miata hits wall under boost
 

pulled my freshly built turbo miata out of garage and test drove it. fine tuned maps on my AEM FIC. Runs great at idle but as soon as it sees boost it bogs down and slows down.

GT2560 turbo
550cc inj
FMIC
10 psi wastegate
boomslang harness

it will build boost up to 6 psi and afr are 12.5 under boost.
gas in tank has sat in tank for two months without starting car.
running ngk R plugs one step colder than stock
timing is retarded 1 degree per pound of boost.
no boost leaks i can see or hear.
brand new O2 sensors
maf seems to be working.

any ideas on whats causing it to hit a wall under boost?

btw its an 01 vvt

Whats the afr gauge say when it bogs down?

12.5 AFR

Mad clamp is set to 4.5v but have maf map dialed in

12.5 is pretty lean especially since u're running a piggy back.

Would that cause it to fall on its face at 1psi boost

1 psi, no, ecu gotta be fucking around with the timing.

I'll try to retard timing going into boost earlier

The ecu, like you, is probably too retarded.

"theres a nasty hole in your fuel map, that's why you're unloading in third"

Came to see a Miata literally hit a wall....

I am disappoint

What happened to camaraderie between car enthusiasts. I seriously need help on this. I know I didn't buy a MS but I have what I have. That's not gonna change. Even though I hate this site. Because people on here are so disrespectful. I know you guys know your stuff.

So please can someone point me in the right direction.

Does it do it at operating temp? Ive experienced some Miatas that do that while cold, but they were all running stock ecu.
The 2 month old gas shouldnt affect it
The 1 step colder NGK plugs are good, but 2 steps colder than stock MIGHT be better.
Everything else seems legit.... BUT the "maf seems to be working." Part makes me wonder. You are running an Aftermarket Management system, and still have a MAF?
I would bet it is either the MAF, or your tune, or a combo of both

Do you have any Data logs of any kind? Can the AEM FIC do that?

It boosted and pulled to 2 psi fine cold.( was still tunning so did little pulls into boost to watch AFR)

I bought a boomslang harness comes with maf wired in. Or I would of deleted it.

FIC can data log. I will do a boost pull and post it.
I have seen on forum guy had this happen because his MAF clamp was to low so stock ecu was seeing boost.

Most folks, including myself do not intercept the MAF when using the FIC6 on a Miata. It simply isn't required under 12 psi with the exception of a small annoyance if you are recirculating your BOV.

If you do intercept, there are some adjustments to be made to account for some 'voltage drop' from what I have read. I didn't intercept mine, so I cannot help you there. There is an old thread on miata.net that describes how one person successfully managed it

You can PM me and we can exchange phone #s and I'll try to see if I can help. I was given a method of setting up my FIC that has worked well for me. Setting it up as they describe in the instructions was not possible on my 2000. The other method is simpler anyhow. I run about 10 psi on my car and have been using the FIC for a couple of years. The FIC is very easy to adjust and has been dead reliable. I love the fact that idle adjustment is a non-event and my AC and cruise control work as well as when the car was stock.

Sure i'll point u to the right direction.

MegaSquirt-II EMS System - SMD PCB3.57 w/ Black Case DIYAutoTune.com

i just read a thread on miata.net that you cant retard timing on FIC with a vvt BP engine?

any truth to this?

Fixed it. FIC ignition retarding and VVT don't mix. Set all cells to 0 and she took off fully boosting bumped up fuel 10% to get AFR to 11.5 at WOT

All cells? U mean for the timing?

Yes I had -1 degree for every PSIA over 15. Would retard so far engine would bog.

Took all retarding out of cells. Car took off and boosted fine.

Almost thinking vvt is fighting the map

" Yes you had it -1 degree for every psi over 15 psi? "

You're telling me until 15 psi you're running 30 degrees of (final) timing?

he's talking about absolute, PSIA

and like I said, he was too retarded

Add 10 pounds of boost I was retarded 10 degrees further than stock

Ah absolute psi, never heard of that term but cool. Well 10 degrees vs stock puts u at 20 degrees at 10 psi. Most people run about 16-17. Anyways u cant be driving with no timing control so figure that out.

Wait so now you're running a boosted VVT motor on factory timing maps?

I just boosted it once I'm not dumb enough to run car like that. Just found what was causing problem

when does it hit a wall?

I have a mint 01 long block sitting here for when you blow this one with the crappy FIC and your crappy tuning

Try reading the thread?

18psi keep on hatin. This is all a learning process.

Well technically he is right. For some the learning process is more expensive than for others.

What's your spark gap?

Subbed for blown motor pics.

..042

42 should be ok for 1-2 psi. Probably will get blowout at over 5 psi though.

What is the "suggested" plug gap?

anything over 10psi on stock nb1 coils at .027-.030"

Its COP ignition was told 42 would be fine

Yeah that sounds about right.