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Tuning

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DsmRalf

Probationary Member
7
0
Sep 1, 2021
Rochester, New York
Hey everyone, i wanted to know how to tune my 1999 Eclipse RS. I’m new to everything so it would be nice if I had someone explain and break down what to do and not to do. I would really appreciate it thanks
 
If there were a way to " tune" your car as is, you lack the necessary hardware to take advantage of any changes. 420a is a low compression, low performance 4 cylinder. You would need to make changes. The only possible exception I can think of is maybe if a person ran high octane fuel then you might be able to lean out some and play with ignition timing but without a way to increase airflow or compression its simply not worth it and not even possible on a stock car. As mentioned you need an aftermarket ecu.
 
Actually, you CAN tune the non turbo model if you install an aftermarket ecu such as the Megasquirt system, most people that install Megasquirt also turbo the car at that time.
Thanks man I appreciate you for helping out. What can I search up for the right ecu
 
Thanks man I appreciate you for helping out. What can I search up for the right ecu
I don't think you understand. There is no "right" ecu. You must go to standalone. Even if you do this you engine currently does not have any additional parts to take advantage of being " tuned ".
If you added a turbo or changed to higher compression pistons etc. Then you could take advantage. As is you would gain very little.

Tuning is popular and necessary on a 4g63 because the typical upgrade path in more boost, larger turbos, larger injectors and more fuel. To accomplish this you must have ecu control and "tune" the car

A stock 420a has no way of increasing airflow so no need to add fuel, change ignition timing etc.
 
Thanks man I appreciate you for helping out. What can I search up for the right ecu
 
There's people selling what's called "syked" ecu's on Ebay and other sites. Stay away from those. Most of the time they're just stock ecu's where a guy is trying to grab extra cash.
As people already pointed out, the stock ecu cannot be tuned (unless you find the guy that has Chrysler software, which is unlikely and beware of scams).
Best option is Megasquirt (preferably MS3, but MS2's are fairly cheap to buy used).

Also as stated, you'll want some modifications before tuning. You really can't do much with the stock 420a. You'd be lucky to gain 3hp tuning it in stock for. Even with full bolt ons 8hp is a stretch.
 
Thank you for the insight and to be honest I rarely just want tunning for pops and cracks
 
If that's what you're looking for... get some headers, test pipe, and high flowing catback system. The biggest thing to achieving these "crackles" and "pops" and shit is a high flowing exhaust system. Set you plug gaps at 0.045", that's as large as they can go without misfiring on the stock ignition system. And get an aftermarket rev limiter. If you're buying a Megasquirt, you'll get launch control and such. But if not you'll want something like the Bee R which is what I have, it has a module I mounted under the dash with a knob you can adjust your Rev limiter with. The stock valve springs seem to get a little shaky at 8000rpm with stage 1 cams. If you're still running stock cams, I don't see why you couldn't go to 8500.

Don't expect to be shooting any large flames or anything. Unless you were running super rich on open headers, the 420a is incapable of it (or boosted with straight pipe).

Just keep in mind, anything you do that raises the rpms or changes the timing and such will probably shorten the life of your engine. Consider changing your service intervals (I oil change every 3000 miles strictly).
 
The pops and bangs tune he wants is achieved on decel only. Honestly, I think it’s dumb, and serves zero purpose. But, to each their own.
Can you tell me a little more about this please and I understand some people say that but I just really love the sounds of it
 
He meant deceleration. Like when you let off the throttle in gear. Basically engine braking. It also happens when you pin it on the rev limiter. But that's very bad for your engine.
 
He meant deceleration. Like when you let off the throttle in gear. Basically engine braking. It also happens when you pin it on the rev limiter. But that's very bad for your engine.
Ahhh okay makes sense I’ll take your for thank you. Is there anything you think I should do to my 420a then to make it pop and cracks?
 
I personally think you should leave it alone. Unless you're going to fully build it and buy the proper tuning equipment. But at this point I just don't see that happening.

There's not a lot you can do in attempt to achieve your goal. And you'll just end up damaging your stock 420a.
 
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