take ve values at known psi and known resulting afr
take desired psi and divide by known psi
now take known values, and that number you just got, and multiply new row by it.

I just walked hi im sean through this too. really simple and effective for roughing in a map

for example, if your VE values are 100 at 8psi
10/8=1.25
100*1.25=125

the most basic math

Sounds a lot easier than just guessing. Now if I could just figure out this sudden 2k idle after the misfire...

Only that doesn't work with boost psi, use absolute pressure. Obviously the engine doesn't breathe in 25% more air going from 8 PSI boost to 10 PSI boost. Going from NA to 15 PSI will more or less double it though.

In his example going from 8 PSI to 10 PSI would be

8 + 14.7 = 22.7 absolute PSI
10 + 14.7 = 24.7 absolute PSI

24.7 / 22.7 = 1.088 = 8.8% more air. So if VE at 8 PSI was 100, at 10 it would be 100*1.088 = ~109 VE

his ve table is in kpa
which is absolute
my post was just an example to show the concept

Your example was trying the help, which is good, but it was a bad example when you use the wrong numbers. If you truely did that on purpose, don't say boost and say it's an example to show concept, and say to use kpa that's absolute. Not say use boost and give an example using boost with numbers and results.

omg stop being such a douchebag. I can't even fully comprehend what you're trying to say in this post.

his ve map is in kpa. everyones map is in kpa in MS

my example was just an example. no one's ve map reads in relative pressure. everyone's is absolute

leaving this thread now. you can help OP out and be the smartest person on the internet.

I said your example had good intent (and most of your post do), but you used the wrong numbers to illustrate your point. If the OP used your example, he would put bad VE values in his table, such as the ones you illustrated. You can be pissy, and get offended, or you could just acknowledge your example used the wrong numbers and not make a big deal about it. Not everyone is always right all the time.

sorry to thread jack...does this work if your known good cells are in vacuum and trying to calculate your cells in boost? I'm still N/A but should be turbo in a couple more weeks. I'm wanting to rough in my boosted cells.

Bumped up the boost, because 10 psi feels slow now. Listen to this new guy / girl. It takes days for 10psi to feel slow. Its like drugs. Really fun drugs.

running 17-20 ish now and it feels fast again. slowly working on the fuel map, but its still super rich in some spots. but here it is.

2 psi @ 1900 rpm, 10psi @ 3250 and 17 @ 4200

To the house Pro's, why the boost drop when still WOT? Is the MBC to blame? or super shitty AFR? or both?


https://www.miataturbo.net/attachmen...ine=1460427082

for starters, that afr is rich. like crazy rich. get it at least into the 11-11.5 range stat
next, where is the mbc referenced?
next, what does your timing look like up there?
next, no leaks right?

Yeah, this was one of the first runs in this much boost, so...rich. tuning that now. Brains spark map for 93 octane, so pretty tough I think. I'll post it tomorrow. Can't imagine any leaks, shit is tight. Real tight, but I'll pressure test it this week. MBC is refeeced at the tubo outlet. Turbo still sounds like a supercharger, kind of unnerving, but I keep driving it. The car is so loud without sound deadening, missing door panels, rattling hard top, and 225's throwing rocks. It's super hard to capture on sound clips.

this is the problem
reference from right before tb for it not to taper

10-4. Will do this today.

https://www.miataturbo.net/attachmen...ine=1464403586

So I went to the 1/8 mile tonight. Gawd damn that beats up your shit. I think I took about 20,000 miles off my fm2 clutch. If i did get a good launch, I would start spinning tire at the 60 foot, tben I'd have to peddal it to get it back. Later in the night I cut some 100 lights, but started hitting boost protection. ...Whatevs.

Nice pass! Yeah it can be tough! I broke an axle last time I was there. Been so busy lately I haven't had time to race the car in over a month.... :( On the clutch it's hell without drag radials. With good tires you can just almost dump the clutch on the launch vs slipping it.

Well this is an unfortunate situation. Seat hates everything about my cage. When I made the cage, I had full range of motion with room to spare, with a factory seat. Crap.

https://www.miataturbo.net/attachmen...ine=1464700075

Picture was lame and I was tired, but it also hit the shoulder area of the seat as well. Soooo, get out the damn SAWSALL!

https://www.miataturbo.net/attachmen...ine=1464700075

https://www.miataturbo.net/attachmen...ine=1464700075

really close, but it fits! Now I have to fill in this void.https://www.miataturbo.net/attachmen...ine=1464700075

Is that a Sparco Evo 2? Contemplating building a cage around that exact seat (I have a strangely long torso for my height so it's hard to find a seat with high enough shoulder belt holes).

It is. Takes up a lot of room.

Still getting this evo2 into my ride. Who new it would be such a mission to get this seat, a 5'-10" driver with a helmet, to pass the broomstick test? Not me.

https://www.miataturbo.net/attachmen...ine=1466789207

https://www.miataturbo.net/attachmen...ine=1466789207

Um I think your shot of NOS was a bit to large and you sprayed to early. Hence why your floorpan fell out.

Also no way you are going to be faster on an onramp from 30-60, you lack the IRTB's and throttle response.

Hahaha, Those dudes are like reading a Calvin and hobbes book. Full of entertainment!

One day once we both get our cars together we should head down to NC to where SJMarcy lives and have some fun fucking around with him.

I am pretty sure you showed up on here after he was around for a bit spouting out nonsense.

Sounds good to me. Road trip. I started poking around there, when he was routing his intake through the radiator. Like actually through it. It would be even better if we could meet up at an event of some sort. He says he can tune my car for me, and make it run correctly. Whatever that means.

He actually seems like an ok guy, just spouts nonsense sometimes.

nice legs.

Whats your plan with the hole? How are you going to redo the frame rail?

I can think of a couple things i'd do to that hole...

This tray is going in the hole. Not sure about the rail. It's tough because I wanted to get lower, but the rail is in the way. I have a pretty stout cage, so not sure how much the rail is even doing. I did bend up some replacement frame rail... we'll see.

https://www.miataturbo.net/attachmen...ine=1466806162

Slow n steady progress. The shifter area is difficult.

https://www.miataturbo.net/attachmen...ine=1466812867

Ryan, you are determined! Damn!

Yeah, the small things drive me nuts and I can't let up. Cops showed up at my house tonight, dog was out roaming the neighborhood. had to shut down early. More progress tomorrow.

Things move at a snails pace sometimes. ..lots of motorcycle racing has sawed progress, but alas, there is progress. All this work, jizz to fit a sweet seat and sit low. Check out this home-made amateur seat mount porn.

https://www.miataturbo.net/attachmen...ine=1467768802

This is the new floor welded in place. As you can see, I had to remove a lot of material, and smash the rest with a hammer. This seat is just so big in the worst spots. The side rail-lip-thing that runs all around the perimeter of these seats, caused most of the problem.

https://www.miataturbo.net/attachmen...ine=1467768802
Some assorted parts. The wedge thing will replace the missing section of the frame rail I had to remove. The floor is already really solid, and the car has an 1-3/4" chromoly cage. Not too worried about flex, but F it. MOAR STIFF.

https://www.miataturbo.net/attachmen...ine=1467768802

So the spars provide a little moar stiff, and the seat mount will be pulled tight against the solid lugs. I made a few different sizes, so I can stack them to achieve the desired seat height and recline angle.

Well I finished it. Rember this was to fit a Sparco evo 2, I'm 5'-10" ,car has a cage that fits just barely under the hard top and I wanted to clear the broomstick test with a helmet. This is not an easy task in the tiny little area.
Shit lighting makes the welds look like poo. I'll get some better pics of everything later. The seat is bolted in now, but it needs to come back out. I mounted it a little too close, and tilted forward a bit much. Anyway, a pic .

https://cimg3.ibsrv.net/gimg/www.mia...4f6c1b4060.jpg

Even with a large section of the frame rail missing, the cage makes up for it. I think. I do have a replacement section made. Just have to crawl under and weld it in. Motivation is low.
Jack placed at forward of cab to show, ohhh how stiff it is.

https://cimg9.ibsrv.net/gimg/www.mia...1aa4f9e117.jpg

Oh my god. The way you work with metal, it makes me tingle. Can I employ you for some radiator ducting?

...and heat shield
...and new floor
...and seat
..and teach me how to weld
...
..
.

I want him to work my body the way he works his metal.

Pretty sure hes in the VA area. You should hit him up. Hes kinda chill.

I can do this. I have taught lots of people to weld. The bad news is that girls for some reason, pic it up faster.


Just kinda chill? What a dick. I'm chill as fuck, gawd dammit. Where'd my beer go? ! Who stole my beer?!

the balls on that guy, calling you just kinda chill

them's fightin words

bring it on bitches

I went on a long drive yesterday, and fully cooked a whole chicken on my center console.

Has anyone ever wrapped a catalytic converter with header wrap? I stand destruction?
I'm hot. I might go cut my hair.

Got any heat shielding on the underside of the tunnel with the new floor?

^^ Solution right tharr. Internal, under carpet barriers can help but keeping the heat from getting into the pan in the first place is key.

Thermo-Tec and DEI make some decent adhesive backed products that actually hold up. I'm using the DEI Floor and Tunnel Shield 2 in a couple of applications and it works great. I've got a huge roll waiting to go into the Miata the next time the drive-train comes out. Just make sure you are buying a barrier product that actually has a barrier in it, not just reflective foil with adhesive backer.

Lots of pics from others' threads, but here is my tunnel with Thermo Tec adhesive fiberglass/reflective matting. I put it on the OEM heat shield that bolts on near the cat, too.

Attachment 177358

Helped a lot for 1hr+ track stints, but I still got my headers ceramic coated for my new engine.

​ I made a really cool shield, sandwiched two layers of heat wrap between two pieces of mirror polished stainless. Looks great, but haven't installed. No excuse besides racing dirtbikes, golf, hiking with the dog, camping, and a few autocross events.
No real idea on how to mount it yet, either.

https://cimg6.ibsrv.net/gimg/www.mia...aa18525634.jpg

https://cimg3.ibsrv.net/gimg/www.mia...42ba5f7136.jpg

You can hold it in your hand while blasting it with a propane torch.

I did it and melted a cat in a few thousands miles. I shield it now to keep heat out of car, but let air flow around it on the bottom.

New problem with tune. Well, old problem, finally bugs me enough.

I have tuned all of the boost area on the fuel map. I have tuned it in incremental boost pressues. It's pretty dialed in, and I can keep the o2 within -.4 to +0 of the AFR table, at all boost levals, all rpm.

With the map like this, if I'm cruising at 4k and go WOT, I trigger the afr safety. Why?
Afr safety is .3 of afr in this trouble area.
Lots of fuel added with AE.
Can only fix it by running the 3.5~4.5 k. Rpm fuel cells REALLY rich. Like a whole point more rich than I want.

You haz ideas?

Can you post log with PW when problem occurs?

I will try to do that tonight.

If the higher cells use lower AFR, then MS will show AFR differential (error) the moment the MAP increases, but before the enriched exhaust reaches the O2 sensor.

Picture: running 60 kPa target AFR of 15.0. A cylinder fires. Punch it and kPa goes to 100, and target is 13.0. Next injection is adequate and engine fires. However, the exhaust gas that is now passing by the O2 sensor was from the previous, 60kPa cycles. AFR safety is triggered because differential is 2.0.

You should likely notice that the actual, measured AFR never goes high, there is only a time delay during which only the differential goes high. If you dump a bunch of fuel, I suspect you will see a dip in AFR, after the rise in AFR differential (if AFR safety doesn't cut first).

Hence, use a time delay so you don't get an AFR triggered spark or fuel cut, only a momentary warning.

EDIT: In other words, the problem can be that: the AFR does not go high, but the AFR TARGET moves low. Proof can be had by temporarily setting AFR at 60 and 100kPa to 13 and punching. If there is a lack of AE, then AFR will increase and you will still have the AFR ERROR. If it is what I suggest, AFR will remain at 13.0, and the issue is target movement, a false issue.

This makes complete sense, and is exactly what I think is going on. Thanks for the insight. I'll log tomorrow and report back.

As i was getting the afr situation figured out, anew problem developed! sputtering at 4k. sounds like a spark cut, But I didn't change any of that. Tested the spark output, from 600 rpm to 10k all coils fire great. check this log, see anything?

Attachment 177549

Looks like misfire in boost. What plugs and what gap? What ignition coils?

Same plugs I've always had. Miata turbo a proved ngk copper @.025. Not sure on number. Need to check.
Coils are 585's. I have put somewhere around 4,000 miles on this set up. Zero issue like this til today. Plugs look great, coils test great.

No change to the tune. Also not boost sensitive, just rpm.

Check the connection at the cas? My friend's car would do this, turned out to be a bad crimp in the repaired harness (PO was an idiot....).

UPDATE on misfire :

Replaced the 585's With a new set, replaced the cam angle sensor. Still misses at 4k under boost. Continues to misfire until I let off and fall below 4k. Going to check plug wires now. Not really sure what to check for besides resistance.

Logs do not show any lost signals.

Next time you are driving and logging, hit the space bar when you get a miss, then post the log. So that was we know where exactly in the log to look for the miss.

In the log I posted up there^^ it's right at about 4200 rpm. When the rpm suddenly gets all erratic. You can see the tps stays at 100, but the rpm rises and falls by a couple 100 but continues to climb slowly.

I'll get another one though.

MISFIRE SOLVED !

It was a plug wire boot. one of the boots on the coil end, must have had a microscopic hole. I had the hood up, in the dark (don't ask), and noticed a giant spark every time the engine had a misfire..
replaced the boot with a new one, problem solved.


Now i need more help. closed loop idle. I still cant get it to do anything other than stall. The engine doesn't respond to ANY changes in the closed loop settings. I am clearly fucking something up. If you open the tune, I am back on open loop, because it works. so if you apply closed loop, does anything look screwey?

HALP ME?

Attachment 177614

Glad to see it was something simple for the missfire!

For closed loop idle, that is my current brick wall. No idea how to work the darn thing... You can get a reaaaaly nice idle playing with open loop if you take the time. I sit at 1100rpm with everything off, 800ish with everything on, and 1500 when the AC is on. No stalls or anything. Idles rock steady.

Check this shit bitches...fun stuff. The inside of a modern 250cc motorcycle engine. Five titanium valves, two cams, one cylinder, 37hp.

https://cimg4.ibsrv.net/gimg/www.mia...ca2828f6b3.png

https://cimg6.ibsrv.net/gimg/www.mia...73c0f5d84c.png

More important then motorcycles, hows that closed loop idle going?

Crummy. It worked pretty good the first time I fired it up. Then I drove it and it constantly stalled. I tried raising the low number on the idle valve, but that just made it idle a little higher initially, then the idle would just droop until it died.
Tried a cold start this morning. It just fired up, ran for about 3 seconds, then died. Tried that a few times, then just turned open loop back on. Smooth, 14.5 but at 900 rpm, as always.

Just not sure what I should be changing to manipulate the closed loop.