420a turbo

[mike11743]

A while ago i posted a thread about turboing my 420a with 704k on the clock and the thread got off topic to a 4g63 vs. 420a fight which eventually got it locked. Well anyways, everything is sucessfully installed and running pretty damn good. Im only at 6 psi right now, but need help with some minor adjustments.

Everything runs great when the motor is cold, but after i warm up, sometimes at hig boost levels (6 psi unfortunately for me) my car seems to cut out pretty bad. Let off the gas, wastegate opens and im fine until boost builds up again and it cuts out again. Now i'll admit, i dont know too much about turbos in general, so what would my next step be?? I know there is no leaks anywhere in the intercooler piping, maybe the BOV needs adjuster. I do have an atmospheric BOV if that makes a difference. I'm thinking its running lean as thats what my narrowband gauge is telling me, but i tend not too read too much into that piece or crap guage. Basically the narrowband drops down to as lean as possible and then the cutting out begins. Any help is greatly appreciated.

 

[Leonthefaded]

Lets get a run down of you fuel supporting mods. Example : Pump, regulators, Lines, Injectors, aftermarket or OEM throttlebody.

Also would you happen to know your operating tempatures are reaching before ou are experiancing cut out? Can you post a video of what EXACTLY is happening?

 

[Fotowntalon]

A while ago i posted a thread about turboing my 420a with 704k on the clock and the thread got off topic to a 4g63 vs. 420a fight

That never ever ever happens here! /sarcasm

Anyways I got to ask, is the 704k a typo for 104k? Because if not, thats rather impressive, and or ballsy to turbo a car with that much mileage.

Next up are you running a fuel cut defender or missing like of some sorts? If npt, that may be your problem.

 

[ThunderChild]

if you dont have supporting fuel upgrades then you will definitely be running lean. at the very least you would need an FMU and AFPR, as well as a better fuel pump (walbro 190/255).

also, spark could be advancing at higher boost levels, exaserbating the problem.

give us a full run down of your supporting mods and that will allow us to better diagnos the problem.

 

[Josh97eclipse]

Do you have a fmu or a sfmu? do you have a fuel cut defender?

 

[mike11743]

sorry not to get back sooner guys. I have nothing as far as fuel support mods, and this only happens after the car is fully warmed up. Sounds like i will need to look into FMU and 255 fuel pump. I am only running 6 psi at this point, i was reading somewhere that supporting fuel mods really arent necessary at real low boost.

Oh BTW 704k is a typo, mileage is 174k

 

[DSM1G90]

174K is a bit on a 420A motor to think of turboing it.

I'd do at least rings and bearings for the bottom and do a full head job before doing this mod.

 

[Anubis_4_99]

174K is a bit on a 420A motor to think of turboing it.

I'd do at least rings and bearings for the bottom and do a full head job before doing this mod.

What is your reasoning for replacing those parts without even suggesting doing any tests to warrant the work?

He could have perfect compression and a good condition head, and if it was the case, then there would be no reason beyond the "O M G your at 200K, your ish will fail!" BS.

 

[stars]

Guess he doesn't know he's going to need oil squirters under the pistons? Wonder how long it will run? This will be interesting.

 

[Anubis_4_99]

Guess he doesn't know he's going to need oil squirters under the pistons? Wonder how long it will run? This will be interesting.

Plenty of people have turbo'd motors without oil squirters without issue. His issue is going to be fuel since it doesn't sound like he did much research before putting a turbo on.

 

[stars]

I could have went on and on but, I thought others had already covered what he needed. If it was me and had the money, I would put a cheap NOS kit on it and run it till it blows. Can't hurt nothing but your engine so, you will make a extra 35 horses with one squirt. That, will then give you a new reason to buy a turbo'd engine which will be cheaper than installing one on a NT.

 

[WES_393]

Many 4g63 owners remove the oil squirters with no problems. In fact you'll have less problems since the crankshaft will receive higher oil pressure.

And swapping a 4g63 into a 420a requires insane amounts of fabrication. Unless you meant turbo DSM, then yes that would be a good idea.

 

[DSM1G90]

He could have perfect compression and a good condition head, and if it was the case, then there would be no reason beyond the "O M G your at 200K, your ish will fail!" BS.

Simple: he wants to mod a motor not designed for turbo .. just a "play it safe" thing.

 

[AK Maniak]

Lets stay on topic guys.
OP, try and describe what's going on in a little more detail. A video would also do the trick. Best advice I can give you is that for every hour you spend modding your car you should do at least 2 hours of research.

 

[99vipereater]

Lets stay on topic guys.
OP, try and describe what's going on in a little more detail. A video would also do the trick. Best advice I can give you is that for every hour you spend modding your car you should do at least 2 hours of research.

This is a good rule but I would even increase that number, the more research you do the more prepared you'll be for success. You cant expect someone to build your car for you over the Internet and give you a quick fix every-time something goes wrong.
It sounds like you are lacking supporting mods which you should know by now with more air ( boost) comes more fuel.

 

[96 420a-t]

I'll get this back on topic.

OP, here is what you need.

1-missing link of fcd.
2- 255lph wally pn-gss342
3- 12:1 fmu

This is what you need to run 6psi safely.

Also dont ignore your narrow band. If it says lean, you're lean. It doesn't give you any info really, but still, lean is lean.

 

[mike11743]

I guess ill have to start with the supporting fuel mods. My plans for this car (since i am fully aware this motor will not last long) were to get a built shortblock in the near future and basically start there. My ultimate goal is to have something that can hold 14 or so lbs of boost. I realize that will not be feasible on my 174k motor as it looks pretty nasty inside and has low compression.

My plans were to try and hold off on fuel until i get up to my final setup, but it is sounding like i may need to go ahead and just start the fuel mods. I've been running this thing for about 1k miles and so far so good minus the fuel issues.

 

[TSi Kid]

i have nothing as far as fuel support mods,

facepalm.jpg

 

[mike11743]

As far as FCD or missing link, ill probably go with the FCD. Does anyone have experience with this one from ebay? I would usually stay away from ebay junk, but it looks like he has sold a lot and everyone seems to be satisfied. Ill just go with symtech unless someone has anything good to say about this one.


95-99 Eclipse/Talon 420a Custom FCD Fuel Cut Defender | eBay

 

[Anubis_4_99]

Simple: he wants to mod a motor not designed for turbo .. just a "play it safe" thing.

Again your reasoning is pointless, countless upon countless people have turbo'd a non turbo motor without issue, they've supercharged a non SC motor without issue, and they have installed nitrous on motors not designed for it without issue if its done correctly.

A buddy of mine is running a stock 4cylinder motor, with factory 9.2:1 compression, on 12PSI and has been doing so for over 50 thousand miles. And his compression is the same as the day he turbo'd it. Want to know the difference? He takes care of his car and understands his mechanical limitations, and did the proper supporting mods.

The 420A i agree isn't the greatest motor in stock form to turbo, but under low levels it would hold up fine, the problem with that is normally anyone who has the time, knowledge and want, to turbo a non turbo car, will want more and more power, eventually exceeding there mechanical limitations. That's when you hear stories of blown motors and expensive rebuilds.

Or there is the other lot, who don't research what they need and assume that they can get away with turboing without proper supporting mods. Which again leads to stories of blown motors, and expensive rebuilds or part outs.

Anyway as to the OP's questions, if you have no supporting fuel mods then you haven't done enough research and are risking your engines life running as it is now, you need to do the proper fuel mods if you expect it to last at all.

 

[Josh97eclipse]

Do not buy the FCD from eBay. They will take a crap in no time, spend the extra 20 bucks and get the one from symtech labs.

 

[96 420a-t]

I ran a fcd but ditched it due to it making my car run like crap. I used a zeneir diode. If i did it again that is what i would do. I picked up 25 diodes for 2 bucks. If you go this route know that you need 4.7v diodes.

Keep in mine that the fcd, fuel pump and 12:1 fmu are MINIMUM required to run boost with this type of setup.