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Turbo 420a

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2000mitsygt

Proven Member
56
0
May 5, 2012
barnegat, New_Jersey
Okay, so I've been searching the forums for about an hour now and can't find the info I need. My question is what Exactly do I need to turbo my 420a. I did a dry compression test and its 120 across the board haven't done wet test but the numbers were 120 even. So I am under the assumption the motor is good doesn't leak or burn. It's a 5 spd and I run full synthetic aside from that ideally after its said and done I want to run about 20psi after I build the block and head up. For right now I would be content with 5-10 psi of boost my question is what fuel mods do I need. I have an idea of what I need A/f gauge, boost gauge, 210 plh fuelpump, 10 gauge rewire. Now do I NEED injectors fuel pump and all that stuff or would a turbo kit, new exhaust, FMIC, boost controller and boost gauge be enough?
 

Colt4G63 also

Proven Member
3,392
49
Jul 23, 2008
Tonawanda, New_York
I guess there's something called a FMU that you could use to control fuel too, but I have no experience using one of those. Funny thing is, I copied and pasted the title of your thread into the search function, and it came up with tons of info about the subject.

And yes, I do agree, you won't need to add any forged internals to the head. Head studs might be a good idea, but other than that, rods and pistons would be the weakest point internally.
 

GSTurbo1

Proven Member
611
1
May 2, 2012
Pickens, SC, South_Carolina
I built one and the parts list came up pretty high. Megasquirt ecu custom tune head studs turbo fmic piping turbo manifold aeromotive fpr bigger injectors lightweight pistons eagle rods clevite bearings. Polish your crank.

420a motors have a weak point where the head bolts to the block. Do some research, probably the only thing good about the boosted 420a is not having to worry about crank walk.
 
Last edited by a moderator:

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
Unless you have about 5K to invest or a few years to gather up parts don't do it. You never want to start something you can't finish then sell your parts for half the price. And the 5k is just for a stock bottom end and everything you need to run 8psi. Which won't even get you past 250hp. You can go with eBay parts and make it last maybe ten thousand miles if your tune is right. Do more research and be realistic with your build. I'm going on 4 years with my car and it's still only a built n/a motor. I'm just getting around to the turbo setup which I have about 1800 dollars in parts and I'm barely half way. Which isn't saying much because the rest of the way is very costly to say the least.
 

grothe3297venge

Proven Member
620
2
Jan 18, 2011
Iowa City, Iowa
Well since no one else said it, you need to figure out a horsepower goal.. Saying you want to run 20 psi doesn't mean jack when it comes to what you need. Say you shoot for 350hp, you would need the obvious built block (low compression pistons, eagle rods, and main and rod bearings, and etc..). Also have the block checked to see if it needs to be bored and honed and what else you will need.

You can stick with the stock head (with a 350hp goal, anything above that you may want to upgrade cams, valves, and so on also), but it would be wise to upgrade to some 2.7 rockers and lifters, even if you stay N/A (pm me I can tell you where to get a steal on them).

With that example of a 350hp goal, you won't need megasquirt, but it gives you more room to grow then you would with the Hahn portfueler. You will also need to start thinking of a way to keep that power to the ground. Things such as a stiffer suspension, LSD, and so forth. Again, these are things I suggest, they are not needed right away, but a good rule of thumb one could say.

I would search around, try to find some good deals on parts. Look on 2gnt, and other sites related with the 420a motor. Lastly, no offense Jayson, love your build and the work you do, but $5,000 seems a little far fetched LOL. I would start collecting parts, don't waste your time boosting a stock motor. Keep it running and healthy and when you have everything, then tear down and rebuild all at once. Do it once and do it right, will enjoy a running motor for a longer period of time ;)
 

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
5k is a realistic price. A hrc kit alone is 3k new and 1.5-2k used but to do it right 5k is fair I think. I like doing things right and stick to high standards. Which is hard on a budget for sure. You definitely put out some good info that shouldn't be ignored. With everything you added it would cost more then 5k. Lsd and suspension alone is 2k that doesn't count a motor build or turbo kit. Sure you can go used and do the work yourself but in the long run you would be doing it twice. Just the questions he asked I'm sure he couldn't do half the work. No offense to the op.
 

2000mitsygt

Proven Member
56
0
May 5, 2012
barnegat, New_Jersey
The results were a dry test with closed throttle havent done a wet test with open throttle yet but honestly people say by a 4g Ive owned a 4g63 and a 420a and I feel if i built and turbod that i would be much more satisfied with it. What i was gonna do is by a junkyard motor and bore it out put new pistons, rings, rods, bearings and leave the head and run around 8 psi just a quick dd
 

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
You might gain 10 more psi you should be closer to 180-190 psi and there's no way a wet test will gain that much. Regardless of that go and turbo your car Gareented it might be quick but it will be quickly parked in the driveway. I'm done with this thread best of luck.
 

FRslimmyjim

Proven Member
144
0
Dec 28, 2010
warwick, New_York
Everyone has very good points. This has been covered a ton of times. I actually have a thread that I started just like this haha. Nevertheless, I am running fully built engine with turbo etc. I am running my fuel with a vortech fmu. If you are thinking of using this as an option, DON'T!!!!! This thing is the worst decision I have made on my build. Its too much fuel pressure and just very unreliable. You can run stock injectors till 6-8psi but it is not recommended. Go megasquirt if you want to do everything easier in the end. Go portfueler if you don't have big plans, I have not heard great things about the portfueler though. If your going to build your engine don't just build half of it. You have to choose between POWER, cheap, or RELIABLE and you can only choose two. You need a wideband 02 gauge. You can pm me with questions if you need, since I am doing what you are talking about.

Oh! You have mentioned fuel and engine but what about your clutch?
 

starfish

Proven Member
450
0
Feb 20, 2010
Hamilton, New_Jersey
I got about $4500 into the turbo kit and everything needed to boost 8psi properly.I drive the car every day(about 300miles a week).I haven't had any pinging or motor issues and I open her up every once and awhile.My bottom end is completely stock!!!Compression is sill perfect after 4 years of boost.I do change the oil religiously and use seafoam before every oil change.dont let the 4g guys discourage you!
 

2000mitsygt

Proven Member
56
0
May 5, 2012
barnegat, New_Jersey
I got about $4500 into the turbo kit and everything needed to boost 8psi properly.I drive the car every day(about 300miles a week).I haven't had any pinging or motor issues and I open her up every once and awhile.My bottom end is completely stock!!!Compression is sill perfect after 4 years of boost.I do change the oil religiously and use seafoam before every oil change.dont let the 4g guys discourage you!

Really? are you being honest? so the motor is all stock? how many miles? i have about 100,000 miles on mine
 

AK Maniak

Proven Member
2,075
14
Jul 9, 2009
Butte, Montana
I got about $4500 into the turbo kit and everything needed to boost 8psi properly.I drive the car every day(about 300miles a week).I haven't had any pinging or motor issues and I open her up every once and awhile.My bottom end is completely stock!!!Compression is sill perfect after 4 years of boost.I do change the oil religiously and use seafoam before every oil change.dont let the 4g guys discourage you!

It's not that we are trying to discourage him, we just want him to get realistic expectations. In all honesty he is going to spend more on parts just to turbo his car than just buying a turbo DSM.

We don't want to see another project go unfinished because some started buying parts before he knew what he was getting himself into, or even because he blew his shit up.
 

Miasma

Proven Member
397
3
Aug 22, 2012
Calgary, AB_Canada
When it comes to going with a turbo'd 420a you will be spending money, we all know that. So if you bought another 4g63 dsm and upgraded it, you would be spending money too. SO do whatever you'd like that makes the project more enjoyable for you.

It is true that you can turbo a stock 420a engine so long as you run no more than 8 psi. Other than the turbo system, you will need to upgrade your fuel system with a wally 255, fuel pressure regulator, and I would also recommend Megasquirt. Do not cheap out on your supporting mods if you want to turbo your stock block, or you will quickly blow it up.

Do not worry about porting your head unless you are looking for 600whp. The factory 420a head has better air flow then a srt4 head used on the neons. The only head work you should upgrade is cams and gears. Upgrading valves, springs, retainers and so on is for if your goal is over 400whp and over 8500rpm. If not don't worry about it.

The stock crank in a 420a is the strongest part, capable of 600whp as well, so for a built block I would only be considered with forged rods, pistons, race bearings, arp fasteners and of course being sure that all oil clearances are within spec.

Before beginning your build process, be very clear with yourself what you want out of the car and stick with that goal.
 

2000mitsygt

Proven Member
56
0
May 5, 2012
barnegat, New_Jersey
I want to say thank you to everyone What ill do is buy a junkyard motor and just build it from there i have a full rebuild book for the 420a Even 250hp is enough for me im not looking for another 350hp 4g63 that is loud and gets me into trouble and for some reason i feel the 420a boosted at 8psi will pull alot harder then 8psi on the 4g63 no idea why
 

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
Me and my buddy talk about that all the time. If you put a gst and 420a with identical upgrades I think the 420a would win. Obviously the gst can handle more boost but both cars at 8-10psi. I feel the same way you do.
 

LeeSD1

Proven Member
152
2
Jun 26, 2012
Miami, Florida
^^because a stock 420a is 9.8:1 compression and the head flows a lot better than a 4g63. Thats why a 420a would make more power...

And to the OP if you want even 8psi to last on a stock motor it has to be tuned just right so you dont get knock on that high compression motor and since the stock ecu doesnt adjust timing, you'll need something that can control your timing and the 'cheapest/best bang for your buck' is MegaSquirt...

so to be realistic about parts and cost when done the best most Cost Effective way of the necessities EXCLUDING built internals, ill list it out for you...none in which includes labor or shipping charges...

Megasquirt ms3x - 470(unassembled)
walbro 255lph fuel pump w/ rewire - 100
aeromotive afpr - 140
rx7 450cc injectors - 75(local shop)
ebay fmic+piping - 150
Log style manifold - 90
used t3 turbo - 350
Tial Wastegate - 150
HKS Blow off valve - 100
Wideband AFR gauge - 150
boost gauge - 50
oil pressure gauge - 50
turbo oil lines - 40
already 1900 but
Still not including various hoses and couplers and clamps and gaskets and fittings. Im sure I missed something but this was the main things off the top of my head you need to run boost effectively and so you can be halfway ready to up the boost when you put in a built motor.
 

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
^^because a stock 420a is 9.8:1 compression and the head flows a lot better than a 4g63. Thats why a 420a would make more power...

And to the OP if you want even 8psi to last on a stock motor it has to be tuned just right so you dont get knock on that high compression motor and since the stock ecu doesnt adjust timing, you'll need something that can control your timing and the 'cheapest/best bang for your buck' is MegaSquirt...

so to be realistic about parts and cost when done the best most Cost Effective way of the necessities EXCLUDING built internals, ill list it out for you...none in which includes labor or shipping charges...

Megasquirt ms3x - 470(unassembled)
walbro 255lph fuel pump w/ rewire - 100
aeromotive afpr - 140
rx7 450cc injectors - 75(local shop)
ebay fmic+piping - 150
Log style manifold - 90
used t3 turbo - 350
Tial Wastegate - 150
HKS Blow off valve - 100
Wideband AFR gauge - 150
boost gauge - 50
oil pressure gauge - 50
turbo oil lines - 40
already 1900 but
Still not including various hoses and couplers and clamps and gaskets and fittings. Im sure I missed something but this was the main things off the top of my head you need to run boost effectively and so you can be halfway ready to up the boost when you put in a built motor.


If you want to get technical and all we can. Compression on a 420a is 9.6:1 and to turbo it with name brand stuff is the right way to do it. There's plenty of guys out there that run a sfmu, fcd, wide band, afc and call it a day. And to run 450cc injectors is not necessary for 8 psi lots of guys run stock injectors too. Anymore boost then that sure you would want to upgrade but the op stated that's not what he is going to do.
 

LeeSD1

Proven Member
152
2
Jun 26, 2012
Miami, Florida
If you want to get technical and all we can. Compression on a 420a is 9.6:1 and to turbo it with name brand stuff is the right way to do it. There's plenty of guys out there that run a sfmu, fcd, wide band, afc and call it a day. And to run 450cc injectors is not necessary for 8 psi lots of guys run stock injectors too. Anymore boost then that sure you would want to upgrade but the op stated that's not what he is going to do.

Well he said he was going to get a junker motor and rebuild it so thats why I stated things such as megasquirt and 450cc injectors. BTW stock injectors are horrible with a fmu or even an sfmu because you force such high fuel pressures and the stock injectors get Maxed out at around 8psi high rpm band.
And the whole fmu sfmu way it cra*p! since that only allows you to create higher fuel pressures, that STILL doesnt stop the fact that the stock ecu is controlling the injectors trying to keep your afr's at 14.7
 

sestepney

Proven Member
63
0
Mar 5, 2011
Mesquite, Texas
I just finished my 420a build a year ago and everything your getting from everyone on here is true. The cost is HIGH with all the parts and labor. I did all the work myself and yes I did a lot of things twice before getting it just right. It really hits you once you crack open that stock block and really see its condition, now your thinking YEAH, this is going to need a lot of attention! A lot of people told me it would be easier to buy a GST/GSX but for me it was just fun of the build and seeing the end results. Do what you want, I think building a 420a is cool because everyone thinks your running a 4g63 until you pop the hood. Enjoy your car mann, just know its alot of work! Good Luck
 

jayson427

Proven Member
1,515
2
Dec 20, 2011
Mesa, Arizona
Well he said he was going to get a junker motor and rebuild it so thats why I stated things such as megasquirt and 450cc injectors. BTW stock injectors are horrible with a fmu or even an sfmu because you force such high fuel pressures and the stock injectors get Maxed out at around 8psi high rpm band.
And the whole fmu sfmu way it cra*p! since that only allows you to create higher fuel pressures, that STILL doesnt stop the fact that the stock ecu is controlling the injectors trying to keep your afr's at 14.7

Your definitely right it's not the way it should be done. And ms is costly and hard to wire up for a rookie mechanic. You can get an afx ecu with better timing maps and tune. Yet again not the best way to go. I haven't read alot on it but I heard the neon guys are getting flashable ecu's programmed for their set ups.
 
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