New here...

[BlackStripes]

hey Guys,

My name is Hector and i just bought a 2002 with a BRP MP62. It has FFS's pullies (65/115) , tensioner and a PC-Pro.

When i got the car i knew that the setup needed a little tweak here and there, which i dont mind since i've been into cars for a long time.. specially forced induction vehicles (MazdaSpeed Miata, STi, GTP, Ram 3500 and my TT Mustang come to my mind).

Anyway, after a couple of hrs driving, the ping was evident at two rpm ranges: at about 3200-3300rpms for like 1/2 second (and 3rd or above gears) and at high rpms, usually well into the 5K's.

So, my little maintenance/cure started with:
-Changed coolant for 75/25 + WW (was WAAAY too green for my taste :biggrin: )
-New air filter.
-Some injector cleaner.
-Talked with Tom like 3 times already :biggrin:

The rest of the week:
-180 thermostat
-16 PSI radiator cap
-SeaFoam treatment
-BKR8EIX spark plugs.
-Change all the rest of fluids.

So, the final thing will be taking the car to the dyno (23rd of this month) and see where the A/F curve is. Since i am a little hesitant to take the car to 7K rpms knowing that it pings, I added some torco yesterday (i have two boxes at home :rofl: ). Today i drove the car hard (not traffic law were violated :driving: ) and there is no ping at all. That kinda tells me that maybe its not a fuel issue, more a timing issue.

What it really bothers me is why it used to ping from 3200 to 3300rpms? Any Ideas?

oh, sorry for the long post.

[socal pat]

You'll probably find your answer on the dyno. Fuel curve likely.

[Serpico]

I hope you're running some type of intercooler. If you're not using an A/A intercooler, you're making about 10-11psi with those pulleys.

High compression and 10-11psi is a recipe for pinging!

Check your A/F ratio first and then look at your intake temps and start to consider things like intercooling (A/A, water injection, ect) and TIMING CONTROL.

[BlackStripes]

I hope you're running some type of intercooler. If you're not using an A/A intercooler, you're making about 10-11psi with those pulleys.

High compression and 10-11psi is a recipe for pinging!

Check your A/F ratio first and then look at your intake temps and start to consider things like intercooling (A/A, water injection, ect) and TIMING CONTROL.

Nope, not intercooler.

We will see what the dyno has to say. If the curve is Ok, i will probably go for WI. I used it before with good results.... well... kinda since i blew my engine when it stopped working :frown:

Another question. When we had the MSM, some people put bigger injectors that could be handled by the stock computer (about 10% bigger), is that possible with the VVT computer?

I ran 199rwhp in my MSM (same inj. size?) and it was leaning out at redline. I guess 170 or so would be ok with a SC setup?

[Serpico]

The Torco is a very good idea for now!!!!

FWIW, I made around 190whp @ 8-8.5psi, so with you're setup now I bet you're making quite a bit more than that ..... Be careful!

I don't know if the stock ECU can handle larger injectors than what you have now.

[BlackStripes]

I don't know if the stock ECU can handle larger injectors than what you have now.

I know that some 1.6 guys have replaced their injectors with 1.8 injectors. I know some have upgraded 1.8's with some sort of RX7 inj... the computer will compensate, obviously only if the different is not more than 10%-20% (don't remember). I wish i can find all that information now!!

[MarkB]

I wonder if it is a lean spike at 3200 RPM - but I thought the PC-Pro was supposed to get rid of that? I know the lean spike was common with the older Powercards on 2001+ Miatae (incl. mine).

I have yet to re-dyno since I got the PC-Pro - no one is answering the phone at the dyno shop! :mad:

Mark

[BlackStripes]

I didnt know that.

I was assuming that was a change in timing from the computer. I guess i'd have to add more fuel to all the range : 2800-5000

[BlackStripes]

I found the chart : http://www.miataturbo.net/forums/showthread.php?t=4288 :seeya:

So, 305cc will give us around 15% more fuel to spare. :gunsmilie:

[MiataVOL]

I’ve also had pinging with my black/black (could that be it?) 2002 since the original MP62 installation. After the engine reaches operating temperature, the J&S lights-up at anything more than moderate (1/2 throttle) acceleration (primarily) at 2500 – 3500 rpm. I have an upcoming date with a dyno to see if it’s A/F related. Please keep me up with what you learn….

MiataVOL

2002 / MP62-S3 (105mm-65mm) / BTB / Small BRP A-A Intercooler / NGK BKR8EIX plugs / PNP-PC-Pro (green=3; yellow=7,8; Red=4,5; Yellow/Blue=8 / Red/Blue=8),+ J&S (Sensitivity = 1:00, Start=full CCW, Rate= 1:00) / TDR Heat Shield / Good-Win-Racing RoadsterSport Mid-pipe / VVT Adj. / 93 Octane gas

[BlackStripes]

I will definetely keep you updated.

I probably will buy a scangauge to monitor spark and intake temps... and try to understand what's going on under the hood.

So far my guts tell me that having a bigger fuel pump, a rail that sprays evenly the injectors and a little bigger injectors will be pretty close to supply enough fuel. About timming.... i still have to investigate a little more... maybe WI will do the trick.

[BlackStripes]

Ok, news...

I took the car to the dyno. It came close to my prediction.

What i didnt expect is how nice a/f curve it had. The red line is 12:1.

About the boost... hmmm.. i guess the tensioner is not doing its job. :shifty:

Good start. I wont be concern about fuel. I might get only get the new timing card.... for now. ;)

Link with HUGE copy : http://www.crossroadforums.com/gallery2/d/334960-1/MiataDyno.jpg?g2_GALLERYSID=40167cead209dd6724327e 4b82b0b06e

[BlackStripes]

Oh btw. I was wrong about the pullies. I have 105mm and 65mm. Now everything makes more sense :)

[Serpico]

Oh btw. I was wrong about the pullies. I have 105mm and 65mm. Now everything makes more sense :)

That makes much more sense now!!!!

FWIW,

I made 174whp @ 7psi
187whp @ 8psi

Your power looks low for your boost level. I bet the ECU is pulling as much timing as it can, so keep adding the Torco!!!!! A TDR intercooler or water injection would be a good thing right about now.

Are you running the stock throttle body?

Where did your PC Pro settings end up?

[BlackStripes]

Yeah, i am sure the computer is pulling timing. For now my main concern is the boost. Even though you can see that max boost is 9.XX PSI, its ALL OVER the place. Probably that's why i am not putting the power either.

Oh yeah, stock TB. And those were my first and second pull. I didnt need to change my PC Pro setup.

[roadsterboy]

Hector,

I am glad you are enjoying the Miata. The settings on the PC-Pro are the ones that Tom gave me over the phone one afternoon. I guess he made a pretty good call. Regarding the tensioner, I know that my mechanic had some issues in installing it.

Regards,
Cem

BTW, I recently aquired a 2002 S2000, 26K miles, in excellent shape. It's no supercharged Miata, but it will keep me entertained for a while.

[BlackStripes]

hey Cem,

I hope the S2000 is working for you!!

I really like the Miata, as i said, its my daily driver and i just want to run it safe. I will try to mess around with the tensioner and hopefully i will fix the fluctuation, i guess that i will start seeing around 9psi all the time and most likely the car will make more power. Then... i will start all over again and probably get the bigger injectors.

I might get a boost gauge as well.