shotgreen

Ok let me rephrase that, IMO the faster spool of the 3" isn't worth the extra cost. So I'm probably going to get a 2.5" midpipe and see what happens. Not sure how restrictive the cobalt muffler is but if it becomes a problem then i'll remove it. I did do some virtual dyno runs when the car was still stock and it showed 107-109 at the wheels. This makes me think that it is pretty accurate.

Joe Perez

iTrader: (8)

So, to summarize the thread to date:


Using an app on your phone, you estimated the output of an unmodified '03 Miata at 108 HP. That's within the realm of plausibility.

You then bolted on a turbocharger and increased manifold pressure by around 58%. Despite the fact that you've made no upgrades to the fuel system, are running a somewhat restrictive exhaust system, and are clearly pinging, you still managed to increase HP by around 47%. That's also within the realm of plausibility.


What about this scenario is confusing?

shotgreen

Nothing is confusing. I just thought 180whp was attainable with my current setup. I clearly need to make some upgrades before I can make more power. Later this week I will dropping the transmission and putting in an ACT HD street clutch. While I've got the exhaust off I will also be swapping in a FM 2.5" midpipe. And to top it off I will install some new forceflow injectors. FYI virtual dyno is not an app on your phone. It is software that looks at a datalog and then computes your whp based on the datalog.

ridethecliche

iTrader: (2)

Virtual dyno is only as good as the data you feed it

shuiend

iTrader: (24)

Coming from someone who makes miata exhausts, the cost difference in material between 2.5" and 3" is extremely small. I would go 3" all the way back. Yes it does make a noticeable difference.

codrus

Virtual dyno requires a flat road on which you can safely make full-throttle accleration runs up to over 100 mph without any legal consequences. It also requires an accurate weight for the car as well as an accurate coefficient of drag. These are not trivial things, and hoping to get a number you can compare to a dynojet on your first try is asking a lot. While there are people on this forum who have had success with virtual dyno, personally I have never managed to get a reasonable number out of it.

While it is theoretically possible to get 180 rwhp out of the stock injectors, that assumes you've got the car tuned ideally and that the rest of the system is built out not to present limitations, and a stock exhaust doesn't qualify. Personally I have reservations about a piggyback system like the FIC ever providing enough controllability to do that. The problem with this kind of thing is that it's programmed as a series of deltas off the stock ECU's output, and the stock ECU is not totally predictable. Timing is trimmed by many factors like intake air temp, coolant temp, time the car has been running, etc. You don't know what all of the tables in the stock ECU are, so you can't ever know exactly what timing value it's going to give you. Imagine a given cell normally gives you 24 degrees, but maybe one day it gives you 25 or 26 instead, another day it gives you 23. To accomodate this you can't tune a piggyback system to the limit of detonation, you need to leave 3-4 degrees of safety margin in to prevent it from pinging itself to death on the day when the ECU gave you 27 for no reason you can figure out.

Other complications of a piggyback system include that it's difficult to change injector sizes, and that you need to keep the stock MAF in the intake. The MAF is restrictive, and once you hit around 220rwhp the stock ECU will stop believing the signal that it's sending and take away all the fuel.

I had a system similar to this (a Link Piggyback) many years ago and after a few years of tuning I outgrew it and moved to a full ECU (first Hydra, now MS3). Piggybacks are great for the reasons you listed -- simple to set up, stock idle, etc, and they can work very well for someone who isn't interested in ultimate power, but just wants to add 40-50 hp without having to think about it too much. If you're worried about 160 vs 180 rwhp, well, a piggyback is probably not the right solution for you.

My advice is to get a 3" exhaust (yes, the small additional cost is worth it), a set of bigger injectors, put the MS3 back in, and spend a few hours tuning it on a real dyno. 230-250 at the wheels awaits.

--Ian

shotgreen

Ian,
I agree with you on the piggyback ECU. It only gives you so much control over the stock ECU and is really just a delta map, not an actual map. This car is my DD and street driveability is very important to me. When I had the MS installed the car would often stall and buck at low speeds. This is ultimately what made me switch to the FIC. I'm thinking about giving MS anther try but I don't want to waste time if OE like driveability isn't possible.

codrus

While the MS3 is never going to have 100% of the drivability of a stock ECU (*), there's no reason it can't be tuned well enough to be a perfectly usable DD.

--Ian

(*) This is IMHO. Note that there are other people on this forum who would disagree and say that it can be BETTER at drivability than a stock ECU. Maybe they're better at tuning than I am, or maybe they just have lower standards, I'm not sure.

sixshooter

iTrader: (12)

Better than stock is achievable but it takes a minute. Close enough for happy smiles is pretty easy.

shotgreen

Just took the car out for one last drive before dropping the tranny and replacing the clutch. It seemed to be down on power a bit and not running like normal.. After about 15 mins of driving the CEL light came on. Just scanned it and got P0012 intake cam over retarded?? I recently took out the oil plug out on the back of the VVT so I could check my oil pressure. Not sure how this would have killed my VVT but it's the only thing I can think of.

shotgreen

Not sure what the problem was but I got my VVT working again. I redlined the engine a couple times and manually supplied 12v to the solenoid to verify operation. The car picked up a bunch of low end torque after doing this. Maybe some air got in it and was casing the issue? Now its time for the clutch replacement.

ridethecliche

iTrader: (2)

Aka also time for ECU replacement.

The 'trick' with a standalone is to limit what you change so you can tune for a singular variable everytime, get that down, and then move forward.

You can get away with swapping pump and injectors together if the data on the injectors is bullet proof.

Do too much at once and you have a headache because it's next to impossible to figure out what's causing what deviation... Unless you really know what you're doing and have some good base stuff to figure out from.

StillSlowMSM

If it helps, my car is also disappointingly slow. But hey it makes angry turbo noises

andyfloyd

My Hydra has 99% like stock driveability. Granted it took a long time to get it to that point. The only issue I have is on cold starts the car isn't perfect, cranks more than it would with a stock ECU. Other than that for a car with 300hp I think it's pretty darn good. Ditch that piggyback

shotgreen

I just finished pulling the tranny and clutch out. The clutch was almost worn down to the notches and the flywheel has some grooves in it. I got very worried about the transmission when I felt some play in the input shaft but after doing some research I guess this is normal? There is about 1/8" to 1/4" of radial play and no axial play. When I spin it by hand it feels smooth but lumpy at the same time. Could someone confirm that this is normal for a 6-speed? I don't want to reassemble everything if the tranny is toast.