Another turbo miata!

[messiahx]

Hello all, was linked linked here by elderc from miataturbo.

I just got my turbo installed on my 97 1.8L miata:

Here's my list o' mods:

GT2554 @ 5ish psi
330cc injectors
BEGI RRFPR
Exhintake cam
9lb flywheel
230 lb-ft clutch/pp
rx-7 clutch type lsd

I was able to take it for a couple datalog runs in 3rd gear last night. AFRs are waaaay too lean. Hovering around 12.9 in boost. And there is, of course, the lean tip-in and closed loop below 4k rpms courtesy of the stock ECU...I think I'll have to get an O2 clamp. I figured the FPR would have made it much richer, though, in boost, but I guess not. (It is set to up fuel pressure to 50psi by 0in vacuum/absolute pressure and quickly raises the pressure to 75-80psi). Makes me wonder how people can get away without running at least a piggyback for fuel control.

So tonight I have to get it richer and hopefully tuned well enough that I can drive the damn thing. Then in a couple weeks I'll put my IC in and hopefully be able to run 10-11psi :cool:

Any comments regarding tuning are more than welcome...I'm learning this stuff on-the-fly.

Thanks for reading.

[Accord2nrz]

Welcome to the site! and umm 12.9 is right about perfect for a turbocharged car. your not running lean. lower the number the richer you get. =)

[messiahx]

From what I've read, 12.9 is at the limit for detonation, especially since I'm not intercooled. I have seen lots of guys at miataturbo recommend tuning for 11.5-12.5 AFRs. What do you typically aim for?

FWIW, I did hear some pinging on one of my first drives, as well (I added some fuel in the airflow map to correct this). I was going to try and get my AFRs to around 12 in boost.

[elderc]

12.9 is way to lean for a Miata, because they tend to run a more advanced timing your A/F should be 11-11.5 at wot, non-turbo Miatas run in the 12's at wot..............trust me shoot for 11.25-11.50 A/F's. Anything above 12 you will get knock. unless you pull a lot of timing and in that case you will have to watch EGT's being to high.

[Dzaster]

I get that lean tip-in business as well because N/A electronics.

I know that oderguy on MiataTurbo sells tan O2 clamp, but do you have another means of aquiring them? I've considered it. As of right now, it's all or nothing regarding the throttle.:D

[Accord2nrz]

well its a perfect reason why this site was created. I had no idea for miatas its like that. on my Honda Accord 12.9 is perfect for me at 10lbs with no pinging or pre-ignition. 12 and 11's are way too rich and foul my plugs out quickly.

[messiahx]

I get that lean tip-in business as well because N/A electronics.

I know that oderguy on MiataTurbo sells tan O2 clamp, but do you have another means of aquiring them? I've considered it. As of right now, it's all or nothing regarding the throttle.:D

Yeah, I know what you mean about the full throttle. I'll probably buy one of olderguy's clamps. Also flyinmiata.com sells one, but I think it's more expensive. The problem with the miata ecu is that it's closed loop below 4K rpms making accurate control of AFR pretty tough...for example...my AFRs go from 14ish to 10 when crossing 4K rpms in boost (yes I know 10 is waaay too rich, but I just had it dump in a bunch of fuel so I could get the car safe to drive and give my parents their garage back, lol).

Accord2nrz, that's an impressive AFR. I would figure you'd need a very rich tune on a Honda engine considering they're usually high compression, high revving engines.

[Accord2nrz]

My Compression ratio is 8.8 to 1. the F22B2 has the lowest of honda compression ratios for the motors. Makes it a good candidate for boost.

[elderc]

Thats a GREAT compression ratio for boost, too bad stock Miatas don't have that , compression ratio the 99-00 Miatas are 9.5.1 the 01-05 are 10.1 thats why they run a little richer than most cars. Mazda also uses the richer fuel mixture for cooling , by the way I bought the Flying Miata 0/2 signal modifier (clamp) it took care of my lean tip-in, I installed it two years ago and have never had to touch it...........http://www.flyinmiata.com/index.php?deptid=4524&parentid=0&stocknumber=07-46300

[messiahx]

Thats a GREAT compression ratio for boost, too bad stock Miatas don't have that , compression ratio the 99-00 Miatas are 9.5.1 the 01-05 are 10.1 thats why they run a little richer than most cars. Mazda also uses the richer fuel mixture for cooling , by the way I bought the Flying Miata 0/2 signal modifier (clamp) it took care of my lean tip-in, I installed it two years ago and have never had to touch it...........http://www.flyinmiata.com/index.php?deptid=4524&parentid=0&stocknumber=07-46300

Yeah I just bought an O2 clamp, should have it by Sat. Tuning below 4K is damn near impossible for me...it's either lean or super rich. Above 4K it is easier, but I screwed up my map and it's too dark to continue road tuning. And I need to get a MAP sensor I think.

I've learned a couple lessons so far...when you're a newb to tuning like me, a Miata NEEDS an O2 clamp. Second lesson is, if your project car is your only car, you better know wtf you're doing. I'm wishing I had something else to drive to work until I get my tune better.

Anyways...I mentioned my AFRs were super rich...will this do anything other than waste fuel? I've heard that too much gas causes oil contamination. Should I just not worry? I'm in the 9's at some points...

Btw, 94-95 miatas have an 8.8:1 comp. ratio. 96-97 has 9:1. But yeah anything newer and they bump it up.

[Dzaster]

I have my wideband simulating my narrowband and have since eliminated the narrowband. You guys know if narrowband is needed with this O2 clamp?

[Accord2nrz]

If you're wideband is setup so that the ECU is reading it instead of the normal band then no I don't believe so. I might be misunderstanding you.

Does your setup use the narrowband o2 at all? if not then clamping it will not do anything for the setup removing it all together might be best.

I need more info on what your setup is doing.

[messiahx]

I have my wideband simulating my narrowband and have since eliminated the narrowband. You guys know if narrowband is needed with this O2 clamp?

This is pure speculation on my part, but if you have the wideband simulating the narrow band signal, won't it still tell the ecu that it's rich when in boost and lean...whenever it's lean?

The O2 clamp is installed to tell the ECU that the AFR is stoichiometric (14.7) while in boost so that you have a much easier time tuning -- basically you can do whatever you want with the fuel because the ECU see everything as peachy.

[Dzaster]

Sorry guys, I kinda forgot about this thread then when I remembered I had to figure out where we talked about this. I used our serach feature for the first time just now, and works champ. lol

So yeah, most widebands have that second wire that can simulate a Narrowband signal so that you can do away with the narrowband O2 all together, get your AFR's and send a simulated narrowand signal from the WB02 to the ECU and ECU thinks its just an ordinary narrowband. It works, however, the guy selling the O2 clamp said a narrowband O2 was needed. I'll just weld in the extra bung for teh Narrowband.

messiah, yes it does tell the ECU the actual state of AFR's when in boost or not and that is why I'm thinking I need an O2 clamp. How much was it shipped from Olderguy? Comes with pressure switch too? What is the switch set at to engage the clamp--just before entering boost?

And lastly, so even with teh clamp, WOT is WOT right? Has nothing to do with O2 clamp. I will still need to tuen WOT when the car enters that state right?

[Accord2nrz]

at WOT most cars refer to a pre-programmed base table and AFR's go out the window so yes you will have to tune for WOT.

[Dzaster]

Good to know.

[messiahx]

Sorry guys, I kinda forgot about this thread then when I remembered I had to figure out where we talked about this. I used our serach feature for the first time just now, and works champ. lol

So yeah, most widebands have that second wire that can simulate a Narrowband signal so that you can do away with the narrowband O2 all together, get your AFR's and send a simulated narrowand signal from the WB02 to the ECU and ECU thinks its just an ordinary narrowband. It works, however, the guy selling the O2 clamp said a narrowband O2 was needed. I'll just weld in the extra bung for teh Narrowband.

messiah, yes it does tell the ECU the actual state of AFR's when in boost or not and that is why I'm thinking I need an O2 clamp. How much was it shipped from Olderguy? Comes with pressure switch too? What is the switch set at to engage the clamp--just before entering boost?

And lastly, so even with teh clamp, WOT is WOT right? Has nothing to do with O2 clamp. I will still need to tuen WOT when the car enters that state right?

The clamp costs $75 shipped. The switch sends a clamping voltage to the ECU as soon as positive pressure is made. Thread from miataturbo: http://www.miataturbo.net/forum/t7987/

I would think you'd be able to wire this into your simulated narrowband signal wire, so you won't have to add in the stock o2 sensor again. All it's doing is sending a certain voltage when the switch is activated, and at that point the o2 sensor signal is ignored.

[Dzaster]

I tried to link that thread to a friend and found you had to be member--sign in--to view that thread. I am a member so I didn't catch it, friend did.

This thread does work though and is somewhat discussed here as well.
http://www.miataturbo.net/forum/t2572/

haha! I just realized that we are totally thread jacking. I'm gonna start a thread about O2 clamp if you wanna add some info to that would be good. I guess this is where being a Mod would come in handy. Split threads.

Anyways, I started the O2 clamp thread. Let's talk story!
http://www.diytuning.com/forums/showthread.php?p=1026#post1026

[BoostedR]

Yeah I just bought an O2 clamp, should have it by Sat. Tuning below 4K is damn near impossible for me...it's either lean or super rich. Above 4K it is easier, but I screwed up my map and it's too dark to continue road tuning. And I need to get a MAP sensor I think.

I've learned a couple lessons so far...when you're a newb to tuning like me, a Miata NEEDS an O2 clamp. Second lesson is, if your project car is your only car, you better know wtf you're doing. I'm wishing I had something else to drive to work until I get my tune better.

Anyways...I mentioned my AFRs were super rich...will this do anything other than waste fuel? I've heard that too much gas causes oil contamination. Should I just not worry? I'm in the 9's at some points...

Btw, 94-95 miatas have an 8.8:1 comp. ratio. 96-97 has 9:1. But yeah anything newer and they bump it up.

Thanks for the info I'm getting ready to turbocharge my 2000 miata some of your info is very helpful.

[Turbineguy]

My 97 was supercharged and was very prone to detonation if run anywhere over 12 for AFR. It liked about 11.5 maybe a little richer but I was also running 12psi.