The Definitive "don't swap in a VVT motor with a stock ECU" non-Megathread - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 08-29-2014, 11:57 AM   #21
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

Quote:
Originally Posted by Amellrotts View Post
The stock ecu with an aftermarket VVTuner piggyback runs the VVT engine perfectly.
FTFY.

Quote:
Originally Posted by Chooofoojoo View Post
at title change.

Good read though. I had been tossing the idea around of a VVT swap. Good thing I have a MS2.
Feel free to read the real VVT swap thread
curly is offline   Reply With Quote
Old 08-29-2014, 12:04 PM   #22
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

This thread has AIDS...



Band Aids
Attached Thumbnails
The Definitive "don't swap in a VVT motor with a stock ECU" non-Megathread-bandaid.jpg  
Dunning Kruger Affect is offline   Reply With Quote
Old 08-29-2014, 12:07 PM   #23
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,775
Total Cats: 1,106
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
I didn't call you a liar, but hey, keep continuing living in your fantasy world with your singular perfect AFR and where I'm making up ****.

You forgot to mention that the safe way to run it is an AFPR.
Do you have any actual evidence that AFR's won't be more then safe on a stock 94 ecu and a VVT head? Have ever tried running a similar setup and seeing what AFR's are? Amellrotts has a wideband installed on the car, has had it on a dyno, and says that AFR's have been within a safe range during the pulls, what data do you have to counter him with? This is not a boosted motor where AFR's have to be absolutely dead on, nor is it a track car. The 94 ecu already runs rich from the factory so I have no doubt that it will provide enough for a safe street tune. No it won't be perfect, but is the cost of a standalone worth the additional 10hp he may pull out of the motor? In his case most likely not.

I have never ran a stock 94 ecu with VVTuner and a VVT head, I have ran a stock 99 ecu with VVTuner and a VVT head on a 99 lower end. Watching AFR's on a wideband and the car had plenty of fuel. I know my stock 94 runs richer stock then my friends 99 did so I don't there is enough fuel.
shuiend is offline   Reply With Quote
Old 08-29-2014, 12:13 PM   #24
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

Quote:
Originally Posted by shuiend View Post
Do you have any actual evidence that AFR's won't be more then safe on a stock 94 ecu and a VVT head? Have ever tried running a similar setup and seeing what AFR's are? Amellrotts has a wideband installed on the car, has had it on a dyno, and says that AFR's have been within a safe range during the pulls, what data do you have to counter him with? This is not a boosted motor where AFR's have to be absolutely dead on, nor is it a track car. The 94 ecu already runs rich from the factory so I have no doubt that it will provide enough for a safe street tune. No it won't be perfect, but is the cost of a standalone worth the additional 10hp he may pull out of the motor? In his case most likely not.

I have never ran a stock 94 ecu with VVTuner and a VVT head, I have ran a stock 99 ecu with VVTuner and a VVT head on a 99 lower end. Watching AFR's on a wideband and the car had plenty of fuel. I know my stock 94 runs richer stock then my friends 99 did so I don't there is enough fuel.
I'm not arguing that it won't run, I'm arguing for things being right vs things working. There's a significant difference between the two.

He also has nothing to lose considering that the car doesn't have OBD2 for inspections in NC.
Dunning Kruger Affect is offline   Reply With Quote
Old 08-29-2014, 12:19 PM   #25
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,775
Total Cats: 1,106
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
I'm not arguing that it won't run, I'm arguing for things being right vs things working. There's a significant difference between the two.

He also has nothing to lose considering that the car doesn't have OBD2 for inspections in NC.
He has $750+ to loose to go to an MS3X or some other modern standalone for minimal gains.
shuiend is offline   Reply With Quote
Old 08-29-2014, 02:26 PM   #26
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,311
Total Cats: 1,335
Default

A bit off topic but this experience might be relevant. We bought this NA6 with a bunch of useful mods off craigslist for parts. PO said the head was shaved. JR header, ceramic cat, 2.25" race exhaust and a Randall snorkel on the airbox. It actually does "run great". So we put it on our dyno to see what it was making. 112whp is strong but one look at those AFR's and I wince. This poor little B6 is begging for an ECU. Anyone who has tuneda B6 on stock cams knows this thing probably has 10 more whp at 7200rpm with a halfway decent tune

Moral is thus: Just because it starts and runs smoothly, makes more power than it did before mods, does not mean it is tuned properly (or at all in this case) or close to optimized. NB engines tend to do the opposite and run dangerously lean on top. Get a WBO2, programmable ECU and have a pro tune it. Or at least let the software autotune for you.

Attached Thumbnails
The Definitive "don't swap in a VVT motor with a stock ECU" non-Megathread-10604411_733149633405264_1938149375999915582_o.jpg  
emilio700 is offline   Reply With Quote
Old 08-29-2014, 03:18 PM   #27
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Oct 2011
Location: Hickory, NC
Posts: 683
Total Cats: 3
Default

I am not going to speculate how other cars run with setups I know nothing about. I promise you there are a lot of other people running VVT engines on stock NA ECU's with no isues. I know mine was right on. Since I am using the NA CAS I can easily adjust timing. I know I bought a MSPNP and when I went to a dyno day the shop owner and tuner told me the ECU was controlling the AFR's perfectly. That if I did install the MS I would be paying him a lot of money to make it do what the stock ECU was already doing. He, and several others in attendance were all very surprised. We even did about four extra pulls with my car just to verify things as well as do a side by side comparison of the VVTuner on vs off. After having another tuner ride in my car and tell me the same thing about my AFR's I decided not to mess with it for now. Then I sold the MSPNP because it is kind of nice to have OEM reliability and not have to **** with tuning it from time to time. It starts great, EVERY time. It idles great, every time. It gets great fuel economy, every time. Sure I could get a LITTLE more power by changing my timing curve and removing the MAF, but at what cost? I have lots of power in my boosted miata. Soon I will have a LS1 swapped miata. This is the wife's car and she insisted it not need a laptop hooked up to it, EVER. Since the bitch left it is even more imperative that the car run properly without the need for occasional tune adjustment. I know it isn't normal, I DON"T CARE. I know this car is working RIGHT. Not just working, but doing everything it should, as it should, SAFELY. I have put 50K hard miles on this setup. I would not trust the next one to do the same and would have wide band in it as well. Today however, I have such faith in my setup that I pulled the LC1 WB because I am tired of ******* with the boosted car's MTX WB that won't stay calibrated. I am installing the LC1 in the boosted 10AE and hoping to have a reliable WB. So at this point, even if Reverant gave me a MS3 for the 94, I would not use it.

Thanks to those that actually gave useful information for others to find in the future. To the other clown, I am glad this thread was able to get your post count up you f*cking troll.
Amellrotts is offline   Reply With Quote
Old 08-29-2014, 06:02 PM   #28
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

Emilio and Savington: known trolls trying to get their post count up.

Between the casual homophobia and misogyny, I don't know why "the bitch" would ever leave you. You seem like a pretty stand-up guy.
Dunning Kruger Affect is offline   Reply With Quote
Old 08-29-2014, 06:40 PM   #29
Junior Member
 
Join Date: Nov 2013
Location: Atlanta, GA
Posts: 53
Total Cats: 5
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
Emilio and Savington: known trolls trying to get their post count up.

Between the casual homophobia and misogyny, I don't know why "the bitch" would ever leave you. You seem like a pretty stand-up guy.
I'm surprised his factory ecu is running it as well as he reports. Friend swapped an 03 into his 97, factory ecu would NEVER pass emissions again, even with all sensors from NA, vvtuner on or off. We stuck a wideband in just to see what was happening and it was lean up top. 15.5-17 under WOT. I was afraid to put any det cans on it. Sounds like this guy's car got lucky though.
Do you go out of your way to be more of an *** than you believe he is?
harrybeachdog is offline   Reply With Quote
Old 08-29-2014, 06:51 PM   #30
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,363
Total Cats: 1,323
Default

Quote:
Originally Posted by harrybeachdog View Post
We stuck a wideband in just to see what was happening and it was lean up top. 15.5-17 under WOT. I was afraid to put any det cans on it. Sounds like this guy's car got lucky though.
Sounds right. To be blunt, until I see a datalog or a dyno chart with an AFR trace, I call bullshit on the idea of perfect AFRs from a '94 ECU. If it's true, and the AFR trace is actually between 12:1 and 13:1 above 4000rpm, then it's a miracle.
Savington is online now   Reply With Quote
Old 08-29-2014, 08:25 PM   #31
Senior Member
iTrader: (5)
 
Join Date: Jul 2005
Posts: 715
Total Cats: 53
Default

It's funny people make **** up based on nothing and call others with actual experience troll...
bcrx7 is offline   Reply With Quote
Old 08-29-2014, 08:34 PM   #32
Junior Member
 
Join Date: Nov 2013
Location: Atlanta, GA
Posts: 53
Total Cats: 5
Default

You know, one thing that could make it safe would be slightly larger injectors. Like a set of 305 greentop supra's I have laying around. Maybe I have a use for those finally!
Or I could do it right and use my ms2...
harrybeachdog is offline   Reply With Quote
Old 08-29-2014, 09:36 PM   #33
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Oct 2011
Location: Hickory, NC
Posts: 683
Total Cats: 3
Default

Quote:
Originally Posted by bcrx7 View Post
It's funny people make **** up based on nothing and call others with actual experience troll...
I do believe I am the only one here who called someone a troll. Someone who had given no first hand knowledge of any actual experience with the situation being discussed. I however, have that experience. I tried to share my actual first hand experience and knowledge to better the community here. I have no problem with people questioning it, I stated upfront that the empirical data was far different than what I expected. But to be bashed and flamed like this, wow. I am more surprised by this than the engine running properly. I also believe those with lots of experience who have given good info to this discussion admitted their experience was not with a 94. I promise I am the only one who has experience with this 94. There will be a dyno day coming up at 42 Autosports in Concord NC. I will have this car there if anyone has the courage to show up. I am not a **** stirrer and I don't troll. I read to learn and try to add to the knowledge base when I can.

But by all means, please, more people tell me how you know what my car is doing better than I do....
Amellrotts is offline   Reply With Quote
Old 08-30-2014, 12:33 AM   #34
MT Pony Underground
iTrader: (6)
 
Nagase's Avatar
 
Join Date: May 2009
Posts: 1,811
Total Cats: 0
Default

So this is where the yikes picture came from. What a disaster.
Nagase is offline   Reply With Quote
Old 08-30-2014, 06:45 PM   #35
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

Quote:
Originally Posted by Savington View Post
Sounds right. To be blunt, until I see a datalog or a dyno chart with an AFR trace, I call bullshit on the idea of perfect AFRs from a '94 ECU. If it's true, and the AFR trace is actually between 12:1 and 13:1 above 4000rpm, then it's a miracle.
I dyno'd a fairly similar combo once. AFRs were surprisingly flat but 13.5-14:1 That car had a big fuel pump and aftermarket adjustable fuel pressure regulator. I was able to increase fuel pressure to keep AFR at a reasonably flat 13:1ish.

Then we installed and tuned the MegaSquirt, and made more power.

I would not call that stock tune good, or even close, but it was "OK". Certainly far from optimal.
Ben is offline   Reply With Quote
Old 09-03-2014, 12:47 AM   #36
Senior Member
 
Join Date: May 2011
Posts: 549
Total Cats: 56
Default

I'm in the process of trying to get an 01+ motor to run on a stock 99 ecu with vvtuner. My MS3 Basic stopped working and this was my stopgap for the miata's @ mazda raceway event.

Anyway. I wired it up to the stock ecu per this. https://www.miataturbo.net/megasquir...nms-ecu-69111/

The only difference being that I seem to have to run 12v switched/fused to pin 5/6 on the vvtuner connector to get it to power up. (found that here) I'm running my 12v from an additional circuit out of the fuse box if that matters.

At any rate I can't get the car to fire like this. I called DIYautotune tech support today and they gave me a handful of resistors to cut out stating issues with the 12v pull ups. Gonna try that tomorrow morning but before I go cutting another perfectly good part up... I just wanted to see what the peanut gallery thought.

TIA
EErockMiata is offline   Reply With Quote
Old 09-03-2014, 09:21 PM   #37
Senior Member
 
Join Date: May 2011
Posts: 549
Total Cats: 56
Default

Hello Chums.

I just thought I'd stop in to say that I ended up getting this working. Was fairly simple on the 99 ecu. I'll do a write up of how it got working but it's "running great"! Most likely dangerously lean but it's going to have to do for a weekend. I'm going to try and throw the car on the dyno to see what it's doing before I convert it back to ms3.

TLR? = Yolo...
EErockMiata is offline   Reply With Quote
Old 09-28-2014, 01:02 AM   #38
Newb
 
Join Date: Sep 2014
Posts: 1
Total Cats: 0
Default

Quote:
Originally Posted by EErockMiata View Post
I wired it up to the stock ecu per this. https://www.miataturbo.net/megasquir...nms-ecu-69111/
So if I start this project using that diagram, I would be on the right track...?


Quote:
Originally Posted by EErockMiata View Post
I called DIYautotune tech support today and they gave me a handful of resistors to cut out stating issues with the 12v pull ups.
Are these resistors in the VVTuner or the ECU? I'm assuming the VVTuner.

Looking forward to your write up.
hrtworms is offline   Reply With Quote
Old 09-28-2014, 02:31 AM   #39
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,363
Total Cats: 1,323
Default

Quote:
Originally Posted by EErockMiata View Post
Hello Chums.

I just thought I'd stop in to say that I ended up getting this working. Was fairly simple on the 99 ecu. I'll do a write up of how it got working but it's "running great"! Most likely dangerously lean but it's going to have to do for a weekend. I'm going to try and throw the car on the dyno to see what it's doing before I convert it back to ms3.

TLR? = Yolo...
Apples and oranges. The '99 ECU is expecting the BP4W ports and 9.5:1 compression, and it's getting a slightly different cam profile and 10:1 pistons. Probably not all that bad, TBQH. The '94 ECU is expecting a head that flows 30+cfm less and a full point less compression. All bad.
Savington is online now   Reply With Quote
Old 09-29-2014, 03:26 PM   #40
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

1.2 points less (13.6%). Please don't troll, Sav.
Dunning Kruger Affect is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Prepping my '95 for track asmasm Build Threads 82 05-26-2016 05:37 PM
Bp5a swap NA8 Will_da_beast Engine Performance 1 09-14-2015 08:06 PM
using 2002 ECU on 1990 Miata btabor ECUs and Tuning 12 09-14-2015 04:45 PM
Mystery Engine Trouble. Halp, mt.net! vehicular General Miata Chat 12 09-14-2015 04:17 PM
Twitchy car (tail happy problem) bigben Race Prep 16 09-11-2015 04:41 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:28 AM.