg. Imo I say that you have the 420a just stick with it.
Btw, its pointless to try to swap the 4g63 into the 420a body, it just doesnt work.

 

[99RedGs]

RedGs do you just have that list saved and give it to everyone who askes about boosting the 420a? Lol
To the OP, many 4g63 guys will tell you just to sell the 420a and get a 4g63. I would suggest listening to the people who actually have facts and more things to say then just sell it.
Now, the 420a is a totally different car from the 4g63 and honestly it will take more work to get the 420a to the same level as the 4g63. The 420a's 9.6:1 compression ratio limits boost right off the bat, the stock ecu isnt meant to see boost (and if it does, it will cut fuel). Most people rebuild the engine and lower the compression ratio to 8.8:1 with forged internals.
Stock internals is what makes the 420a seem weaker, as it can only handle around 15/16psi. But once you rebuild you are only limited by the same things that every other factory turbo'd car is: fuel setup (being the main one), a way to pull timing, ect.
This is the tip of the iceberg. Imo I say that you have the 420a just stick with it.
Btw, its pointless to try to swap the 4g63 into the 420a body, it just doesnt work.

Yes, I do because this question gets asked too often and it is just easier to answer it this way than to type the same thing worded differently over and over again.

Eventually I plan on making a tech post that includes everything someone would need to know or have when planning a 420a build. Everyone always just says search and believe me it is a total pain in the ass to find out everything you will need. As far as I know, there is no one thread where you can find out every part and such you would need for a complete turbo build. (Not the $1,500 budget build)

 

[joeyzaza]

I had a 2gnt for almost 5 years. I sold it not to long ago and got a 97 gsx for 500 more then I sold my NT for, woot woot. I had a stock crate engine and ran a 75 shot of nitrous on it, and some other bold ons. Car still couldnt touch my GSX. My budy does have a built up 420a, all rebuilt with a star stage 2 turbo system in it, its fast, but he put a stupid amount of money into it to get their. So if you have enough cash laying around to build up your 420a like you want, I would sell it and by a gst or gsx. Oh and yes I researched the heck out of the engine swap, definatly not cost effective!!!

 

[bagged420a]

I would suggest using your 420a that you already have and build it.
With the right setup you can easily run 300-350 hp.
Or if you want to go all out and build the top end and bottom end theres no reason why you can't hit 500hp.
I'm running about 250whp on a built bottom end w/ hahn stage II turbo kit(16G) on 6lbs.
but the actuator doesn't support boost controllers so you might as well get the 20G
and portfueler.
It'll costs you close to 5k but if you buy a gst or gsx you'll spend more money for the car in most cases and by time you get to 500hp out of it you'll spent 5k
So i would suggest sticking with what you have and build it.
The best advantage of goin with a gsx is there awd

 

[jrohner]

I believe getting a gst would be a more economical way to go, and obviously much easier. You can run the bone-stock engine, and a chipped stock ecu even if you have 500+hp in mind. No need to dig into the engine or electronics. Get a turbo and the supportings mods, tune the car and you're good to go.

 

[jrohner]

I'm running about 250whp on a built bottom end w/ hahn stage II turbo kit(16G) on 6lbs.
but the actuator doesn't support boost controllers so you might as well get the 20G
and portfueler.

With a 4g63 powered car, you could bolt on a 16G (a $560 MHI, or a $200 imitation from ebay which works fine), some injectors and exhaust, chip the ecu and tune and have at least 300WHP (or even better, 300AWHP so you can actually use it in 1st gear). Get cams for under $400, a FMIC for $300, and tune for E85 and there's 400HP or 400 all-wheel burning HP. The extra cost of building up the 420A could buy you the factory turbo-charged car.

 

[PCD_RS]

Keep your 420A and mod the crap out of it. Seriously, man, do your research on the 420A. You'll be surprised how many are out there! I feel like I'm the only one in my area with a 420A Turbo!

My personal advice. And it was mentioned earlier too. Replace your rods and pistons with forged components (don't forget to replace your bearings too! Main and rods). And upgrade your fuel set-up with bigger injectors, 12:1 FMU, a Wablro 255lph fuel pump, 1:1 FPR, Missing Link, OR a Fuel Cut Defender (I suggest the FCD over the ML). And a SAFC. This is the set-up I used for my 420A. Pushing 10lbs and going strong still! With over 240,000miles on the sucker too (Mostly highway miles though).

And the 4G63 swap is a no no in my book. Because there is no point in doing that. All the money and energy and time. Shoot dang, man.. It'd be faster to just rebuild it!

Good luck on your decision.

 

[Brian O Conner]

for the dude that said swap the engine your ignorant. If your obsessed with rebuilding your car like me be far warned your playing a rich mans game. Per pound of boost the 420a puts out more hp than the 4g63 but the 4g63 internals are better and you will need to take precautions and do a engine rebuild if you plan to boost more than 8 psi. Its all up to you but dont be ignorant and do an engine swap

 

[99 gs iowa]

could i get a price list for everything to turn a 420 to a boosted 420 included labor an such

 

[96 420a-t]

Boost that 420 son!

 

[Absit]

could i get a price list for everything to turn a 420 to a boosted 420 included labor an such

You sure can, call up a shop.

 

[Fotowntalon]

Thank you for reviving a thread that has been dead for almost 3 years...

 

[glowryder]

call a local shop that KNOWS the 420a.. dont let just any shop build that engine, every engine has nuances and special needs.. not many know the special needs of the 420a.... check other posts.. youll see the same advice. Sent you a PM

 

[CODE4]

Thank you for reviving a thread that has been dead for almost 3 years...

Seriously. For ####'s sake, please note the thread dates.