My 1.6 Turbo Dyno Results
 

I have been working most of the spring and summer on my turbo build seen here: Oochi's turbo 1.6 build - ClubRoadster.net and I recently took it a buddy of mine to straighten out the high and medium loads on the map. I trusted him much more than myself. And here are my results on a mustang dyno.

Quick rundown:
Stock 90 1.6 with 166k miles
Megasquirt 3X built myself
Tacotaco cast iron manifold
Ebay Godspeed T3 48trim turbo
RX7 460cc injectors
Walbro 190 fuel pump
1.8 driveshaft, axles, welded diff
Conquest intercooler with custom endtanks
Custom 2.5'' over-the-radiator intercooler piping
Custom 2.5'' to 3'' vband downpipe (open)
Variable TPS
NGK BRK7E-6097 Spark plugs
Mazdaspeed comp motor mounts
Urethane diff mounts

https://www.miataturbo.net/attachmen...ine=1377643302
https://www.miataturbo.net/attachmen...ine=1377643302
https://www.miataturbo.net/attachmen...ine=1377643302
https://www.miataturbo.net/attachmen...ine=1377643302

The result on his very first base conservative map made 208whp @5800something rpm. I was having boost creep issues after that and was hitting boost cut. Has anyone with this turbo had wastegate issues like this?

I was surprised with this power and trying to make it any higher makes me worry about the tranny.

The idle still sucks balls. I closed off my IACV. So if someone would be as so kind of helping with that I would be delighted to send you the .msq

200+whp is pretty good on a mustang dyno. I'm sure it's fun as hell.

how accurate are mustang dyno's typically?

everyone with a 3" exhaust has this issue.

no.

tune.



why is your dyno going from 4700 to 5800?

If I read the mod list right, he's not even running an exhaust. Open 3" downpipe.

Based upon that, power is not surprising. Good numbers. Mustangs are usually pretty consistent and conservative.

+1 on this must be fun!

Oh god yes. It's just annoyingly loud and makes me smell bad

So are my options just going with an external gate or could I grind some junk out behind the flap so it opens up a bit more?

You are correct. I wish I had full exhaust though. It is fun for sure haha

Full exhaust might help your creep. Porting the IWG port will definitely help.

did you ever see my post (circa 2009) where I showed how I ported this exact same turbo's wastegate?

No I don't believe I have! what should I search for or do you have a link?

https://www.miataturbo.net/diy-turbo...t=chinacharger

crap, was posted before the automatic dl/attach feature. I dont have the pics online anymore.

Do you have them offline?

Got pics of your timing map and AFR logs? I'm curious to see how DK did.

I can grab them sometime. We installed the most current to my megasquirt using his laptop so I'm going to have to redo the firmware with mine to pull junk off of it. My gas mileage is that of a tractor though

yes

Thanks, man. I was expecting something like this but I figure your way works as well if not better. And what about porting the hole a tad?
https://www.miataturbo.net/attachmen...ine=1377808775

porting the hole is trivial.

If you don't saying where and how much was the tuning? I'm in your area and will need similar services shortly.

Louisville, DK Goodrich tuning. There's actually a bunch of good tuners there.

Sorry to answer for OP, I've just talked with most of them in the area.

He's actually in frankfort, KY. Standard rate is $350

If it was properly tuned you should be getting ~30mpg and have a good idle. Get your money back if not.

I beg to differ. :fawk:

Exact same turbo, 2.5" V-band downpipe to 3" no cat... Ran into creep as well,
I even disconnected the wastegate entirely to trouble shoot but realized that the out of control creep still existed, so the problem is traced down to the turbine housings port being way to small..

Exact same housings, before and after. Yes I have 2 of these turbos, one is a spare so a perfect opportunity to showcase them side by side.

Note the black soot outline on the used left housing! Its a good idea since your in there to gasket match it to gain better flow, less lag which is exactly what I did as per right side ported housing.

You don't have to go to the extreme as mine and polish the housing (promotes higher exhaust gas velocity btw) but definitely should at least do what Braineack did on his, which has a similar shape to channel the gasses into the wastegate port.

Its hard to see this from my pic since I polished and smoothed mine out but the idea is the same. Keep in mind I am running a upgraded 1.5" flapper (yours is 1.25") and a Kinugawa billet wastegate : Results: boost creep? Whats that?!!

I'm pretty sure he meant making the hole larger in diameter.

He clearly showed porting his housing, but not hogging out the port itself.

Dann

Note the larger diameter on the ported housing (right)

And?

Lol. Dumping a fixed amount of gases through a 1.25" diameter hole vs. 1.25" hole . Which one will evacuate the gases first! ..

Go ask companies that make variable size wastegates why they don't just use one size pistons and you will get your "and"

Or

Ask yourself why a 3" exhaust makes more power over the stock 2"...

Sure opening up the hole .5-1mm is trivial ok
But .250" makes a difference

You have your answer.

Nobody has to do what I did, the above method and pictures I posted is to help others see the merits of:

Simple fluid dynamics :)

Huh? Is this a riddle?

that turbo had a severely undersized outlet to begin with. Look how much bigger the flapper area is compared to it. I've never dealt with a turbo like that, where I'm used the flapper just being maybe 2-4mm or so larger in diameter than the outlet.

There's also fear that if you do enlarge the hole that it's possible the extra exhaust gasses/pressure could force the wastegate open faster; but that sounds like a long math equation that I don't want to tackle.

also my comments were directed to that specific turbo itself: I have the same turbo; I don't have creep. The outlet doesn't need to be enlarged and there's little wiggle room to do so anyways.

is it not just pressure over area?

plus the negative pressure of the wastegate actuator.

That's why I'd only go with external wastegate.

OH COOL STORY!!! YOURE SO FUCKING AWESOME!

Expensive EWG setup for a $150 turbo. Makes sense.

The 2 housings i posted are the exact same turbos, same specific one as you, and OP. the one on the left is untouched, the right one was after I ported it.

Yes I agree with you 100% that a channel is all thats needed on this turbo, the process I did would be considered the "ultimate internal gate mod" lol, the step one would take if they don't want to go down the external wastegate route, but still want the same flow capability of a 38mm external gate, (exact same size) .

I love your heat shield! I have an old stop sign that I cut up and use for random things.

Thanks lexintexan!

I blew my turbo inlet gasket yesterday so while I have the turbo off I plan to get it fixed up like the picture brain posted to rid of the boost creep. Brain, do you use the same flapper?

I am getting like extremely bad gas mileage. I talked to the tuner about it because I am running around mid 11s to mid 12s AFRs when cruising and he told me that it is like that because I would have a constant light load misfire when cruising (trying to stay the same speed) so he had to richen (that's not a word) it up to prevent that. Has anyone encountered this before and know of a fix or what's causing it?

I cruise around 15.5 to 16. I get extremely good gas mileage and the car runs beautifully. I also don't use a "tuner" (unless you count VEA).

Haha, I was just referring to the guy who tuned my car because I don't trust myself enough. I had it running around there before I took it to him, it just misfired when I tried to cruise around

You should not be misfiring at those AFR's. Is your WBO2 accurate? Have you done a free air calibration lately?

it only misfires at very light throttle, goes lean, no matter the RPM. As far as I know it's accurate. No I have not done a free air cal.

Edit: Sounded wrong

The misfire honestly would worry me more than your other problems. Figure that out and fix it.

Another thing that worries me is my cluster going willy nilly at high speeds/rpm but usually not in first gear. My Tach, oil pressure, and temp gauge go a bit crazy when im at highway speeds or high rpm. It didn't do this before I pulled my motor, so I assumed it was a ground somewhere, but from what I can tell, they all look fine.

the last thing you want is an erratic oil pressure gauge. sounds like maybe you forgot to reconnect some grounds?

That's what I thought, but unless I'm missing one, I don't see any that I missed

Fixed my boost creep issue, and switched the map sensor to be T'd off from the FPR and then T'd into boost gauge and map sensor. But still want to get the finnicky gauge problems and the light load misfires so I can get better than 15 mpg. I'm thinking about just replacing the engine ground on the exhaust side. I don't know what else to do.

This is getting really frustrating. I replaced the grounding strap from the engine to the firewall, and sanded down the contacted for unpainted metal and the gauges are still going nuts at high speeds/rpm. IDK what else to try

BTW, on a '90, the oil pressure gauge can be an excellent detonation indicator. It is located at the perfect place on the block to pick up det (where the knock sensor went on later models). Might be worth backing down the spark map to see if it goes away. If it does . . . you owe me! ;)

I don't think it's that because it happens to all the gauges except for speedo and gas. You can watch the tach, water temp, and oil pressure gauges get weird in this video

20131014_125236_zpsb99acba9.mp4 Video by Minimullen02 | Photobucket

I'd guess a loose connection somewhere. I started having an erratic OPG which eventually ended up being a loose wire making and breaking contact to the sender.

you have bad grounds.

your MS has nothing to do with the opg and tach.

I agree, I just can't find them/it

Anyone feel like checking out my tune? Whether for help or curiosity, I don't mind. But now that it is cold, my car is refusing to start and I already fouled some plugs. So it is time for cranking PW/ASE/WUE tuning. I have been dong research and for what I could find, my cranking pw is EXTREMELY high compared to what I've seen. Mine being in the hundreds and others being in the single digits. (Edit: I think I have confused them with something else). Idk if MS3 is different than 2 or what for those settings. I have attached my tune and here are my settings. I was hoping for any input before I dig in. Thanks.
https://www.miataturbo.net/attachmen...ine=1385587760

Lowered the priming PW quite a lot and it started but took about 5 seconds on the second try.

Alright apparently I lied about fixing the boost creep. I had the turbo ground out some and I thought it fixed it but I just wasn't driving it like a man and it still creeps in 3rd-5th gear. I got a full 3" stainless exhaust put on over the weekend. I hoping it would help but it srill creeps. F me, right? I guess it's either time for more porting, opening the hole a bit more, grinding behind the flapper, or ewg :(

That heat shield is f'in cool

I'd just build the motor and run more boost :)

Seriously though, wastegate porting is how FM/BEGI addressed this IIRC, good luck!

Usually, a better exhaust makes boost creep worse.