Artech 1.6 at 10 psi
 

After helping a friend with some MS tuning on the dyno, apparently the "boss" was gone for the day, so I got two free runs on the dyno. Only changed boost, from 9psi to 10.5psi ish. Dyno and data logs below. I'm not terribly happy, but whatevers, I'll work on it.

https://www.miataturbo.net/attachmen...ine=1342656433

First, 165kpa log datalog:
https://www.miataturbo.net/attachmen...ine=1342656433

2nd, 174kpa run:
https://www.miataturbo.net/attachmen...ine=1342656433

Hmm, setup is pretty much in my signature, 3" downpipe choked down to a 2.5" cat and 2.5 crush bent exhaust, unknown health on the engine, hopefully the compression is higher than my boost.

Comments welcome, not sure where to go from here...the shop did name their dyno "dream crusher".

ouch...

you look like you're running *decent* amount of timing...
is your timing synchronized correctly?

Wow. Not what I expected. Is this a Greddy turbo?

SR20 T25.

I should double check both the timing belt and the timing light thingy, I just redid them and they were pretty spot on. Doesn't hurt to check. Timing map:

https://www.miataturbo.net/attachmen...ine=1342657498

timing map looks good

I don't like this dyno.

Explain.

That is some limp dick weaksauce timing for 10psi.

It still doesn't explain the 50hp gap between dyno'd hp and what it should be at.

Did the guy running the dyno have the right correction values in? If the engine is healthy, the exhaust is 3", then you should have made 50-75whp more.

Edit:
I changed my mind, don't load that table. Did you hit MBT?

Come on. Unless he shaved his head a foot he is like 6* away from MBT

Not sure about how good your gayz gas is, but over here besides e85 we only have CA 91 camel piss. On said camel piss 14-16* is about the max I'd run @ peak tapering up to about 18-19* at redline depending on turbo and setup.

More timing and the engine pulls a Faeflora

If you have 93 and its good quality, then nevermind

Ah, wow, ok. That explains your subaru timing map too.

I have no experience tuning CA 91.

update your sig? I am only 157....

exactly what I expected considering his exhaust setup.

Yeah, that non hi-flow cat and 2.5 isnt helping.

I'm running 93 octane all the time.

Hustler showed me his timing map and I split the difference between his and diy's ultra conservative base map. Should I go for something more aggressive? Playing with the timing with the NA car certainly showed what timing changes can do, it really liked 30*. I wanna be pretty safe though.

will adding timing decrease your backpressure?

Not 3", see above.

You need to listen to teh Brainz and increase VE instead of ramping up timing on a constipated setup. 3" all the way would be a good start. Then you can bump up timing another 6* like Fae is suggesting without much ill effect

Should pick up a large chunk of power

I'll keep that in mind, i also know how much choked. Exhaust adds heat, I wonder if I should be looking at my cat for cloggage. It's pretty old.

let's see new ignition table.

Here is what I currently have in mine (car still not back up running).. not dyno tuned or anything, but basing it off of info I've found on here, probably a bit on the safe side.

https://www.miataturbo.net/attachmen...ine=1342702048

edit: was on my phone earlier and posted the wrong table.... that's the one im still in progress making for my new low CR built motor.

Also forgot you were 1.6 guy. Here is DIY base map for a 1.6L motor with GT2560r...... probably a good starting point for you.

http://i165.photobucket.com/albums/u...Tables/diy.png

I wouldn't run that on my car.

On the safe side if you have a built motor

Oh yeah, I still have stock rods and pistons too.

Ok vote:

Track day on the 31st or artech 3" cat? Followed eventually by a 3" exhaust. For some reason if I want to blame something, it's not the muffler or 2.5" piping, it's the ancient 2.5" cat.

the cat is the biggest bottleneck.

with 155whp I wouldn't even want to track it lol
get the cat

Hey, it's really fun on the track.

Metal core or ceramic core? This car still needs to pass the sniffer test every other year.

metal core 200 cell.

I run 2 1/2" from the turbo back...with no cat. Is 3" really necessary for a turbo that small?
I'll upload my spark table from when I dyno'd at 225whp at like 12psi when I get home.
I'm curious to see your guy's thoughts about it.

yes, always.

Does no cat, a 99 vs. '93 motor, 2psi, and possibly a more aggressive spark map really make 70hp?

apples vs oranges

Big difference though

my 2.25" exhaust vs. a little porting of the head and a 3" cat/exahaust:


https://www.miataturbo.net/attachmen...ine=1342706460

Great Scott!!!! That's a big difference!!!

whats funny is your "old" curve looks almost exactly like curly's

I can't believe you picked up 45ft/lbs more torque...that's insane!

Scott, looks like the old curve was a good bit richer as well -- how much do you think you gained just by leaning out the tune?

IIRC both were tuned at 12:1, so take that with a grain of salt.

But yeah, other than fuel tuning, nothing else changed. Spark exact spark map, boost level (although it had a bit of creep), turbo, manifold, dp, etc etc etc.

.5-1 AFR won't bump it up any more than 5-7whp. 10 in some bigger setups. at least from what I've seen.

Bust the guts out of the cat you have and go to the track day. Then, before your next sniffer test you can buy a new cat and swap it in. That way everyone wins... except the planet.

You should be looking at 3". Back when I had the Corrado, the 3" exhaust was the last thing I added. It went from like 380whp to 480whp just from the exhaust, removing the cat, and added spark angle.

I suspect the exhaust is your bottle-neck.

I cant read and so i missed the crushed exhaus and resonator

Id say that could accout for 20-30hp. Rest could be timingz.

Btw i wouldnt jack timing without a way to check for knock. This is not the stone age.

Yeah 20-30hp would be 175-185, I would NOT be disappointed with that, and could probably find the other 10-20hp to make me really happy with a little fiddling with the MBC and timing.

Threads like these make me afraid to get on a dyno, but also more determined to find out what I'm making. What do you guys think about using the dyno software that reads a log to generate a dyno chart? Anyone compare one of those outputs to a real dyno?

just strap on a dynojet for realsies.

Cat looks ok:

https://www.miataturbo.net/attachmen...ine=1342713376

Dunno if you can tell, but there's no melted sections and I can see through it easily. Damn inner diameter is only 2.3". I don't care if the O.D. is 2.5", that's a ------- 2.25" cat if you ask me.

Gotta fix this damn thingy too. Those two center bolts on the timing plate broke off a while ago, it's never scraped until I started it up. Should be an easy fix. Might gut the plate to the bare timing marks. Or just bash it back with a hammer.

my 300? cell metal core:

https://www.miataturbo.net/attachmen...ine=1342713529

http://www.boostedmiata.com/gallery2...huza_cat_2.jpg


there's maybe like 3-4" at most of length of catalyst.

Curly, I have a brand new 3" metal core stainless cat with a little straight pipe on it sitting in my garage. Yours for $120 shipped.



The largest and shortest pipe is always best. It will always make a big differene in both spool and overall power.

Why don't you just use a test pipe for track days/ everything else, and just bolt a cat on to pass a sniffer???

about 3 hours to the closest one .. =(

I will do that though, eventually.

^^^ Put that thing on the DynoDynamics in town when you come up for the hillclimb.

Curly, any chance you'd punch your log into VirtualDyno for a comparison?

Show me some pics! I'd probably have you send it to Artech for modification. PM some pics!

This has been suggested, and it's certainly a possibility. I already jack the car up to bolt my seat in for tracks farther away, undoing two V-band clamps and sliding in a test pipe wouldn't be much more work. The ~$200 cat and 3 v-band clamps wouldn't sit well for only using it once every couple years.

However, since I drive this on the street, I should think of it more like a straight piece of $20 pipe with v-bands that I only use for track days, as the cat would help muffle things.

Actually, ignore the v-bands, cause I'd have to send my dp back to him for modification, and I'm not doing that.

I pm'd artech. I'm pretty sure he hates me.

Sure, lemme d/l the program. Is it free?

Yep, well donation based. Close :D

http://www.bradbarnhill.com/projects/VirtualDyno/

I like this idea. Where is it located, and who would I contact about it? If it's reasonably priced I may do exactly that. We just put a gt2560 on my brothers s14 and he wants to dyno it as well.

PM'd to end the threadjack :)

Looks exactly like this, but without the flanges.

NA, miata, mx5, racing, cat pipe, off road, stainless steel

Probably costs you around 10 HP at 200hp level.

Cat converters are for homosexuals and women. I didn't compare to a dyno, but I went from 11.5-11.8AFR on ramp runs when I removed the cat converter from my car. That's more air, son.

There's a good chance that the muffler shop who made the crush bent exhaust also used a chambered, not straight through, muffler. Add that to the list of bottlenecks.

You have pm.

I think I'll take it, dunno if it's being sent to Artech or not yet.

Yeah, I can't get it to work. Won't accept my MLV logs.

Lies! I has no PM.

I bought the muffler myself, it's a magnaflow straight through design, specifically for turbo cars.