420A I want to turbo my 420a eclipse

[CertifiedBot]

So basically I want to turbo my eclipse GS, I know there is going to be a lot of work and time spent on it. I don’t have a lot of mechanic/fabrication skills but one of my friends will help me put it all together. I was just curious as to what to expect/not expect with the car if I decide to go turbo. Everything is pretty much stock besides it has a SPEC-D exhaust, stage 2 clutch and a short throw shifter. The engine has just over 200k miles and I’m pretty sure has a head gasket leak. Should I get the engine rebuilt or one with lower miles or could I run low boost and it still be reliable? What size turbo should I choose to have decent power but still be reliable? How much should I expect to spend on putting together my own parts list for everything needed? Is there anything I could replace to get ready to turbo when I get ready to? Is there anything that I’ll have to remove or relocate to be able to turbo? Thanks in advance for your guys’ time.

 

[VelocitàPaola]

With that many miles and a suspected head leak, I'd rebuild the engine before anything else.

 

[CKOPOCT]

2nd the rebuild. You will need to ensure the engine is solid before you put boost to it. Boost adds a lot of extra stress on the engine internals, especially if it wasn't designed for it. If you have a weak bottom end you're asking for problems.

There's a lot to consider beyond just putting boost to the engine. What are your goals? How much power do you want to make?

There's a whole thread category dedicated to boosting the 420A. You'll likely find your answers, and more things to consider, and then more answers, and then more questions... etc. in that forum:

http://www.dsmtuners.com/forums/420a-turbo-conversion/

Steve

 

[CertifiedBot]

2nd the rebuild. You will need to ensure the engine is solid before you put boost to it. Boost adds a lot of extra stress on the engine internals, especially if it wasn't designed for it. If you have a weak bottom end you're asking for problems.

There's a lot to consider beyond just putting boost to the engine. What are your goals? How much power do you want to make?

There's a whole thread category dedicated to boosting the 420A. You'll likely find your answers, and more things to consider, and then more answers, and then more questions... etc. in that forum:

http://www.dsmtuners.com/forums/420a-turbo-conversion/

Steve

By weak bottom end do you mean like stock pistons? I’d like to make 200+ hp, but probably less than 250. I want to make it a fun and peppy daily that is reliable, but I don’t mind working on it.

 

[CKOPOCT]

Good question. By "weak bottom end" I mean if you've got excessive slop due to excessive clearance in the rotating assembly (worn bearings, rings, etc.). At 200K+ miles on the 420A I would do both a compression and leakdown test to check the integrity of the engine. If you are going to consider boosting the engine as it is your compression numbers should be 150 psi or higher (factory specs are 170-225) and should be pretty even across all 4 cylinders (within 5 psi). Others might disagree with this but my thinking is that if your compression numbers are below 150 then your engine is losing air as a NA motor, so adding pressure from boost may accelerate this wear exponentially and lead to big problems fairly soon. Likewise if your compression numbers aren't even across the cylinders you have uneven wear and adding boost can exacerbate the problem.

Most engines can handle a few pounds of boost without an issue, but only if they are in good condition. To get 200-250 hp out of your 420A you'll need to push more than just a few pounds of boost - more like 8-12 PSI depending on other mods. As the 420A wasn't designed to handle the stress of boost you'll need to strengthen it (rebuild with boost in mind) to hit your goal.

 

[CertifiedBot]

Good question. By "weak bottom end" I mean if you've got excessive slop due to excessive clearance in the rotating assembly (worn bearings, rings, etc.). At 200K+ miles on the 420A I would do both a compression and leakdown test to check the integrity of the engine. If you are going to consider boosting the engine as it is your compression numbers should be 150 psi or higher (factory specs are 170-225) and should be pretty even across all 4 cylinders (within 5 psi). Others might disagree with this but my thinking is that if your compression numbers are below 150 then your engine is losing air as a NA motor, so adding pressure from boost may accelerate this wear exponentially and lead to big problems fairly soon. Likewise if your compression numbers aren't even across the cylinders you have uneven wear and adding boost can exacerbate the problem.

Most engines can handle a few pounds of boost without an issue, but only if they are in good condition. To get 200-250 hp out of your 420A you'll need to push more than just a few pounds of boost - more like 8-12 PSI depending on other mods. As the 420A wasn't designed to handle the stress of boost you'll need to strengthen it (rebuild with boost in mind) to hit your goal.

Okay sweet, so I probably need to rebuild the engine regardless right? And keeping in mind what the compression test and leak test show, beyond a rebuilt motor would I need to upgrade pistons or anything? And if I make 8-12 pounds of boost reliably, would that give me over 200hp reliably?

 

[CertifiedBot]

Good question. By "weak bottom end" I mean if you've got excessive slop due to excessive clearance in the rotating assembly (worn bearings, rings, etc.). At 200K+ miles on the 420A I would do both a compression and leakdown test to check the integrity of the engine. If you are going to consider boosting the engine as it is your compression numbers should be 150 psi or higher (factory specs are 170-225) and should be pretty even across all 4 cylinders (within 5 psi). Others might disagree with this but my thinking is that if your compression numbers are below 150 then your engine is losing air as a NA motor, so adding pressure from boost may accelerate this wear exponentially and lead to big problems fairly soon. Likewise if your compression numbers aren't even across the cylinders you have uneven wear and adding boost can exacerbate the problem.

Most engines can handle a few pounds of boost without an issue, but only if they are in good condition. To get 200-250 hp out of your 420A you'll need to push more than just a few pounds of boost - more like 8-12 PSI depending on other mods. As the 420A wasn't designed to handle the stress of boost you'll need to strengthen it (rebuild with boost in mind) to hit your goal.

Never mind, I see that you said if I want to turbo as is. Would it be a bad idea to turbo without fixing the head leak first? I put head gasket seal in it and it’s been good but I know it’s gonna be an issue eventually.

 

[BLACK'98DSM]

If the head is leaking I wouldn't turbo it until that's fixed. If you replaced the headgasket already then where is it leaking from now?

 

[99dsmer4g63]

We turbo’d my dads car a couple years back…..First time his motor had 120k on it and was quite healthy; he blew a head gasket 1 month after. Reinstalled turbo kit after engine rebuild.
Rebuilt motor- completely stock rebuild minus
BC valve springs and retainers.
List of what I felt was a budget/bare minimum build:
Stock injectors
255 walbro fuel pump not rewired
Either 10:1 or 12:1 FMU drilled and tapped manifold for boost reference line.
AEM wideband, boost/vacuum and oil pressure
420a log manifold with 35/38 external
Universal intercooler and pipe kit
T3/t4 .63 turbo
Chinabay EX wastegate 11 psi spring
Chinabay knock off greddy bov
Oil filter sandwich adapter for turbo feed
-10 bung welded to oil pan
4g63 gst downpipe with the 90 cut off and flipped and welded -bolts directly to cat back
Custom made turbo elbow to said downpipe
4g63 radiator slim fans with the aluminum housing- bolts directly to the 420a rad for more room in the front near turbo

There is no fuel cut defender or map sensor fooler on the car. Idles perfect and a/f ratios at wot are pretty damn good for a ghetto fmu setup.

Sounds like if you turbo your car you’d be lucky to take it for a drive around the block before something blows.
-Daniel

 

[CKOPOCT]

As the veterans on here have advised countless others, the first step to taking you from current ride to the goal line is have a budget. Know how much time and $$$ you are willing and ready to spend. Once you have that you can do the research on here and begin to formulate a plan.

If I told you it will take you $10,000 to get your gs to 250 reliable hp, is that okay? Is that too much? What about $5,000? That answer will determine if you rebuild and beef up your current ride, sell it and get a gst/gsx, or just stick with it as a daily as is. No matter what you're looking to spend some decent coin to get what you're looking for.

And, no, you can't add boost to your engine now with the head gasket leaking. The head gasket seal is a band aid at best - like taking an aspirin so you can run a marathon without feeling your knee pain. Bad and expensive things will happen.

Determine your budget. Do the research. Then decide to fix/sell/run as is.

 

[CertifiedBot]

If the head is leaking I wouldn't turbo it until that's fixed. If you replaced the headgasket already then where is it leaking from now?

I haven’t replaced the head gasket yet, I’m trying to decide how much money I want to spend on this and what I want to do with the motor.

 

[CertifiedBot]

We turbo’d my dads car a couple years back…..First time his motor had 120k on it and was quite healthy; he blew a head gasket 1 month after. Reinstalled turbo kit after engine rebuild.
Rebuilt motor- completely stock rebuild minus
BC valve springs and retainers.
List of what I felt was a budget/bare minimum build:
Stock injectors
255 walbro fuel pump not rewired
Either 10:1 or 12:1 FMU drilled and tapped manifold for boost reference line.
AEM wideband, boost/vacuum and oil pressure
420a log manifold with 35/38 external
Universal intercooler and pipe kit
T3/t4 .63 turbo
Chinabay EX wastegate 11 psi spring
Chinabay knock off greddy bov
Oil filter sandwich adapter for turbo feed
-10 bung welded to oil pan
4g63 gst downpipe with the 90 cut off and flipped and welded -bolts directly to cat back
Custom made turbo elbow to said downpipe
4g63 radiator slim fans with the aluminum housing- bolts directly to the 420a rad for more room in the front near turbo

There is no fuel cut defender or map sensor fooler on the car. Idles perfect and a/f ratios at wot are pretty damn good for a ghetto fmu setup.

Sounds like if you turbo your car you’d be lucky to take it for a drive around the block before something blows.
-Daniel

Heck yeah thank you for your input, I’ll definitely keep all of that in mind when planning a build and budget. I’ve gotta do something with the motor asap if I go turbo

 

[CertifiedBot]

As the veterans on here have advised countless others, the first step to taking you from current ride to the goal line is have a budget. Know how much time and $$$ you are willing and ready to spend. Once you have that you can do the research on here and begin to formulate a plan.

If I told you it will take you $10,000 to get your gs to 250 reliable hp, is that okay? Is that too much? What about $5,000? That answer will determine if you rebuild and beef up your current ride, sell it and get a gst/gsx, or just stick with it as a daily as is. No matter what you're looking to spend some decent coin to get what you're looking for.

And, no, you can't add boost to your engine now with the head gasket leaking. The head gasket seal is a band aid at best - like taking an aspirin so you can run a marathon without feeling your knee pain. Bad and expensive things will happen.

Determine your budget. Do the research. Then decide to fix/sell/run as is.

Thank you very much for the advice. I’m going to be thinking about a budget and how much I want to spend to build the car. I definitely think $10000 for just the rebuild and turbo is too much for me. Whenever I make a decision I’ll have to reply on the post, I might have some more questions . Thanks again!

 

[CKOPOCT]

I agree - $10,000 would be a bit high for just those two things ... but add in injectors, ems, intake, exhaust, fuel pump, bov, waste gate, intercooler, etc. and $10,000 is very reasonable with a beefy rebuild and quality turbo.