420a is turbo. need help

[eclipse787]

so basically when i hit boost the motor ran super rich and heated the hell out of the rings untill they finally melted away? so heres the list of what i need. walbro fuel pump, 12:1 fmu, boost gauge, boost controller. fuel pressure regulator? SAFC? whats the difference between an apexi AFC and a SAFC? what size injectors? lets go with a safe 6-7 psi of boost for a daily driven goal. any thing else i should think about getting?

[eclipse787]

also what should i be tuning with?

[david-b]

When you hit boost, you had to have hit fuel cut. Only way to run rich is if you were getting fuel there. You have NO fuel mods, so there's no way in hell for you to be pushing more fuel than needed. You're pretty positive it's the rings huh?


I'm only running 7.25psi, so you can use the same setup I'm working with.

-FMU. Would recommend SFMU since you have more control with it.
-255 Walrbo Fuel Pump
-Stock injectors work fine, but will be maxed out.

Tuning---
-Wideband O2
-Fuel Pressure gauge
-EGT gauge would be nice also
-SAFC is good, but there's others like Megasquirt. All depends on what you want to do in the long run. I'm not going above 7psi for a long long time, probably ever with this car, so the SAFC is perfect.

What year is your car? If it's a 95, you can still use the stock FPR built into the rail. But if it's 96-99, you need a FPR. Depending on year also, you may need some sort of missing link or fuel cut defender.

Any injectors larger than I believe 250s (someone correct me) will need something other than SAFC to control. There's not enough compensation in the SAFC for them.

[david-b]

Why can I not edit my posts at all lately?

The edit was get a 12:1 FMU if you're going to get a FMU. And DO NOT buy an eBay brand or "jdm" one.

[eclipse787]

its a early 95 (the one with the different main bearings) i havent
taken anything apart yet because of work and wont have time till friday. but i checked the timing and everthing was line up. unless there are holes in every piston, i dont know any other reason i could have such low compression. i'm supposed to have 175-200 right? thats what i thought i saw on spec charts of 420a motors

[eclipse787]

what about the aem or greddy computer - http://www.cimotorsports.net/motor-s...l-controllers/
could i use one of these instead of a SAFC. i guess i would rather set my self up for higher performance in the future if i have to spend alot of money on engine management.

[david-b]

Originally Posted by eclipse787

what about the aem or greddy computer - http://www.cimotorsports.net/motor-s...l-controllers/
could i use one of these instead of a SAFC. i guess i would rather set my self up for higher performance in the future if i have to spend alot of money on engine management.

I don't see why not. I haven't heard too too much about them. Sounds like it though.

[SilvrEclipse]

Ok, first you need to decide what fuel system your going with and how much power you want. If you want over 250whp or so you will need to control spark and the only way to do it is with megasquirt or the MSD-2 ignition box. I am about to run megasquirt but I have also used emanage. Its a good fuel controller but cant do ignition so thats where it falls short. You could also run an 8-injector setup. Once you pick out what your going to tune with then you will know what FPR you will need. I am about to buy a 1:1 for use with Megasquirt but I ran a SFMU and 310cc injectors for over a year with no problems on 9psi. That was with no other tuning.

You will also need a fuel pump, since you have a 95 you dont need a fuel cut defender.

Now with the motor you just blew up, you ran super lean and got some massive knock and probably cracked the ring lands on the pistons. Thats the same thing I broke, it pretty much breaks the same thing everytime unless you throw a rod.

Let us know what your goals are and we can point you in the right direction. Also are you building the motor up some?

[eclipse787]

my goal for my winter rebuild ( drive the truck in the winter) is 400 whp. i kno wdamn sure i'm not getting that on stock internals. for right now i'm going to buy new hastings rings. for my fuel/ ingnition controller i think im going with the aem one from ci-motorsports. it seems perfect, being that it has fuel and ignition control and i can tune with it. on stock internals the tech guy told me 10psi is all i should run. i'm thinking i'll run 8 just to be safe for now. will the walbro 255l pump support that much power? and in the description for the aem computer it says it doesn't need an FMU, or am i being confused with something else? http://www.cimotorsports.net/motor-s...ontroller.html

so, if this computer will control everything i need it to control for 8 psi, my list is the aem computer, fuel pump, fuel pressure regulator and possibly bigger injectors. will stock ones supply fuel for 8 psi or should i get 330cc's

[SilvrEclipse]

Your going to need forged pistons and rods to get that kind of power. With the AEM you should only need a new FPR. A 1:1 ratio should be what you need. Also I would get at 440s just to be safe. 330s may feed enough fuel but you will be close to maxing them out.

[steviek]

Whoa for that kind of horsepower we aren't talking just bolt ons. 400 whp is going to need about 850cc injectors. a 255 for sure (minimum). Adjustable fpr. Needless to say built bottom end. Head work for sure. Full exhaust intake header big turbo kit. man the list goes on and on. Drivetrain everything clutch tranny no way stock rs tranny will take 400whp. Don't forget an LSD for that fwd and nothing less than streetable slicks for traction. That number I don't want to say is unobtainable in a rs but with the amount of crap you would have to source and buy and then install plus the nagging problem of still having an fwd you might as well just buy something very nice. I mean we all love our projects but at some point you gotta look at a cost benefit type of analysis and ask yourself will it be worth it to have a fwd that runs 13.5 @ 125mph???

[eclipse787]

don't worry, i know that i'm nowhere near 400 whp, and wont be till lots and lots of money rolls in. what does a stock 420a have like 140-150 hp? my cars a gs by the way if it makes any difference. For know, i just want a faster then your average car kinda setup. for know im getting the computer, 440 injectors, fuel pump and a fpr. thanks for all the help guys.

[steviek]

Yes stock gs/rs's have 140 crank horsepower... Thats bout 110ish to the wheels.

[eclipse787]

so wheres that 30 hp going, weight and tire friction?

[MazdaX]

Drivetrain loss.