I have a 97 eclipse GS 420a motor. I wanna slap a 18g or 20g turbo on it. My question is does the 420a have forged internals if not, will it handle a 18g or 20g turbo with a mild cam? New to 4 banger scene so don't be too harsh on me ha.

 

It's a waste of time and money to boost the 420a, you'd be better off buying a 4g63 eclipse.

 

ya that seems to be the consensus from everyone i talked to

 

Okay, if you're honestly going to sell it and get a GS-T/GSX, then do it. But if you don't want to do that, you can definitely turbo it. Most people I've seen don't buy a 420a, find out from people "they shouldn't turbo it" and then sell it for a turbo. A LOT of people have turbo'd the 420a. Is it easier to just buy a 4g63? Yeah, of course. But I honestly see no reason not to go for it if you want. You might even come out more knowledgable. People've done it for under $1000. I posted this on your other thread 1998 t/a:


This is an excerpt from another DSM site and was written by a poster named PWEE05
I don't know the rules on posting outside links here, especially links from other DSM sites. But I figure I'll give as much credit as I can.

"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
Suggestions
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"

 

ya i got an amazing deal on this car I paid 900 and it had a blown head gasket, needed tires, a window motor, new exhaust and some body work. I do almost all the work myself on my cars so it only took me a few hundred to get it nice and I got an amazing deal on the tires. maybe I'll put it up for sale and look for a GS-T...if I go the GS-T route am I gonna have to replace the pistons, rods and bearings if i replace the stock turbo with a 20g?

 

Okay, now you're hitting the edge of my knowledge (I don't know too much about the turbo eclipses) but too my knowledge you don't have to upgrade internals. I think you just need to upgrade the internals when you are running high psi's. Generally, I don't think you'll run into that quite yet.
If I remember correctly, it's a common turbo swap
Hope this helps man!